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Full text of "Flora Costaricensis"

.LLINOIS LIBRARY 
URBANA-CHAMPAI' 
HIST SUP' 



FIELDIANA 



Botany 

Published by Field Museum of Natural History 



WraWlH/JTBgys^ 

6 1985 






FLORA COSTARICENSIS 

FAMILY #54 PODOSTEMACEAE 

FAMILY #55 PROTEACEAE 

FAMILY #56 OLACACEAE 

FAMILY #57 OPILIACEAE 

FAMILY #58 LORANTHACEAE 

FAMILY #59 ARISTOLOCHIACEAE 

FAMILY #60a HYDNORACEAE 
FAMILY #60b RAFFLESIACEAE 

FAMILY #61 BALANOPHORACEAE 

FAMILY #62 POLYGONACEAE 

FAMILY #63 CHENOPODIACEAE 

FAMILY #64 AMARANTHACEAE 

FAMILY #65 NYCTAGINACEAE 

FAMILY #66 PHYTOLACCACEAE 

FAMILY #67 AIZOACEAE 

FAMILY #68 PORTULACACEAE 

FAMILY #69 BASELLACEAE 

FAMILY #70 CARYOPHYLLACEAE 

WILLIAM BURGER, Editor 



mber 29, 
Publication 1350 



Families of seed plants known or expected to occur in Costa Rica and adjacent areas, 
listed alphabetically and numbered according to the sequence of Engler s Syllabus der 
Pflanzenfamilien, edition 11, reworked by L. Diels (1936). 



96 Caesalpiniaceae, 

see Leguminosae 



200 Acanthaceae 
136 Actinidiaceae 
67 Aizoaceae 
11 Alismataceae 
64 Amaranthaceae 
30 Amaryllidaceae 
117 Anacardiaceae 
77 Anonaceae 

184 Apocynaceae 
119 Aquifoliaceae 

19 Araceae 
166 Araliaceae 

4 Araucariaceae 
59 Aristolochiaceae 

185 Asclepiadaceae 
61 Balanophoraceae 

127 Balsaminaceae 
69 Basellaceae 

48 Batidaceae 

153 Begoniaceae 
74 Berberidaceae 

49 Betulaceae 
194 Bignoniaceae 
145 Bixaceae 
133 Bombacaceae 
189 Boraginaceae 

24 Bromeliaceae 
91 Brunelliaceae 
38 Burmanniaceae 

106 Burseraceae 
12 Butomaceae 

115 Buxaceae 

154 Cactaceae 

lpiniacea 
Legumin 
114 Callitrichaceae 

207 Campanulaceae 
36 Cannaceae 

83 Capparidaceae 
203 Caprifoliaceae 
151 Caricaceae 
138 Caryocaraceae 

70 Caryophyllaceae 
40 Casuarinaceae 

120 Celastraceae 
72 Ceratophyllaceae 
63 Chenopodiaceae 
42 Chloranthaceae 

144 Cistaceae 

169 Clethraceae 

146 Cochlosperraaceae 

161 Combretaceae 
25 Commelinaceae 

208 Compositae 
95 Connaraceae 

186 Convolvulaceae 
116 Coriariaceae 
168 Cornaceae 
89 Crassulaceae 

84 Cruciferae 
206 Cucurbitaceae 

92 Cunoniaceae 
6 Cupressaceae 
1 Cycadaceae 

18 Cyclanthaceae 

16 Cyperaceae 
118 Cyrillaceae 
112 Dichapetalaceae 
135 Dilleniaceae 

32 Dioscoreaceae 
205 Dipsacaceae 

88 Droseraceae 
178 Ebenaceae 
156 Elaeagnaceae 
130 Elaocarpaceae 
143 Elatinaceae 
172 Ericaceae 

23 Eriocaulaceae 



102 Erythroxylaceae 
113 Euphorbiaceae 

96 Fabaceae, 

see Leguminosae 

50 Fagaceae 
148 Flacourtiaceae 

82 Fumariaceae, 

see Papaveraceae 

45 Garryaceae 
183 Gentianaceae 

99 Geraniaceae 

198 Gesneriaceae 

7 Gnetaceae 

15 Gramineae 
142 Guttiferae 

29 Haemodoraceae 
165 Halorrhagaceae 

93 Hamaraelidaceae 

81 Hernandiaceae 
124 Hippocastanaceae 
121 Hippocrateaceae 
101 Humiriaceae, 

see Linaceae 
60a Hydnoraceae 

13 Hydrocharitaceae 
188 Hydrophyllaceae 
142 Hypericaceae, 

see Guttiferae 
123 Icacinaceae 

33 Iridaceae 

47 Juglandaceae 

27 Juncaceae 

97 Krameriaceae 
191 Labiatae 

43 Lacistemaceae 

80 Lauraceae 
159 Lecythidaceae 

96 Leguminosae 

20 Lemnaceae 

199 Lentibulariaceae 

28 Liliaceae 
101 Linaceae 
152 Loasaceae 
182 Loganiaceae 

58 Loranthaceae 
157 Lythraceae 

76 Magnoliaceae 
108 Malpighiaceae 
132 Malvaceae 

37 Marantaceae 
139 Marcgraviaceae 
196 Martyniaceae 

21 Mayacaceae 

163 Melastomataceae 

107 Meliaceae 
75 Menispermaceae 
96 Mimosaceae, 

see Leguminosae 
79 Monimiaceae 

170 Monotropaceae 
52 Moraceae 
87 Moringaceae 
34 Musaceae 
46 Myricaceae 
78 Myristicaceae 

174 Myrsinaceae 

162 Myrtaceae 
10 Najadaceae 
65 Nyctaginaceae 
71 Nymphaeafeae 

137 Ochnaceae 

56 Olacaceae 
181 Oleaceae 
164 Onagraceae 

57 Opiliaceae 
39 Orchidaceae 

197 Orobanchaceae 
98 Oxalidaceae 



17 Palmae 

82 Papaveraceae 
150 Passifloraceae 
195 Pedaliaceae 

66 Phytolaccaceae 
5 Pinaceae 

41 Piperaceae 
171 Pyrolaceae 
201 Plantaginaceae 
176 Plumbaginaceae 
3 Podocarpaceae 

54 Podostemonaceae 
187 Polemoniaceae 
111 Polygalaceae 

62 Polygonaceae 
26 Pontederiaceae 
68 Portulacaceae 

9 Potamogetonaceae 
175 Primulaceae 

55 Proteaceae 
158 Punicaceae 
140 Quiinaceae 
60b Rafflesiaceae 

73 Ranunculaceae 

86 Resedaceae 
128 Rhamnaceae 
160 Rhizophoraceae 

94 Rosaceae 
202 Rubiaceae 

104 Rutaceae 
126 Sabiaceae 

44 Salicaceae 
125 Sapindaceae 
177 Sapotaceae 

90 Saxifragaceae 
193 Scrophulariaceae 

105 Simarubaceae 
192 Solanaceae 
122 Staphyleaceae 
134 Sterculiaceae 
180 Styracaceae 
179 Symplocaceae 

2 Taxaceae 
141 Theaceae 
173 Theophrastaceae 
155 Thymelaeaceae 
131 Tiliaceae 
85 Tovariaceae 

109 Trigoniaceae 
14 Triuridaceae 

100 Tropaeolaceae 

149 Turneraceae 

8 Typhaceae 

51 Ulmaceae 
167 Umbelliferae 

53 Urticaceae 
204 Valerianaceae 

31 Velloziaceae 
190 Verbenaceae 
147 Violaceae 
129 Vitaceae 

110 Vochysiaceae 
22 Xyridaceae 
35 Zingiberaceae 

103 Zygophyllaceae 



FLORA COSTARICENSIS 



FAMILY #54 
FAMILY #55 
FAMILY #56 
FAMILY #57 
FAMILY #58 
FAMILY #59 
FAMILY #60a 
FAMILY #60b 
FAMILY #61 
FAMILY #62 
FAMILY #63 
FAMILY #64 
FAMILY #65 
FAMILY #66 
FAMILY #67 
FAMILY #68 
FAMILY #69 
FAMILY #70 



PODOSTEMACEAE 

PROTEACEAE 

OLACACEAE 

OPILIACEAE 

LORANTHACEAE 

ARISTOLOCHIACEAE 

HYDNORACEAE 

RAFFLESIACEAE 

BALANOPHORACEAE 

POLYGONACEAE 

CHENOPODIACEAE 

AMARANTHACEAE 

NYCTAGINACEAE 

PHYTOLACCACEAE 

AIZOACEAE 

PORTULACACEAE 

BASELLACEAE 

CARYOPHYLLACEAE 



FIELDIANA 
Botany 



Published by Field Museum of Natural History 



New Series, No. 13 



FLORA COSTARICENSIS 



FAMILY #54 
FAMILY #55 
FAMILY #56 
FAMILY #57 
FAMILY #58 
FAMILY #59 
FAMILY #60a 
FAMILY #60b 
FAMILY #61 
FAMILY #62 
FAMILY #63 
FAMILY #64 
FAMILY #65 
FAMILY #66 
FAMILY #67 
FAMILY #68 
FAMILY #69 
FAMILY #70 



PODOSTEMACEAE 

PROTEACEAE 

OLACACEAE 

OPILIACEAE 

LORANTHACEAE 

ARISTOLOCHIACEAE 

HYDNORACEAE 

RAFFLESIACEAE 

BALANOPHORACEAE 

POLYGONACEAE 

CHENOPODIACEAE 

AMARANTHACEAE 

NYCTAGINACEAE 

PHYTOLACCACEAE 

AIZOACEAE 

PORTULACACEAE 

BASELLACEAE 

CARYOPHYLLACEAE 



WILLIAM BURGER, Editor 

Curator and Chairman 
Department of Botany 
Field Museum of Natural History 



Accepted for publication October 18, 1982 
December 29, 1983 



Publication 1350 



Library of Congress Catalog Card Number: 78-172358 

ISSN 0015-0746 
PRINTED IN THE UNITED STATES OF AMERICA 



CONTENTS 

LIST OF ILLUSTRATIONS vi 

ACKNOWLEDGMENTS vii 

PODOSTEMACEAE by William Burger (based on P. Van Royen) 1 

PROTEACEAE by William Burger 8 

OLACACEAE by William Burger 14 

OPILIACEAE by William Burger 27 

LORANTHACEAE (in a wide sense) by William Burger and Job Kuijt 29 

EREMOLEPIDACEAE 31 

LORANTHACEAE (in a narrow sense) 33 

VISCACEAE 59 

ARISTOLOCHIACEAE by Kerry Barringer 79 

HYDNORACEAE by Luis D. Gomez 87 

RAFFLESIACEAE by Luis D. Gomez 89 

BALANOPHORACEAE by Luis D. Gomez 93 

POLYGONACEAE by William Burger 99 

CHENOPODIACEAE by William Burger 138 

AMARANTHACEAE by William Burger 142 

NYCTAGINACEAE by William Burger 180 

PHYTOLACCACEAE by William Burger 199 

AIZOACEAE by William Burger 213 

PORTULACACEAE by William Burger 217 

BASELLACEAE by William Burger 222 

CARYOPHYLLACEAE by Richard Baker and William Burger 227 



LIST OF ILLUSTRATIONS 

1. Podostemaceae 2 

2. Proteaceae 10 

3. Olacaceae and Opiliaceae 15 

4. Olacaceae: Heisteria 18 

5. Loranthaceae (s.s.): Psitticanthus and Gaiadendron 34 

6. Loranthaceae (s.s.): Struthanthus and Phthirusa 35 

7. Loranthaceae (s.s.): Struthanthus 36 

8. Loranthaceae (s.s.): Oryctanthus. Eremolepidaceae and Rafflesiaceae 37 

9. Viscaceae: Dendrophthora and Phoradendron 61 

10. Viscaceae: Phoradendron, second group 62 

11. Viscaceae: Phoradendron, third group 63 

12a. Aristolochiaceae: A. maxima and its allies 80 

12b. Aristolochiaceae: six species 81 

13. Hydnoraceae 88 

14. Rafflesiaceae: Bdallophyton 92 

15. Balanophoraceae: Langsdorffia and Helosis 94 

16. Balanophoraceae: Corynaea 95 

17. Polygonaceae: Polygonum 102 

18. Polygonaceae: Rumex 103 

19. Polygonaceae: climbing species 104 

20. Polygonaceae: species with winged fruit 105 

21. Polygonaceae: Coccoloba with rounded leaves 108 

22. Polygonaceae: Coccoloba with epistipular petioles 109 

23. Polygonaceae: Coccoloba with basal petioles 110 

24. Polygonaceae: Coccoloba, rarely collected species Ill 

25. Amaranthaceae: Achyranthes and Cyathula 146 

26. Amaranthaceae: Alternanthera and Gomphrena 149 

27. Amaranthaceae: Alternanthera and Pfaffia 152 

28. Amaranthaceae: Amaranthus 158 

29. Amaranthaceae: Celosia, Chamissoa, and Pleuropetalum 163 

30. Amaranthaceae: Iresine 171 

31. Nyctaginaceae: Bougainvillea and Mirabilis 182 

32. Nyctaginaceae: Boerhavia and Salpianthus 183 

33. Nyctaginaceae: Guapira and Pisonia 184 

34. Nyctaginaceae: Neea psychotrioides complex 185 

35. Nyctaginaceae: Neea amplifolia complex 186 

36. Phytolaccaceae: Microtea, Rivina, and Trichostigma 200 

37. Phytolaccaceae: Phytolacca 201 

38. Phytolaccaceae: Petiveria and Stegnosperma. Chenopodiaceae 202 

39. Caryophyllales: succulent species 223 

40. Caryophyllales: Basellaceae and Portulacaceae 224 

41. Caryophyllales: herbs with narrow opposite leaves 225 

42. Caryophyllales: herbs with opposite or whorled leaves 226 



ACKNOWLEDGMENTS 

This is the fourth issue of the Flora Costaricensis. The first dealt with Piperaceae 
(Fieldiana, Bot. 35, 1971), the second dealt with the families Chloranthaceae 
through Urticaceae (Fieldiana, Bot. 40, 1977), and the third dealt with Gramineae 
by Richard Pohl (Fieldiana, Bot., new series No. 4, 1980). In the work of preparing 
both this present volume and in all previous volumes, we have had the generous 
cooperation and support of the Museo Nacional de Costa Rica. Use of special 
facilities at the Museo for drying, processing, and shipping have been essential to 
our field program. Sr. Luis D. Gomez has been especially helpful to the flora 
program during the years he served as Director and since that time. Sr. Jorge 
Gdmez-Laurito, associated with both the Herbario Nacional at the Museo Na- 
cional and the Biology Department of the University, has also been most helpful. 

We are especially grateful for the assistance of the National Science Foundation, 
Program for Systematic Biology, which has aided this program for many years. 
Financial support for fieldwork, assistants, and a postdoctoral position have been 
provided by NSF grants DEB 74-08575 and DEB 81-03184. 



vii 



PODOSTEMACEAE 

REFERENCE: P. van Royen, The Podostemaceae of the New World, pt. 1, Meded. 
Bot. Mus. Herb. Rijks Univ. Utrecht 107:1-150, 1951. Part 2, Acta Hot. Neerl. 
2:1-21. 1953. 

Small herbs, growing in fast-moving freshwater rapids and waterfalls, usually attached 
to larger rocks (rarely wood), annual or perennial, bisexual, very variable in size and form, 
ranging from thalloid and closely attached to rocks to mosslike or with long branched 
leaves, sterile plants usually larger and thicker than the fertile, stems usually forming a 
broad holdfast and difficult to distinguish from the roots in some genera; lateral stipules 
or intrapetiolar stipules sometimes present. Leaves very different in different genera and 
species, in 2 or 3 ranks or borne from the edge or center of the thalloid stem, minute and 
appressed (in Tristichia) to large and much branched (in Marathrum). Inflorescences of 
solitary or fascicled pedicellate flowers, terminal, axillary or extra-axillary on special 
shoots or in 2-sided spikelike monochasia, each flower at first enclosed within a thin 
spathella or a few leaves or with groups of 10-20 flowers at first enclosed within a 
thickened spathe. Flowers bisexual, radially symmetrical or bilaterally symmetrical, very 
small (mostly less than 1 cm), borne on prominent pedicels often slightly expanded at the 
apex; perianth of 2 to many parts, in 1 or several whorls or on only 1 side, either thin and 
petal-like or reduced to small scales, free or united at the base; stamens 1 to many, often 
alternate with the perianth parts (tepals) in 1 or 2 whorls, in a whorl or on only 1 side of 
the flower, filaments free or united (rarely on an andropodium), anthers opening by 2 
longitudinal slits, introrse or extrorse, basifixed or dorsifixed; ovary superior, narrowed at 
the base or on a short stalk, sometimes obliquely oriented in the flower, 1- to 3-locular, 
placentation axile with 2 to many anatrapous ovules, styles (1) 2 or 3, usually slender. Fruit 
a thin-walled capsule, seeds 2 to many, without endosperm, embryo straight. 

A family of about 200 species in 43 genera, pantropical but reaching the middle 
Atlantic states of the United States and Japan in the Northern Hemisphere and 
northeastern Australia in the Southern Hemisphere. This is one of the most 
unusual families of angiosperms, both in morphology and in habitat. Because of 
their restriction to fast-moving water, these plants are difficult to collect, and our 
knowledge of them is poor. Fortunately, we have the excellent monograph by van 
Royen covering the American genera and species (see the references above). 
Nearly all of this treatment is based on van Royen's work, but it may be that some 
of his species of Marathrum were circumscribed too narrowly. 

KEY TO THE GENERA OF PODOSTEMACEAE 

la Leaves minute (to 4 mm), in 3 imbricate ranks on short erect stems and resembling 
bryophytes; young flowers protected by a few leaves, with 3-5 broad perianth parts; 
ovary 2- or 3-locular Tristichia 

Ib Leaves 1-50 cm long, cuneate to much branched and divided or tripinnate, borne on 
flat thalloid stems and resembling algae; young flowers enclosed in a narrow spath- 
ella, perianth parts very narrow or minute and scalelike; ovary 1- or 2-locular 

Marathrum 



MARATHRUM 
tenue 



10cm 




M. utile 

FIG. 1. Podostemaceae: species of Marathrum and Tristichia trifaria, lower left, enlarged. 



BURGER: FLORA COSTARICENSIS 3 

MARATHRUM Humboldt and Bonpland 

Small aquatic herbs attached by a broad irregular base to rocks in fast-moving water, 
glabrous, bisexual, sterile plants often larger than the fertile, the stem often difficult to 
distinguish from roots or leaf bases; an intrapetiolar stipule or ligule often present. Leaves 
variously inserted on the thalloid base or distichous, very variable in size and form, from 
subentire with a few distal lobes to repeatedly forked or repeatedly pinnate and branch- 
like, conforming to the flow of water or prostrate on the rocks, petiole and rachis often 
fleshy. Inflorescences of solitary or fascicled flowers arising from between the leaf bases, 
each flower at first enclosed within a translucent tubular-clavate spathella which splits 
irregularly near the apex, pedicels becoming elongate and often slightly expanded at the 
apex; flowers bisexual, radially symmetrical (stamens and perianth on only 1 side in M. 
tenue), perianth of 3-25 parts in 1 or several whorls or on only 1 side, lanceolate to linear 
or filiform or reduced (0.3 mm) and scalelike at the base of the flower, free or united at the 
base, sometimes inserted on the cuplike apex of the pedicel; stamens 2-25, whorled or on 
only 1 side, united only at the base, filaments linear to lanceolate, anthers introrse; ovary 
superior and 2-locuIar, usually ellipsoid and narrowed at the base, with 6 or 8 longitudinal 
ribs, styles 2, free or united near the base. Fruit a capsule, splitting along the longitudinal 
ribs to produce 2 equal halves each with 5 ribs, seeds small and numerous. 

Marathrum includes about 20 to 25 species, ranging from Mexico and Cuba 
through Central America to northwestern South America where the genus inter- 
grades with Apinagia (see van Royen, 1951). Different species have leaves that vary 
from short, simple, and rhombic or flabellate to much longer and divided or 
compound-pinnate, but the flowers and fruit seem quite similar. Standley noted 
that the name Pasacarnehas been used for these plants in Costa Rica and that cattle 
will wade out into stream rapids to feed on them in the dry season (see Fieldiana, 
Bot. 24, pt. 4:402, 1946). Fertile material has only been collected in the dry season, 
from early January to middle May. 

While appreciative of van Royen's excellent monograph, I believe that some of 
his species are separated on rather minor characters. Nevertheless, it seemed 
important to provide the user of this flora with the distinctions that van Royen 
used to separate species. Accordingly, the key utilizes van Royen's dichotomies 
for all the species of Costa Rica and adjacent areas, but the last five species in the 
key are probably covered under the expanded description of M. oxycarpum. In his 
monograph of 1951, van Royen had already submerged some of the species he 
described for the Flora of Panama (Ann. Missouri Bot. Card. 37:126-137, 1950); 
see the discussion under M. oxycarpum. 

KEY TO THE COSTA RICAN SPECIES OF Marathrum 
BASED ON THE KEY OF VAN ROYEN (1951) 

la Leaves cuneate or somewhat flabellate, relatively broad (2-30 mm), lobed or pin- 
natisect only distally, with distinct reticulate venation when dry M. utile 

Ib Leaves with a central narrow (1-4 mm) rachis or much divided from near the base, 
often twice pinnatifid and branchlike in appearance, without broadly reticulate 
venation 2a 

2a Stamens and perianth parts 2 or 3, borne on 1 side of the flower, apex of the pedicel 
often becoming asymmetric in fruit with ribs of the fruit decurrent into the pedicel on 
1 side; anthers 1 mm long or less; ultimate divisions of the leaf short and very slender, 
producing a characteristically "fimbriate" ultimate cluster M. tenue 

2b Stamens and perianth 5-10 or more, in whorls around the flower and fruit; apex of the 
pedicel not strongly asymmetric; anthers to 2 mm long; distal leaf segments not 
usually densely fimbriate with short filiform divisions 3a 

3a Pedicel usually becoming broadened and cuplike at the apex 4a 

3b Pedicel only slightly enlarged at the apex, never forming a cuplike base for the 
flower . . . . 5a 



4 FIELDIANA: BOTANY 

4a Leaf segments repeatedly forked, with long (0.5-12 mm) and very slender terminal 
divisions, never pinnatisect in appearance; rare in Central America 

M. foeniculaceum 

4b Leaf segments usually in alternate arrangements on the central rachis and giving a 
pinnatifid appearance, ultimate division 1-3 mm broad or if slender not usually 
exceeding 5 mm in length; common in Central America but may intergrade with M. 
oxycarpum M. schiedeanum 

5a Fully developed stamens about half as high as the ovary; not recorded from Costa Rica: 
M. stenocarpunt (Weddell) van Royen, Panama and Colombia. 

5b Fully developed stamens more than half as high as the ovary, usually equalling or 
exceeding the ovary in height; all the following species (as separated by van Royen) 
seem very similar, and a description is provided only for M. oxycarpum in a wider 
sense 6a 

6a Styles filiform, widened at the top; sometimes emarginate, 2-3 mm long, cohering 
over a long distance; stamens 8-10; ultimate divisions of the leaf up to 3 cm long 
(= 3 mm?) and up to 0.3 mm wide M. oxycarpum 

6b Styles of different shape, cohering at the base only, up to 2 mm long; stamens 5-9; 
ultimate divisions of the leaf 5 mm long or less 7a 

7a Largest leaves shorter than 7 cm long 8a 

7b Largest leaves up to 30 cm long 9a 

8a Leaves repeatedly pinnate, 3-6 cm long; styles filiform, up to 1 mm long; pollen grains 
20 x 11 ^.m: M. leptophyllum van Royen, western Panama. 

8b Leaves repeatedly pinnate or cuneate and dissected at the top, up to 1 cm long; styles 
cylindrical, ca. 1.5 mm long; pollen 15 x 14 /im: M. pusillum van Royen, central 
Panama. 

9a Leaves without an intrapetiolar stipule at the base M. cheiriferum 

9b Leaves with an intrapetiolar stipule at the base M. minutiflorum 

Marathrum cheiriferum van Royen, Ann. Missouri Bot. Card. 37:134-135. 
1950. 

It is very difficult to see the intrapetiolar stipules on many specimens of Mar- 
athrum, and to use such a characteristic to separate species seems impractical. In 
addition, the separated specimens seem so similar in other aspects of both vege- 
tative and floral morphology that one doubts they are different species. Costa 
Rican material identified as M. cheiriferum by van Royen is tentatively being placed 
under M. oxycarpum in a wide sense (q.v.). 

Marathrum foeniculaceum Humboldt and Bonpland, Plantae Aequin. 1:40-41, 
t. 11. 1808. Lads foeniculacea (H. & B.) Martius, Nov. Gen. & Sp. 1:6. 1824. 

Aquatic herbs to 50 cm long, attached by an irregular base to 2 cm broad; intrapetiolar 
stipules present, to 3 mm high. Leaves repeatedly divided or forked (rarely repeatedly 
pinnate in early stages), 2.5-50 cm long, petiole flattened, 1-8 cm long, widened at the 
base, ultimate divisions usually very slender and without a midvein, to 15 mm long. 
Flowers solitary or fascicled, spathella up to 15 mm long, pedicels up to 35 mm long and 
expanded at the apex to form a broad shallow cup; perianth parts 5-8, linear, ca. 1 mm 
long, arising from the edge of the disklike pedicel apex; stamens 5-8, 4-6 mm long, 
anthers ca. 1 mm long; ovary 3-4.5 mm long, 1-1.5 mm in diameter, styles 1-2.5 mm long. 
Fruit ca. 4.5 mm long, each valve with prominent ribs. 

This species ranges from Belize to Colombia, but has not been collected from 
Costa Rica. 

Marathrum foeniculaceum is characterized by the pedicels expanded at the apex 
to form a shallow "floral" cup and the relatively long slender distal divisions of the 
leaves which obscure the pinnate form of the leaf and give the leaf a more alga-like 
appearance. This leaf form is quite distinctive and unlike that of other species of 
Marathrum in our area. 



BURGER: FLORA COSTARICENSIS 5 

Marathrum minutiflorum Engler, Bot. Jahrb. Syst. 61, Beibl. 138:4. 1927. M. 
allenii Woodson, Ann. Missouri Bot. Card. 25:827-828. 1938. M. indifferens van 
Royen, loc. cit. 37:132-133. M. minutiflorum forma allenii (Woods.) v. Royen, 
Meded. Bot. Mus. Herb. Rijks Univ. Utrecht 107:80. 1951. M. minutiflorum forma 
diversifolium v. Royen, loc. cit. 81. M. minutiflorum forma indifferens (v. Royen) v. 
Royen, loc. cit. 81. M. minutiflorum forma intermedium v. Royen, loc. cit. 81. 

At present, it seems best to interpret material placed under the above names by 
van Royen (1951) as robust specimens of M. oxycarpum in a wide sense; see the 
description and discussion under M. oxycarpum. 

Marathrum oxycarpum Tulasne, Ann. Sci. Nat. Paris, ser. 3, 11:94-95. 1849. 

Small- to medium-sized herbs, 2-50 cm long, base with an irregular shape, ca. 1 cm wide 
and to 3 cm long; intrapetiolar stipules usually present. Leaves usually 3 x pinnate, 3-20 
(50) cm long, petiole terete or compressed, to 12 cm long, pinnae alternate on the rachis, 
ascending, ultimate divisions of the leaf spathulate (rarely filiform). Flowers solitary, at 
first enclosed in a tubular spathella to 12 mm long, pedicels slightly thickened at the apex 
but never forming a cup, to 5 (9?) cm long; perianth parts 5-10, 1-3 (4) mm long, narrowly 
lanceolate; stamens 5-10, 2.5-4.5 (6) mm long, anthers 1-2 mm long; ovary 2-4 mm high, 
1-2 mm in diameter, with 8 distinct longitudinal ribs, styles 1-3 mm long, slender. Fruit 
2.5-5 mm long, the smaller rounded and obtuse at the apex and the longer more ellipsoid, 
each valve with 5 prominent ribs. 

Aquatic plants of rocky streams growing at or up to 1 m below the water level. 
Ranging from near sea level to 1,200 m elevation in Costa Rica and flowering 
from January to May. Most collections are from the Pacific slope, but a few 
come from the Caribbean watershed. This species, defined in a wider sense, 
ranges from Mexico to Colombia. 

Marathrum oxycarpum is recognized by its distally slender pedicel, whorled 
perianth and stamens, strongly ribbed fruit, and its complex tripinnate leaves. 
This species may be polymorphic, with some plants (often collected without 
leaves) producing smaller, often stalked round fruit and other plants (usually 
leafy) producing larger (3.5-5 mm) sessile ellipsoid fruit. These latter plants look 
similar to specimens of M. schiedeanum, with some individuals actually having an 
expanded pedicel apex. Some plants have large (2 mm) anthers, but with other 
floral characters being typical. The minute perianth parts at the base of the flower 
(and alternating with the longer narrow perianth parts) are often conspicuous in 
this species. All perianth parts may be deciduous before the fruit is mature. 

Marathrum oxycarpum, as here defined, may be something of a catchall, since the 
more distinctive entities of the genus are separated in the earlier dichotomies of 
the key to species. Nevertheless, the material identified by van Royen as M. 
cheiriferum and M. minutiflorum seems to fall into this assemblage very naturally; 
all these plants seem to share exactly the same altitudinal range, and their inclu- 
sion in one species gives a more evenly distributed pattern of collecting localities 
through Central America. Perhaps M. leptophyllum and M. pusillum of Panama 
belong here as well (see the key). This larger circumscription of M. oxycarpum also 
allows us to identify the small-fruited material lacking well-developed leaves 
which may represent late-flowering plants (in respect to local water level) that are 
less robust. Another reason for the broader interpretation of this species is that 
one does not expect so many similar sympatric species in a genus whose life-style 
is so specialized and so dependent on effective dispersal. See the discussion 
under M. schiedeanum. 



6 FIELDIANA: BOTANY 

Marathrum schiedeanum(Cham.) Tulasne, Ann. Sci. Nat. Paris, ser. 3, 11:95. 
1849. Lads schiedeanum Chamisso, Linnaea 9:504-505, t. 566. 1835. Marathrum 
flexuosum Liebmann, Fdrh. Skand. Naturf. 5:511. 1849. Figure 1. 

Aquatic herbs to 50 cm long, base irregular, to 2 cm wide; intrapetiolar stipules usually 
present, 1.5 mm long, obtuse. Leaves up to 50 cm long, repeatedly pinnate, the young 
leaves sometimes repeatedly divided, petiole terete or slightly flattened, 0.5-13 cm long, 
pinnae usually ascending, ultimate divisions of the leaf to ca. 3 mm long and varying from 
2-3 mm broad to filiform, acute to obtuse at the apex, with or without a midvein. Flowers 
solitary or fascicled, spathella 1-1.5 cm long, pedicels 1-4 (9) cm long, expanded at the 
apex and forming a distinctive shallow or deep (2 mm) cup, 2 mm broad at the apex; 
perianth parts 5-8, linear to lanceolate, 0.5-1.5 mm long; stamens 5-8, 3.5-4.5 mm long, 
anthers ca. 1 mm long; ovary 2-5.5 mm long, 1.5-3 mm in diameter with 8 longitudinal 
ribs, styles 1-2 mm long. Fruit to 5.5 mm long and 3 mm thick, ellipsoid, each valve with 
5 prominent ribs. 

This species is found from near sea level to 1,200 m elevation on the Pacific slope 
and ranges from Mexico to southern Costa Rica; it flowers and fruits from January 
to May. 

Marathrum schiedeanum is characterized by the pedicel expanded at the apex to 
form a "floral" cup from which the perianth and stamens arise and the often large 
tripinnate leaves with ultimate divisions that may be broad and pinnatifid or 
slender and filiform. This species may hybridize or intergrade with M. oxycarpum. 
An alternative interpretation is that the cupulate nature of the pedicel apex is not 
a character worthy of distinguishing species in this instance; the character seems 
variable in some collections and there do appear to be intermediate individual 
collections, such as Bunting & Licht 1018 from Nicaragua. It may be that all the 
material under both M. oxycarpum in its expanded circumscription and M. schie- 
deanum is part of a single polymorphic species. For this reason, it seems best to 
place sterile material under the oldest name (M. schiedeanum), but to continue to 
use the pedicel apex to distinguish fertile material into two species. 

Marathrum tenue Liebmann, Forh. Skand. Naturf. 5:511. 1849. Neolacis myr- 
iophylla Weddell, in DC., Prodr. 17:63-64. 1873. Blandowia myriophylla (Wedd.) 
Nash, N. Amer. Fl. 22, pt. 1:5. 1905. Apinagia myriophylla (Wedd.) Engler, Natur. 
Pflanzenfam. 18a:38. 1930. Figure 1. 

Small aquatic herbs to 20 cm long, from a flat or branched base to 1.5 cm high; stipules 
absent but the petioles sheathing at the base. Leaves repeatedly pinnate, central rachis to 
15 (20) cm long, petiole usually terete and up to 6 cm long, ultimate divisions filiform and 
less than 2 mm long and resulting in distinctive densely 3-dimensional pinnae. Flowers 
solitary or fascicled, spathellae 3-10 mm long, pedicel to 2.5 cm long, somewhat asym- 
metric at the apex or becoming asymmetric; perianth parts 2, 3, or 4, on 1 side of the 
flower, lanceolate to filiform, to 1.5 mm long; stamens 2 or 3, 2.5-4.5 mm long, filaments 
lanceolate (resembling perianth parts), anthers 1-1.5 mm long; ovary 2-3 mm long, 1-2 
mm in diameter, styles ca. 1 mm long. Fruit ca. 3 mm long, strongly ribbed with the ribs 
on the side of the flower lacking perianth and stamens often decurrent on the pedicel, each 
half of the fruit with 5 prominent ribs or with 3 prominent and 2 less prominent ribs. 

Usually submerged aquatic plants growing on rocks in fast water and flowering 
in the dry season, January to May. The species is found from near sea level (100 
m) to 1,600 m elevation in Costa Rica, but has only rarely been collected below 
1,000 m elevation. The species ranges from Mexico to Costa Rica and is to be 
expected in western Panama. 

Marathrum tenue is distinguished by the small number of stamens and perianth 
parts arising on only one side of the flower. Because of this asymmetry, the apex 



BURGER: FLORA COSTARICENSIS 

of the pedicel is usually enlarged on one side, and the ribs of the fruit are often 
decurrent into the pedicel on the opposite side; no other species in our area has 
similar flower and fruit. In addition, the leaves with prominent central rachis and 
alternate pinnae with numerous (often closely crowded) ultimate divisions are 
quite different from typical leaves of the other species in our area. 

Marathrum utile Tulasne, Ann. Sci. Nat. (Paris), ser. 3, 11:95. 1849. Figure 1. 

Small aquatic herbs, to 35 cm long, base ca. 2 cm long, shoots opposite along the root 
but difficult to see. Leaves 3-35 cm long, 1-6 cm broad, often rhombic when young, 
becoming spathulate to cuneate, entire to pinnatisect or palmisect distally, the distal lobes 
or segments usually few (2-8), broad areas of the leaf with distinctive venation (dichoto- 
mous and reticulate), the lamina gradually narrowed to the base and the petiole not clearly 
differentiated. Flowers solitary or in fascicles, spathella 2-2.5 cm long, pedicels 1-4 cm 
long, expanded distally and forming a short broad cup; perianth parts 5-8, up to 2 cm 
long (difficult to distinguish from the filaments); stamens 5-8, 2-5.4 mm long, anthers 
1-1.5 mm long; ovary 2-4 mm long, ellipsoid to ovoid, style 1.5-2 mm long. Fruit to 4 mm 
long, with conspicuous longitudinal ribs. 

Herbs growing in the fast water of streams and known only from the Pacific 
slopes of the Cordillera Central and Cordillera de Talamanca between 1,000 and 
2,000 m elevation in Costa Rica. The species is known from Costa Rica, Colombia, 
and Panama. 

Marathrum utile is immediately distinguished by its broad laminae with anas- 
tomosing venation and divided only near the apex. The pedicels slightly cupulate 
at the apex are also distinctive. Although only collected above 1,000 m in Costa 
Rica, this species is known from lower elevations in Colombia. 

TRISTICHA Du Petit-Thouars 

Bryophyte-like herbs, forming dense mats on rocks in fast-moving water, stems thin and 
terete, glabrous, bearing leaves on 3 sides; stipules absent. Leaves alternate and in 3 ranks 
or becoming whorled in groups of 3 or 6, subsessile, lamina small and usually imbricate, 
entire or divided at the tip, with or without a midvein. Inflorescences absent, the flower 
solitary and terminal on the main stems or on short lateral shoots, young flower buds 
protected by 2 or 3 distinctly larger overlapping leaves, pedicels long and slender; flowers 
small and radially symmetrical, perianth 3-parted, free or united into a 3-lobed tube; 
stamen 1, filament slender, anthers introrse with an elongate connective; ovary 3-locular, 
with 3 slender erect styles. Fruit a capsule dehiscing by 3 equal valves, each valve with 3 
ribs, seeds numerous. 

A genus of three species in tropical and subtropical America, Africa, and Asia. 
Only one species is known to occur in the Americas. Like other members of the 
family, these plants are found only in fast-moving fresh water, and they resemble 
mosses and leafy liverworts more than they do flowering plants; even the little 
flowers and fruits resemble the stalked capsules of mosses. 

Tristicha trifaria (Bory ex Willd.) Sprengl, Syst. Veg., ed. 16, 1:22. 1825. Du- 
fourea trifaria Bory ex Willd., Sp. PI., ed. 5:55. 1811. Duforea hypnoides St. Hil., 
Mem. Mus. Hist. Nat. 10:472. 1823. Tristicha hypnoides (St. Hil.) Spreng., Syst. 
Veg. 4, pt. 2:10. 1827. T. trifaria (Bory ex Willd.) Tulasne, Arch. Mus. Hist. Nat. 
6:179. 1852. Figure 1. 

Small herbs, 1-4 (10) cm high, mosslike and firmly attached to rocks, often forming 
dense mats, stems often numerous, terete, leafy stems 1-3 cm long; without stipules. 
Leaves very small and overlapping on the stem, often somewhat dimorphic, with those on 
the upper stems 0.3-1 mm long and ovate, those of the lower stems to 0.4 mm broad and 



8 FIELDIANA: BOTANY 

2 mm long and spatulate in form, apex of the lamina entire or rarely split into 2-4 acute 
lobes, glabrous. Flowers at first enclosed within 2 or 3 larger leaves, borne on a slender 
pedicel 3-10 (20) mm long; perianth of 3 free or united petals, 1-2 mm long, perianth lobes 
obtuse; stamen 1.5-2.5 mm long, anthers ca. 0.8 mm long; ovary 0.5-1 mm long and ca. 
0.8 mm in diameter, ellipsoid, rounded or narrowed at the base, styles ca. 0.5 mm long. 
Fruit an ellipsoid thin-walled capsule, ca. 1.5 mm long, with prominent longitudinal ribs. 

Aquatic plants attached to rocks in fast-flowing freshwater streams from near 
sea level to 1,300 m elevation; flowering and fruiting from January through April 
in Costa Rica. The plants also flower in November and December in El Salvador 
and Nicaragua where the dry season may begin earlier. They are found on both 
the Pacific and Caribbean slopes. The species ranges from Cuba and southern 
Mexico to Colombia, Venezuela, Brazil, Uruguay, and northern Argentina. 

Tristicha trifariais recognized by its small bryophyte-like stems, with three ranks 
of very small leaves attached by holdfasts to rocks in rapidly moving water. The 
small flowers and ellipsoid fruit borne on a slender pedicel resemble the stalked 
capsule of a moss. 



PROTEACEAE 

REFERENCE: H. Sleumer, Proteaceae americanae. Bot. Jahrb. Syst. 76:139-211. 
1954. 

Trees or shrubs (in ours), usually bisexual; stipules absent. Leaves simple or compound, 
the juvenile leaves often pinnately compound and the mature foliage often simple, alter- 
nate in a spiral to opposite or whorled (sometimes on the same stem), the laminae usually 
stiff and drying coriaceous, entire to serrate or pinnately lobed. Inflorescences racemes, 
spikes, umbels, or heads, rarely with flowers solitary or paired; flowers radially or bilater- 
ally symmetrical, perianth of 1 outer whorl of usually 4 parts, free or united, valvate and 
tubular but splitting apart at the apex and usually becoming recurved, sometimes splitting 
on only 1 side; stamens opposite the perianth parts and the filament often adnate to them, 
the anthers introrse and often exposing the pollen to the air or transferring pollen to the 
style prior to pollination, an inner whorl of perianth-like nectar scales of hypogynous disk 
elements usually present around the base of the ovary; pistil superior and often short- 
stipitate, solitary, 1-carpellate, ovary with 1 loculeand 1 to many ovules, style solitary and 
unbranched with a thickened or enlarged stigma. Fruit usually woody, splitting open (a 
follicle) or remaining closed (a nut) with 1 to many seeds; seeds flattened or round, 
sometimes winged, the cotyledons often unequal, lacking endosperm. 

A moderately large family of about 60 genera and a little more than 1,000 species 
largely restricted to the warmer portions of the Southern Hemisphere. The family 
is best represented in Australia and southern Africa, especially in areas marked by 
a long dry season. A number, such as Banksia and Protect, are cultivated in the 
subtropics for their spectacular inflorescences. The stiff foliage usually evergreen 
and often with both pinnate and simple leaves on different parts of the same plant 
help to distinguish these woody plants. The usually narrow-tubular flower buds 
with four valvate perianth parts, perianth-opposing stamens, and one-locular 
pistils with simple style and stigma further distinguish the family. These plants 
may resemble some members of the Loranthaceae which have inferior ovaries and 
are often parasitic. 

la Introduced plants of gardens and roadsides; mature leaves pinnate or deeply pin- 
natifid, alternate along the stem, (simple leaves absent); flower buds bent backward 
and somewhat U-shaped Grevillea 

Ib Native plants of forest and woodland; mature leaves usually simple, alternate to 
opposite or whorled on the stems (pinnately compound leaves present or absent); 
flower buds straight 2a 



BURGER: FLORA COSTARICENSIS 9 

2a Leaves isomorphic, always simple and entire, the tertiary veins becoming prominent 
on both surfaces when dry; anthers borne on prominent filaments; fruit round and not 
splitting open Panopsis 

2b Leaves heteromorphic, immature and flowerless shoots usually with pinnately com- 
pound leaves and mature or flowering shoots usually with simple leaves; anthers 
sessile or subsessile on the perianth parts; fruit somewhat flattened and splitting open 
along the edge Roupala 

GREVILLEA R. Brown 

Shrubs or trees, bisexual, evergreen. Leaves alternate, simple to pinnately compound or 
pinnately divided. Inflorescences usually terminal, racemes or umbels, flowers in pairs 
along the rachis, with hairs usually attached in the middle; flowers bisexual, radially or 
bilaterally symmetrical, the perianth tube straight and slender or curved, the apical part 
of the perianth usually expanded and bearing the sessile stamens, anthers ovate, the 
connective not produced beyond the anthers, hypogynous disk usually a single semi- 
circular gland on the upper side of the receptacle or rarely completely circular or absent; 
ovary usually stipitate, the 2 ovules attached laterally near the middle of the locule wall, 
style filiform, often protruding from the slit in the underside of the perianth tube before 
the perianth opens completely, stigma on the terminally expanded style. Fruit a follicle, 
coriaceous or woody, often with the long style persisting, usually opening along the upper 
margin; seeds flat or round, usually bordered by a wing. 

A primarily Australian genus of about 190 species. Two species are widely 
planted in the tropics and in Central America. They have large (12 to 35 cm) 
pinnate or pinnatifid leaves, colorful racemes, and small (2 cm) follicles splitting 
open along one side. 

la Trees to 20 (30) m tall, often planted along avenues and in parks; leaves pinnate with 
pinnatifid pinnae; flowers orange; fruit glabrous G. robusta 

Ib Shrubs or small trees to 7 m tall; leaves pinnate or once pinnatifid; flowers red; fruit 
villous G. banksii 

Grevillea banksii R. Brown, Trans. Linn. Soc. 10:176. 1810. 

Tall shrubs or slender trees to 7 m tall, branches and inflorescences reddish brown 
tomentulose. Leaves pinnate or pinnatifid, 10-20 cm long, with 3-11 linear or lanceolate 
segments, 5-10 cm long, margins entire and revolute. Flowers red to rose red, in compactly 
flowered racemes 5-12 cm long, pedicels ca. 5 mm long, perianth tube strongly recurved 
below the apex, ca. 1.5 cm long, densely puberulent; fruit ca. 1.5 cm long with a long (4 
cm) persisting style. 

Usually planted in gardens and near houses. 

Grevillea robusta Cunningham, in R. Br., Prot. Nov. 24. Figure 2. 

Small and slender to large and robust trees, branches and inflorescences pale grayish to 
orange-brown tomentulose. Leaves usually pinnate, 15-30 cm long with ca. 10-20 pin- 
natifid leaflets, pinnae or leaflets ca. 5-10 cm long, margins usually lobed and revolute. 
Flowers orange, in loosely flowered racemes 10-20 cm long, pedicels ca. 1.5 cm long, 
perianth tube strongly recurved at about the middle, 1 cm long (2 cm measured along the 
curve); fruit ca. 2 cm long. 

Often planted in parks and along streets and avenues. 

PANOPSIS Salisbury 

Trees, bisexual, the foliage monomorphic. Leaves alternate, subopposite, opposite, or 
whorled, simple, entire, drying coriaceous. Inflorescences terminal or axillary, usually 
solitary, racemose with many flowers, the flowers arising solitary, 2, or 3 together on the 
rachis, with or without bracts; flowers bisexual, radially symmetrical, the perianth cylin- 





VGREVILLEA, 
irobusta&'t 




Juvenile leaves 




From a 

ROUPALA |I photograph 
loranthoides II of the type 



10 cm 



FIG. 2. Proteaceae: a cultivated species of Grevillea and native species of Roupala and 
Panopsis. Note: reduced scale. 



10 



BURGER: FLORA COSTARICENSIS 11 

drical and straight in bud, separating at anthesis into 4 perianth parts (tepals), the tepals 
free to the base and becoming recurved; stamens arising from the lower half of the tepals 
or from their base, filaments largely free, anthers oblong, connective apiculate; hypogy- 
nous disk a thin 4-lobed cup resembling a short perianth tube; ovary subsessile, ovules 2, 
pendulous, stigma terminal. Fruit indehiscent with a thick woody pericarp, seeds lacking 
wings, rounded. 

An American genus of about 11 species ranging from Costa Rica southward to 
Peru, Bolivia, and Brazil. The lack of pinnate leaves on younger parts, racemose 
flowers with distinct filaments, and the hard fruit that do not split open dis- 
tinguish this genus from other Proteaceae. 

Panopsis suaveolens (Kl. & Karst. ex Klotzsch) Pittier, Contr. Fl. Venez. 22. 
1923. Andripetalum suaveolens Klotzsch & Karsten ex Kl., Linnaea 20:472. 1847. 
Panopsis costaricensis Standl., J. Wash. Acad. Sci. 17:164. 1927. Figure 2. 

Trees 5-15 (25) m tall, trunks to 80 cm in diameter, with brown bark, leafy internodes 
(1) 5-30 mm long, 2-5 mm thick, reddish brown strigulose at the nodes but soon becoming 
glabrous, with conspicuous lenticels 0.3-1 mm long, axillary buds densely covered with 
lustrous reddish brown hairs. Leaves alternate to opposite, often clustered near the ends 
of branchlets, petioles 2-12 mm long, 1-2 mm thick, striate and glabrous; laminae (3) 5-15 
(17) cm long, (1.3) 2-6 (9) cm broad, narrowly oblong to elliptic or narrowly to broadly 
obovate, bluntly obtuse and rounded at the tip, obtuse to cuneate at the base and some- 
what decurrent on the petiole, margins entire or slightly undulate, lamina drying very 
stiffly chartaceous to subcoriaceous, smooth and glabrous on both surfaces when mature, 
often lustrous, the 4-8 pairs of major secondary veins arising at angles of 30-65, arcuate 
and weakly connected near the margin, tertiary veins raised and prominent on both 
surfaces (dry). Inflorescences axillary or in terminal clusters, always near the ends of 
stems, 6-16 cm long, racemes with more than 30 flowers each, rachis with slender as- 
cending yellowish brown hairs 0.1-0.5 mm long, pedicels 2-5 mm long, densely ap- 
pressed puberulent, perianth 6-7 mm long, sparsely puberulent; filaments 4-5 mm long, 
anthers ca. 1.5 mm long with a slender apiculate connective, hypogynous disk forming a 
thin cup or tube 0.5-0.7 mm long, enclosing the base of the ovary and mostly glabrous; 
ovary ca. 1.5 mm long, densely covered with hirsutulous orange-brown hairs to 0.5 mm 
long, style ca. 5 mm long. Fruit indehiscent, a very hard woody nut, 3.5-6 cm long and 
becoming 4.5 cm in diameter, ellipsoid to ovoid or subglobose, narrowed at the base and 
apex, the surface smooth and glabrous, dark brown with paler markings. 

Trees of the very wet forests along the Continental Divide and the Caribbean 
slopes between 1,000 and 2,200 m elevation in Costa Rica; flowering from April to 
July and fruiting from July to March. The species ranges from central Costa Rica 
southward to Colombia, Venezuela, and Ecuador. 

Panopsis suaveolens is recognized by its glabrous leaves with prominent tertiary 
venation that are alternate, subopposite, or opposite, often on the same stem. The 
puberulent racemes with many flowers and hard round fruit that do not open 
further distinguish the species. The trees have been called Palo de papa and Papa 
in Costa Rica and Aguacatia in Panama. 

ROUPALA Aublet 

Shrubs or trees, bisexual, the juvenile and sterile shoots usually with pinnately com- 
pound leaves and the flowering branches usually with simple foliage. Leaves hetero- 
morphic with both pinnately compound and simple leaves, alternate in a spiral to sub- 
opposite or opposite, the laminae very stiff, dentate to entire with the pinnate leaves 
usually dentate. Inflorescences axillary or terminal, spikes or racemes, flowers often aris- 
ing 2 or 3 together on the rachis; flowers bisexual and radially symmetrical, the perianth 
cylindrical and straight in bud, separating at anthesis into 4 perianth parts (tepals), the 
tepals free to the base and becoming recurved; stamens adnate to about the middle of the 



12 FIELDIANA: BOTANY 

tepals, the filament almost entirely adnate, anthers linear-oblong, sessile or subsessile, 
connective slightly prolonged beyond the thecae, a hypogynous disk or perianth-like 
whorl of flat scales or glands present at the base of the pistil; ovary with 2 pendulous 
ovules, stigma terminal. Fruit a short-stipitate follicle with thick hard walls, splitting 
obliquely into 2 flattened or slightly rounded valves, the seeds winged. 

An American genus of about 50 species ranging from southern Mexico south- 
ward to Peru, Bolivia, and Rio Grande do Sul, Brazil. Three species have been 
reported from Costa Rica. The very stiff often heteromorphic leaves, glabrous 
except at the base of the petiole in the leaf axil, and often alternate to subopposite, 
help to distinguish these woody plants. 

la Inflorescence and flowers sparsely puberulent, perianth parts 7-9 mm long; simple 
leaves long-acuminate; fruit ca. 3.5 cm long; trees and shrubs of the seasonally dry 
Pacific slope, 40-1,200 m elevation R. montana 

Ib Inflorescence and flowers glabrous (in ours); trees of moist cloud forests and evergreen 
montane forests 2a 

2a Simple leaves on mature shoots with laminae 5-15 cm long and with acuminate 
apices; perianth parts 10-14 mm long; fruit ca. 4 cm long; trees of wet evergreen forests 
(800) 1,500-2,500 m elevation R. glaberrima 

2b Simple leaves on mature shoots with laminae 3-7 cm long and with bluntly obtuse or 
rounded apices; perianth parts 7-9 mm long; fruit unknown; habitat unknown but 
may be exposed ridges and montane wind gaps R. loranthoides 

Roupala glaberrima Pittier, Contr. U.S. Natl. Herb. 18:299. 1917. Figure 2. 

Trees 5-20 (30?) m tall, bark gray, leafy internodes 3-30 mm long, 1-5 mm thick, very 
minutely puberulent but soon becoming glabrous, grayish. Leaves alternate, subopposite, 
or occasionally opposite, heterophyllous and pinnately compound on the young snoots or 
simple, rarely pinnate on the flowering shoots, simple leaves with petioles 1-8 cm long, 
1-2 mm thick, very minutely puberulent near the base adaxially but glabrous elsewhere, 
simple leaves with laminae 5-15 cm long, 2.5-6 cm broad, narrowly ovoid to rhombic or 
obovate in outline but very variable (often on the same twig), gradually tapering to an 
obtuse to acuminate or caudate-acuminate apex, occasionally rounded or slightly emar- 
ginate at the tip, abruptly to gradually narrowed below the middle but decurrent and 
forming small winged margins on the petiole, margin entire to undulate or bluntly den- 
tate, the laminae drying subcoriaceous, smooth and glabrous on both surfaces, usually 
slightly lustrous above, the 2-4 pairs of major secondary veins arising at angles of 15-35 
degrees from the proximal half of the midvein, secondary veins slightly raised beneath 
(dry), tertiary veins obscure. Inflorescences usually solitary in the axils of persisting leaves, 
8-22 cm long, racemose with more than 40 flowers, rachis glabrous and ca. 1 mm thick 
(dry), pedicels 3-7 mm long, ca. 0.5 mm thick; perianth parts 10-14 mm long, ca. 1 mm 
broad, linear oblanceolate, glabrous, white when flowering; anther ca. 3 mm long on a 
filament 1 mm long borne on the upper third of the tepal, hypogynous glands ca. 0.5 mm 
long, rounded apically; pistil ca. 10-11 mm long with the ovary 1 mm long and glabrous. 
Fruit ca. 4 cm long and 2 cm broad, flattened and asymmetrically obovate, abruptly 
narrowed at apex and base, opening distally and along one side, surface smooth and 
glabrous; seeds not seen. 

Trees of the wet cloud forests along the Continental Divide and adjacent areas 
on both the Pacific and Caribbean slopes between (800) 1,500 and 2,500 m ele- 
vation; flowering from March to July and fruiting from October to February in 
Costa Rica. The species ranges from El Salvador to the western part of the Cor- 
dillera de Talamanca. The species is apparently rare east of Volcan Barba. 

Roupala glaberrima is recognized by the stiff leaves that are pinnately compound 
on juvenile shoots but usually simple and long-petiolate on flowering stems, the 
conspicuous racemes, and the lack of pubescence on most parts. The collections 
from El Salvador differ from ours in having slightly puberulent inflorescences and 
resembling Roupala montana. There are no collections from Honduras or Nica- 



BURGER: FLORA COSTARICENSIS 13 

ragua. The white flowers are very fragrant in anthesis; their odor resembles that 
of vanilla. Common names associated with these plants in Costa Rica are Danto 
hediondoand Lora malodora. The latter name refers to the bad odor of the cut bark. 
This tree was common in the forests around Zarcero; the westernmost collection 
in Costa Rica comes from near Monteverde, Guanacaste. 

Roupala loranthoides Meisner, in DC., Prodr. 14:425. 1856. Figure 2. 

Probably small trees, the branchlets thick with many short twigs and clustered leaves, 
twigs at first reddish brown tomentulose. Leaves alternate or subopposite, pinnate leaves 
not seen, petioles 6-15 mm long, 1.2-2.2 mm thick, glabrous except for the very base in 
the leaf axil (adaxially); laminae (3) 4-7 cm long, 1.4-4.5 cm broad, broadly elliptic or oval 
to slightly obovate, bluntly obtuse to rounded at the apex and often emarginate, abruptly 
rounded or narrowed near the base and attenuate to form short wings on the petiole, 
margin entire in the few leaves seen and the edge revolute, drying very stiffly coriaceous, 
smooth and glabrous on both sides, the 3-5 pairs of major secondary veins arising at 
angles of ca. 20-30 degrees, both the secondary and tertiary veins slightly impressed 
above, venation obscure beneath. Inflorescence 5-8 cm long, axillary, exceeding the termi- 
nal leaves, racemose, glabrous, the flowers borne on thick (1-1.8 mm) pedicels, perianth 
ca. 8-10 mm long, less than 1 mm thick in the lower half and ca. 1.5 mm thick near the 
apex (dry) before anthesis, the hypogynous scales thin and triangular, very short, stigma 
subclavate and obtuse, thicker than the style. Fruit unknown. 

A very poorly known species. Type material was destroyed by fire in Vienna, 
and only two small leaves and photograph remain (F). The original Friedrichsthal 
collection was only labeled Monte Rincon, which may be Volcan Rincon de la 
Vieja, Guanacaste, of northwestern Costa Rica. The thick small clustered leaves on 
short thick twigs suggest that this is a tree of wind gaps or exposed elfin forest. 

Roupala montana Aublet, PI. Guyan. Franc. 1:83. 1775. R. complicata H.B.K., 
Nov. Gen. & Sp. 2:153, t. 119. 1817. R. borealisHemsl, Biol. Centr. Am. Bot. 3:78, 
t. 76. 1882. R. panamensis Pittier, Contr. U.S. Natl. Herb. 18:229. 1917. Figure 2. 

Shrubs or small trees 2-8 (rarely 18) m tall, leafy internodes 1-30 mm long, 1-6 mm 
thick, minutely reddish brown strigulose but quickly becoming glabrescent, becoming 
grayish, the axillary buds densely brownish strigulose. Leaves alternate or subopposite, 
heteromorphic, simple on the flowering branches, juvenile leaves pinnately compound but 
very variable in the number of leaflets and usually coarsely serrate, adult (simple) leaves 
with petioles 1.5-6 cm long, 0.7-2.5 mm thick, minutely puberulent near the base ad- 
axially; simple leaves with laminae 4-14 cm long, 2-7.5 (9) cm broad, narrowly to broadly 
ovate, gradually or abruptly narrowed to the often long-acuminate apex, abruptly nar- 
rowed at the obtuse or rounded base, decurrent and forming small winged margins on the 
petiole, margins entire or undulate, rarely coarsely serrate as on the juvenile foliage, the 
laminae drying coriaceous, smooth and glabrous (in ours), often lustrous above, the 3-6 
pairs of major secondary veins arising at angles of 20-50 degrees, secondary and tertiary 
veins slightly raised on both surfaces (dry). Inflorescences usually axillary, solitary, 7-15 
(18) cm long, racemose with more than 40 flowers, rachis densely puberulent with as- 
cending yellowish hairs 0.2-0.3 mm long, pedicel becoming 4-5 mm long densely strigu- 
lose; perianth parts 7-9 mm long, 1 mm broad, linear-oblanceolate, puberulent near the 
base, anthers 2-3 mm long on filaments ca. 0.5 mm long, hypogynous glands thick, ca. 0.5 
mm tall, pistil ca. 6 mm long, ovary 1-1.5 mm long and densely strigose. Fruit 3-4 cm long, 
ca. 1.3 cm broad, asymetrically obovate or elliptic and somewhat flattened, the surface 
glabrous and often lustrous, opening distally and along 1 side; seeds winged, thin and flat, 
ca. 2.4 cm long and 1.2 cm broad. 

Trees and shrubs of the seasonally very dry deciduous and seasonally dry 
partly deciduous (tropical and premontane dry and moist) forest formations of the 
Pacific slope between 40 and 1,200 m elevations, flowering from January to March 



14 FIELDIANA: BOTANY 

and fruiting from June to October in Costa Rica. The species ranges from 
Veracruz, Mexico, to Peru, Bolivia, and Brazil. 

Roupala montana is recognized by the stiff leaves that dry grayish and are pin- 
nately compound on juvenile shoots, but simple and long-petiolate on flowering 
stems, and the long puberulent racemes. Sleumer recognized both the typical 
form of this species and var. dentata (R. Br.) Sleumer as occurring in Costa Rica, 
but the differences between these appear to be inconsequential. 

OLACACEAE 

Trees, shrubs, or woody climbers, bisexual (in ours), autotrophic or hemiparasites on 
roots of the host, stems with or without spines, mostly glabrous; stipules absent. Leaves 
alternate in a spiral or distichous (rarely opposite), simple, petioles often with ridges 
continuous with the laminae margins; laminae usually entire and glabrous, venation 
pinnate. Inflorescences 1 to several or fasciculate in the leaf axils, paniculate, racemose, 
cymose, or umbellate in form, often few-flowered and the flowers sometimes in groups of 
3, bracteoles present or absent. Flowers bisexual, or rarely unisexual, radially symmetrical, 
sometimes polymorphic, often small and inconspicuous (not so in Ximenia, Chaunochiton, 
et al.); calyx united and usually a shallow cup with 3-6 small lobes or teeth, free or united 
to the ovary (as in Schoepfia), corolla of 3-6 petals, valvate in bud, free or united, sometimes 
puberulent on the inner surface; stamens as many as or 2-3 x as many as the petals, 
opposite the petals or petal lobes when of the same number, filaments free or adnate to the 
corolla tube, anthers 2-thecous with mostly lateral dehiscence; a disk said to be present at 
the base of the ovary but usually obscure in ours, ovary superior or half-inferior (in ours), 
1-5 locular (at least at the base) with the partitions often failing to reach the upper part of 
the ovary, ovule 1 in each locule, pendulous from the apex of the central placenta, style 
1 or none, stigma 1- to 5-lobed. Fruit usually a drupe with fleshy exocarp and single seed, 
with endosperm, in some genera the calyx enlarges to form a colorful structure subtending 
the fruit. 

The Olacaceae are a pantropical family with about 27 genera and 230 species. 
The family exhibits some interesting South American- African relationships. The 
Olacaceae are characterized by the woody habit, simple alternate leaves usually 
articulate at the base, a general absence of pubescence on vegetative parts (but not 
in Minquartia), regular flowers with very small calyx and valvate petals or petal 
lobes, and pistil with single style and the unusual arrangement of locules. Some 
genera are known to be root parasites, while others appear to be normal auto- 
trophs; all have green leaves and resemble nonparasitic trees and shrubs. This 
family is very closely related to the Opiliaceae, and some authors unite the two. 
These families are, in turn, related to the Loranthaceae (in a wide sense) and 
Santalaceae (not recorded for Central America). Together, they make up the very 
natural order Santalales. This is a unique and rather isolated order of di- 
cotyledons, many of which show tendencies or adaptations for parasitism and 
reduction of ovule structure. They share many vegetative and reproductive fea- 
tures, such as simple articulate entire leaves, absence of stipules, scarcity of 
pubescence, flowers often in triads, valvate perianth parts, poorly differentiated 
calyx, and pistil with an undivided style. Members of the Olacaceae may be 
confused with plants of the Rhamnaceae, Celastraceae, and Opiliaceae. 

la Young stems and inflorescences with minute branched hairs; leaves with subparallel 
tertiary veins; calyx not becoming expanded in fruit; corolla tube campanulate and ca. 
2 mm long; tall trees of evergreen wet forests Minquartia 

Ib Young vegetative parts and inflorescences essentially glabrous, hairs unbranched 
where present; leaves lacking consistently subparallel tertiary venation 2a 

2a Stems often with short thick spines, leaves often clustered on short shoots; petals free 



XIMENIA 
americana 

1: 



SCHOEPFIA 
schreberi 



SCHOEPFIA 
vacciniiflora 



MINQUARTIA 
guianensis 




FIG. 3. Olacaceae: Minquartia, Schoepfia, and Ximenia species. Opiliaceae: Agonandra 
macrocarpa, upper left. 



15 



16 FIELDIANA: BOTANY 

and with conspicuous hairs within; calyx remaining small in fruit; shrubs and small 
trees flowering in the dry season in the Pacific lowlands Ximenia 

2b Stems lacking spines, leaves rarely borne on short shoots 3a 

3a Calyx very small and becoming almost completely united to the fruit, forming much 
of the smooth covering of the fruit and defining a small round distal area at the tip; 
petals united to form a short tube; shrubs to large trees in wet and dry areas 

Schoepfia 

3b Calyx becoming enlarged in fruit and separate from the fruit, a fleshy disk or thin and 
broadly rotate structure 4a 

4a Common understory shrubs and small trees to 8 m tall; the fruit subtended by a fleshy 
red disk (the calyx); flowers very small and fasciculate, petals separate and 1-2 mm 
long, glabrous Heisteria 

4b Rare trees 10-30 m tall; fruit subtended and partly enclosed in a thin papery calyx 
5-10 cm broad; flowers 1-3 cm long, petals united in the lower half and puberulent 
within Chaunochiton 

CHAUNOCHITON Bentham 

Medium-sized to large trees, bisexual, stems glabrous, lacking spines; stipules absent. 
Leaves simple and alternate, articulate at the base, petiolate; laminae elliptic and entire, 
pinnately veined, glabrous. Inflorescences of congested cymules forming small panicles in 
the axils of leaves. Flowers bisexual, radially symmetrical 2-6 cm long but only 2-5 mm 
in diameter; calyx small and cuplike, 5-toothed, becoming greatly enlarged and thin in 
fruit; petals 5, very narrowly linear-spatulate, valvate in bud, united in the lower half to 
form a narrow tube, pilose within for almost their entire length, a disk absent; stamens 5, 
opposite the petals and united to their base, filaments long and slender, anthers very small 
and clavate; ovary superior, free or united with the calyx only near the base, 2-locular with 
1 pendulous ovule in each locule, style very long with globose or 5-lobed stigma. Fruit a 
drupe united at the base to the thin broadly expanded calyx, the calyx broadly cam- 
panulate to rotate and chartaceous, exocarp fleshy with a crustaceous endocarp. 

Chaunochiton is a very poorly known genus ranging from Costa Rica to the 
Amazonian Basin. The genus is readily recognized in fruit with an expanded 
rotate papery thin calyx that may be 10 cm broad. The slender flowers resemble 
those of Psittacanthus (Loranthaceae), but the long narrow petals are united near 
the base and are puberulent within. 

Chaunochiton kappleri(Sagot ex Engler) Ducke, Arch. Jard. Bot. Rio de Janeiro 
3:41. 1922. Heisteria kappleri Sagot ex Engler, in Martius, Fl. Brasil. 12, pt. 2:14. 
1872. Figure 4. 

Medium-sized to tall trees 12-30 m high, bisexual, leafy internodes 0.5-4 cm long, 1-4 
mm thick, ashy gray in color, glabrous. Leaves alternate in a spiral, articulate at the base, 
petioles 6-12 mm long, with lateral ridges continuous with the lamina margins; laminae 
ca. 3-6 cm long and 2-3.5 cm broad, ovate-elliptic to ovate-oblong or broadly elliptic, 
obtuse or bluntly acute at the apex, obtuse or rounded at the base, decurrent on the 
petiole, margin entire, the laminae drying thin-chartaceous, smooth and glabrous above 
and below, with 4-7 pairs of major secondary veins, the lower secondaries often more 
strongly ascending than the upper. Inflorescences not seen. Flowers not seen, but if C. 
breviflorum Ducke is synonymous with this species, then the calyx should be ca. 1 mm long 
and the corolla ca. 1 cm long with the petals ca. 0.5 mm broad at the base and 1 mm broad 
at the thickened apex. Fruit a drupe 6-10 mm long and 5-10 mm in diameter, with a 
somewhat muricate surface when dry, the fruit is subtended by the expanded calyx which 
may be 8-12 cm broad, subentire or weakly 5-lobed, drying pale brown and mem- 
branaceous, apparently rotate or slightly campanulate in form, the fruiting pedicel 15-20 
mm long. 

Plants of lowland evergreen wet forest formations and known from only a single 
collection in North America. Fruit and leafless stems were collected by Pittier 



BURGER: FLORA COSTARICENSIS 17 

(11948) in the Diquis basin at ca. 600 m altitude on March 15th, 1898. The species 
is otherwise only known from Amazonian Brazil and the Guianas. 

Chaunochiton kappleri is recognized by the fruit being subtended by a thin broad 
calycular development and the slender flowers with the petals puberulent within. 
The small leaves clearly articulate at the base, lack of pubescence, weakly five- 
lobed calyx, and small ovary are all characteristic of Olacaceae. The collection from 
Costa Rica is said to have been a small slender tree 12-15 m high and 20-25 cm 
diameter. Its local name is said to be Manglillo. Botanists visiting the General 
Valley, Osa Peninsula, and Golfo Dulce region should keep this unusual plant in 
mind; the species and the genus are very poorly known. 

HEISTERIA Jacquin 

Shrubs or small trees, rarely woody lianas as in H. scandens, not known to be parasitic, 
bisexual, the young stems with longitudinal ridges, glabrous. Leaves alternate and often 
distichous, articulate at the base, petioles usually with 2 adaxial ridges continuous with 
the lamina margins; lamina entire, glabrous, with laticiferous ducts. Inflorescences of few 
to many flowers in axillary fascicles, often forming a raised mound of tissue with sessile 
scarious bracts irregularly arranged over the surface. Flowers bisexual, very small, pale 
green to white or yellowish, pedicellate to subsessile, glabrous on the outside, calyx 
usually broadly cup-shaped, subentire to 5- or 6-toothed or -lobed, free from the ovary, 
becoming enlarged and thickened in fruit; petals usually 5 (6), valvate in bud, free or united 
at the very base, glabrous or puberulent within; stamens 10 or 12 (rarely 5 or 6), free or 
united to the base of the petals, antipetalous stamens often shorter than the antisepalous, 
anthers rounded and minute; ovary superior, rounded to conical, with 3 locules in the 
lower half, 1 pendulous ovule in each locule, style short or none and with 3 poorly 
differentiated stigmas. Fruit a drupe with thin fleshy exocarp that is often black and borne 
on the expanded brightly colored calyx, the fruiting calyx annular, broadly cupulate or 
becoming reflexed, fleshy in texture and red to purple in color, the embryo small in the top 
of the endosperm. 

The genus, with probably fewer than 20 species, ranges from southern Mexico 
and the Lesser Antilles to southern Brazil and Bolivia. Two species are native to 
West and Central Africa. Species of Heisteriaare easily recognized in fruit because 
of the expanded, slightly fleshy calyx. The usually black fruit and bright red calyx 
produce a striking contrast, undoubtedly an adaptation for seed dispersal. The 
very small flowers arising directly from an axillary base are difficult to see and rare 
in collections. The American species are seriously in need of revision, and our 
own species represent some difficult unresolved problems. This is particularly 
true regarding H. acuminata, H. macrophylla, and H. costaricensis. A number of 
collections appear to be intermediate between these taxa, and all three may 
prove to be part of a polymorphic complex. All our species appear to be plants 
of the forest shade. 

la Woody lianas (perhaps beginning as shrubs); laminae occasionally with the lowest 
pair of secondary veins quite prominent and almost triplinerved; petals puberulent 
within; fruit red at maturity and subtended by a small (10-15 mm) calyx; 0-800 m 
elevation H. scandens 

Ib Shrubs or trees; laminae never with the basal pair of secondary veins very prominent; 
fruiting calyx often more than 12 mm broad 2a 

2a Petals puberulent within; fruit white at maturity, fruiting calyx conspicuously and 
deeply 5-lobed; leaves lustrous above and subcoriaceous when dry with the margins 
recurved, short-acuminate at the apex; 0-800 m elevation H. concinna 

2b Petals glabrous within; fruit becoming black in late stages, fruiting calyx shallowly or 
obscurely 5-lobed; leaves not usually lustrous or with the margins recurved when dry, 
chartaceous . . . . 3a 



HEISTERIA 
scandens 



CHAUNOCHITONV fruitm 9 




flowers of 
H. acuminata 



FIG. 4. Olacaceae: Costa Rican species of Heistcria and Chaunochiton. 



18 



BURGER: FLORA COSTARICENSIS 19 

3a Laminae usually abruptly narrowed at both ends; petiole deeply and narrowly cana- 
liculate above (adaxially); fruit becoming black only in late stages, the fruiting calyx 
often reflexed; 0-300 m elevation H. cyanocarpa 

3b Laminae usually gradually narrowed to the apex; petiole with the adaxial ridges 
forming a V-shaped or broadly U-shaped sulcus above, rarely narrowly canaliculate 
above; 0-1,700 m elevation. (Note: The following 3 species are differentiated here 
on the bases of leaf form and habitat. Plants with intermediate characteristics are 
not uncommon, and it may be that these 3 taxa are part of a single polymorphic 
complex.) 4a 

4a Laminae linear-lanceolate, widest below the middle and often narrowed abruptly at 
the base; 0-700 m elevation H. costaricensis 

4b Laminae not linear-lanceolate 5a 

5a Plants rarely found below 500 m elevation; laminae rarely more than 15 cm long, not 
usually tapering gradually to both base and apex, often drying pale in color; under- 
story plants of montane and seasonally dry evergreen moist forest formations; fruit 
ellipsoid-oblong H. acuminata 

5b Plants rarely found above 500 m elevation; laminae usually more than 15 cm long, 
often tapering gradually to both base and apex, drying dark in color; plants of wet 
forest formations; fruit globose H. tnacrophylla 

Heisteria acuminata (H. & B.) Engler, in Martius, Fl. Brasil. 12(2):14, nota. 1872; 
and in Flora 56:135. 1873. Rhaptostylum acuminatum Humboldt and Bonpland, 
Plant. Aequinox. 2:129, 5:125, 1809, and in H.B.K., Nov. Gen. & Sp. PI. 5, t. 621, 
emended illustration. 1824. Figure 4. 

Shrubs or small treelets 0.7-3 m tall, glabrous, the leafy internodes 0.3-4 cm long, 1-4 
mm thick, with 2 or 4 distinct longitudinal ridges, becoming terete and often drying pale 
in color. Leaves obscurely articulate at the base, petioles 4-8 (11) mm long, the 2 longi- 
tudinal adaxial ridges separate or forming a V-shaped sulcus above; laminae 6-14 (23) cm 
long, 2-5 (7) cm broad, elliptic to very narrowly elliptic or elliptic-oblong (rarely lanceolate 
or ovate elliptic), usually widest near the middle, tapering gradually to the short- or 
long-acuminate apex, obtuse to acute at the base, margin entire or undulate when dry, the 
laminae drying thin- to stiff-chartaceous, glabrous and smooth above and below, the 5-10 
pairs of major secondary veins usually quite distinct from the tertiary veins. Inflorescences 
in the axils of leaves, or less often in the axils of fallen leaves and undeveloped leaves, 
usually with only 1 or 2 flowers in anthesis at a node at one time, pedicels 2-4 mm long; 
flowers 2-3 mm long, calyx prominently 5- toothed, 1.5-2 mm broad, petals ca. 2 mm long 
and 1 mm broad, glabrous within; stamens 10 and clearly of 2 lengths with the longer 
alternipetalous, filaments to 0.4 mm broad, anthers 0.2-0.3 mm broad, pistil ca. 1.2 mm 
long and 1 mm broad at the base. Fruit ca. 8-10 mm long and 6-8 mm in diameter, globose 
to ellipsoid, soon becoming black, longitudinally ribbed when dry, the fruiting calyx 12-20 
(30) mm broad, inconspicuously 5-lobed, bright red, fruiting pedicels ca. 7 mm long. 

Plants of forest understory in moist evergreen montane or, less often, lowland 
formations; collected with fruit from October to April, but probably flowering 
throughout the year. The plants are most often encountered between 600 and 
1,600 m elevation in Costa Rica. The species ranges from Chiapas, Mexico, to 
Colombia (see below). 

Heisteria acuminata is recognized by its small- to medium-sized, usually elliptic 
leaves that taper gradually to an acuminate apex, glabrous flowers, weakly lobed 
fruiting calyx that is broader than the fruit, and its frequent occurrence in cloud 
forests on the Pacific slope. These plants are not known from below 600 m on the 
Pacific slope of Costa Rica and adjacent Panama. The few lowland collections of 
the Caribbean slope appear to be restricted to the moist (not the wet) forest 
formations as diagrammed by Tosi in the Mapa Ecologico. Our highland material 
is very similar to that of Guatemala and Chiapas, but I have seen no comparable 
highland material from Colombia. Much of the Central American material has 
been referred to as H. tnacrophylla or misidentified as H. longipes in the past. 



20 FIELDIANA: BOTANY 

The original collection of Heisteria acuminata is from Popayan, Colombia, at 
about 2,000 m elevation. The leaf shape and venation and floral details illustrated 
for this species agree well with Central American highland material. In a recent 
letter, Dr. Sleumer points out that the fruit of H. acuminata is larger and ellipsoid- 
oblong, whereas the fruit of H. macrophylla is smaller and globose. He thus inter- 
prets the species in a way that has H. acuminata reaching its northern limit in Costa 
Rica, whereas H. macrocarpa reaches its southern limit in Costa Rica. This species 
may also intergrade with H. costaricensis, and it is closely related to H. cyanocarpa: 
see the discussions under those species and H. macrophylla. 



Heisteria concinnaStandley, Publ. Field Columbian Mus., Bot. Ser. 8:137. 1930. 
Figure 4. 

Small- to medium-sized trees 3-10 (20) m tall, the branches often said to be drooping, 
leafy internodes (0.5) 1-4 (7) cm long, 1-3 (4) mm thick, yellowish or pale brown with 2 
often obscure longitudinal ridges, becoming minutely striate and yellowish or pale brown 
when dry, glabrous. Leaves distichous, often clearly articulate only in age, petioles 7-20 
mm long, 1-2 mm thick, often bent distally and thickened beneath, the adaxial petiolar 
ridges usually forming a narrow (0.5 mm) sulcus above; laminae (3) 5-15 cm long, 2.5-6 
(7) cm broad, elliptic to broadly elliptic to ovate-elliptic, tapering gradually or abruptly to 
the acuminate apex, obtuse or somewhat rounded at the base, margins entire but be- 
coming undulate and recurved when dry, the laminae drying subcoriaceous or very stiffly 
chartaceous and lustrous above, smooth on both surfaces, the 5-8 pairs of major secondary 
veins often difficult to distinguish from the tertiary venation. Inflorescences in the axils of 
current or fallen leaves, pedicels 3-6 mm long; flowers white, flower buds ca. 2-3 mm long 
before anthesis, calyx ca. 1 mm high and 2-3 mm broad, petals ca. 2 mm long, puberulent 
within, anthers 0.2-0.3 mm long, ovary conical, 1.5 mm long. Fruit 10-14 mm long and 
8-10 mm thick (dry), ellipsoid to globose, becoming white, fruiting calyx 2-4 cm in 
diameter with usually 5 shallow or relatively pronounced rounded lobes, rose red to dark 
red in color. 

This species is found in moist (partly deciduous) and wet evergreen forest 
formations between sea level and about 800 m elevation on both the Caribbean 
and Pacific slopes in Costa Rica; fruiting collections have been made from Sep- 
tember through March. The species probably ranges from the Caribbean side of 
Honduras (Standley 55292) to eastern Panama. 

Heisteria concinna is distinguished by its stiff lustrous leaves with unusual pet- 
ioles, puberulent petals, and the mature white fruit subtended by a bright red 
five-lobed calyx that is 2 to 4 cm broad. Most of our collections come from season- 
ally dry evergreen forests on the Pacific slopes, but none come from the seasonally 
very dry and largely deciduous formations of lowland Guanacaste. This species is 
apparently very closely related to H. cocinnea Jacquin of the Lesser Antilles. 



Heisteria costaricensis Donnell Smith, Bot. Gaz. 19:254. 1894. Figure 4. 

Shrubs or slender treelets 1.5-2.5 (3) m tall, leafy internodes 0.3-4 cm long, 0.7-3 (5) mm 
thick, with 2 or 4 longitudinal ridges 0.1-0.3 mm high, the stems becoming smooth and 
terete. Leaves alternate and distichous, indistinctly articulate at the base, petioles 4-8 (13) 
mm long, the longitudinal adaxial ridges usually forming a shallow groove ca. 1 mm wide 
above, the petiole occasionally thickened and bent; laminae 12-22 (30) cm long, 1.5-3.5 
(4.5) cm broad, narrowly lanceolate to linear-lanceolate, broadest below the middle (rarely 
near the middle), tapering very gradually to the acute or acuminate apex, narrowed more 
abruptly to the acute or slightly rounded base, margin entire or slightly undulate, the 
laminae drying chartaceous to stiffly chartaceous, smooth on both surfaces, the 7-37 pairs 
of major secondary veins usually easy to distinguish from the tertiary. Inflorescences small 



BURGER: FLORA COSTARICENSIS 21 

axillary fascicles with apparently only a few flowers at any one time; flower buds ca. 1.5 
mm long and subglobose, mature flower with 5-toothed calyx, petals ca. 2 mm long and 
1 mm broad, glabrous on both surfaces; stamens 10, filaments liguliform, anthers 0.2-0.3 
mm long; pistil conical, ca. 1 mm long and 1 mm in diameter. Fruit globose or ovoid 6-8 
mm long, becoming black, vertically ribbed when dry, fruiting calyx 12-25 mm broad, 
obscurely or shallowly 5-lobed, bright red, the fruiting pedicels 3-9 mm long. 

Plants of wet and moist evergreen forest formations on both the Caribbean and 
Pacific slopes from sea level to 700 (1,000) m elevation, but not as yet collected from 
below 500 m on the Caribbean side; probably flowering and fruiting throughout 
the year. This species is known only from Costa Rica and Panama. 

Heisteria costaricensis is immediately recognized by its long linear-lanceolate 
leaves, widest below the middle and usually abruptly narrowed near the base. 
Characters of flower and fruit are probably the same as those of H. acuminata and 
H. macrophylla. These three species are separated here primarily on their different 
leaf shape, but they may prove to be members of a single polymorphic species. 
Collections from around San Ramon, Alajuela, appear to be intermediate between 
typical H. acuminata and H. costaricensis. 

Heisteria cyanocarpa Poeppig, Nov. Gen. Sp. 3:35, t. 241, 1845 (fide Sleumer in 
herb.). H. longipes Standley, J. Wash. Acad. Sci. 17:8. 1927. Figure 4. 

Shrubs or small- to medium-sized trees (1.5) 3-12 (20) m tall, leafy internodes 0.5-3 cm 
long, 1-3 mm thick, with 2 or 4 longitudinal ridges, becoming terete, glabrous. Leaves 
alternate, usually distichous, articulate at the base, petioles 4-12 mm long, 1-1.5 mm 
thick, the 2 adaxial longitudinal ridges forming a very narrow sulcus above, becoming 
longitudinally striate and thickened abaxially throughout the length of the petiole; lami- 
nae (4) 6-14 cm long, 2-6 (7) cm broad, elliptic to ovate-elliptic, obovate, or oblong, 
gradually or abruptly narrowed to the short acuminate apex, abruptly narrowed at the 
obtuse (rarely acute) base, margin entire or undulate when dry, laminae drying stiffly 
chartaceous, smooth on both surfaces, with 5-9 pairs of major secondary veins but the 
secondaries often difficult to distinguish from the tertiaries. Inflorescences in the axils of 
current or recently fallen leaves, with 5-10 flowers but only 1 or 2 flowering at a node at 
one time, flower buds 1.5-2 mm long, pedicels 1-4 mm long; flowers with a 5-lobed calyx, 
petals 1.5-2 mm long, glabrous within; anthers 10, borne at the edge of the disk, filament 
ca. 1.2 mm long and 0.5 mm broad, narrowed below the minute (0.2 mm) anther, ovary 
1-1.3 mm broad near the base, ca. 1.2 mm long, abruptly narrowed above, stigma ob- 
scurely lobed. Fruit 8-12 mm long, 6-8 mm in diameter, ellipsoid, apparently remaining 
green for a time but becoming black, fruiting calyx (1) 1.5-2 (2.5) cm broad, bright red, 
often reflexed, usually bluntly 5-lobed. 

Plants of evergreen and partly deciduous wet and moist forest formations from 
sea level to about 300 m elevation on both the Caribbean and Pacific slopes; 
flowering collections have been made from December through July, and fruiting 
collections have been made from January to September. The species, as presently 
understood, ranges from southwestern Costa Rica and the Bocas del Toro region 
of Panama to Colombia. 

Heisteria cyanocarpa is recognized by the laminae usually being abruptly nar- 
rowed at both ends, the petiole narrowly canaliculate above, and the five-lobed 
fruiting calyx subtending a green fruit that becomes black only at maturity. The 
species appears to be restricted to the lowlands (below 300 m) in our area, but 
collections from Colombia which appear to be this species come from as high as 
1,500 m. Rather similar looking plants from above 500 m elevation on the Pacific 
slope and along the Caribbean slope are here placed under H. acuminata. In a 
recent letter (June 1980), Dr. Sleumer suggests that this species might be made 
part of H. acuminata in a very wide sense. 



FIELDIANA: BOTANY 

Heisteria macrophylla Oersted, Vidensk. Meddel. Dansk Naturhist. Foren. 
Kjoebenhavn 1856:40. 1857, sensu stricto. H. latifoliaStandley, ]. Wash. Acad. Sci. 
17:8. 1927. 

Shrubs or small treelets (0.5) 1.5-3 (7) m tall, glabrous, the leafy internodes 0.3-6 cm 
long, 1-5 mm thick, with 2 or 4 distinct longitudinal ridges, becoming terete in age, often 
drying pale in color. Leaves obscurely articulate at the base, petioles 3-18 mm long, ca. 3 
mm thick, the 2 adaxial longitudinal ridges separate or forming a broad V-shaped sulcus 
above; laminae 15-36 cm long, 5-10 (17) cm broad, very narrowly elliptic to broadly elliptic 
or ovate-elliptic, tapering very gradually to the long-acuminate apex, tapering gradually 
to the acute or obtuse base, occasionally slightly rounded at the petiole in larger laminae, 
margin entire (undulate when dry), the laminae drying thin-chartaceous and often dark 
in color, glabrous and smooth on both surfaces, the 9-17 pairs of major secondary veins 
usually quite distinct from the tertiary veins. Inflorescences in the axils of leaves or fallen 
leaves, pedicels 1-3 mm long; flowers 2-3 mm long, calyx 5- (rarely 6-) toothed, petals 5 
(rarely 4), ca. 2 mm long and 1 mm broad, glabrous; stamens 10, filaments ca. 0.5 mm 
broad, 0.7-1.5 mm long, anthers ca. 0.5 mm broad, pistil conical ca. 1 mm broad at the 
base. Fruit ca. 8-10 mm long and 6-9 mm in diameter, globose to ovoid or ellipsoid, soon 
becoming black, longitudinally ribbed when dry, the fruiting calyx 16-30 mm broad, 
inconspicuously 5-lobed, bright red, the fruiting pedicel ca. 7 mm long. 

Plants of the wet evergreen forest formations of the Caribbean lowlands and 
adjacent slopes between sea level and about 300 m elevation; fruiting collections 
have been made from August to October and January to May. The species, as here 
delimited, ranges from southern Nicaragua to eastern Panama. 

Heisteria macrophylla (in a narrow sense) is recognized by its larger leaves usually 
widest near the middle and gradually tapering to both apex and base and the wet 
forest habitat on the Caribbean slope. The large thin leaves are often rhombic in 
outline. There are collections (Molina et al. 17339, Pittier & Tonduz 9174, Donnell 
Smith 6462, and Standley 37332) which appear to be intermediate between typical 
H. macrophylla and H. acuminata. Further study may show that H. macrophylla 
is only an unusual lowland form of H. acuminata in a wide sense (q.v.); see 
Figure 4. 

Heisteria scandens Ducke, Arch. Jard. Bot. Rio de Janeiro 4:9. 1925. H. fatoensis 
Standl., Publ. Field Columbian Mus., Bot. Ser. 8:137. 1930. H. eurycarpa Standl., 
loc. cit. 11:148. 1936. Figure 4. 

Woody lianas climbing to the tops of trees as much as 30 m tall, perhaps beginning as 
small shrubs 3-4 m tall, leafy internodes 0.6-4 (6) cm long, 0.7-2.5 (5) mm thick, the 2 
longitudinal ridges absent or inconspicuous, the stems soon becoming terete, longi- 
tudinally minutely striate and pale gray to dark brown when dry, the axillary cushion-like 
inflorescence bases often conspicuous on the leafless stems. Leaves usually distichous 
with the laminae in a single plane, articulate at the base, glabrous, petioles 5-12 (20) mm 
long, 0.6-1.3 mm thick, the 2 adaxial ridges forming a shallow groove above; laminae (4) 
5-13 cm long, (1.5) 3-6 cm broad, ovate-oblong to elliptic-oblong or broadly elliptic, 
abruptly narrowed to the short (0.5-1 cm) acuminate apex, obtuse to abruptly rounded at 
the base, margin entire or slightly undulate, the laminae drying thin chartaceous or 
chartaceous, smooth on both surfaces and often somewhat lustrous above, venation with 
3-5 pairs of major secondary veins, occasionally with the lowest pair of veins quite 
prominent and the lamina almost triplinerved. Flowers fasciculate from a broad minutely 
bracteate mound in the axils of leaves or fallen leaves, each axil producing up to 30 (50) 
flowers but only a few seen in anthesis in our material, pedicels 3-6 mm long, ca. 0.3 mm 
thick, flowers 2-3 mm long, glabrous on the outside, calyx 1-2 mm broad, with 5 short (0.5 
mm) teeth, petals 1.5-2 mm long, minutely puberulent near the apex within; stamens 10, 
filaments 1-1.5 mm long, anthers 0.2-0.3 mm long; ovary conical and ca. 1 mm broad at 
the base, with shallow longitudinal sulci. Fruit 9-14 mm long, 8-12 mm in diameter, 
globose to ellipsoid, becoming red at maturity and longitudinally ribbed when dry, fruit- 



BURGER: FLORA COSTARICENSIS 23 

ing pedicel ca. 1 cm long, fruiting calyx 10-15 mm broad with 5 shallow lobes, the calyx 
smaller than the fruit and often reflexed. 

This species is known from only two collections in Costa Rica, both from the 
Golfo Dulce region: Allen 5838 at 75 m altitude and Lent 447 at about 650 m. Fruit 
have been collected in February and March and in July and August in Costa Rica 
and Panama. The species, as presently known, ranges from the Golfo Dulce area 
of Costa Rica (on the Pacific side) and the province of Bocas del Toro in Panama 
(on the Caribbean side) southward to Peru and Amazonian Brazil. 

Heisteria scandens is immediately distinguished by its climbing habit, apparently 
unique in the genus. The smooth terete branches with well-spaced leaves, un- 
usual leaf venation, petals puberulent within, and the fruit apparently red at 
maturity with relatively small fruiting calyx further distinguish these plants. This 
species may be closely related to H. acuta Engler of Brazil. 



MINQUARTIA Aublet 

Trees, often large, apparently autotrophic, bisexual, the young branches rusty tomen- 
tulous with branched hairs, the older stems sometimes perforated, lacking spines. Leaves 
alternate, not clearly articulate at the base, petiolate; laminae elliptic and acuminate, 
entire, chartaceous to coriaceous, glabrous above but minutely puberulent beneath, with 
resin canals and lactiferous ducts. Inflorescences spicate, solitary in the leaf axils, puber- 
ulent, with small bracts subtending the subsessile or short-pedunculate cymelike groups 
of flowers; flowers bisexual, calyx cuplike and 5-toothed, persistent but not enlarging in 
fruit, petals connate into a bell-shaped or campanulate tube, puberulent to villous within, 
the 5 (6) lobes valvate in bud; stamens 10 (12) in 2 whorls, adnate to the lower part of the 
corolla tube at 2 levels, sessile or on short filaments, the antepetalous anthers longer than 
the antesepalous; ovary with 3-5 locules, stigma 3- to 5-lobed. Fruit with a somewhat 
fleshy exocarp and crustaceous endocarp. 

A genus of perhaps three species, ranging from southern Central America to 
the Amazonian Basin. The genus stands out among our representatives of the 
family because of the unusual pubescence. Plants with immature inflorescences 
may be mistaken for species of Euphorbiaceae or Malvales. 

Minquartia guianensis Aublet, Hist. PI. Guyan. Franc., Suppl. 4, t. 370. 1775. 
Figure 3. 

Trees 10-35 m tall, developing low buttresses, sapwood yellow with dark red or dark 
brown heartwood, bisexual, leafy internodes 0.7-3 cm long, 1.4-3 mm thick, at first 
slightly angled but soon becoming terete, very minutely (0.05 mm) brownish puberulent 
but soon becoming glabrous, smooth and brownish; stipules none but the young folded 
leaves stipule-like, often ca. 1 cm long and 1.5 mm thick and tapering to a narrow apex. 
Leaves alternate and distichous, petioles 8-30 mm long, 1-2.8 mm thick, with 2 longi- 
tudinal adaxial ridges continuous with the margins of the lamina, the ridges expanded and 
slightly vaginate just below the apex of the petiole; laminae 8-16 (22) cm long, 3-7 (11) cm 
broad, elliptic-oblong to ovate-oblong, abruptly short (1-2 cm) acuminate at the base, 
margin entire but often slightly undulate, drying chartaceous and slightly lustrous above, 
smooth and glabrous above and below, venation pinnate with 3-14 pairs of major second- 
ary veins, arcuate ascending only near the margin and never loop-connected, tertiary 
venation often subparallel between the secondaries. Inflorescence solitary in the leaf axils, 
spikelike with alternate groups of usually 3 flowers subtended by a bract, rachis with a 
covering of minute scurfy or branched reddish brown hairs, ca. 5 cm long at anthesis and 
to 15 cm long in fruit. Flowers apparently bisexual, short pedicelled, calyx broadly cupulate 
with 5 very short teeth, ca. 1 mm long and 1.5-2 mm broad, reddish brown puberulent, 
corolla a campanulate tube ca. 2 mm long with 5 recurved lobes, puberulent, stamens 10, 
borne on the tube on very short (0.5 mm) filaments, anthers broader than long; ovary with 



24 FIELDIANA: BOTANY 

an unusual pubescence forming ca. 10 small pocket-like depressions on the upper (distal) 
sides, style with 5 distinct finger-like stigmas. Fruit becoming 3 cm long and 2 cm thick, 
black and fleshy, edible but with an acrid taste, borne on a short (5 mm) thick (2 mm) 
pedicel. 

Trees of the lowland evergreen wet forest formations below 500 m elevation in 
Costa Rica; mature fruit have been collected in July, but mature flowers have not 
been collected in Central America. The species ranges from southern Nicaragua 
to Ecuador and Amazonian Brazil. 

Minquartia guianensis is recognized by the tall habit, simple alternate distichous 
glabrous leaves with unusual petioles and subparallel tertiary venation, solitary 
spikelike reddish brown inflorescences, and small densely puberulent flowers. 
These trees are known by the names Manu, Crillo, Nispero, Negro, Cricamola, and 
"Black Manwood" in Costa Rica and Panama. The species is largely represented 
by sterile collections in herbaria; the flower descriptions are based on South 
American material. The wood is very hard and very durable, resisting both ter- 
mites and fungal decay (see Biotropica 8:71-95, 1976). 



SCHOEPFIA Schreber 

Shrubs or trees, reported to be root parasites, bisexual, without spines, the vegetative 
parts glabrous; stipules none. Leaves alternate, clearly articulate at the base, petiolate, the 
laminae entire and stiffly chartaceous to coriaceous, glabrous, venation pinnate. In- 
florescences solitary to several or fasciculate in the leaf axils, racemose or spicate with 
usually 3 (2-5) flowers closely clustered or short-pedicellate at the end of a short peduncle 
(and often resembling the triads of Loranthaceae), bract subtending the ovary of each 
flower a shallow usually 3-lobed cup, glabrous or puberulent. Flowers small, calyx united 
with the ovary and with an obscurely 3- to 6-lobed or entire distal margin, glabrous, 
usually green, corolla united to form a tube, the corolla lobes usually 5 (3-6), short and 
valvate in bud, the corolla glabrous on the outside and usually puberulent near the stamen 
attachment within; stamens epipetalous, high on the corolla tube, anthers sessile or sub- 
sessile, small, about as wide as long; ovary half-inferior, the upper surface often minutely 
puberulent, style 1 with a prominent rounded or 3-lobed stigma, base of the ovary imper- 
fectly 3-locular, ovules 3, lacking an integument. Fruit a drupe enclosed by the smooth- 
walled calyx except near the apex where a circular area of different texture is demarcated 
by the calycular rim, seed 1 and apparently erect, embryo small at the top of the endo- 
sperm. 

A genus of about 35 species in tropical Asia and ranging in the New World from 
Mexico through Central America and the West Indies to Bolivia and southern 
Brazil. The genus is distinguished by the simple stiff alternate leaves articulate at 
the base, short few-flowered axillary inflorescences, tubular corolla with epi- 
petalous stamens opposite the valvate corolla lobes, half-inferior ovary with 
poorly differentiated adnate calyx, and unusual fruit with circular apical area of 
different texture than the smooth lower surface. 

la Trees to 20 m tall in the wet evergreen forests of the Caribbean lowlands; leaves 3-6 
cm broad with strongly ascending basal secondary veins S. species A 

Ib Shrubs or trees rarely more than 10 m tall in deciduous and partly deciduous forests 
of the Pacific slope in Costa Rica; leaves 1-4 cm broad 2a 

2a Corolla tube campanulate, 2-5 mm long and 2-3 mm in diameter; flowers usually 
sessile in groups of 3; leaves ovate to lanceolate on pale grayish white stems; 0-1,000 
m altitude S. schreberi 

2b Corolla tube cylindrical, 4-7 mm long and 2-3 mm in diameter; flowers often short- 
pedicellate; leaves usually elliptic on brownish stems; 800-1,800 m altitude 

S. vaccinii flora 



BURGER: FLORA COSTARICENSIS 25 

Schoepfia schreberi J. F. Gmel., Syst. Veg. 2:376. 1791. S. americana Willd., Sp. 
PL 1:9%. 1798. S. arborescens Roem. & Schult., Syst. 5:160. 1819. Figure 3. 

Trees 4-8 (rarely 25) m tall, without spines, leafy internodes 0.5-2.5 cm long, 0.7-3 mm 
thick, at first somewhat angular or ridged but soon becoming terete, becoming pale 
grayish white and smooth, then dark in later years. Leaves alternate and distichous, 
clearly articulate at the base; petiole differentiated from the lamina, ca. 4-8 mm long, with 
lateral ridges continuous with the lamina margins, not sulcate above; lamina 3-8 cm long, 
1.5-3.5 cm broad, ovate, ovate-elliptic to narrowly elliptic or lanceolate, acute to acu- 
minate at the apex, acute to obtuse at the base and with the margins attenuate on the 
petiole, margins entire and often undulate, lamina drying very stiffly chartaceous or 
subcoriaceous, smooth and glabrous above and below, venation pinnate with 2 or 3 
(sometimes to 5) pairs of major secondary veins, the basal secondaries often strongly 
ascending, prominent beneath. Inflorescences fasciculate in the leaf axils, the flowers 
usually borne in groups of 3 (triads) on short (2-6 mm) thin (0.4 mm) glabrous peduncles, 
flowers sessile within broad (1.5-2 mm) shallow (0.5-1 mm) cuplike bracts with irregular 
and partly puberulent margins, the bracts closely approximate at the apex of the peduncle. 
Flowers 3-5 mm long, calyx glabrous and obscurely 5-lobed, or entire, corolla tube cam- 
panulate, 2-4 (5) mm long, 2-3 mm in diameter, the corolla lobes 1-2 mm long and 
recurved, glabrous on the outside but puberulent around the anther attachment within, 
stamens sessile high on the corolla tube, anthers ca. 0.6 mm long; top of the half-inferior 
ovary minutely grayish puberulent, style ca. 1 mm long with a prominent flattened 
disklike stigma ca. 0.5 mm broad. Fruit globose to ellipsoid, ca. 7 mm long and 6 mm in 
diameter, greenish (immature?) with a red apex, the glabrous lower ovary and calyculus 
defining a small circular distal minutely puberulent area at the top of the fruit ca. 2 mm 
broad and yellowish in color. 

Trees of deciduous and partly deciduous forest formations on the Pacific slope 
of Costa Rica between sea level and 1,000 m elevation; flowering material has been 
collected from December to February and in June and July in Costa Rica. The 
species, as presently understood, ranges from southern Florida and Mexico to 
northern South America and the West Indies. 

Schoepfia schreberi is recognized by its glabrous alternate stiff little leaves that are 
clearly articulate on pale-colored twigs, the triads or diads of flowers arising from 
small mounds of tissue in the axils of leaves, and the small bracteate flowers with 
campanulate corolla tube, epipetalous sessile anthers, and internal pubescence. 

Schoepfia vacciniiflora Planch, ex Hemsley, Diag. PL Mex. 5. 1878. Figure 3. 

Shrubs or small trees 2-8 (12) m tall, without spines, leafy internodes 0.3-3 cm long, 
0.6-4 mm thick, strongly 2-ridged or angled in early stages but becoming terete, pale 
brown to pale gray. Leaves alternate and distichous, clearly articulate at the base, petioles 
weakly differentiated from the lamina, ca. 2-5 mm long, with lateral margins continuous 
with the lamina margins, flat above (adaxially); laminae (2) 3-8 (10.5) cm long, 1-3 (4.5) 
cm broad, elliptic to elliptic-oblong or ovate-elliptic, acute to short-acuminate at the apex, 
acute to obtuse at the base and somewhat attenuate at the petiole, margins entire or 
slightly undulate, drying stiffly chartaceous to subcoriaceous, smooth and glabrous on 
both surfaces, venation pinnate with 3-6 pairs of major secondary veins, the lower pairs 
of secondaries often strongly ascending (in ours), sometimes loop-connected near the 
margin. Inflorescences usually 1 or 2 in the axils of leaves, the peduncle branched above 
the 1st flower or the flowers subsessile and clustered at the end of the peduncle, flowers 
2 to 4 per inflorescence (most often 3), the flowers usually on short pedicels with shallow 
cupulate bracts beneath the base, the bracts 1.5-2 mm broad, generally 3-lobed, glabrous. 
Flowers 6-8 mm long, calyx fused with the ovary and with an entire or obscurely 5-Iobed 
distal margin, corolla tube (4) 5-7 mm long, 2-3 mm in diameter, cylindrical, corolla lobes 
1-1.5 mm long, slightly reflexed at anthesis, glabrous on the outside, puberulent near the 
stamen attachment within, anthers sessile high on the corolla tube, style ca. 2 mm long 
with stigma 1 mm broad. Fruit ellipsoid, ca. 10 mm long and 6 mm in diameter, glabrous, 



26 FIELDIANA: BOTANY 

longitudinally striate when dry, glabrous except for a sharply defined circular distal area 
1.5-2 mm in diameter at the apex. 

Plants of the partly deciduous forest formations on the Pacific slope between 800 
and 1,200 (1,800) m elevation in Costa Rica; apparently flowering from June to 
January. The species ranges from Guatemala to Costa Rica. 

Schoepfia vacciniiflora is characterized by the stiff distichous leaves articulate at 
the base, small usually pedicellate flowers with tubular corolla, and ellipsoid fruit 
with circular distal area of different texture around the apex. This species is quite 
easily distinguished from S. schreberiin Guatemala where the plants differ consis- 
tently in flower form and altitudinal range. These distinctions are not so clear-cut 
in Costa Rica where we have very few collections that are clearly referable to S. 
vacciniiflora: Brenes 3554, 5367, 5661, 20334, 21051, all from near San Ramon, Ala- 
juela province. Two high-altitude collections from 1,700 to 1,800 m altitude with 
shorter less cylindrical corolla tubes are tentatively placed here: A. Jimenez 289 and 
M. Valeria 1657 from San Jose province. 

Schoepfia species A. Figure 3. 

Trees ca. 20 m tall, leafy internodes 1-3 cm long, 1.5-3 mm thick, 2-ridged in early 
stages, becoming terete and grayish brown. Leaves distichous, articulate at the base, 
petioles 3-6 mm long, with 2 adaxial ridges becoming lateral in the distal half of the petiole 
and continuous with the margins of the lamina, sulcate above at the base; laminae 5-11 
cm long, 3-6 cm broad, ovate to ovate-oblong, acute to short-acuminate at the apex, 
rounded and truncate or occasionally obtuse at the base, margins entire and revolute when 
dry, laminae drying stiffly chartaceous, smooth and glabrous above and below, venation 
pinnate with 3-5 pairs of major secondary veins, the lowest 2-4 secondary veins strongly 
arcuate ascending. Inflorescences 1 or 2 in the axils of leaves, the peduncles becoming 6-12 
mm long and bearing usually 3 subsessile or shortly pedicellate flowers distally. Flowers 
not known. Fruit ellipsoid, ca. 12-14 mm long and 9-12 mm in diameter, red but drying 
dark brown and lustrous with numerous longitudinal shallow grooves, a circular area of 
different texture ca. 4 mm wide delimited by the calycular rim near the apex of the fruit. 

Plants of the lowland Caribbean rain forest formations. The species is known 
only from a single fruiting collection made in March, near the Rio Kama-Rio 
Escondido in Bluefields, Nicaragua, by Proctor, Jones, & Facey (26972). 

Schoepfia species A is recognized by the stiff ovate leaves articulate at the base 
and with ascending basal secondary veins, the characteristic fruit on short pedun- 
cles, and the lowland Caribbean forest habitat. This species resembles S. obliq- 
uifolia Turcz. of Venezuela and Brazil, but without flowers it is difficult to say 
where its true affinity lies. The very distinctive fruit and articulate leaves leave no 
doubt that this tree is placed in the correct genus. 

XIMENIA Linnaeus 

Shrubs and small trees, hemiparasitic on roots of other plants, bisexual, stems with thick 
spines produced by modified axillary branchlets, glabrous or puberulent. Leaves alternate, 
articulate at the base, often borne in fascicles from short shoots, deciduous; laminae ovate 
to elliptic, entire, pinnately veined. Inflorescences axillary, 1 to several and fasciculate, 
usually a few- to many-flowered bracteate cyme or umbel, flowers sometimes solitary. 
Flowers bisexual, regular, hypogynous, medium-sized, whitish; calyx small with 4 or 5 
small teeth or lobes, not expanding in fruit; corolla of 4 or 5 free petals, valvate in bud, with 
conspicuous hairs on the inner surface; stamens twice as many as the petals, filaments 
usually narrow, anthers linear to oblong, 2-thecous, dehiscing longitudinally; a disk 
absent; ovary superior, 3- or 5-chambered throughout the height of the ovary, ovules 
pendulous from the central axis, with 1 integument, style narrow, stigma simple or 
slightly lobed. Fruit a globose to ellipsoid drupe, yellow to deep purple, often with a juicy 
edible pulp, seed with a small embryo at the apex of the fleshy endosperm. 



BURGER: FLORA COSTARICENSIS 27 

A circumtropical genus of eight species of which only one is known from 
Central America. The presence of spines, articulate simple leaves often borne on 
short shoots, the free petals densely hairy within, and the ovules pendulous from 
a central column defining three or four separate locules help distinguish these 
plants. The genus is named in honor of Francisco Ximenez, who, in 1615, pub- 
lished an important work on the plants and animals of Mexico. 

Ximenia americana L., Sp. PL 1193. 1753. Figure 3. 

Shrubs and small trees to 7 m tall, branches often with thick spines formed by modified 
axillary branches, leafy internodes (0) 0.5-4 cm long, 1.5-6 mm thick, with longitudinal 
ridges in very early stages but soon becoming terete, pale grayish and lenticellate in age, 
short shoots with clustered leaves often present. Leaves alternate, usually in a spiral, 
clearly articulate at the base, petioles 3-8 mm long, with 2 longitudinal adaxial ridges 
forming a narrow sulcus above that is minutely puberulent within; laminae (1.5) 3-8 (11) 
cm long, (1) 1.5-4 (5) cm broad, elliptic to ovate-elliptic, acute to obtuse at the apex and 
slightly retuse with a small mucro at the tip, acute to obtuse at the base, margins entire 
and decurrent on the petiole, the laminae drying stiffly chartaceous but usually very brittle 
and often dark in color, smooth and glabrous above and below, the 3-6 pairs of major 
secondary veins becoming obscure in the distal half of the lamina. Inflorescences 1 to 
several in the axils of leaves or fallen leaves, of 3-12 flowers in cymose, umbellate or 
racemose arrangements, 1-3 cm long, the flowers often in groups of 3, primary peduncles 
7-15 mm long, pedicels 2-6 mm long, subtended by minute (0.5 mm) deciduous bracts; 
flowers ca. 5-10 mm long, glabrous on the outside, white or cream-colored but usually 
drying dark, calyx forming a very shallow (0.5 mm) broad (1-1.5 mm) cup with 4 (3) blunt 
teeth or lobes, the margin erose; petals usually 4, liguliform, 6-8 mm long, 1-1.5 mm 
broad, valvate in bud, and becoming reflexed, with dense tomentulous hairs 1-2 mm long 
on the inner surface, these white but turning reddish brown; stamens 8, equal, glabrous, 
filaments 3-5 mm long, anthers linear, 3-4 mm long, ca. 0.7 mm broad, ovary 3-4 mm long 
and 1-1.5 mm in diameter, glabrous, style 3-4 mm long, stigma simple. Fruit a yellow- 
orange drupe, 2-3 cm long, 1.5-2.5 cm in diameter, ellipsoid, edible but with an acid taste. 

Plants of seasonally dry deciduous and semideciduous forest formations of the 
Pacific slope below 300 m elevation in Costa Rica; flowering material has been 
collected from January to April, and fruit has been collected from March to May. 
The species is pantropical. 

Ximenia americana is recognized by the pale grayish branches often bearing thick 
spines and leaves clustered on short shoots, small leaves with a minutely mu- 
cronate tip and clearly articulate base, flowers with long hairs on the interior of 
the petals, and the acid-tasting fruit. The small stature, deciduous leaves, and 
restriction to the seasonally dry Pacific lowlands are further distinctions. The 
indigenous name Tsu-kra has been recorded from the Boruca area (Pittier 11983). 
The Central American representatives of this species have been placed in variety 
americana by DeFilipps (Trans. Illinois State Acad. Sci. 62:350-358, 1969). 

OPILIACEAE 

Trees, shrubs, or climbers, bisexual or unisexual, generally glabrous; stipules absent. 
Leaves alternate in a spiral, simple and entire. Inflorescences spikes, racemes, umbels, or 
panicles, at first enclosed in imbricate bud scales; flowers bisexual or unisexual, radially 
symmetrical, small; sepals united and minutely 4- or 5-lobed or reduced to a rim and not 
apparent, petals (or tepals if the sepals are not apparent) 4 or 5, free and valvate in bud; 
stamens as many as the petals and opposite them, filaments free, anthers 2-thecous, a disk 
of 4 or 5 lobes or separate glands present outside the stamens and alternate with them; 
ovary superior or united with the disk and half-inferior, 1-locular with 1 ovule pendulous 
from a central basal placenta or erect from the base of the locule, style short or none, stigma 
1. Fruit a drupe, seed with endosperm. 



28 FIELDIANA: BOTANY 

A family of seven or eight genera and about 50 to 60 species, mostly of African 
and Asian tropics. The plants are probably all root parasites. The family is closely 
related to the Santalaceae and Olacaceae and has been considered a part of 
the Olacaceae by some workers. The Opiliaceae differ from the Olacaceae in the 
structure of the disk, the usual reduction of the calyx, the lack of chambers at the 
base of the ovary, and the lack of lignified cells in the leaves. This small family 
resembles Olacaceae and Celastraceae in general appearance. The leaves often 
turn a dull or dark yellowish green on drying. 

AGONANDRA Miers 

REFERENCES: L. O. Williams, The Agonandras of Mexico and Central America. 
Ciencia (Mexico) 25:227-228. 1966. P. C. Standley, The North American species 
of Agonandra. ]. Wash. Acad. Sci. 10:505-508. 1920. 

Small trees, shrubs, or somewhat vinelike, usually dioecious, the bark generally corky 
and drying pale gray, often with short shoots; stipules none. Leaves alternate and articu- 
late at the base, petiolate, the laminae generally small and ovate to elliptic, entire. In- 
florescences axillary, racemes at first subtended by decussate and caducous bracts (bud 
scales); flowers small and unisexual, pale yellowish to greenish in color, calyx subentire or 
minutely 5- or 4-lobed, petals usually 4 (5), free, valvate in bud, usually caducous in the 
female flowers; stamens opposite the petals, filaments slender and equal, (stamens absent 
in the female flower, a pistillode usually present in the male flower), disk present and 
annular or of separate erect glands alternating with the stamens; pistil 1, superior or with 
the disk adnate near the base, style absent and with a single sessile stigma. Fruit a drupe 
with fleshy rind and stiff endocarp. 

An American genus of about 20 species ranging from Mexico to Argentina and 
most often found in seasonally very dry habitats. The genus is recognized by the 
pale grayish bark, small alternate leaves distinctly articulate at the base, and the 
small unisexual flowers in a racemose inflorescence at first enclosed in several 
series of decussately imbricate bud scales. 

Agonandra macrocarpaL. O. Williams, Ciencia (Mexico) 24:227. 1966. Figure 3. 

Shrubs or small trees to 7 m tall (also said to be vinelike), unisexual, leafy internodes 
0.1-2 cm long, 0.7-2.5 mm thick, green and strongly 2- or 3-ridged in early stages, older 
stems with gray bark and becoming longitudinally furrowed when dry, glabrous. Leaves 
alternate in a spiral, petiole 4-10 mm long, ca. 1-2 mm broad with winglike margins 
continuous with the margin of the lamina, slightly expanded at the articulate base; lami- 
nae 2-5.5 cm long, 1-3 cm broad, elliptic to ovate-elliptic, obtuse to bluntly acute at the 
apex, rounded at the tip, acute to obtuse at the base, margin entire or undulate (dry) and 
decurrent on the petiole, the lamina drying stiffly chartaceous or subcoriaceous, glabrous 
and smooth above and below, venation pinnate with 3 or 4 pairs of major secondary veins. 
Inflorescences originating from a bud covered with 4 distichous series of imbricate bud 
scales (bracts) 1-2 mm broad at the base. Male racemes less than 3 cm long, the rachis 
essentially glabrous, with 3 or 4 ridges and 0.3-0.5 mm thick, pedicels ca. 2 mm long, the 
male flowers ca. 3 mm long with reflexed tepals (the calyx obscure), glands of the disk ca. 
0.5 mm long, filaments 1.5-3 mm long, anthers 0.5 mm long. Female racemes less than 1 
cm long, pedicels ca. 2 mm long, tepals caducous, a yellowish annular disk ca. 1.5 mm 
broad conspicuous beneath the ovary, pistil ca. 1.2 mm long, ovary ca. 0.6 mm thick. Fruit 
globose or slightly ellipsoid, ca. 2 cm long (dry), the outer fleshy exocarp drying to form 
a smooth coriaceous yellowish brown surface, endocarp hard and yellowish, ca. 16 mm in 
diameter. 

Plants of the seasonally very dry deciduous (tropical dry and tropical dry-moist 
zone transition) forest formations below 200 m elevation in northwestern Costa 
Rica; flowers have been collected in January and mature fruit in May. The species 



BURGER: FLORA COSTARICENSIS 29 

is known only from Central Honduras and the provinces of Guanacaste and 
northern Puntarenas in Costa Rica. 

Agonandra macrocarpa is recognized by the small alternate leaves articulate at the 
base, unusual inflorescence buds, minute unisexual flowers in small racemes, and 
distinctive fruit. The seasonally very dry habitat, grayish corky stems, and gla- 
brous parts further distinguish this species, which resembles some of our species 
of Olacaceae. This species is apparently quite rare, with only three collections 
known from Costa Rica: Brenes 22481 near Los Loros (Puntarenas), and Daubentnire 
755 and Opler 508, both from near Canas. Agonandra obtusifolia Standley of north- 
ern Central America and Mexico has minutely puberulent stems, whereas A. 
brasiliensis Benth. & Hooker has longer finely puberulent inflorescences and 
smaller fruit. Our species is closely related to A. racemosa (DC.) Standley of Mexico 
and northern Central America, which has smaller fruit. The genus is poorly 
represented in collections, and species designations can only be regarded as first 
approximations. 

LORANTHACEAE sensu lato 

by William Burger and Job Kuijt 

REFERENCES: B. A. Barlow and D. Wiens, The classification of the generic segre- 
gates of Phrygilanthus(=Notanthera) of the Loranthaceae. Brittonia 25:26-39. 1973. 
Job Kuijt, The Biology of Parasitic Flowering Plants. Univ. Calif. Press, 1-246. 
1969. J. Kuijt, Mutual affinities of the Santalalean families. Brittonia 20:136-147. 
1968. J. Kuijt, A revision of the Loranthaceae of Costa Rica. Bot. Jahrb. Syst. 
83:250-326. 1964. J. Kuijt, Commentary on the mistletoes of Panama. Ann. Mis- 
souri Bot. Card. 65:736-763. 1978. C. T. Rizzini, in Woodson and Schery, Lo- 
ranthaceae, Flora of Panama. Ann. Missouri Bot. Card. 47:263-290. 1960. 

Shrubs or small trees, unisexual or bisexual, usually leafy hemiparasites with chloro- 
phyll, erect or scandent, parasitic on the aerial stems of the host or rarely terrestrial and 
root parasites (as in Gaiadendron) , usually parasitic on the stems of dicotyledonous trees 
and shrubs, attaching to the host by means of a haustorium (that developed from the 
radical of the seed), sometimes with additional haustoria on epicortical roots, stems some- 
times with thickened or articulate nodes. Leaves present or reduced to small scale leaves 
(squamate) and apparently absent, usually opposite or subopposite, rarely whorled (some 
Psittacanthus) or rarely alternate throughout (Antidaphne, Cladoclea), simple, glabrous, often 
articulate at the base, laminae usually very stiff and drying brittle, with entire or undulate 
margins, venation pinnate to palmate. Inflorescence basically an unbranched axis with 
sessile or pedunculate flowers in groups of 2 (diads), 3 (triads), or solitary (monads), the 
flower groups borne in a spicate, racemose, or paniculate arrangement, the flowers emerg- 
ing from depressions in the rachis in some genera, bud scales enclosing young in- 
florescences in some genera, bracts subtending the flowers or flower groups (monads, 
diads, triads, etc.); flowers bisexual or unisexual, radially symmetrical or nearly so, peri- 
anth present (absent only in male Antidaphne), floral morphology quite variable (see under 
segregated families below), stamens usually as many as the perianth parts and opposite 
them, pistil 1 and usually inferior, locule 1 or none, the ovule solitary and often not clearly 
differentiated, style and stigma 1. Fruit a 1-seeded berry with a layer of viscous tissue, 
often dispersed by birds, endosperm present in all but Psittacanthus, the endosperm with 
or without chlorophyll, cotyledons 2 or rarely as many as 12 (in species of Psittacanthus). 

While obviously related, the plants included here represent a wide range of 
floral morphology and appear to include several different parallel lineages with 
unusual adaptation to the parasitic life-style. The reduction of the ovarian cavity 
and simplification of tissues of the ovule are probably associated with the evo- 
lution of a fruit that germinates on the host and develops parasitizing roots. 



30 FIELDIANA: BOTANY 

Recent students of these plants are agreed that they are better treated as several 
smaller families (see Kuijt, 1968, referred to above). 

The plants included in this alliance (Loranthaceae in a wide sense) are usually 
easy to recognize because of their shrubby epiphyte-resembling habit and para- 
sitic attachment to the aerial stems of the host. The very stiff, usually opposite 
leaves with entire or undulate margins and lack of pubescence are also character- 
istic. Gaiadendron, a root parasite often found as a terrestrial tree, superficially 
resembles our native species of Proteaceae, as do some of our larger species of 
Psittacanthus. Cladocolea and Antidaphnehave consistently alternate leaves, whereas 
the apparently naked flowers of Antidaphne are quite unique. 

The genera of the Loranthaceae in a wide sense (sensu lato) are here placed 
under the following families and in the following order: Eremolepidaceae, Lo- 
ranthaceae in a narrow sense (sensu stricto), and Viscaceae. The following key 
treats all these plants. Additional keys will be found under Loranthaceae (sensu 
stricto) and Viscaceae. The figures of Eremolepidacae and Loranthaceae (sensu 
stricto) are under the latter family, while the illustrations of Viscaceae are with the 
keys to that family. 

KEY TO THE LORANTHACEAE IN A WIDE SENSE IN COSTA RICA 

Genera and species without family designation 
will be found under the Loranthaceae in a narrow sense 

la Leaves always alternate on all the stems, foliage leaves present 2a 

Ib Leaves opposite, whorled, or occasionally alternate with some opposite or sub- 
opposite leaves present, or the leaves reduced to opposing pairs of scale leaves and 

foliage leaves absent 3a 

2a Flowers apparently bisexual with conspicuous male and female parts in the 
same flower (but the stamens or the pistil nonfunctional); perianth of 4 con- 
spicuous petals, style at least 4 mm long; spikes without distal leaflike 

parts Cladocolea 

2b Flowers obviously unisexual, possessing organs of only 1 sex, petals absent in 
the male flower and scalelike (2) in the female, style less than 1 mm long; female 

spikes often with small distal leaves; (Eremolepidaceae) Antidaphne 

3a Flowers solitary in axillary positions on main stem, or borne singly on spikes and 

racemes, not found in diads, triads, or in longitudinal or whorled series 4a 

3b Flowers borne in diads or triads on spikes and racemes or in longitudinal or whorled 

arrangements on thick spikelike axes 5a 

4a Inflorescence a raceme, the individual flowers pedicellate, the pedicel support- 
ing a bract and 2 fused bracteoles beneath the flower, foliage leaves present 

Struthanthus panamensis 

4b Inflorescence of 1 to several flowers borne in the leaf axils; normal foliage leaves 
absent, scale leaves present. Doubtfully present in Panama and not recorded 

from Costa Rica Ixocactus 

5a Flowers obviously borne in diads (groups of 2) or triads (groups of 3) and pedun- 
culate or sessile on relatively thin (1-3 mm) axes, the diads and triads clearly 

separated from each other 6a 

5b Flowers borne in longitudinal ranks (or occasionally in whorls or forming rounded 
flat groupings) on relatively thick (2-5 mm) spikelike axes, the flowers rarely in 
clearly isolated groups of 2 or 3, the flowers often partly sunken into the axis of the 

inflorescence lOa 

6a Flowers more than 1 cm long, perianth bright red, orange, or yellow, bisexual, 
the flowers occasionally smaller and subtended by leaflike bracts in Gaia- 
dendron 7a 

6b Flowers less than 1 cm long, perianth dull yellow to dark red, bisexual or 
unisexual, never subtended by small leaflike bracts 8a 



BURGER: FLORA COSTARICENSIS 31 

7a Flowers golden yellow, subtended by green leafy bracts 3-20 mm long; 

terrestrial or growing on branches of trees Gaiadendron 

7b Flowers at least partly bright red or orange, subtended by a cupulate pedicel 

apex and without leaflike bracts; parasites of aerial stems Psittacanthus 

8a Flowers bisexual, both the pistil and anthers functional, perianth dark red or 
dull yellow (in ours), inflorescences axillary and racemose or terminal and 

paniculate Phthirusa 

8b Flowers functionally unisexual, organs of both sexes may be present but either 
the stamens or the pistil not functional, the male flower buds usually thickened 
distally with the fertile anthers, the female flowers with tubular flower buds and 

the anthers absent or reduced, perianth yellowish to dull white 9a 

9a Filaments thin or the anthers subsessile; inflorescence always a simple racemose 
or spikelike axis with sessile or pedunculate diads and triads of flowers 

Stmthanthus 
9b Filaments thick, the upper ones with lateral depressions; inflorescence often a 

paniculate arrangement at the ends of twigs Phthirusa adunca 

lOa Perianth parts usually 6, the flowers in 4 vertical (longitudinal) ranks on the thick 
inflorescence axis, with 2 minute bracteoles subtending each flower and usually 
found within the floral depression; spikes without distinct internodes; foliage leaves 

present Oryctanthus 

lOb Perianth parts usually 3, the flowers variously arranged on the spike, the individual 
flowers not subtended by minute bracteoles; spikes with distinct internodes defined 

by opposite pairs of scale leaves (also called bracts); (Viscaceae) lla 

lla Anthers unilocular; plants with or without foliage leaves; flowers in single or 
multiple longitudinal ranks (series) above each scale leaf (bract), the arrangement of 
flowers on the internode often somewhat irregular; from 1,500-3,500 m in Costa 

Rica Dendrophthora 

lib Anthers bilocular; plants with foliage leaves; flowers always in multiple longitudinal 
ranks above each scale leaf, flowers usually in regular ranks on the internode; from 
sea level to 3,000 m in Costa Rica Phoradendron 



EREMOLEPIDACEAE 

REFERENCE: Job Kuijt, Mutual affinities of Santalalean families. Brittonia 
20:136-147. 1968. 

Shrubs, epiphyte-like hemiparasites, unisexual (or bisexual in some species of Ere- 
molepis), epicortical roots produced in young stages (or possibly lacking in Eubrachion). 
Leaves alternate and simple but reduced to scalelike squamae in Eubrachion, petiolate, the 
lamina stiff with entire margin. Inflorescence spicate or racemose, at first enclosed in a 
conelike bud of spirally arranged imbricate and scarious bud scales, the female in- 
florescence often continuing with new vegetative growth distally in Antidaphne; flowers 
very small and unisexual, sessile or the male pedicellate in Antidaphne, with a single 
perianth whorl or apparently naked, the male flowers 2- to 4-parted, a perianth absent in 
Antidaphne, the stamens opposite the perianth parts in Eremolepis and Eubrachion, filaments 
present and free, anthers 2-thecous and dehiscing longitudinally; the female flowers 2- or 
3-parted, ovary inferior (apparently half-inferior in Antidaphne and with 2 or 3 minute 
deciduous perianth parts borne halfway up the pistil), locule 1, style 1, stigma capitate. 
Fruit a small 1-seeded sessile berry, the endosperm with some chlorophyll in Antidaphne, 
embryo with 2 cotyledons, viscous layer of the berry formed between the vascular bundles 
of the perianth and the bundles of the ovary. 

A small family of three genera ranging from southern Mexico and the largest 
Caribbean Islands through tropical South America. The Eremolepidaceae are rep- 
resented in our area by a single species of Antidaphne. These plants are easily 
recognized because of their hemiparasitic habit on the aerial stems of host plants, 
stiff alternate leaves, inflorescences emerging from buds with imbricate and alter- 
nate bud scales, and the very small, naked or virtually naked unisexual flowers. 



32 FIELDIANA: BOTANY 

ANTIDAPHNE Poeppig and Endlicher 

Shrubs, hemiparasites on aerial woody branches, unisexual, stems and leaves glabrous. 
Leaves alternate in a spiral, simple and entire, epidermal cells sclerified except around the 
stomata. Inflorescences at first enclosed in overlapping small bracts (resembling the scar- 
ious bud scales of Fagaceae and other temperate plants), spicate or racemose, the female 
inflorescences often with smaller than normal leaves distally and the inflorescence axis 
sometimes continuing as a woody stem, the bracts (bud scales) deciduous and subtending 
1 to several small flowers. Male flowers without a perianth, pedicellate, the stamens borne 
from a central disklike cushion, stamens usually 2-4, filaments slender, thecae 2 and borne 
on opposite sides of the connective, dehiscing laterally. Female flowers with 2 or 3 usually 
caducous, minute, triangular tepals halfway up the ovary, pistil with a short distinct style 
bearing a broad and flattened crescent-like stigma. Fruit a small 1-seeded berry; endo- 
sperm pale green. 

A genus of only a few species ranging in montane forests from southern Mexico, 
Guatemala, and Costa Rica through northern South America to Peru, Bolivia, and 
Brazil. 

Antidaphne viscoidea Poeppig & Endlicher, Nov. Gen. & Sp. PI. 2:70, t. 199. 
1838. Figure 8. 

Epiphyte-like hemiparasitic shrubs 30-120 cm in diameter, unisexual, green to olive 
green, leafy internodes 5-20 mm long, 1-3.5 mm thick, smooth and glabrous, becoming 
longitudinally striate and grayish when dry. Leaves alternate in a 2/5 spiral, often articu- 
late at the base, petioles 1-4 mm long, broad and with lateral wings continuous with the 
lamina margins; laminae 1.4-8 cm long, 0.7-6 cm broad, obovate or occasionally elliptic 
to ovate, rounded to bluntly obtuse at the apex, gradually narrowed to the attenuate or 
subcuneate base, margin entire and of tissue differentiated from the leaf epidermis, the 
laminae drying coriaceous, smooth and glabrous, venation varying from subpalmate with 
dichotomizing primary veins to pinnately veined with 1-4 pairs of major secondary veins, 
the major veins slightly raised on both surfaces when dry, obscurely punctate. In- 
florescences at first resembling small axillary shoots enclosed by several series of caducous 
pale brown bracts resembling scarious bud scales, the inflorescences 1 to several per node, 
unisexual, the female often terminating in small leaves. Male inflorescences 5-15 mm long 
(only rarely terminating in leaves as in Standley 43340 at US), racemose with 4-12 nodes, 
each node with usually 1 (2, 3) naked flowers; male flowers 2-3 mm long (including the 
short pedicels), lacking perianth, stamens 2-4 and arising from beneath the edge of a 
central disklike cushion, filaments ca. 1 mm long, anthers dehiscing laterally with longi- 
tudinal slits. Female inflorescences spicate, at first ca. 5-10 mm long but soon becoming 
woody and with small leaves distally, with ca. 10 nodes, the lower nodes with caducous 
bracts (bud scales) and the upper with small leaves, with 1-3 flowers per node; female 
flowers less than 1 mm long, sessile, lacking perianth-like whorls but with 2 or 3 deciduous 
scalelike perianth parts attached halfway up the ovary, style very short, stigma crestlike 
and flattened. Fruit a berry ca. 3 mm long, ovoid, sessile on a woody rachis 2-5 cm long 
and terminating with leaves 1-5 cm long, the infructescence sometimes continuing to 
grow beyond the distal leaves and producing new axillary shoots. 

Parasites of trees in moist and wet montane evergreen forest formations be- 
tween (700) 1,000 and 2,000 m elevation; probably flowering throughout the year, 
but collected with flower or fruit primarily from December to April. The species 
ranges from southern Mexico to Amazonian Brazil, Peru, and Bolivia. 

Antidaphne viscoidea is distinguished from our other shrubby and epiphyte-like 
parasites by the alternate leaves with variable venation, young shoots and in- 
florescences enclosed by overlapping caducous bud scales giving a conelike ap- 
pearance, and the flowers lacking a perianth in the male or with a very minute 
scalelike perianth in the female. 



BURGER: FLORA COSTARICENSIS 33 

LORANTHACEAE sensu stricto 

Shrubs or small trees, leafy hemiparasites with chlorophyll, bisexual or the flowers 
functionally unisexual and the plants unisexual (dioecious), parasitic on aerial stems and 
resembling epiphytes or a few genera parasitic on roots and terrestrial or epiphytic and 
parasitizing the roots of epiphytes (as in Gaiadendron), attaching to the host by means of 
roots provided with haustoria, stems sometimes with thickened nodes, glabrous or with 
a scurfy epidermis. Leaves usually opposite and decussate, sometimes whorled, sub- 
opposite and alternate leaves occasionally present, simple, often articulate at the base, 
laminae usually very stiff and drying brittle, with entire or undulate margins, glabrous in 
ours. Inflorescences usually with an unbranched axis (in ours) with sessile or pedunculate 
flowers in decussate groups of 3 (triads), 2 (diads), or solitary (monads), the flowers 
emerging from depressions in the rachis in Oryctanthus; flowers bisexual or functionally 
unisexual (and then the plants always unisexual), the perianth generally interpreted as 
representing 2 whorls, the outer whorl a calyculus and the inner a well-defined whorl of 
petals, the calyculus with small teeth or with only a thin rim (at the distal periphery of the 
ovary) continuous with and of the same texture as the ovary wall, inner perianth of 6 (7) 
petals, valvate in bud, longer than broad, often brightly colored, stamens equal in number 
and opposite the petals, borne on the petals, filaments present or the anthers subsessile 
on the petals, dehiscing by longitudinal slits, pollen usually 3-lobed; pistil with inferior 
ovary, locule 1 or ovary solid, ovules replaced by a central papilla in the locule, style 1 with 
capitate stigma. Fruit a 1-seeded berry, endosperm compound and lacking chlorophyll, 
cotyledons 2 or rarely as many as 12 (in Psittacanthus); seed surrounded by viscid tissue in 
all but Gaiadendron. 

The Loranthaceae (in a narrow sense) are a largely pantropical family of about 
65 genera and 900 species. None of the New World genera occur in the Old World. 
The definition of genera in the family is often very unsatisfactory, especially 
regarding South American representatives. Many neotropical species of this fam- 
ily were at one time assigned to the genus Phrygilanthus which has been shown 
to be a rather heterogeneous assemblage by Barlow & Wiens (1973), who have 
distributed all species over several other genera. Additionally, these authors have 
pointed out that Phrygilanthus is nomenclaturally illegitimate. One of the main 
tasks ahead is the evaluation of the resultant genera in terms of various mor- 
phologic and other features. Another extremely difficult complex is present in 
Struthanthus and Phthirusa; few botanists, if any, have followed Baehni and Mac- 
bride's union of these two genera into one (Struthanthus), but no one has pro- 
posed a satisfactory separation. A special case is the remarkable Phrygilanthus 
panamensis Rizzini, occurring in Chiriqui Province, Panama. It was placed in 
Struthanthus by Barlow & Wiens (1973), a practice here accepted as expedient but 
not final (see under Struthanthus). 

Among these parasitic plants, the genus Oryctanthus, while very distinctive, 
may be difficult to distinguish from the Viscaceae. Collections of Oryctanthus often 
resemble species of Phoradendron or Dendrophthora (Viscaceae) because of the soli- 
tary flowers emerging from the rachis and the fruiting rachis with longitudinal 
ranks of fruit or depressions left by the fruit. In contrast to Central American 
species of the last two genera, where series or groups of unisexual flowers are 
present above each inflorescence bract, Oryctanthus has a solitary flower in the axil 
of each bract, and all flowers are perfect and accompanied by two minute lateral 
bracteoles. Oryctanthus almost invariably has several epicortical roots at its base, 
organs which are unknown in any Viscaceae. 



PSITTACANTHUS 
nodosus 



PSITTACANTHUS Nsfl ramiflorus 



GAIADENDRON 
punctatum 




FIG. 5. Loranthaceae (s.s.): species of Psittacanthus and Gaiadendron. 



34 



10 cm 




STRUTHANTHUS 
panamensis 




S. woodsonii 




leptostachyus 




PHTHIRUSA 
retroflexa 




\ 




FIG. 6. Loranthaceae (s.s.): species of Struthanthus, Phthirusa, and Cladocolea. 



35 



S. rotundatus 




5 mm 



STRUTHANTHUS 
oersted ii 








FIG. 7. Loranthaceae (s.s.): additional Costa Rican species of Struthanthus. 



36 



ANTIDAPHNE 
viscoidea 




A stem of Casearia 
with old flowers 
of the parasite 
Apodanthes caseariae 




ORYCTANTHUS 

alveolatus 




O. spicatus 





ORYCTANTHUS 
occidentalis 




FIG. 8. Eremolepidaceae: Antidaphne, upper left. Rafflesiaceae: old flowers of Apodanthes 
on the stem of a Casearia (Flacourtiaceae), upper right. Loranthaceae (s.s.): four species of 
Oryctanthus. 



37 



38 FIELDIANA: BOTANY 

KEY TO THE COSTA RICAN GENERA OF LORANTHACEAE IN A NARROW SENSE 

la Flowers unisexual (aborted stamens or styles sometimes present) 2a 

Ib Flowers bisexual (perfect) 4a 

2a Phyllotaxy alternate throughout; flowers mostly single in the axis of squamate 

inflorescence bracts, the latter sometimes caducous 3a 

2b Phyllotaxy decussate; flowers in paired triads Struthanthus 

3a Flowers with clearly recognizable aborted organs of the opposite sex; spikes 
never with terminal leafy organs; petals conspicuous, always 4; style at least 

4 mm long Cladocolea 

3b Flowers lacking aborted organs of the opposite sex; female spikes normally 
with small, distal leaves which may expand into full size after flowering; 
petals lacking in male, less than 0.5 mm in female, 2 or 3 in number; style less 

than 0.5 mm long Antidaphne 

4a Inflorescence a spike or raceme with decussate single flowers 5a 

4b Inflorescence a spike or raceme with decussate triads or diads 6a 

5a Flowers less than 4 mm long, sessile or even sunken in inflorescence axis, flanked 
by minute separate bracteoles within the rachis cavity; pollen with 3 circular 

depressions on each hemisphere Oryctanthus 

5b Flowers more than 6 mm long, sessile in a cup made up of primary bract and 2 
conspicuous bracteoles, this compound structure elevated on a 1-mm long pedi- 
cel; pollen lacking depressions Struthanthus panamensis 

6a Flowers less than 4 mm long; epicortical roots from base of plant Phthirusa 

6b Flowers longer than 4 mm; basal roots absent or resembling those of normal terrestrial 

plants 7a 

7a Floral bracts green and foliose, flowers golden yellow; plants either of true epi- 
phytic habit or terrestrial; fruit with abundant, grooved endosperm 

Gaiadendron 

7b Floral bracts never bright green and foliose; flowers always with some red; plants 
parasitic on tree branches, lacking any epicortical or other roots; fruit lacking 
endosperm Psittacanthus 

CLADOCOLEA Van Tieghem 
REFERENCE: Job Kuijt, The genus Cladocolea. ]. Arnold Arbor. 56:265-335. 1975. 

Erect or scandent shrubs, hemiparasitic on aerial stems, bisexual or unisexual, lateral 
branches and inflorescences often emerging in a pseudoendogenous fashion, glabrous or 
puberulent in early stages; epicortical roots absent or present, on stems or at the base of 
the plant. Leaves opposite and decussate, alternate, or irregularly arranged, simple and 
entire, sometimes reduced to scales. Inflorescences usually a determinate spike, a capitu- 
lum, dichasium, or raceme, in some species the terminal flower is lost and in a few the 
inflorescence is reduced to a solitary flower with a pair of bracts, inflorescences usually 
axillary to leaves or fallen leaves; lateral flowers borne in the axils of scalelike or leaflike 
bracts but without bracteoles. Flowers bisexual or functionally unisexual with organs of 
the nonfunctional sex often well developed, mostly green to yellow in color, sessile or 
pedicellate, 4-, 5-, or 6-parted, stamens borne on the petals, monomorphic or dimorphic 
within the flower, anthers 4-thecous, pollen rounded-triangular, style straight or often 
geniculate or curved distally. Fruit a 1-seeded berry with endosperm, embryo di- 
cotyledonous, elongate or globose, the haustorial disk weakly developed. 

The genus Cladocolea, with 23 species, is centered in Mexico north of the Isth- 
mus of Tehuantepec. A single species ranges to Panama in a (presently) disjunct 
distribution, and four species occur in tropical South America. The genus is 
distinguished from closely allied plants by the terminal floret (determinate in- 
florescence) and by the lack of bracts (bracteoles may be present). Most of the 
species of the genus have bisexual flowers, but our species has functionally uni- 
sexual flowers that may appear to be bisexual. The genus Cladocolea is closely 
related to Struthanthus, especially species such as S. orbicularis and S. polystachyus. 



BURGER: FLORA COSTARICENSIS 39 

Cladocolea oligantha(Standl. & Steyerm.) Kuijt, J. Arnold Arbor. 56:317. 1975. 
Struthanthus oliganthus Standley & Steyermark, Publ. Field Mus. Nat. Hist., Bot. 
Ser. 23:154-155. 1944. Figure 6. 

Small shrubs, branch parasites, unisexual, few branched with relatively straight stems, 
terete, becoming dark brown and often with transverse lenticels; no basal or stem roots 
seen. Leaves alternate, gradually narrowed at the base and the petiole (not clearly differ- 
entiated) ca. 2-4 mm long and 0.5-2 mm thick; laminae 2-3.5 (4.5) cm long, 0.8-1 (1.6) cm 
broad, oblanceolate or occasionally lanceolate, apex acute or rounded, attenuate at the 
base, venation usually obscure, pinnate or subpalmate. Inflorescences of 2 kinds: (1) the 
primary inflorescences borne on the current year's growth are mostly solitary in the axil 
of a leaf with usually simple 3-flowered dichasia borne on peduncles 4-5 (10) mm long and 
1 mm thick with the flowers borne in 1 plane, and (2) the secondary inflorescences (very 
similar to the primary but borne on the year-old growth) with 4-6 flowers borne in a 
congested spiral at the apex of a short peduncle and having a single terminal flower, the 
secondary inflorescence subtended by 1 or 2 secondary leaves that resemble primary 
foliage leaves but developed later. Flowers functionally unisexual, apparently bisexual but 
the anthers of female flowers nonfunctional and the male flowers with a prominent style 
but lacking a functional stigma, male and female flowers of about the same size and form, 
ca. 5 mm long and 2 mm thick in bud before anthesis, said to be reddish, 4-parted, anthers 
1.5 mm long and subsessile halfway up the petals, 4-thecous with a projecting connective, 
style at least 4 mm long, stigma inconspicuous. Fruit red becoming black, ovoid, ca. 7 mm 
long and 5 mm in diameter, smooth, embryo nearly 4 mm long, with 2 cotyledons. 

Epiphyte-like hemiparasites found between 800 and 2,000 m elevation in Gua- 
temala and Mexico and from near sea level in Panama. The species ranges from 
central Mexico to central Panama, but has not been collected in El Salvador, 
Honduras, Nicaragua, Costa Rica, or the westernmost provinces of Panama. The 
species is usually found on trees of the Burseraceae, but is also recorded on 
Leguminosae. 

Cladocolea oligantha is recognized by the shrubby parasitic habit (usually on trees 
of the Burseraceae), the small oblanceolate alternate leaves, the small in- 
florescences with three to six congested flowers at the apex of the peduncle, and 
the flowers that appear to be bisexual but are functionally unisexual. 

GAIADENDRON G. Don 

Shrubs or trees to 14 m tall, terrestrial or epiphytic, hemiparasites on the roots of shrubs 
or herbs. Leaves opposite or subopposite, petiolate, usually dark green, thick, minutely 
punctate beneath. Inflorescences raceme-like panicles with a single main axis bearing 
usually opposite triads of flower, the triads short-pedunculate, the flowers each sub- 
tended by a bract, larger bracts leaflike; flowers bisexual and regular, narrow and tubular 
before anthesis, ovary inferior with a short calyculus, the epigynous perianth parts (petals) 
6 or 7, free and often recurving, bearing the adnate stamens, anthers dorsifixed and 
versatile, dehiscing longitudinally. Fruit a berry, subtended by the persisting bracts. 

A very small genus ranging from the mountains of Nicaragua southward to 
Peru. These plants resemble some of our native Proteaceae as well as species of 
Psittacanthus and Struthanthus (q.v.). 

Gaiadendron punctatum (R. & P.) G. Don, Gen. Syst. 3:431. 1834. Loranthus 
punctatus Ruiz & Pavon, Fl. Peruv. & Chil. 3:47, pi. 277a. 1802. G. poasense Donn. 
Sm., Bot. Gaz. 56:61. 1913. Figure 5. 

Shrubs or small trees, hemiparasites, epiphytic or if terrestrial often on disturbed sites, 
bisexual, leafy internodes 5-40 mm long, 1.5-6 mm thick, glabrous, longitudinally ridged 
and grayish in age, terete. Leaves opposite or subopposite, petioles4-10 mm long, 1-2 mm 



40 FIELDIANA: BOTANY 

thick, sulcate above, revolute margin of the lamina base continuous with the margins of 
the petiole; laminae 3-8 (10) cm long, 1.3-4 (4.7) cm broad, elliptic or somewhat obovate, 
usually obtuse at the apex and the tip bluntly rounded, acute to obtuse at the base, margin 
entire and revolute (especially near the petiole), the laminae drying subcoriaceous, smooth 
on both surfaces and often lustrous above, glabrous, the 6-16 pairs of major secondary 
veins often obscure on both surfaces or slightly impressed above, small dark punctate dots 
usually visible on the lower surface. Inflorescences 1-3 in the axils of leaves or several 
terminal (and occasionally causing a forked growth pattern), usually near the ends of 
twigs, 4-8 (14) cm long, raceme-like panicles with a single prime rachis and up to 16 triads 
often in opposite pairs, the triads on peduncles 1-3 mm long with 2 shorter (3-8 mm) 
bracts subtending the lateral flowers and a larger (5-20 mm) bract subtending the median 
flower. Flowers bisexual, perianth of 6 (7) parts, 7-12 (20) mm long, narrow and hooked 
apically, golden yellow to orange-yellow, recurved after anthesis, filaments borne halfway 
up the perianth, free portion variable in length, anthers (0.5) 0.7-1.5 (2) mm long, ver- 
satile; ovary inferior, ca. 3-4 mm long with a short (0.3 mm) flared calyculus, ca. 1 mm 
thick, style to 15 mm long, stigma simple. Fruit often in triads subtended by the persisting 
bracts and on peduncles to 10 mm long, orange berries 7-10 mm long, ellipsoid or slightly 
obovoid (dry), apically blunt, endosperm with as many lobes (in cross section) as the 
flower had perianth parts, embryo with 2 (3) cotyledons. 

Plants of the evergreen montane forest formation between (800) 1,600 and 2,800 
(3,000) m elevation; flowering throughout the year, but collected most often be- 
tween October and April in Costa Rica. The species ranges from Nicaragua south- 
ward to Peru. 

Gaiadendron punctatum is recognized by its narrow flower with showy orange 
and recurving perianth parts, flowers usually borne in threes on an unbranched 
raceme-like axis, conspicuous floral bracts (especially those of the central flowers), 
and lustrous leaves. The plants and their flowers resemble our native species of 
Proteaceae, some of which occur in the same habitats. Plants of this species are 
parasites of herbs and small trees. These plants can be both true epiphytes and 
true parasites by being epiphytic and parasitizing other epiphytes, but not the 
supporting tree (see Kuijt, On the ecology and parasitism of the Costa Rican tree 
mistletoe, Gaiadendron punctatum, Canad. J. Bot. 41:927-938, 1963). 



ORYCTANTHUS Eichler 
Nomen Conservandum Propositum 

REFERENCE: J. Kuijt, Revision of the genus Oryctanthus (Loranthaceae). Bot. 
Jahrb. Syst. 95:478-534, 1976. 

Small shrubs, hemiparasites of aerial stems, bisexual, young stems terete or with longi- 
tudinal ridges, often with contiguous small lenticels or with a scurfy reddish brown 
surface; attached to the host by a primary haustorium and a small number of epicortical 
roots from the base of the plant only, or rarely such roots absent. Leaves opposite or 
subopposite, rarely with a few alternate leaves on a stem, symmetrical, sessile or petiolate, 
edge of the lamina often with differentiated tissue, venation palmate to pinnate, stellate 
fiber bundles of lamina often visible when leaves dry. Inflorescences short to long spikes, 
1 to several in the axils of leaves or on squamate (leafless) terminal shoots and forming 
compound inflorescences (as in some O. alveolatus) , the flowers in 4 longitudinal (vertical) 
ranks and emerging from depressions within the rachis, the depressions (pits) subtended 
by a floral bract that is often largely united with the thickened rachis and obscure, 2 minute 
lateral prophylls (bracteoles) present on each side (proximal) within the floral depression; 
flower small, sessile, bisexual (in ours) solitary in the depressions in the rachis, calyculus 
subentire, perianth of 6 free parts (petals), stamens adnate to the lower half of the perianth 
parts, filaments very short, anthers very small and rounded but with variably prominent 
connective, 4- or 2-thecous, dehiscing longitudinally; both petals and stamens dimorphic; 
pollen globose, triangular-rounded with 3 deep circular depressions on each hemisphere, 



BURGER: FLORA COSTARICENSIS 41 

style slender, stigma capitate. Fruit a 1-seeded berry, ovoid to cylindrical, truncate at the 
apex with the calyculus prominent and often with a persistent circular perianth scar. 

A genus of about 10 species ranging from southern Mexico to Brazil and Bolivia. 
Our species are found only in evergreen or partially deciduous life zones. The 
emergence of solitary flowers from depressions in the inflorescence axes in early 
stages is an unusual feature in the Loranthaceae (s.s.), but is superficially similar 
to the situation in Phoradendron and Dendrophthora of the Viscaceae (q.v.). The 
genus also possesses anatomical peculiarities (see Kuijt, Notes on the anatomy of 
the genus Oryctanthus, Canad. J. Bot. 39:1809-1816, 1961). 

la Young stems flattened or with longitudinal ridges, at least when young 2a 

Ib Young stems terete 3a 

2a Leaves petiolate, laminae generally small (1.8-7 cm) and elliptic; stems with 
longitudinal ridges with rough reddish brown surface; spikes to 2.5 cm long, 
flowers inclined forward (toward the apex of the spike); 500-1,800 m elevation 

O. spicatus 

2b Leaves sessile or subsessile, laminae usually broadly ovate, 4-14 cm long; stems 
lacking scurfy reddish brown ridges; spikes 2-12 cm long, flowers emerging at 

right angles to the spike; 0-1,000 m elevation O. cordifolius 

3a Spikes always axillary to foliage leaves; fruits and flowers emerging at right angles to 
the rachis; fruit usually constricted around the center; 0-1,400 m elevation 

O. occidentalis 

3b Spikes axillary to foliage leaves but also often on squamate (leafless) terminal shoots 
resembling panicles; fruits and flowers inclined forwardly on the rachis (toward the 
apex of the spike); fruit ovoid; 0-800 (1,200) m elevation O. alveolatus 

Oryctanthus alveolatus (H.B.K.) Kuijt, Bot. Jahrb. Syst. 95:504. 1976. Loranthus 
alveolatus H.B.K., Nov. Gen. & Sp., Quarto text, 3:444. 1820. L. amplexicaulis 
H.B.K., loc. cit. 445, non DC., Prodr. 4:305-306. 1830. Oryctanthus botryostachys 
Eichl., Fl. Brasil. 5, pt. 2:89-90. 1868. Figure 8. 

Small shrubs, usually less than 1 m in diameter, leafy internodes (1) 2-8 cm long, 1.3-4 
mm thick, bark flaking off or rough and scurfy on young stems and inflorescences, reddish 
brown, terete. Leaves opposite or subopposite, petioles 0-4 mm long, 1-2 mm broad, flat 
or slightly sulcate above, scurfy margins of the lamina continuous with the upper edges 
of the petiole; laminae 2-8 (10) cm long, 1.5-5 (9) cm broad, narrowly to broadly ovate or 
suborbicular in the larger leaves, bluntly obtuse to rounded at the apex, obtuse to rounded 
at the base, margin entire and occasionally undulate (dry) with a distinct edge of differ- 
entiated slightly roughened or scurfy reddish brown tissue, the laminae drying stiffly 
chartaceous to subcoriaceous, smooth and glabrous, venation palmate to subpalmate with 
3-7 primary veins, the major veins slightly raised above and usually obscure below. 
Inflorescences 1 or a few in the axils of leaves or at nodes in long terminal squamate shoots 
that resemble a racemose panicle, spikes 1-4 (6) cm long, peduncle less than 3 mm long, 
rachis 1.5-3 mm thick, terete, reddish brown with rough or scurfy texture; flowers emerg- 
ing from deep depressions in the rachis, inclined forwardly at an angle of ca. 45, alternat- 
ing in 4 vertical ranks, perianth 1-1.5 mm long, green on the outside and reddish within. 
Fruit becoming 5 mm long and 3.5 mm thick, ovate, lower half white, upper half dark 
green, truncated at the apex, the mature fruit usually angled forwardly as in the flowers. 

Epiphyte-like hemiparasites of evergreen wet lowland forest formations usually 
below 1,000 m elevation; probably flowering throughout the year, but collected 
only between January and August. The species ranges from central Costa Rica on 
both the Caribbean and Pacific coastal plains to Brazil and Bolivia. 

Oryctanthus alveolatus is recognized by the sessile to short-petiolate leaves, the 
scurfy reddish brown young stems that are always terete, and the relatively short 
spikes that are often found in opposite groups or pairs on terminal leafless stems 
that resemble open compound inflorescences. In Costa Rica, O. alveolatus seems to 



42 FIELDIANA: BOTANY 

fall rather clearly into two categories corresponding to what has been known as 
O. amplexicaulis and O. botryostachys. The former has nearly orbicular sessile leaves 
and a terminal compound inflorescence; the latter bears more ovate leaves with 
short, stout petioles, and seems to produce axillary inflorescences only. In South 
America, however, no such distinction can be maintained, and the present con- 
servative arrangement is therefore considered advisable for Costa Rica. 

Oryctanthus cordifolius (Presl) Urban, Bot. Jahrb. Syst. 24:30. 1898. Viscum 
cordifolium Presl, Epim. Bot. 253. 1849. Figure 8. 

Large shrubs, leafy internodes 3-12 cm long, 1.8-6 mm thick, with a roughened or 
minutely striate surface in early stages (dry), with 2 (4) longitudinal ridges and somewhat 
flattened but soon becoming terete. Leaves opposite, sessile or subsessile with the petiole 
obscured by the basal lobes; laminae 4-14 cm long, 3-12 cm broad, narrowly to broadly 
ovate or suborbicular, bluntly obtuse to rounded and emarginate at the apex, truncate to 
rounded and cordate at the base, margins entire and somewhat revolute, tissue of the edge 
differentiated, usually brownish and smooth, the laminae drying very stiffly chartaceous 
to subcoriaceous, smooth and glabrous, dark green and lustrous in life, venation palmate 
or subpalmate with 5 or 7 primary veins (occasionally pinnate), the major veins arcuate 
ascending, prominent above and somewhat obscure beneath. Inflorescences 1-3 in the 
axils of leaves, 2-12 cm long, peduncles 4-20 mm long, brownish and smooth; flowers 
sessile in depressions of the spike at right angles or slightly angled toward the apex, the 
4 vertical ranks of closely spaced flowers often producing an alternating position in flowers 
of adjacent ranks, perianth ca. 2.5 mm long, red, ovary usually included in the depression 
at anthesis. Fruit becoming 5 mm long and 3 mm thick, ovoid to somewhat thickened 
above and obovoid, becoming dark maroon or black, smooth or occasionally muricate near 
the truncated apex. 

Epiphyte-like hemiparasites of evergreen wet forest formations between sea 
level and 1,000 m elevation on both the Caribbean and Pacific sides of Costa Rica; 
probably flowering throughout the year, but collected only from February to April 
and in August and September. The species ranges from southern Mexico to 
Colombia. 

Oryctanthus cordifolius is recognized by its strictly opposite sessile and subcor- 
date leaves, young stems with longitudinal ridges, fruit becoming over 5 mm long 
(3 mm dry), and the spikes often becoming more than 8 cm long. This species is 
very similar to O. occidentalis, and occasionally, collections seem to be intermediate 
between the two. However, this may be due more to the variability within popu- 
lations of O. cordifolius than to a close relationship. 

Oryctanthus occidentalis (L.) Eichler, in Martius, Fl. Brasil. 5, 2:89. 1868. Lo- 
ranthus occidentalis L., Amoen. Acad. 5:396. 1760. Figure 8. 

Small shrubs ca. 1 m long, leafy internodes (1) 2-7 (10) cm long, (0.7) 1.2-3 (5) mm thick, 
terete, with a scurfy reddish brown surface when young and often with many lenticels; 
epicortical roots slender. Leaves opposite or subopposite, petioles (0) 2-6 mm long, 1.4-4 
mm broad, somewhat sulcate above with wings formed by the decurrent lamina margins; 
laminae 3-9 (16) cm long, 2-8 (14) cm broad, elliptic to elliptic-ovate or ovate, very broadly 
ovate in the unusually large leaves, bluntly obtuse to rounded at the apex, obtuse to 
rounded (truncate to subcordate in the very large laminae) at the base, margin entire and 
with differentiated rough brownish tissue along the edge, slightly revolute near the pet- 
iole, laminae drying very stiffly chartaceous to coriaceous, smooth and glabrous, the 1-3 
pairs of major secondary veins arising from the lower V* of the midvein, arcuate ascending, 
usually slightly raised above and obscure beneath. Inflorescences axillary to the current 
foliage, 2-6 spikes per leaf axil, 8-30 mm long and elongating in fruit to as much as 10 (15) 
cm, peduncles 2-15 (25) mm long, 0.8-1.6 mm thick, scurfy brown; flowers usually 
emerging at right angles to the rachis, closely approximate in 4 vertical ranks of circular 



BURGER: FLORA COSTARICENSIS 43 

depressions, perianth 1-2 mm long, yellowish orange to red, anthers 4- (rarely 2-) celled. 
Fruit 2-3 mm long, cylindrical and abruptly truncate at the apex, ca. 1.7 mm in diameter 
(dry), yellowish at the base, green above but with the calycular ring sometimes becoming 
thickened and red (in ours), closely spaced circular depressions left by the falling fruit. 

Epiphyte-like hemiparasites of evergreen moist and very wet forest formations 
from sea level to 1,000 (1,400) m elevation; flowering throughout the year, but 
collected most often in January and February and from May through August. The 
species ranges from Costa Rica to Colombia with a morphologically distinct pop- 
ulation on the island of Jamaica (the type locality). 

Oryctanthus occidentalis is recognized by its stiff strictly opposite leaves on terete 
stems, small bisexual flowers emerging in perpendicular fashion from deep de- 
pressions in the axis of the spike, and fruit somewhat constricted around the 
middle. The leaves vary greatly in different plants and occasionally on the same 
plant. The larger leaves (over 8 cm long and 6 cm broad) are not found associated 
with the smaller (5- by 2-cm) elliptic leaves, but many collections contain inter- 
mediate sizes. 

Within Costa Rica, considerable differences seem to exist between individuals 
from the Atlantic and Pacific slopes. Collections from the General Valley-Golfo 
Dulce area have longer petioles and peduncles, larger leaves, a much more prolific 
production of spikes, and a fruit which lacks the tubercular distal surface (Kuijt, 
1964). Some plants from this region are capable of originating as many as four or 
five shoots from a single root (as in Kuijt 2440). 

Oryctanthus spicatus Qacq.) Eichler, in Martius, Fl. Brasil. 5, pt. 2:89. 1868. 
Loranthus spicatus Jacq., Enum. PL Carib. 18. 1760. Struthanthus guatemalensis 
Standl., Field Mus. Nat. Hist., Bot. Ser. 17:237. 1937. Oryctanthus guatemalensis 
(Standl.) Standl. & Steyerm., Publ. Field Mus. Nat. Hist., Bot. Ser. 23:40. 1944. 
Figure 8. 

Small shrubs, ca. 50 cm in diameter but occasionally with stems 1 m long, leafy inter- 
nodes 1-4 (6) cm long, 1.5-4 mm thick, with 2 or 4 longitudinal scurfy reddish brown 
ridges, often smooth between the ridges or entirely scurfy on the very young stems, often 
somewhat flattened but becoming terete in age; epicortical roots usually 3. Leaves opposite 
or subopposite (occasionally alternate), petioles (2) 4-8 mm long, 0.7-1.8 mm thick, 
slightly sulcate above with ridges continuous with the lamina margins, the lower side with 
a longitudinal scurfy ridge continuous with the midvein; laminae 1.8-6 (8) cm long, 
0.8-2.5 (3.5) cm broad, elliptic to oblong or slightly obovate, bluntly obtuse to rounded and 
emarginate at the apex, acute to subtruncate at the base, margin entire and becoming 
somewhat revolute, edge with differentiated brown and slightly roughened tissue, the 
laminae drying stiffly chartaceous to subcoriaceous, smooth and glabrous but the midvein 
often raised and with scurfy tissue beneath (abaxially), venation pinnate with 2-4 pairs of 
major secondary veins arising from the lower half of the midvein and arcuate ascending, 
raised or obscure on either surface. Inflorescences 1 or 3 in the axils of current foliage, 
0.4-2.5 cm long, peduncles 2-7 mm long, rachis ca. 1.4 mm thick (dry) with up to 24 
flowers; the flowers emerging from shallow depressions in the rachis at an acute angle to 
the apex, perianth ca. 1.5 mm long, dark wine red. Fruit to 5 mm long and 3.5 mm thick 
(dry), ovoid to somewhat cylindrical, truncated at the apex, smooth. 

Epiphyte-like hemiparasites of evergreen or partly deciduous forest formations 
between 500 and 1,800 m elevation; apparently flowering throughout the year. 
The species ranges from Guatemala to Peru and Venezuela, where it intergrades 
with the South American O. florulentus (Rich.) Urban. It is remarkable that the 
species has not yet been collected from either Nicaragua or Panama. 

Oryctanthus spicatus is recognized by the generally smaller leaves on young 
stems with longitudinal scurfy ridges, the small spikes with relatively few flowers, 



44 FIELDIANA: BOTANY 

and the restriction to middle elevation habitats. The few flowers obscure the 
four-ranked nature of the flowers on the spike, leaving the old spike terete rather 
than four-angled as in fully mature fruiting spikes in some of the other species. 

PHTHIRUSA Eichler 
Nomen Conservandum Propositum 

Erect or scandent shrubs, usually bisexual, hemiparasitic on aerial stems; rooting only 
from the base of the plant (in our species) or also from the stems. Leaves opposite and 
becoming articulate at the base (in ours), subopposite or rarely alternate. Inflorescences 
usually solitary in the leaf axils, on leafless terminal or lateral shoots in a few species 
(South America), imbricate bud scales lacking in early stages, racemose or spicate to 
paniculate in superficial appearance, an indeterminate thyrse of decussate dichasia (triads) 
in ours, the flowers borne in triads (dichasia) or rarely in monads, each triad subtended 
by 1 primary and 2 secondary bracts, the lateral flowers associated with 3rd- and 4th-order 
bractlets, bracts and bractlets often connate to form a cup at the base of the flowers, triads 
sessile or very short pedunculate; flowers usually bisexual, calyculus thin and entire, 
petals usually 6 (4), stamens of 2 lengths, usually borne on the base of the perianth parts, 
filaments of 2 lengths, the longer often scalloped by the pressure of adjacent anthers on 
the shorter filaments, anthers dehiscing longitudinally, said to produce pollen grains of a 
single type: triangular in shape with finely granulose exine and 3 pores, ovary with or 
without a locule, with only 1 functional megaspore (in ours). Fruit a 1 -seeded berry, 
endosperm without chlorophyll. 

A genus of about 30 species ranging from southern Mexico and the West Indies 
southward to Brazil. The genus is poorly defined and may not be distinct from 
Struthanthus. One of our species seems to be self-pollinating (see Kuijt & 
Weberling, The flowers of Phthirusa pyrifolia, Ber. Deutsch. Bot. Ges. 85:467-480, 
1972). 

In 1830 Martius erected the genus Phthirusa on the basis of a single species now 
placed in Cladocolea (Kuijt, 1975). In order to reduce nomenclatural confusion, it 
has been proposed that Phthirusa in the sense of Eichler (1868) be conserved over 
the original sense of Martius (see Taxon 24:389, 1975). Phthirusa pittieri Krause, 
based on a type from Colon, Panama, has proven to be Struthanthus leptostachyus. 

KEY TO THE SPECIES OF PHTHIRUSA IN COSTA RICA AND PANAMA 

la Inflorescence always simple and usually axillary (a racemose unbranched axis with 
pedunculate triads); flowers bisexual and less than 4 mm long; wine red to dark red 
or maroon; 0-1,200 m elevation and widespread P. pyrifolia 

Ib Inflorescence often terminal and panicle-like, simple racemose inflorescences may also 
be present; plants and flowers said to be unisexual, flowers 4-5 mm long and yellow- 
ish; 0-1,800 m in Panama P. retroflexa 

Phthirusa pyrifolia (H.B.K.) Eichler, Fl. Brasil. 5(2):36. 1868. Loranthus pyrifolius 
H.B.K., Nov. Gen. & Sp. 3:441. 1820. Figure 6. 

Shrubs or vinelike, to 1 m long, often pendant, hemiparasitic epiphytes, bisexual, leafy 
internodes 1-7 cm long, 1.6-5 mm thick, thicker below the nodes, glabrous but often 
forming brownish flakes on drying, usually with 2 longitudinal ridges continuous with 
the petioles of the next distal node; epicortical roots arising only from the base of the plant. 
Leaves opposite, subopposite, or occasionally alternate, dark green and lustrous, petioles 
4-20 mm long, 0.8-3 mm thick, distinct, sulcate above with adaxial ridges continuous with 
the lamina margins; laminae 4-14 cm long, 2-8 cm broad, elliptic to oblong, ovate or 
lanceolate, rounded to obtuse or less often acute at the apex, often mucronate with a small 
(1-2 mm) narrow tip but this readily breaking off when dry, subtruncate to obtuse at the 
base, margin entire and the edge drying roughened brownish, differentiated from the 



BURGER: FLORA COSTARICENSIS 45 

epidermis, the laminae drying subcoriaceous, glabrous and smooth, venation pinnate 
with the 4-6 pairs of major secondary veins arising throughout the length of the midvein, 
the secondaries often abruptly arcuate ascending about halfway between the midvein and 
margin in larger leaves. Inflorescences solitary or paired in the leaf axils or from leafless 
terminal shoots and paniculate, usually spicate and 4-12 cm long, the triads of flowers 
subsessile or on very short (1-2 mm) peduncles, bracteate apically beneath the flowers, 
triads usually in opposite pairs 3-12 mm distant on the rachis, rachis ca. 0.8 mm thick and 
with minute scaly surface when dry; flowers sessile, bisexual, perianth parts ca. 1.5 mm 
long, wine red or maroon, ovary 1-1.5 mm long and ca. 1 mm thick, without a locule, 
calyculus small (0.3 mm) and slightly flaring, style simple. Fruit a blunt ellipsoidal berry, 
bright orange-red with yellowish apex and dark purple base, ca. 8 mm long and 5 mm thick 
but 3-5 mm long and 1.5-3 mm thick when dry, smooth and with a minutely (0.05 mm) 
reticulate surface, the triads often projecting obliquely downward (toward the base of the 
spike). 

A common and widespread hemiparasite on tree branches in evergreen and 
partly deciduous forest formations between sea level and about 1,200 m elevation; 
apparently absent from the deciduous (tropical dry) forests of lowland Gua- 
nacaste. Flowering throughout the year in Costa Rica, but collected most often 
between January and August. The species ranges from southern Mexico to the 
West Indies and northern South America. 

Phthirusa pyrifolia is recognized by its ridged stems, opposite and subopposite 
(alternate) leaves often on the same stem, pinnate venation, subsessile triads of 
very small flowers well spaced along the slender spikelike inflorescence, and fruit 
with unusual minutely reticulate surface. These plants resemble species of Stru- 
thanthus, but differ in having very small apparently bisexual dark red flowers and 
in the fact that epicortical roots are not produced from the stem, but only from the 
cotyledonary zone. 

Phthirusa retroflexa (R. & P.) Kuijt, Brittonia 32:521. 1980. Loranthus retroflexus 
Ruiz & Pavon, Fl. Peruv. 3:49-50, t. 279b. 1802. L. adu ncus Meyer, Prim. Fl. Esseq. 
149. 1818. L. paniculatusH.B.K., Nov. Gen. & Sp. 3:422. 1820. L. theobwmaeWilld. 
ex R. & S., Syst. Veg. 7:132. 1829. Struthanthus retroflexus (R. & P.) Blume, in 
Schult, Syst. Veg. 7:1731. 1830. Phthirusa paniculate (H.B.K.) Macbr., Field Mus. 
Nat. Hist., Bot. Ser. 11:17. 1931. P. adunca (Meyer) Maguire, Bull. Torrey Bot. Club 
75:301. 1948. Figure 6. 

Shrubs, the stems often scandent, unisexual, leafy internodes 0.5-4.5 (8) cm long, 1.1-4 
(5.5) mm thick, terete and smooth, drying pale brown or grayish; roots borne on the stems. 
Leaves opposite, subopposite, or alternate, clearly articulate at the base, petioles well 
defined, 8-23 mm long, 1-2 mm broad, adaxial groove formed by ridges continuous with 
the lamina margins; laminae 3.8-8 cm long, 2.5-5 cm broad, ovate to broadly elliptic or 
broadly oblong, acute to short-acuminate at the apex (emarginate only where damaged 
during development?), obtuse to rounded at the base, margin entire, stiffly chartaceous 
and drying dark and brittle, glabrous, venation pinnate with 4-7 pairs of major secondary 
veins arising throughout the length of the midvein, often irregular in arrangement and 
sometimes obscure on both surfaces. Inflorescences an unbranched solitary raceme of 
triads in the axils of leaves or more often a compound panicle at the ends of stems (formed 
by the failure of distal leaves to develop), triads (occasionally diads and monads) borne on 
peduncles 1-3 mm long, small triangular bracts ca. 1-2 mm long borne at the apex of the 
peduncle beneath each flower and often deciduous; flowers unisexual(?), rather similar in 
size and form, perianth ca. 4-5 mm long, pale yellow, anthers ca. 1.5 mm long; ovary ca. 
1.5mm long and 1.5 mm broad at the apex, narrowed at the base. Fruit tol cm long, oblong 
and pedicellate, orange. 

Hemiparasites of both evergreen and deciduous forest formations from sea level 
to 1,800 m elevation. Probably flowering throughout the year, but collected most 



46 FIELDIANA: BOTANY 

often between April and July. The species ranges from westernmost Panama to 
Peru and Paraguay (fide Rizzini). 

Phthirusa retroflexa is recognized by its epiphyte-like parasitic habit, small leaves 
narrowed at the apex (and quite variable as regards arrangement on the stem), 
triads of yellow flowers, and the very unusual terminal panicle-like inflorescences 
in addition to simpler axillary inflorescences. Although not yet recorded from 
Costa Rica, this species is likely to occur near the border with Panama. 

PSITTACANTHUS Martius 

Hemiparasitic shrubs, parasitizing the aerial parts of trees and shrubs, often large, 
bisexual, leafy stems strongly ridged to terete; epicortical roots absent, the haustorium 
often becoming large. Leaves opposite, whorled, or very variable in some species and 
ranging from alternate to whorled (often on the same stem), symmetrical to asymmetric, 
articulate at the base, simple and entire, glabrous. Inflorescences axillary or terminal, 1 to 
several per leaf axil, fasciculate at older leafless nodes in some species, primary peduncles 
bearing 1-3 secondary peduncles subtending the triads or diads of flowers, floral pedicels 
expanded at the apex to form a deep or shallow cup, the cup usually becoming asym- 
metrically expanded on 1 side, entire; flowers 2-10 cm long, bisexual, brightly colored and 
usually reddish or orange near the base grading into a yellowish apex, the calyculus little 
differentiated from the ovary, thin, entire or minutely denticulate, perianth forming a 
slender tube before anthesis, thickened distally around the anthers and in some species 
expanded just above the base, the 6 perianth parts separating at anthesis, filaments mostly 
free, of 2 lengths with the anthers superposed at 2 levels of 3 just beneath the apex of the 
perianth, anthers dorsifixed and versatile, slender, style long and slender with a simple 
slightly thickened stigma. Fruit a smooth bluish black berry. 

An American genus of uncertain size that has not been revised since Eichler 's 
work in the Flora Brasiliensis more than 100 years ago. The species are largely 
continental and range from Southern Mexico to Argentina. The very colorful 
perianth and the numerous inflorescences of some species often make the plants 
very conspicuous. The pedicels are expanded to form a dishlike base beneath the 
flowers, probably representing a fusion of bracts and bracteoles. The plants may 
be confused with our species of Gaiadendron, but other members of the Lo- 
ranthaceae in a wide sense are quite different in having much smaller flowers. 

la Larger leaves asymmetric and with the midvein curved to 1 side; leafy stems strongly 
4-angled with 4 longitudinal ribs or wings; inflorescences terminal, flowers usually in 
triads 2a 

Ib Leaves symmetrical with the midvein usually straight; stems rarely 3- or 4-angled, 
soon becoming terete; inflorescences axillary or borne on older wood, flowers usually 

in diads 3a 

2a Larger laminae asymmetrically ovate; flowers to 9 cm long; evergreen montane 

forests, 1,700-3,300 m elevation P. schiedeanus 

2b Larger laminae asymmetrically lanceolate or falcate; flowers to 5 cm long; decid- 
uous lowlands P. calyculatus 

3a Leaves usually in whorls of 4 and separated by long (3-12 cm) internodes; flowers 4-6 
cm long on small axillary inflorescences, anthers subsessile with slender hairs from the 
base; evergreen forests, 500-1,000 m elevation P. nodosus 

3b Leaves alternate, opposite or in whorls of 3 (very rarely 4), leafy internodes 1-8 cm 
long; flowers 3-4 cm long; anthers on long filaments, without hairs 4a 

4a Laminae ovate to suborbicular or elliptic, to 14 cm long and 10 cm broad; inflorescences 
often on older stems more than 1 cm thick, primary peduncles less than 5 mm long; 
(1,000) 1,500-2,500 m elevation P. scheryi 

4b Laminae usually elliptic-oblong, to 8 cm long and 4 cm broad; inflorescences from leaf 
axils or on older stems not usually more than 1 cm thick, primary peduncles 4-14 mm 
long; 500-1,800 (2,200) m elevation P. ramiflorus 



BURGER: FLORA COSTARICENSIS 47 

Psittacanthus calyculatus(DC) G. Don, Gen. Syst. 3:415. 1834. Loranthus calyc- 
ulatusDC., Coll. Mem. pi. 10. 1830. P. chrismarii ; Urban, Bot. Jahrb. Syst. 24:331. 
1897. Figure 5. 

Shrubs, branch parasites with the branches often long and trailing, leafy internodes 1-6 
cm long, 1.7-7 mm thick, 4-angled in cross section with 4 longitudinal ribs, green but 
becoming gray. Leaves opposite or subopposite (occasionally alternate), decussate, dark 
green, asymmetric and usually somewhat curved, petioles 0-8 mm long, gradually merg- 
ing with the lamina, 1-2.5 mm broad with wings continuous with lamina margins; lami- 
nae 4-15 (20) cm long, (1) 1.4-3.5 (5) cm broad, lanceolate to falcate or narrowly ovate, 
usually with the midvein curved to 1 side, tapering gradually to the acute or blunt apex, 
acute to cuneate or attenuate at the base, margin entire or undulate and decurrent on the 
petiole, the edge slightly differentiated, the laminae drying coriaceous, smooth and gla- 
brous, venation subpalmate or pinnate with 2-4 pairs of major secondary veins arising 
from near the base of the lamina, strongly ascending, usually obscure. Inflorescences 
terminal with the lowest units axillary to a pair of foliage leaves, or less often axillary, 
paniculate, 5-12 cm long, usually with a basal peduncle 1-2 cm long and 1 or 2 secondary 
peduncles, peduncles of the triads (diads) 4-16 mm long, pedicels of the flowers 6-20 mm 
long, 0.6-1.2 mm thick, flared near the apex to form a somewhat asymmetric cup 3 mm 
broad enclosing the base of the ovary; flowers ca. 4 cm long before anthesis, slender but 
dilated at base and apex, incurved, ovary ca. 3-4 mm long including calyculus and 2.5-3 
mm thick, the calyculus very slightly flared, 3-4.5 mm broad, subentire with several small 
notches and differentiated margin, perianth parts 3-4 cm long, ca. 1-2 mm broad, orange 
to red, filaments subequal, differing by ca. 4 mm in length, anthers 3 mm long, dorsifixed 
and versatile, stigma ca. 3.5 cm long, very slender, stigma slightly thickened. Fruit black 
and ellipsoid, becoming 9 mm long and 5 mm in diameter. 

Colorfully flowered hemiparasites of the seasonally very dry deciduous forest 
formations of Guanacaste and the Nicoya peninsula; probably flowering through- 
out the year, but only collected from September to March in Costa Rica. The 
species ranges from southern Mexico to northern South America. 

Psittacanthus calyculatus is recognized by the medium-sized bright orange-red 
flowers, curved narrow leaves that are opposite to almost alternate on the strongly 
angled gray stems, and the seasonally very dry lowland habitat. Psittacanthus 
mayanus Standl. & Steyerm. of northern Central America with smaller sym- 
metrical leaves may prove to be no more than an unusual form of this species. 

Psittacanthus nodosus(Desr.) G. Don, Gen. Syst. 3:417. 1834. Loranthus nodosus 
Desr., in Lamarck, Encycl. 3:601. 1809. Aethanthus nodosus (Desr.) Engler, in En- 
gler & Prantl, Nat. Pflanzenfam., Nachtr. 1:136. 1897. Figure 5. 

Shrubs to ca. 1 m tall, leafy internodes (1) 3-12 cm long, 2.3-7 mm thick, terete, pale 
grayish with narrow longitudinal lenticels, the nodes conspicuously thickened. Leaves 
almost always in whorls of 4 and producing a striking verticellate appearance, sym- 
metrical, articulate at the base, petioles 0-10 mm long, the adaxial ridges continuous with 
the lamina margins, ca. 2 mm broad; laminae 5-10 (12) cm long, 2-4.5 (7) cm broad, elliptic 
to obovate, ovate, or ovate-elliptic, bluntly acute to rounded at the apex, gradually taper- 
ing to the acute, obtuse, or cuneate base, margin entire and becoming recurved, decurrent 
on the petiole, the laminae drying stiffly coriaceous, glabrous and smooth but with a rough 
appearance, venation pinnate with 2 or 3 pairs of major secondary veins arising from the 
lower half of the midvein, secondary veins strongly ascending and usually obscure be- 
neath. Inflorescences axillary, 1-6 (rarely more) per node, ca. 6-10 cm long including the 
flowers, peduncles and pedicels together usually less than 2 cm long, primary peduncle 
2-5 mm long, 1 mm thick (dry), peduncles of the diads about the same length, pedicels 
ca. 5 mm long and flared at the apex to form a shallow asymmetric cup 3 mm broad; flowers 
4-6 cm long, slender and straight before anthesis, ovary and calyculus ca. 4 mm long and 
2 mm thick, perianth ca. 4.5 cm long, the tube 2-4 mm thick before anthesis, yellow 



48 FIELDIANA: BOTANY 

apically and brilliant red toward the base, filaments apparently equal, anthers ca. 3 mm 
long, stigma slightly thickened. Fruit to ca. 12 mm long and 8 mm in diameter, green 
becoming black (dry), epidermal cells apparent (0.1 mm) on the lustrous surface. 

Unusual branch parasites of premontane wet forest formations between about 
500 and 1,000 m elevation; probably flowering throughout the year. The species 
ranges from northern Costa Rica to Ecuador. 

Psittacanthus nodosusis recognized by its large colorful flowers, round stems with 
distant nodes of four whorled leaves, and relatively small inflorescences. Material 
of this species has been mixed with Struthanthus costaricensis under the numbers 
11458 and 11611 (Tonduz and Herb. Inst. physico-geogr. nat. costar.). Thus, we 
believe, the locality of Santa Maria at 1,450 m elevation may be in error and have 
listed the altitudinal range as lower. This species is known only from the following 
collections: Lent 2563 Rio Naranjo west of Volcan Tenorio, Poveda 965 Pavones de 
Turrialba, Standley & Valeria 46816 near Pejivalle, Cartago, Tonduz 11458 near Tuis, 
Cartago. 

Psittacanthus ramiflorus (DC.) G. Don, Gen. Syst. 3:415. 1834. Loranthus rami- 
florus DC., Prodr. 4:308. 1830. P. allenii Woodson & Schery, Ann. Missouri Bot. 
Card. 27:309. 1940. P. lateriflorus Woodson & Schery, loc. cit. Figure 5. 

Shrubs, branch parasites, leafy internodes 0.1-3 (5) cm long, 2-6 mm thick, terete or 
angled and with longitudinal ridges in early stages but becoming terete in age, smooth and 
gray green but becoming rough and dark gray in age. Leaves opposite, subopposite, in 
whorls of 3, or alternate (often on the same stem), symmetrical, articulate at the base, 
petioles 2-12 mm long, 1-2 mm broad, the lateral wings continuous with the lamina 
margins; laminae 3-8 cm long, 1.3-4 cm broad, elliptic-oblong to narrowly elliptic, ovate- 
elliptic, ovate, elliptic, or obovate-elliptic, bluntly obtuse to rounded at the apex, tapering 
gradually or abruptly at the acute to obtuse or cuneate base, margin entire and decurrent 
on the petiole, becoming revolute, the laminae drying subcoriaceous, smooth and gla- 
brous, venation pinnate, the 3 or 4 pairs of major secondary veins arising from throughout 
the length of the midvein. Inflorescences in leaf axils or at leafless nodes on stems usually 
less than 1 cm thick, 5-8 cm long, primary peduncle 4-14 mm long, peduncles of the diads 
3-6 mm long, pedicels ca. 5 mm long, 0.5-0.8 mm thick and expanded at the apex to form 
a flattened shallow cup 2-3 mm broad; flowers 3-4 cm long, ovary ca. 3 mm long and 2 
mm in diameter, calyculus thin and entire (subentire), perianth parts ca. 3-3.5 cm long at 
anthesis, forming a slender tube before anthesis, thickened at the apex and at the base, 
small projections ("ligule") at the apex of the basally expanded portion of the perianth 
parts on the inner surface, filaments of 2 lengths, anthers 2-3 mm long, stigma simple and 
very slightly thickened. Fruit not seen. 

Epiphyte-like hemiparasites of trees and shrubs in premontane and lower mon- 
tane wet forest formations between 600 and 1,800 (2,200) m elevation on the Pacific 
watershed; collected with flowers from April to December. The species, in our 
area, ranges from the Sierra de Tilaran in Costa Rica to Central Panama. 

Psittacanthus ramiflorus is recognized by the usually small symmetrical leaves 
alternate to whorled on rounded stems and the 3-4 cm long flowers on short 
inflorescences that occur in leaf axils or on slender leafless stems. This species is 
very closely related to P. scheryi (q.v.), and that species may be no more than a 
large-leaved form of P. ramiflorus. Psittacanthus dilatatus A. C. Smith of Colombia 
appears to be closely related to P. ramiflorus. 

Psittacanthus scheryi Woodson, Ann. Missouri Bot. Card. 28:426. 1941. Fig- 
ure 5. 

Shrubs 1-2.5 m tall, leafy internodes 1-8 cm long, 3-11 mm thick, terete and relatively 



BURGER: FLORA COSTARICENSIS 49 

smooth, becoming rough and longitudinally striate with narrow lenticels in age. Leaves 
variable in position, alternate to subopposite, opposite, or in whorls of 3 (4), symmetrical, 
articulate at the base, petioles 4-14 mm long, 1.3-4 mm broad with ridges continuous with 
the lamina margins; laminae 4.5-15 (18) cm long, (2) 3-10 (12) cm broad, ovate to elliptic- 
ovate or occasionally narrowly elliptic or suborbicular, obtuse and blunt or rounded at the 
apex, abruptly or gradually narrowed at the base, margin entire, often becoming revolute 
and undulate, the laminae drying very stiffly coriaceous and often pale in color, smooth 
and glabrous, venation pinnate with the 3-6 pairs of major secondary veins arising from 
throughout the length of the midvein, usually obscure beneath. Inflorescences fasciculate 
in the axils of leaves or fallen leaves, often on older stems over 1 cm thick, to 5 cm long 
including flowers, primary peduncles usually less than 5 mm long, peduncles of the diads 
(very rarely triads) 3-6 mm long, pedicels 3-7 mm long, ca. 1 mm thick (dry), flared at the 
apex and forming an asymmetric cup 3-4 mm wide at its broadest; flowers ca. 3-4 cm long, 
ovary ca. 3 mm long and 2 mm in diameter, flared slightly at the short (0.7 mm) thin entire 
calyculus, perianth parts ca. 3 cm long, slender and thickened near the apex, abruptly 
expanded for ca. 3 mm above the base, a slight projection ("ligule") at the apex of the 
basally expanded portion of the perianth parts on the inner surface, orange or reddish near 
the base and yellow-orange apically, filaments of 2 lengths and differing by ca. 4 mm, 
anthers 2-3 mm long, stigma simple, very slightly thickened. Fruit ca. 12 mm long and 8 
mm in diameter, ellipsoid, black and borne on red pedicels, calyculus very short on the 
truncate apex. 

Epiphyte-like hemiparasites of wet evergreen montane (premontane wet to 
montane rain) forest formations between (1,000) 1,500 and 2,500 m elevation in 
Costa Rica; flowering throughout the year. The species, as presently understood, 
ranges from the Cordillera Central de Costa Rica to western Panama. 

Psittacanthus scheryiis recognized by its fasciculate inflorescences often on older 
stems, slender medium-sized flowers apically yellowish, and often large thick 
leaves that vary from alternate to opposite or whorls of three. This species is 
related to P. dilatatus of Colombia with narrower obovate leaves, and it may be no 
more than a large-leaved form of P. ramiflorus in a wider sense. The specimens that 
have been placed here are being kept separate from P. ramiflorus because their 
overall appearance is quite different, and the distinctions given in the key seem 
to be working well with newly collected specimens. 

Psittacanthus schiedeanus (Schlecht. & Cham.) Blume, in Schult., Syst. Veg. 
7:1730. 1830. Loranthus schiedeanus Schlecht. & Cham., Linnaea 5:172. 1830. Fig- 
ure 5. 

Shrubs, to 3 m long, often high up in tall trees and conspicuous because of the bright 
red-orange inflorescences, leafy internodes 0.5-10 cm long, 2-9 mm thick, glabrous, 
4-angIed with 4 prominent longitudinal wings, nodes somewhat flattened; haustorial 
connections becoming 35 cm in diameter. Leaves opposite or subopposite, usually bluish 
green, petioles 3-20 mm long, distinct, 1-2.5 mm thick, inconspicuously winged; laminae 
4-26 cm long, 2-10 cm broad, narrowly ovate (rarely lanceolate) to broadly and inequi- 
laterally ovate, the larger laminae often very asymmetric in the lower half with the midvein 
curved, gradually narrowed to an acute or acuminate apex, narrowed to abruptly rounded 
at the often unequal base, margin entire and decurrent on the petiole, edge differentiated 
from the epidermal tissue, the laminae drying subcoriaceous to coriaceous, smooth and 
glabrous, venation pinnate with the 3-5 pairs of major secondary veins usually obscure. 
Inflorescence axillary or terminal at the ends of twigs (and resulting in forked growth), 
leafless, 10-20 cm long including the flowers, of a condensed axis 1-3 cm long bearing 
8-14 triads in opposite or subopposite pairs, paniculate in general form, peduncles of the 
triads 12-35 mm long, bracteate at the apex by adnation, bracts broad based and ca. 2 mm 
long, pedicels of the flowers 10-20 (30) mm long, flaring into a cupulate apex enclosing the 
flower base, peduncles, pedicels, and exposed areas of buds becoming bright red or 
orange; flowers 8-9 cm long before anthesis, ovary ca. 4 mm long and 5 mm thick, crowned 
by a short (3 mm) tubular calyculus continuous with the ovary, subentire and minutely 



50 FIELDIANA: BOTANY 

3-toothed, perianth becoming 9 cm long and only 2-4 mm broad, linear, slightly thickened 
below the apex and with an acuminate tip, brilliant orange, becoming recurved, decid- 
uous, filaments 4-6 cm long, dimorphic and differing by ca. 5 mm in length, anthers 
dorsifixed and versatile, ca. 6 mm long, style ca. 7.5 cm long, stigma slightly thickened. 
Fruit a blackish berry 1.5-2 cm long, ca. 1 cm thick, ellipsoid, on pedicels to 3 cm long; 
embryo with 6-12 awl-shaped cotyledons triangular in cross section. 

Large epiphyte-like parasites, conspicuous when in flower in evergreen mon- 
tane forests between about 1,700 and 3,300 m elevation; flowering from December 
to August. This species is especially common on the central Volcanos; it ranges 
from central Mexico to western Panama. 

Psittacanthus schiedeanus is recognized by its large and colorful slender flowers, 
the ridged stems, asymmetric larger leaves, and montane habitat. The number of 
cotyledons is unusual. The cotyledons persist for some time, becoming raised and 
separated from each other by the rapid expansion of the haustorial body. It is 
probably this species that is responsible for the majority of "rosas de palo" or "flares 
de palo" which are sold as curiosities in Mexico and Guatemala. These represent 
placenta-like host malformations from which the parasite has fallen away and 
form an intricate, fluted pattern of a radial arrangement (Kuijt, 1964). 

STRUTHANTHUS Martius 
Nomen Conservandum Propositum 

Shrubs, epiphyte-like hemiparasites of trees, often unisexual, glabrous, stems erect, 
pendent, clambering, or climbing by means of twisted (grasping) petioles, twining termi- 
nal shoots, or attaching roots; epicortical roots from base and stems. Leaves opposite or 
subopposite (often on the same stem), articulate at the base (the leaves of new young 
shoots often very different from the leaves of mature flowering stems), lamina margins 
usually decurrent on the petiole and usually with differentiated tissue on the edge, 
venation pinnate. Inflorescences 1 to several (9) in the axils of leaves, ours with an un- 
branched axis of sessile or pedunculate triads (monads in S. panamensis) to produce spicate 
or racemose panicles, peduncle of the triads associated with bracts that are usually cadu- 
cous, central flower of the triad usually sessile, the laterals often becoming short pedi- 
cellate, floral bracts very small and usually caducous, the flowers generally small (less than 
10 mm) with denticulate or entire calyculus and free petals; male flowers with the distal 
part of the bud expanded to include the anthers, petals valvate in bud, usually 6, becoming 
reflexed at anthesis, stamens epipetalous and slightly dimorphic, the anthers borne at 2 
superposed levels on adjacent petals, filaments usually very short, anthers dehiscing 
longitudinally, pollen said to be of 2 types (functional and rugose, sterile and smooth), 
nonfunctional style slender, stigma absent; female flowers often smaller than the male, 
buds narrowed toward the apex, the petals not usually becoming reflexed, epipetalous 
staminodes usually small and slender, style simple and equaling the petals, with longi- 
tudinal ridges, stigma often capitate. Fruit a berry, the calyculus not developing, rounded 
at the apex, seed with white endosperm. 

Struthanthus is a neotropical genus of probably more than 60 species. The genus 
has never been monographed nor has its relationship with closely similar genera 
been properly defined. The recent segregation of Cladocolea (Kuijt, 1975) has re- 
solved some issues, but the problem of distinguishing Phthirusa remains. The 
species of Struthanthus also present problems; e.g., they are often not easily iden- 
tifiable. This is partly due to similarity of flowers and unisexuality of the plants, 
but the variation of floral and vegetative characters within each species adds to the 
problem. An extreme example is seen in young plants of S. leptostachyus, the 
leaves of which may be up to 11 cm long and 0.5 cm wide. These long, linear, 
fleshy, pendent leaves are gradually replaced by the broad thin organs of the 
mature plant (Kuijt, 1964). 



BURGER: FLORA COSTA RICENSIS 51 

KEY TO THE SPECIES OF Struthanthus 

la Inflorescences at first enclosed by 4 ranks of decussate imbricate bud scales, these 
broadly triangular and scarious, mostly deciduous; flowers bisexual or functionally 
unisexual and similar in form in the 2 sexes 2a 

Ib Inflorescences not at first enclosed in an imbricate series of decussate bud scales; 
flowers in triads or monads with abaxial bracts that may persist or be caducous, but 
not thin and scarious; flowers unisexual with the male flower buds distinctly broader 
near the apex and enclosing the functional anthers, the female flower buds with 
a narrow tubular perianth and with the nonfunctional anthers small or undevel- 
oped 3a 

2a Flowers in monads, subtended by 3 persisting and conspicuous bracts on a short 
thick peduncle; leaves to ca. 10 cm long, often short-acuminate; rare plants 
known only from ca. 1,800 m elevation in Chiriqui province, Panama 

5. panamensis 

2b Flowers usually in triads (groups of 3), sessile on the axis of the inflorescence, 
the subtending bracts quickly deciduous; leaves to 20 cm long (in ours); ever- 
green and partly deciduous vegetation, 0-2,000 m 5. leptostachi/ns 

3a Inflorescence very short, rarely more than 2 cm long, rarely with more than 3 pairs 
of triads; laminae usually less than 8 cm long and often rounded or blunt at the apex; 
stems terete and often becoming reddish lenticellate, 0-2,100 m S. oerstedii 

3b Inflorescences usually more than 2 cm long, rarely with less than 4 pairs of 
triads 4a 

4a Inflorescences with conspicuous (3 mm) persisting bracts beneath the triads and 
obscuring the base of the ovaries; apex of the ovary (edge of the calyculus) 2-2.7 mm 
broad, anthers 1.2-1.6 mm long on short filaments; fruit becoming 10 mm long and 
6 mm thick; laminae rounded or emarginate apically and usually less than 7 cm long; 
1,200-2,000 m in western Panama S. rotundatus 

4b Inflorescences with the bracts at the apex of the peduncle less than 3 mm long 
or deciduous before the flowers open; flattened apex of the ovary less than 2 mm 
broad 5a 

5a Leaves often grasping stems with twisting petioles, laminae usually less than 8 cm 
long, usually rounded apically; male perianth 4.5-6 mm long, anthers 0.8-1.3 mm 
long and usually subsessile; fruit becoming 10 mm long, cylindrical and bluish on 
lenticellate peduncles; 0-1,200 m and widespread S. orbicularis 

5b Leaves lacking twisting petioles, but the leaves sometimes curved and the stem 
sometimes twining; fruit usually less than 7 mm long and the fruiting peduncle 
without lenticels 6a 

6a Some stems twining and with the leaves early deciduous, laminae attenuate at the 
base and often obovate, rounded to short-acuminate at the apex, the secondary veins 
prominent on dried laminae; flowers sessile or subsessile, male perianth 4.5-5.5 mm 
long, anthers 1-1.2 mm long; female perianth 2.5-3.5 mm long; fruit becoming 
pedunculate, berries orange-red and becoming constricted around the middle, the 
central berry (of a triad) often projecting obliquely downward/backward (toward the 
inflorescence base); (100) 500-1,800 m S. costaricensis 

6b Tips of some stems not quickly losing their leaves and twining; fruit not constricted 
centrally or projecting backward; leaves often relatively thin and drying stiffly char- 
taceous, often with acuminate apices 7a 

7a Laminae narrowly ovate-elliptic to lanceolate, long-acuminate at the apex, secondary 
veins strongly ascending and usually drying dark and prominent; male perianth ca. 
4.5 mm long with anthers 1.2 mm long; female perianth 3-4 mm long; ovary ca. 1 
mm thick; 0-500 m elevation S. woodsonii 

To Only the smaller leaves lanceolate, the venation often obscure; plants of higher 
altitudes, 1,000-3,000 m 8a 

8a Stems usually terete, laminae acute to short-acuminate; male flowers 6-8 mm long, 
anthers 1-1.6 mm long; female flowers 4-6 mm long; fruit to 7 mm long; areas around 
Volcan Irazu and Volcan Turrialba S. marginatus 

8b Stems usually 4-angled, laminae often long-acuminate; male flowers 4-5 mm long, 
anthers ca. 0.8 mm long; female flowers 3-4.5 mm long; fruit to 5 mm long (dry); 
Central Volcanic Highlands to the Cordillera de Talamanca S. quercicola 



52 FIELDIANA: BOTANY 

Struthanthus costaricensis Standley, Publ. Field Columbian Mus., Bot. Ser. 
4:202, 1929. Figure 7. 

Shrubs, branch parasites often forming pendent masses, tips of stems often twining 
about supporting branches, leafy internodes 2-12 cm long, 1.2-5 (8) mm thick, terete or 
obscurely angled (flattened) at first, becoming terete with small lenticels and longi- 
tudinally striate, gray; epicortical roots often produced on stems contacting other objects. 
Leaves opposite, subopposite, or alternate, recurved when young but not prehensile, often 
early deciduous when near the apex of a twining stem, articulate at the base, petioles 
10-20 mm long, somewhat vaginate near the base with winglike margins continuous with 
the laminae margins; laminae 3-9 (14) cm long, 2-5 (9) cm broad, broadly elliptic to 
obovate or spatulate (rarely suborbicular), obtuse to short-acuminate (rarely rounded) at 
the apex, gradually tapering to the attenuate base or occasionally obtuse to truncate, 
margin entire and slightly revolute (dry), decurrent on the petiole, the laminae drying 
subcoriaceous to coriaceous, venation pinnate with 4-7 pairs of major secondary veins 
arising mostly from the lower half of the midvein and ascending at angles of ca. 45. 
Inflorescences 1-3 (occasionally to 9 in the males) in the axils of leaves, the spicate panicles 
2-6 cm long, triads sessile or subsessile, alternate to opposite and 3-15 mm distant along 
the slender (0.5-1.7 mm) ridged rachis, ca. 8 triads on female inflorescences, more in the 
male, flowers sessile or the lateral females with very short pedicels, floral bracts minute 
and caducous, male flowers 5-7 mm long, ovary and calyculus 1-1.5 mm long, narrowed 
at the base and flared at the calyculus to 2 mm broad, perianth ca. 4 mm long before 
anthesis, becoming reflexed, stamens with short (0.5 mm) filaments, anthers 0.8-1.2 mm 
long; female flowers ca. 4-5 mm long, petals ca. 3 mm long with minute (0.3 mm) slender 
epipetalous staminodes, style ca. 3 mm long with capitate stigma. Fruit ellipsoid to cylin- 
drical, becoming ca. 5 mm long and 3 mm thick, slightly constricted in the middle, red to 
orange, the lateral fruit of a triad on pedicels becoming up to 3 mm long. 

Epiphyte-like hemiparasites of moist evergreen or partly deciduous forest for- 
mations between 500 and 1,800 m elevation on both the Caribbean and Pacific 
slopes of Costa Rica; flowering collections have been made between November 
and July. The species is found only in Costa Rica and western Panama. 

Struthanthus costaricensis is recognized by the presence of stems with small- 
leaved twining tips, subopposite leaves on terete stems, stiff laminae with atten- 
uate base (decurrent on the petioles), and relatively small red-orange fruit slightly 
constricted in the middle. This species is closely related to S. orbicularis, but that 
species lacks the twining stems and has prehensile (grasping) petioles, angled 
stems, and larger bluish fruit on lenticellate pedicels. 

Struthanthus leptostachyus (H.B.K.) G. Don, Gen. Hist. Dichlam. PI. 3:411. 
1834. Loranthus leptostachyusH.B.K., Nov. Gen. Sp. 3:440. 1818. Peristethium lepto- 
stachyum (H.B.K.) Van Tieghem, Bull. Soc. Bot. France 42:175. 1895. Phthirusa 
pittieri Krause, Feddes Repert. 15:441-442. 1919. Struthanthus polystachyus sensu 
auctores. Figure 6. 

Large shrubs, with horizontal or scandent branches over 2 m long, leafy internodes 2-9 
cm long, 1.5-8 mm thick, raised brownish lenticels often present on older and thicker 
stems; epicortical roots produced from the base and from the stems, those from the base 
occasionally becoming over 30 cm long. Leaves opposite or subopposite (occasionally a few 
alternate leaves present), articulate at the base, petioles 10-25 mm long, 1.4-4.5 mm thick, 
slightly sulcate above with adaxial ridges continuous with the lamina margins; laminae 
5-16 (20) cm long, 3-8 (12) cm broad, broadly ovate-lanceolate to ovate, elliptic-ovate, or 
elliptic-oblong, usually gradually narrowed to the acuminate apex, rounded and sub- 
truncate to obtuse at the base, margins entire and becoming revolute, tissue of the edge 
slightly differentiated and smooth, the laminae drying stiffly chartaceous, glabrous and 
smooth, venation pinnate with 5-10 pairs of major secondary veins arising throughout the 
length of the midvein, secondary veins slightly raised above and often obscure beneath. 
Inflorescences solitary or 2-4 in the axils of leaves or fallen leaves, unisexual, at first 



BURGER: FLORA COSTARICENSIS 53 

enclosed in pale scarious keeled bracts (scales) ca. 3 mm long, these caducous with 
expansion of the spike, the spikes becoming 2-8 cm long, with ca. 14-18 opposite triads 
of flowers or with solitary flowers near the apex of the spike, triads subtended by the bract- 
(scale-) scar, rachis ca. 1 mm thick and longitudinally striate when dry, glabrous but 
developing lenticels in fruit; flowers 4-6 mm long, unisexual, the female somewhat more 
slender than the male, ovary 1-1.5 mm long with thin subentire calyculus, perianth parts 
3-4 mm long, male flowers with anthers sessile on the perianth, subequally attached, 1 
mm long. Fruit becoming 6 mm long and 4 mm thick, truncated at base and apex or 
somewhat ellipsoid. 

Epiphyte-like hemiparasites of wet evergreen or partly deciduous forest for- 
mations from sea level to 2,000 m elevation on both the Caribbean and Pacific 
slopes; probably flowering throughout the year, but not collected in September, 
October, and November in our area. The northernmost collection of the species 
comes from near Tilaran, Guanacaste, while the southernmost are reported to be 
from Peru. 

Struthanthus leptostachyus is recognized by its large size (for a parasite), epi- 
cortical roots arising from various areas on the stems, leaves with acuminate 
apices, small unisexual yellow flowers in sessile triads, and the spikes at first 
enclosed in imbricate bracts resembling bud scales. These scales and the rather 
large leaves distinguish this species from most of our other species of Stru- 
thanthus. This species resembles Phthirusa pyrifolia in a superficial way. 

Struthanthus marginatus (Desr.) Blume, in Schult., Syst. Veg. 7, pt. 2:1731. 
1830. Loranthus marginatus Desr., in Lam., Encycl. 3:596. 1789. Figure 7. 

Shrubs or climbers, branch parasites, often covering the crowns of small trees, leafy 
internodes 2-5 cm long, 1.3-3.5 (5) mm thick, pale brown and smooth, becoming grayish 
with small round lenticels, longitudinally striate (dry) but terete; clasping roots produced 
in groups or series on stems and often ramifying. Leaves opposite, subopposite, or occa- 
sionally alternate, petioles 3-5 mm long, ca. 1.3 mm thick, somewhat sulcate above or 
slightly winged; laminae 4-8 (12) cm long, 1-4 (7) cm broad, narrowly elliptic-oblong to 
broadly elliptic, ovate, or lanceolate, tapering gradually to an acuminate to acute apex 
(rarely rounded), obtuse to acute at the base with the margins decurrent on the petiole, 
margin thin and becoming slightly revolute, laminae drying stiffly chartaceous and often 
brittle, smooth and glabrous, the 3-7 pairs of major secondary veins often difficult to 
distinguish from the tertiaries, the teritary veins obscure or slightly raised on the dried 
surfaces. Inflorescences solitary or 2-3 in the axils of leaves, racemose panicles 2-7 cm 
long, the 8-14 triads evenly spaced in usually opposite or subopposite pairs along the 
slender (0.7-1.4 mm) rachis, peduncles of the triads 1-3 (5) mm long with a small (3 mm) 
caducous bract at the apex, triads with the central flower sessile and the lateral flowers 
sessile or very short- (0.3-1 mm) pedicellate; male flowers 6-8 mm long, ovary and 
calyculus 1.5-2 mm long, perianth cream color, 5-6 mm long, becoming reflexed, stamens 
with very short filaments, anthers 1-1.6 mm long and almost versatile; female flowers 4-6 
mm long, the perianth ca. 3.5-4 mm long, narrow, yellow-green, staminodes with re- 
duced anthers ca. 0.6 mm long, style 3.3-4 mm long with a capitate stigma. Fruit ovoid, 
becoming 7 mm long and 5 mm in diameter, the central fruit of a triad sessile, the laterals 
usually pedicellate. 

Epiphyte-like hemiparasites of moist evergreen forest formations between about 
1,000 and 3,000 m elevation; flowering collections have been made between Feb- 
ruary and July. The species has been collected only from around the eastern edge 
of the Meseta Central and the adjacent volcanoes (Irazu and Turrialba) and in the 
Chiriqui Highlands (Panama) in our area. The species is also known from Brazil 
(but see below). 

Struthanthus marginatus is distinguished by its (sub)opposite leaves on smooth 
often climbing stems, thin laminae that often have short-acuminate apices, evenly 



54 FIELDIANA: BOTANY 

spaced short-pedunculate triads with sessile central flowers, and the lack of 
apparent bracts beneath the flowers or at the apex of the peduncle in flowering 
and fruiting stages. The restriction to the eastern edge of the central volcanic area 
is a further unusual characteristic. Specimens of S. quercicola have frequently been 
placed under this name, and the two species are similar in appearance. They seem 
to share the same habitats, and yet, if present collections are truly representative, 
they are not found in the same localities. It may be that S. marginatus is restricted 
to the premontane and lower montane wet forests, while S. quercicola is found in 
the moister rain forest life zones as defined by Tosi & Holdridge. 

There is some question regarding the use of the name Struthanthus marginatus 
in our area. A photograph of the type and material from eastern Brazil, where the 
type was collected, differ from our specimens in having smaller (0.5 mm) anthers 
more versatile on filaments which average about 1.5 mm long (dry). Both male and 
female flowers of the Brazilian material are smaller than their Central American 
counterparts. However, it seems best to let current usage stand until this very 
difficult genus receives monographic treatment. 

Struthanthus oerstedii (Oliv.) Standley & Calderon, Lista Prelim. PI. Salvad. 
74. 1925. Loranthus oerstedii Oliver, Vidensk. Meddel. Dansk Naturhist. Foren. 
Kjoebenhavn 1864:171. 1865. Figure 7. 

Shrubs, unisexual, branches not usually over 1 m long, leafy internodes 0.4-5 (8) cm 
long, 1.4-4 mm thick, terete, usually becoming rough and reddish brown with many small 
(0.1-0.2 mm) lenticels; epicortical roots developed from the stem and numerous. Leaves 
opposite, subopposite, or occasionally alternate, articulate at the base, petioles 2-5 mm 
long, ca. 1.5 mm broad, slightly sulcate with edges continuous with the lamina margins; 
laminae 1.5-8 (10) cm long, 1-3 (5) cm broad, elliptic to slightly ovate or rhombic, tapering 
gradually or abruptly to an acute, obtuse or rounded (rarely acuminate) apex, obtuse to 
attenuate at the base, margin entire and revolute on drying, decurrent on the petiole, 
laminae drying very stiffly chartaceous to subcoriaceous, smooth and glabrous, venation 
pinnate with 2-6 pairs of major secondary veins difficult to distinguish from the tertiaries, 
the proximal secondaries usually arcuate-ascending, tertiary veins often raised above. 
Inflorescences 1 to several in a leaf axil, 1-2 cm long, usually with ca. 4 triads, primary 
peduncle 0-5 mm long, peduncles of the triads 1-5 mm long, bracts subtending the 
flowers ca. 1 mm long; flowers sessile, unisexual, the male 4-6 mm long, petals slightly 
dimorphic and reflexed at anthesis, ca. 4 mm long, anthers subsessile, ca. 0.7 mm long, 
yellow; female flowers ca. 4-5 mm long and narrowed to the apex before anthesis, stami- 
nodia fused with the petals, stigma undifferentiated. Fruit ovoid, becoming ca. 5 mm long, 
green (immature?) truncated at the apex and with a thickened area interior to the calycu- 
lus, bracts persisting but small. 

Epiphyte-like hemiparasites of deciduous and evergreen forest formations be- 
tween sea level and 2,100 m elevation; flowering collections have been made 
between June and September and in January and February. The species appears 
to be endemic to the area between central Nicaragua and central Costa Rica, but 
it has not been found below 500 m elevation on the Caribbean slope. 

Struthanthus oerstedii is recognized by the reddish brown lenticellate stems, 
small elliptic leaves blunt at the apex, and the very small inflorescences with 
sessile flowers. The southernmost collections of the species come from La Suisa 
(Cartage) on the Caribbean slope and from Puntarenas on the Pacific slope. An 
unusual collection from the Pacific coast near Nicaragua (Howell 20243) was segre- 
gated by Kuijt as species number 38 in his study of 1964. Comparison with 
material from Nicaragua, where Oersted collected the type, suggests that this 
specimen falls within the pattern of variation encompassed by S. oerstedii. 



BURGER: FLORA COSTARICENSIS 55 

Struthanthus orbicularis(H.B.K.) Bl., in Schult., Syst. Veg. 7, pt. 2:1731. 1830. 
Loranthus orbicnlaris H.B.K., Nov. Gen. & Sp. 3:434. 1820. Loranthus chordocladus 
Oliver, Vidensk. Meddel. Dansk Naturhist. Foren. Kjoebenhavn 1864:173. 1865. 
S. chordocladus (Oliv.) Eichl., Fl. Brasil. 5, pt. 2:70. 1868. S. belizensis Lundell, 
Lloydia 2:83. 1939. Figure 7. 

Scandent shrubs, often climbing over small trees or with pendent stems to 2 m long, 
leafy internodes 3-9 cm long, 1.5-5 mm thick, quadrangular or flattened with 2 longi- 
tudinal ridges, smooth and striate (dry); epicortical roots from base and stems. Leaves 
opposite or subopposite (occasionally alternate), at first lanceolate and recurved and func- 
tioning to climb over adjacent vegetation, the later leaves as described, articulate at the 
base, petioles 4-12 mm long, ca. 1.5 mm broad with lateral ridges continuous with the 
lamina margins; laminae 2.5-6 (8) cm long, 1.2-3 (6) cm broad, obovate to suborbicular or 
elliptic, bluntly obtuse to rounded at the apex with apiculate to emarginate tip, obtuse to 
rounded at the base, margin entire, becoming slightly revolute, the edge thin and smooth, 
decurrent on the petiole, the laminae drying stiffly chartaceous to subcoriaceous, venation 
pinnate with 3-7 pairs of major secondary veins arising throughout the length of the 
midvein. Inflorescence solitary in axils of leaves (occasionally fallen leaves), 3-16 cm long, 
unbranched spicate or racemose panicles, the triads 3-11 mm distant on the smooth, 
striate (dry) and ridged rachis 1-3 mm thick, peduncles of the triads 0-2 mm long, 
subtended by caducous bracts 3-6 mm long (rarely seen on dry specimens), pedicels of the 
flowers 0-1 mm long at anthesis, not expanded at the apex beneath the ovary (the floral 
bracts not apparent); male flowers 6--8 mm long, yellowish, ovary ca. 1.7 mm long with 
slightly flared calyculus 0.5 mm long and 1-1.8 mm broad at the apex, perianth 5-6 mm 
long, anthers subsessile or on very short filaments at 2 different levels on alternating 
petals, anthers 0.8-1.5 mm long, 1 mm broad, the connective apiculate; female flowers 
more tubular, 4-6 mm long, staminodes reduced to ridges on the perianth, stigma sub- 
capitate. Fruit borne on pedicels becoming 8 mm long and 2 mm thick with conspicuous 
(0.7 mm) brownish lenticels, fruit becoming 10-13 mm long, 6-8 mm thick, truncated at 
the apex, ellipsoid to cylindrical, purple to blue. 

Epiphyte-like hemiparasitic climbers in evergreen or partly deciduous forest 
formations from sea level to 1,200 m elevation; collected with flowers from Octo- 
ber to June in Costa Rica. The species ranges from southern Mexico to Brazil and 
Peru. 

Struthanthus orbicularis is distinguished by its usually opposite rounded leaves 
on smooth climbing or trailing stems, spicate inflorescences with subsessile triads 
of flowers that develop expanded lenticellate pedicels in fruit, and moist lower 
elevation habitats. The species is apparently rare on the Caribbean slope of Costa 
Rica. 



Struthanthus panamensis(Riz.) Barlow & Wiens, Brittonia 25:39. 1973. Phrygi- 
lantlms panamensis Rizzini, Ann. Missouri Bot. Card. 47:270. 1961. Figure 6. 

Shrubs or clambering branch parasites, apparently bisexual, leafy internodes 1-6 cm 
long, 1-4 mm thick, terete or slightly ridged in early stages, smooth and grayish. Leaves 
opposite or subopposite, articulate at the base, petioles 7-22 mm long, 1-2 mm thick, 
narrowly sulcate above with thin adaxial margins continuous with the lamina margins; 
laminae 3.5-10 cm long, 1.5-6 cm broad, ovate to ovate-oblong, acute to acuminate or 
caudate-acuminate at the apex, the tip often elongate, truncate to obtuse or rounded at the 
base, margins entire and slightly revolute (dry), the edge differentiated and smooth, the 
laminae drying stiffly chartaceous to subcoriaceous, venation pinnate, the 3-7 pairs of 
major secondary veins usually obscure on both surfaces. Inflorescences 1-3 in the axils of 
leaves, at first subtended by 4-6 pairs of stiff decussate imbricate bracts resembling bud 
scales, racemose, 1-3 (4) cm long with flowers borne on pedicels bracteate at their apex, 
pedicels 1-2 mm long and 0.5-1 mm broad, the pediceled flowers (opposite monads) 2-6 
mm distant along the thick (1 mm) strongly 4-angled rachis, the abaxial bract decurrent on 
the peduncle with free apex ca. 2 mm long, lateral bracts ca. 1 mm long, persisting; the 



56 FIELDIANA: BOTANY 

flowers and bracts drying black, flower buds becoming 8-12 mm long, 2 mm thick distally 
but narrowed to an acute and often slightly curved apex, yellow, calyculus minute and 
entire, petals 6 and narrowly acute at the apex, yellow-green, anthers sessile at 2 different 
levels on adjacent petals, ca. 1.2-1.8 mm long, apiculate, style ca. 5 mm long, stigma only 
slightly thickened. Fruit apparently globose, 5-8 mm long and equally thick, yellow, apex 
with a thick central disklike area within the thin calyculus, bracts and bractlets persisting 
in fruit. 

Epiphyte-like hemiparasites of evergreen montane (lower montane rain) forest 
formations between 1,800 and 2,200 m elevation in western Panama. The species 
is known only from Chiriqui, Panama. Flowers were collected in March (Davidson, 
431, the type, and 392) and May (Luteyn 3786), and mature fruit, in January 
(Wilbur & Teeri 1310a). 

Struthanthus panamensis is recognized by its stiff opposite leaves on terete stems, 
laminae often ovate and caudate-acuminate at the tip, short racemose in- 
florescences, and single flowers on short stalks with one larger (abaxial) bract and 
two smaller lateral bracts that persist in fruit. The flowers appear to be bisexual, 
but may be functionally unisexual and male in the type, the only flowering 
material seen. The very narrow petal tips are unusual among our species of 
Struthanthus. 

The correct genus for this species is in doubt, and its placement in Struthanthus 
should be considered provisional. See the discussion by Kuijt in Ann. Missouri 
Bot. Card. 65:761, 1978. The term pedicel is used in this description for stalks 
bearing a single flower or monad. 

Struthanthus quercicola (S. & C.) Blume, in Schult., Syst. Veg. 7:1731. 1830. 
Loranthus quercicola Schlecht. & Cham., Linnaea 5:173. 1830. L. cansjeraefolius 
Oliver, Vidensk. Meddel. Dansk Naturhist. Foren. Kjoebenhavn 1864:173. 1865, e 
descr. et photo. Struthanthus cansjeraefolius (Oliv .) Eichler, in Martius, Fl. Brasil. 5, 
pt. 2:87. 1868. Figure 7. 

Shrubs or with climbing or pendent stems, to over 3 m long, leafy internodes 2-12 cm 
long, 1-4 mm thick, smooth, strongly 4-angled or with 4 longitudinal ridges but becoming 
terete, pale gray; epicortical roots common on stems. Leaves opposite, subopposite, or 
occasionally alternate, articulate at the base, petioles 3-8 (11) mm long, 1-2 mm broad, 
slightly sulcate or flattened and continuous with the lamina margins; laminae (3.5) 5-10 
(13) cm long, (1) 2-5 (7) cm broad, ovate to elliptic-ovate, gradually tapering to the 
cuspidate or long-acuminate apex, obtuse at the base with the margin decurrent on the 
petiole, margin entire and becoming slightly revolute, the laminae drying very stiffly 
chartaceous, smooth and glabrous, venation pinnate with 3-6 pairs of major secondary 
veins often difficult to distinguish from the tertiary veins, the tertiaries usually slightly 
raised above. Inflorescences usually solitary (3-5) in the axils of leaves, racemose panicles 
2-6 cm long with 5-12 triads 3-10 mm distant on the slender (0.7-1.5 mm) rachis, the 
rachis usually with 4 longitudinal ridges, peduncles of the triads (1) 2-3 (6) mm long, 
bracts beneath the flowers 0.5-2 mm long, deciduous or occasionally persisting; the central 
flowers sessile and the laterals subsessile or very short pedicellate, male flowers 4-5 mm 
long, ovary and the very short calyculus ca. 1 mm long, perianth 3-4 mm long, becoming 
reflexed, stamens with very short filaments, anthers ca. 0.8 mm long; female flowers 
3.2-4.5 mm long, perianth 2-3 mm long and not becoming reflexed, staminodes small 
with very slender nonfunctional anthers, style 2-3 mm long, stigma capitate and faintly 
3-lobed. Fruit becoming ca. 5 mm long and 4-5 mm thick, ellipsoid to ovoid, bright orange. 

Epiphyte-like hemiparasites of evergreen montane forest formations of the Cor- 
dillera de Tilaran, Central Volcanic Highlands, and the Cordillera de Talamanca 
between (600) 1,200 and 2,300 (2,800) m elevation; flowering material has been 
collected from December to June. The species, as here interpreted, ranges from 
Jalapa, Mexico, to western Panama. 



BURGER: FLORA COSTARICENSIS 57 

Struthanthus quercicolais distinguished by its opposite and subopposite leaves on 
smooth stems, relatively thin laminae with long-acuminate apices, evenly spaced 
triads on slender peduncles, inconspicuous floral bracts, and orange fruit. Stru- 
thanthus quercicola has been collected along the Caribbean side of the Central 
Highlands (Zarcero, Volcan Poas, Volcan Barba, La Palma, to the vicinity of 
Cartago) and along the Talamanca mountains to above San Isidro del General. 
This distribution differs from that of S. marginatus which is found on the slopes 
of Volcan Irazu and Volcan Turrialba. The two distributions overlap in the area 
between San Jose and Cartago, and yet there are no collections of the two species 
from the same locality, such as Tres Rios or the campus of the university. Material 
of this species has usually been identified as S. marginatus; see the discussion 
under S. marginatus. Struthanthus papillosus Standl. & Steyerm. of Guatemala may 
prove to be this species. 

Included here are specimens from between 600 and about 1,100 m altitude on 
the Pacific slope of Costa Rica that were segregated as a separate entity (No. 37) 
by Kuijt in 1964. These plants tend to have more narrow leaves, shorter in- 
florescences, and longer peduncles, and the little bracts subtending the flowers 
are less often persisting. While they do appear quite different from most of the S. 
quercicola material collected from the Central Highlands, they do not appear as 
different when compared with material from Chiriqui, Panama. This group of 
specimens ranges from the area of San Ramon (Brenes 1704 and 22889) to the 
highlands bounding the Pacific side of the General Valley (Allen 5891, Burger & 
Baker WW5 and 10108, Kuijt 2446), all between about 800 and 1,100 m elevation. 
A very unusual specimen (Skutch 3954) with small (5 by 1.5 cm) lanceolate laminae 
and very short (2 cm) inflorescences from the area of El General at 610 m altitude 
is also included here. 

Kuijt (1978) has recently identified a number of Panamanian collections as 
Struthanthus aff. dichotrianthus Eichler. These have a leaf form and habit very 
similar to those of S. quercicola, but they differ in having longer and narrower 
leaves and much shorter inflorescences with fewer triads. These characteristics 
have not been seen in Costa Rican collections. 

Struthanthus rotundatus Rizzini, Rev. Brasil. Biol. 10:401. 1950. Figure 7. 

Climbing branch parasitic shrubs, leafy internodes (2) 4-18 cm long, (1.5) 2-6 mm thick, 
smooth but with longitudinal ridges and somewhat 4-angled, soon becoming terete; 
epicortical roots few from the internodes, more often from the nodes. Leaves opposite or 
subopposite, articulate at the base, petioles 5-20 (28) mm long, 1.1-2 mm thick, often 
somewhat sulcate above with adaxial ridges continuous with the lamina margins; laminae 
2.5-7 cm long, 2-6 cm broad, broadly obovate to suborbicular or broadly oblong, usually 
rounded and emarginate at the apex, obtuse to subtruncate at the base, margin entire and 
decurrent on the petiole, often undulate and slightly revolute when dry, the laminae 
drying subcoriaceous to stiffly chartaceous and brittle, smooth and glabrous, venation 
pinnate with 4-8 pairs of major secondary veins arising from throughout the length of the 
midvein, ascending at angles of ca. 45. Inflorescences solitary in the axils of leaves or fallen 
leaves, 5-15 cm long, unbranched racemose panicles with opposite or subopposite triads 
3-12 mm distant on the rachis, rachis 1.5-2 mm thick (dry) and with longitudinal ridges, 
peduncles of the triads 1-3 mm long with the subtending (abaxial) bract adnate and 
persisting, these bracts ca. 6 mm long from base of the peduncles to the acute or obtuse 
tip, apparently fleshy, the sessile flowers subtended by shorter (2-3 mm) floral bracts 
similar to the larger bract in texture; male flowers ca. 8 mm long, ovary and calyculus 2 mm 
long and 2-2.7 mm in diameter distally, perianth parts (petals) ca. 6 mm long, stamens 
with very short (0.5 mm) filaments, borne at 2 levels on adjacent perianth parts, anthers 
1-1.7 mm long, connective apiculate; female flowers similar in size and form to the male, 



58 FIELDIANA: BOTANY 

calyculus subentire and thin, staminodes with reduced (0.5 mm) anthers on very short 
filaments, style ca. 5 mm long with thickened stigma. Fruit ca. 10 mm long and 6 mm thick, 
ellipsoid or somewhat truncated at base and apex, becoming red, borne on thick (2 mm) 
peduncles to 5 mm long with occasional round brownish lenticels, bracts persisting at the 
base of the sessile fruit. 

Epiphyte-like hemiparasitic climbing plants of the wet montane forests of west- 
ernmost Panama between 1,200 and 2,000 m elevation; probably flowering 
throughout the year, but collected with flowers only in January, March, June, July, 
and September. The species is known only from western Panama and Brazil (fide 
Rizzini). 

Struthanthus rotundatus is distinguished by its opposite rounded leaves on 
smooth climbing stems often slightly quadrangular in cross section, racemose 
inflorescences with sessile flowers in bracteate and pedunculate triads, the bracts 
adnate to and persisting on the apex of the peduncles, and the restricted higher 
elevation habitat. The anthers and staminodes with very short filaments further 
distinguish this species from the very similar S. orbicularis. While not yet recorded 
from Costa Rica, this species is to be expected in the montane forests adjacent to 
Panama. Struthanthus macrostachyus Lundell from Chiapas, Mexico, appears to be 
a close relative of S. rotundatus. 

Struthanthus woodsonii Cufodontis, Arch. Bot. Sist. 10:31. 1934. Figure 6. 

Twining shrubs with slender stems, leafy internodes (2) 4-12 cm long, 1-4 mm thick, 
terete, smooth and usually drying dark; epicortical roots not usually found on flowering 
stems. Leaves opposite, subopposite, or alternate, articulate at the base, petioles 2-7 mm 
long, 0.6-1 mm thick, sulcate above with the adaxial margins continuous with the lamina 
margins; laminae (2.5) 4-10 cm long, (0.6) 1.5-4 cm broad, very narrowly ovate to lanceo- 
late or narrowly elliptic-ovate, gradually tapering to the acute to long-acuminate apex, 
acute to obtuse at the base, margin entire, the laminae drying stiffly chartaceous, the 24 
pairs of major secondary veins usually arising from the proximal half of the midvein and 
strongly ascending, occasionally with the basal pair of secondaries very prominent and the 
leaf appearing trinerved, secondary and tertiary veins usually slightly raised on both 
surfaces when dry. Inflorescences 1 or 2 in the axils of leaves or fallen leaves, 2-6 cm long 
and becoming 10 cm long in fruit, the male with sessile or subsessile triads and the 
inflorescences spicate, the female becoming racemose panicles, the 10-16 triads 3-5 mm 
distant on the slender (1 mm) ridged rachis, peduncles of the female triads 0.5-3 mm long, 
ca. 0.5 mm thick, bract at the apex of the peduncle persisting or deciduous; male flowers 
5-6 mm long, ovary narrowed at the base and expanded at the minutely denticulate or 
erase distal margin of the calyculus, anthers subsessile, 1-1.4 mm long and apiculate; 
female flowers ca. 4 mm long, ovary only slightly expanded distally, with the calyculus 
obscurely denticulate (erose), staminodes minute (0.2 mm), style ca. 3 mm long, stigma 
capitate. Fruit ca. 5 mm long and 3 mm thick, cylindrical or ellipsoid, slightly constricted 
around the middle, orange, the triads borne on peduncles to 8 mm long, the lateral fruits 
of a triad on pedicels to 3 mm long and 1.5 mm thick. 

Epiphyte-like hemiparasites of aerial branches in evergreen lowland forest for- 
mations between sea level and about 500 m elevation found mostly on the Carib- 
bean side of Costa Rica; probably flowering throughout the year, but collected 
with flowers only in October, February, March, and May. This species appears to 
be endemic to the area of Costa Rica and Bocas del Toro, Panama. A single 
collection from the Pacific slope (Brenes 22889, Rio Jesus de San Ramon, Alajuela- 
Puntarenas) appears to be this species. 

Struthanthus woodsonii is recognized by its slender twining stems, the distant, 
usually lanceolate leaves with thin laminae and prominent ascending secondary 
veins (when dry), the calyculus with minutely denticulate or erose margin, and 
usual restriction to the lowland Caribbean area. 



BURGER: FLORA COSTARICENSIS 59 

VISCACEAE 

Small- to medium-sized shrubs, mostly with some chlorophyll and hemiparasitic, para- 
sitic on the aerial stems of dicotyledonous trees and shrubs (in ours) or less often on 
gymnosperms, attaching to the host by means of a primary haustorium which often 
branches within the host, young stems terete, angular, or compressed, often articulate 
above the node, glabrous (in ours) or rarely puberulent, the plants unisexual or bisexual, 
with foliage leaves or with all the leaves reduced to minute scale leaves, paired opposing 
scale leaves present on the inflorescences (and often called bracts), on lateral branches 
above branching nodes, and on percurrent stems in leafy species or defining all the nodes 
in leafless (squamate) species; stipules absent, paired lateral prophylls occasionally persist- 
ing above the base of lateral branches, epicortical roots absent. Leaves present or all 
reduced to scale leaves (squamate), opposite and decussate in ours, the foliage leaves in 
leaf-bearing species usually articulate at the base, simple and entire, usually thick and 
drying stiff or brittle, venation palmate to pinnate, glabrous in ours; the small pairs of 
opposite scale leaves often united at the base across the stem, generally less than 5 mm 
long. Inflorescence basically a spike, borne in the axils of leaves or scale leaves, rarely 
terminal, not ensheathed by deciduous scale leaves in early stages, bisexual or unisexual, 
with the male and female flowers in a variety of arrangements, the spikes composed of 
internodes defined by small paired scale leaves (bracts), the lower (proximal) internode(s) 
sterile and functioning as a peduncle, the flowers arising individually from depressions in 
the rachis of the fertile internodes, arranged in longitudinal ranks or other configurations 
on the rachis; the flowers very small and unisexual, the same color as the stems in ours, 
perianth of a single whorl, a calyculus absent, the perianth united with the inferior ovary 
beneath and usually 3-parted or 3-lobed distally, valvate in bud; male flowers with the 
stamens equal in number and opposite the perianth parts, stamens often borne on the 
perianth, on short filaments or sessile, anthers 1- or 2-thecous in ours, opening by pores 
or irregular slits, pollen mostly spherical; a style-like pistillode present or absent; female 
flowers without staminodes, ovary inferior with single locule, style and stigma 1, ovules 
not differentiated. Fruit a fleshy 1-seeded berry, seed solitary and surrounded by viscous 
tissue, endosperm with chlorophyll. 

A family of about 11 genera and several hundred species; most diversified in 
tropical areas, but extending into milder parts of the temperate zone. Dendroph- 
thora and Phoradendron are the New World counterparts of Viscum which is indig- 
enous to Africa and parts of Europe and Asia. The epiphyte-like habit, parasitic 
attachment to aerial parts of trees and shrubs, stiff opposite leaves or absence of 
foliage leaves, and minute flowers arising from depressions in spikelike in- 
florescences distinguish these plants from virtually all other Costa Rican families. 
Only Oryctanthus of the Loranthaceae (s.s.) is easily mistaken for a genus of 
Viscaceae. 

A discussion of inflorescence types (mentioned in some of the descriptions) can 
be found in Kuijt's "A study of heterophylly and inflorescence structure in Den- 
drophthora and Phoradendron" (Acta Bot. Neerl. 8:506-546, 1959). 

KEY TO THE GENERA OF VISCACEAE IN COSTA RICA 

la Anthers with a single theca (locule), the flowers in 2, or less often 4-6, longitudinal 
ranks on each fertile internode, the fertile rachis often somewhat flattened with the 
floral ranks on opposing narrower edges or the 6 ranks somewhat irregularly arranged 
on a terete rachis; plants lacking expanded foliage leaves (in 2 species) or with ex- 
panded foliage leaves and then lacking paired scale leaves on percurrent stems and 
with paired scale leaves ca. 5-10 mm above branching nodes on lateral stems; growing 
as high as 3,500 m, but rarely found below 1,800 m elevation Dendrophthora 

Ib Anthers with 2 thecae (locules), the flowers usually in 4-6 longitudinal ranks on each 
fertile internode or rarely in broad circular areas, the fertile rachis terete or 4-angled 
in cross section; plants always with expanded foliage leaves, percurrent stems with 
or without paired scale leaves above the leaf-bearing node, lateral stems with paired 
scale leaves above the branching node (in ours); plants growing from sea level to ca. 
3,000 m elevation . Phoradendron 



60 FIELDIANA: BOTANY 

DENDROPHTHORA Eichler 

REFERENCES: Job Kuijt, A Revision of Dendrophthora. Wentia 6:1-145, 1961. A 
Revision of the Loranthaceae of Costa Rica. Bot. Jahrb. Syst. 83:250-326. 1964. 

Shrubs, usually small (20-50 cm) but occasionally to 2 m tall (as in D. ambigua), branch 
parasites of a great variety of dicotyledonous (rarely gymnospermous) trees and shrubs, 
often densely branched and olive green or yellow-green in color, unisexual or bisexual, 
stems terete and usually articulate (winged, ridged, or compressed in some species), 
paired scale leaves often present on lateral stems above branching nodes, many species 
with all the leaves reduced to scale leaves (i.e., squamate); haustorial system apparently 
simple (lacking lateral expansion with aerial shoots), epicortical roots unknown. Leaves 
present or apparently absent and represented by minute paired scale leaves, opposite and 
decussate, foliage leaves with poorly differentiated petioles or subsessile, often articulate 
at the base, simple and entire, the scale leaves acute to obtuse, often united at the base 
across the stem, occasionally tubular. Inflorescences solitary in the axils of leaves or scale 
leaves or in groups forming compound inflorescences, rarely solitary and terminal (as in 
D. terminalis), unisexual or bisexual, basically a spike with 1 to several basal sterile inter- 
nodes functioning as a peduncle, flowers arising from depressions in the rachis of the 
fertile internodes and arranged in 2-6 longitudinal ranks (series) on each internode (1-3 
ranks above each bract in a variety of arrangements); flowers unisexual and very small, 
perianth of a single 3-parted or 3-lobed whorl (calyx), stamens sessile on the calyx-lobes, 
anthers 1-thecous and dehiscing by a transverse slit, female flowers with inferior uni- 
locular ovary and single short style, stigma scarcely differentiated, ovules not differ- 
entiated. Fruit a berry, a layer of fleshy tissue and viscin surrounding the single seed; 
endosperm almost completely surrounding the undifferentiated embryo and bright green. 

A genus of about 53 species in tropical America; especially numerous in eastern 
Cuba, Hispaniola, and the higher mountains from southern Mexico to the Boliv- 
ian Andes. Almost all the continental species and a great majority of the insular 
ones are restricted to mountainous areas. 

The unilocular anther used to distinguish this genus from the closely allied 
Phoradendron is a very difficult character to ascertain in flowers that are so small. 
Most workers have, nevertheless, been able to work with these plants without 
having to examine the male flowers of each species. The complete or almost 
complete lack of foliage leaves immediately distinguish D. squamigera and D. 
terminalis from all our species of Phoradendron. Dendrophthora costaricensis looks 
very much like some species of Phoradendron, but has the male flowers terminal 
and opening later than the female flowers of the same internode, and the arrange- 
ment of flowers on the internodes is often quite irregular. Dendrophthora lacks the 
paired scale leaves found above percurrent stems (above nonbranching nodes) 
found in some species of Phoradendron. 

la Foliage leaves absent or a few pairs of leaves present near the base of the plant, almost 

all nodes with small scale leaves in opposing pairs; spikes axillary or terminal. ... 2 

Ib Foliage leaves present on the stems, small scale leaves present on inflorescences and 

above branching nodes; spikes only from the axils of leaves 3 

2a Spikes numerous and arising from the axils of scale leaves, in opposing pairs; 
scale leaves to 2 mm long, prophylls obscure; common plants of high montane 

formations, 2,400-3,400 m D. squamigera 

2b Spikes fewer, solitary and terminal on short stems; scale leaves to 5 mm long, 
prophylls ca. 2 mm long and persisting above the branching node; rare plants 

known only from around 1,700 m D. terminalis 

3a Plants to ca. 1 m in diameter, leaves without a stiff leathery margin, drying thin and 
yellowish; spikes solitary in leaf axils, flowers in 6 irregular ranks on each fertile 
internode, flowering rachis terete; common plants from (1,500) 1,800-3,300 m 

elevation D. costaricensis 

3b Plants to 2 m in diameter, leaves with a stiff leathery margin, drying thick and dark 
in color; spikes 1 or several in the leaf axils, flowers in 2 opposing ranks or up to 6 



PHORADENDRON 
quadrangulare 




FIG. 9. Viscaceae: species of Dendrophthora and two species of Phoradendron. 



61 




FIG. 10. Viscaceae: species of Phoradendron, second group. 



62 




Fie. 11. Viscaceae: species of Phoradendron, third group. 



63 



64 FIELDIANA: BOTANY 

ranks on a fertile internode, variable in the number of ranks but often with the rachis 
flattened and the flower ranks on the opposing edges of the rachis; rare plants 
probably not growing below 2,500 m D. ambigua 



Dendrophthora ambigua Kuijt, Wentia 6:29-30. 1961. Figure 9. 

Shrubs or subshrubs to 2 m in diameter, bisexual, leafy internodes 5-30 mm long, 2-6 
mm thick, becoming striate and dark on drying, terete or slightly flattened beneath the 
nodes, branching vegetative stems with a pair of scale leaves ca. 1 cm above the branching 
node, the scale leaves (cataphylls) appressed to the stem in life but becoming separate in 
herbarium material, the node bearing the scale leaves swollen in living material. Leaves 
present throughout the plant, symmetrical, petioles 4-12 mm long but not clearly differ- 
entiated from the lamina, lateral ridges of the petiole continuous with the lamina margins; 
laminae 2-5 (7) cm long, 1.5-3 (5) cm broad, obovate to spatulate or elliptic-obovate, 
rounded at the apex, gradually narrowed at the base, entire and with a brown leathery 
margin, the laminae drying very dark and stiffly coriaceous, venation palmate, the 3-5 
primary veins usually obscure. Inflorescences solitary or several in the axils of leaves, up 
to 9 cm long with 2 or 3 fertile internodes 2-3 cm long, arrangement of sexes and flowers 
very variable, both sexes may be present on the same internode or even above the same 
bract (in the same rank), female flowers normally in an apical position in bisexual inter- 
nodes and most commonly in a single median rank (series), the fertile internodes most 
often with 2 opposing longitudinal ranks, but also with 2 or 3 ranks on each side above 
the bract (2-6 ranks or series per internode in 2A or IB arrangements); flowers 1-2 mm in 
diameter. Fruit a translucent white berry, flattened apically and discoid, ca. 6 mm long and 
5 mm thick, flesh not viscid but the seed with thin viscid coating, endosperm dark green. 

Branch parasites of evergreen montane forest formations known from only two 
collections in Costa Rica: Kuijt 2420 and 2468, both from near Villa Mills between 
2,500 and 2,800 m elevation. The species is also known from Colombia and 
Ecuador at elevations over 2,500 m. 

Dendrophthora ambigua is recognized by its thick rounded leaves, terete stems 
with paired scale leaves on lateral branches, and the very unusual spikes. Al- 
though these plants are very difficult to distinguish from species of Phoradendron, 
there are usually some spikes present with only two flower-series on opposing 
sides of the fertile internode. Also, there are spikes in which the two or three 
ranks above each bract are separated from those above the opposing bract by a 
somewhat flattened rachis. The impressions in the rachis made by fallen flowers 
and fruit are often continuous between the points of floral attachment to give a 
more or less continuous longitudinal groove. 

Dendrophthora costaricensis Urban, Ber. Deutsch. Bot. Ges. 14:285. 1896. 
vhoradendronflavescensKuntze, Rev. Gen. 2:587. 1891, non Nuttall 1847. P. crispum 
Trel., Gen. Phorad. 77. 1916. P. alleniilrel., in Woodson & Schery, Ann. Missouri 
Bot. Card. 27:307. 1940. D. costaricensis subsp. poasensis Kuijt, Wenria 6:51. 1961. 
Figure 9. 

Small shrubs to 1 m tall, bisexual, leafy internodes 0.3-3.5 (6) cm long, 1-3 mm thick, 
glabrous and becoming wrinkled on drying, terete, lateral stems with 1 (2) pair of scale 
leaves 5-18 mm above the branching node, percurrent stems without paired scale leaves. 
Leaves well developed, petioles 1-6 mm long but not clearly distinguished from the 
laminae, 1-2 mm wide, the lateral margins continuous with the lamina margin; laminae 
1.5-4.5 (6) cm long, 1-3 (4.5) cm broad, broadly obovate to elliptic-oblong or oblong (rarely 
suborbicular), abruptly rounded to bluntly obtuse at the apex, gradually narrowed to the 
attenuate base, margin entire and of somewhat thinner differentiated tissue (dry), ve- 
nation palmate with the 3 major veins usually obscure on both surfaces. Inflorescences 
solitary in the axils of leaves (2 per node), 1-3 (4) cm long, the basal sterile internode 2-8 



BURGER: FLORA COSTARICENSIS 65 

mm long with distal paired scale leaves fused at the base and flaring distally to become 2-3 
mm broad, flowering internodes usually 2 (3, 4), the fertile internodes producing 10-30 
flowers in basically 6 vertical (longitudinal) ranks but these often becoming obscured, male 
flowers 0.5-1 mm broad and distal on the internodes, as many as 12; female flowers 
forming later and proximal on the internodes but sometimes opening earlier, lacking 
staminodes. Fruit opaque white, globose to lobed, up to 6 mm in diameter, the calyx lobes 
persistent on the apex, seeds ca. 1.5 mm long and 1 mm thick, endosperm dark green. 

Branch parasites of moist montane evergreen forest formations between (1,500) 
1,800 and 3,300 m elevation; flowering throughout the year, but collected most 
often in the dry season: December to March. The species ranges from El Salvador 
to western Panama. 

Dendrophthora costaricensis is recognized by its small opposite leaves rounded at 
the apex, terete stem with united scale leaves on branching stems, small spikes 
solitary in leaf axils, distinct basal flowerless internode, and crowded flowers in 
(more or less) six longitudinal ranks on each internode. The regularly spaced 
nodes and regular branching often produce a symmetrical treelike form. These 
plants are difficult to distinguish from species of Phoradendron. 

.* 

Dendrophthora squamigera(Benth.) Kuntze, Rev. Gen. 585. 1891. Viscumsqua- 
migerum Bentham, PI. Hartw. 190. 1845. Phoradendron squamigerum(Benth.) Oliver, 
Danske Vidensk. Meddel. 176. 1864. Dendrophthora biserrula Eichler, in Martius, 
Fl. Brasil. 5:104. 1868. D. geniculata Rizzini, Rodriguesia 18-19:219-220. 1956. 
Figure 9. 

Small subshrubs (5) 10-40 cm tall, leafless and much branched with short crowded 
internodes, bisexual, the nodes demarked by paired scale leaves, internodes 2-50 mm 
long, 1-3 mm thick, glabrous and becoming roughly wrinkled when dry, terete. Leaves 
absent or 2 or 3 pairs of leaves at the base of the plant and grading into the scale leaves 
above, the scale leaves 1-2 mm long and opposite, partly united and with 2 sinuses or 
almost completely united and entire distally, 2-5 mm broad distally or becoming broader 
at branching nodes; the early-formed basal leaves up to 12 mm long, lanceolate and 
succulent, usually absent on flowering collections. Inflorescences solitary in the axils of 
scale leaves, 2 per node, 5-40 mm long, bisexual with the female flowers distal in an 
internode, male flowers formed later and proximal on the fertile internode, the spikes with 
a basal sterile internode (peduncle) 2-13 mm long and terminated by the cupulate united 
scale leaves, fertile internode usually 1 (2 or very rarely to 4), the 2 opposing spikes of a 
node often mirror images of each other, the fertile internode often somewhat flattened 
with the 2 longitudinal ranks of flowers imbedded in the narrow opposing edges (in a 2A 
arrangement), to as many as 40 flowers per internode and the flowering rachis to 4 mm 
broad, flowers ca. 1 mm broad. Fruit globose or somewhat oblate (compressed at base and 
apex), pearly to translucent white, 4-7 mm in diameter, drying yellowish, leaving shallow 
depressions in the rachis ca. 1 mm wide. 

Branch parasites of higher montane forest formations between 2,400 and 3,500 
m elevation; flowering throughout the year. The species ranges from the northern 
Andes of Colombia and Venezuela northward at higher elevations to Honduras 
and Guatemala. 

Dendrophthora squamigera is recognized by the lack of foliage leaves, short inter- 
nodes and symmetrical growth that often give a dense treelike form, flowers 
arranged in only two ranks, and the absence of terminal inflorescences. The 
restriction to higher altitudes and the usual yellowish green color of the plants 
further characterize this species. These plants are often dense and compact in 
their form, but it is not unusual to find individuals with longer thin internodes 
and a much more open habit. It is the most common parasite of the higher (above 
3,000 m) subparamo formations that are dominated by ericaceous shrubs. 



66 FIELDIANA: BOTANY 

Dendrophthora terminalis Kuijt, Wentia 6:109-110. 1961. Figure 9. 

Small subshrubs ca. 20 cm high, leafless and with open regular branching, bisexual but 
female flowers rare, the nodes demarked by conspicuous paired scale leaves, internodes 
quite uniform in length, ca. 2 cm long and 1-2 mm thick (dry), glabrous and becoming 
wrinkled on drying, terete; prophylls prominent (2 mm long) and resembling the scale 
leaves, lateral and persistent on the base of branching stems. Leaves absent, the scale 
leaves 2-5 mm long, acute, opposing scale leaves united only near the base, the united 
basal margins concave and minutely erose, the paired scale leaves widely (4-6 mm) spread 
at branching nodes and when dry. Inflorescences terminal in those seen, made up of 3 or 
4 fertile internodes, each fertile internode 5-10 mm long, the fertile rachis 1-1.5 mm thick, 
somewhat flattened with the 2 longitudinal ranks of flowers imbedded in the opposing 
narrow edges with the broader flat surface between the ranks, (2) 3-7 flowers per rank, 
flowers 1-1.5 mm broad, yellow. 

This species is known only from a single collection by Alexander Skutch (3570) 
from Vara Blanca de Sarapiqui between Poas and Barba volcanoes at about 1,680 
m elevation. The plant was collected in February and was found as a parasite on 
Clusia, which itself may have begun as an epiphyte. 

Dendrophthora terminalis is very similar to D. squamigera and differs primarily in 
the terminal inflorescences, the prominent prophylls, and the larger, more acute 
scale leaves united only near the base. The regular branching and lack of foliage 
leaves are characteristic of both species. This species seems to have thinner and 
somewhat more openly branched stems than most specimens of D. squamigera, but 
some individual specimens of D. squamigera do have thinner stems branching 
more distantly. Lateral branches develop in the axils of scale leaves one or two 
internodes below the spikes, producing a somewhat dichasial habit. 

PHORADENDRON Nuttall 

Small- to medium-sized (3 m) shrubs, aerial (branch), parasites and attached to the host 
by specialized roots but with chlorophyll in the leaves and stems, bisexual or unisexual, 
glabrous in ours, young stems terete or angular, the nodes with a narrow constriction 
around the circumference (articulate), often breaking easily, sometimes thickened, the 
stems often bearing pairs of small (1-5 mm) basally united scale leaves just above the base 
of lateral branches and/or between the leaf-bearing nodes. Leaves opposite and decussate, 
articulate at the base, petioles often not clearly differentiated from the laminae, our species 
with well-developed coriaceous laminae, margins entire or slightly undulate, venation 
palmate to pinnate. Inflorescence axillary or rarely terminal, a thick spike with partly 
imbedded flowers, divided by opposing pairs of scale leaves into 1 basal sterile and 1 to 
several distal fertile internodes, the internodes with basal intercalary growth, the oldest 
flowers distal on the internodes and the youngest emerging from the proximal scale leaves 
(bracts), the flowers often in 4 longitudinal ranks with 2 alternate distal flowers (1A type), 
less often in 6 ranks per internode (IB type), and rarely in annular or in broad groups 
among our species, the spikes unisexual or bisexual; flowers very small and unisexual, 
perianth of 1 series of 3 (2-5) lobes, united near the base, valvate in bud, the male flowers 
with sessile or subsessile stamens at the base (opposite) the calyx lobes, anthers with 2 
thecae; female flowers with inferior 1-locular ovary and 1 basal ovarian papilla, style short, 
stigma capitate. Fruit a fleshy, 1-seeded berry with viscid pulp, the endosperm copious 
and green; sepal lobes persistent. 

A large American genus, mainly tropical, but extending into the temperate 
zones in the United States and in Argentina. The genus was reviewed in 1916 
when 240 species were recognized and more than half described as new (see 
William Trelease, The Genus Phoradendron, A Monographic Revision, Urbana, 
Illinois). 

The shrubby semiparasitic and epiphyte-like habit is often associated with thick 
semisucculent leaves, stems, and inflorescences. The articulate nodes, strictly 



BURGER: FLORA COSTARICENSIS 67 

opposite leaves, glabrous parts (in ours), and flowers arising from depressions in 
the rachis further characterize the genus. The flowers in usually more than four 
vertical (longitudinal) ranks and lacking subtending bracteoles distinguish Pho- 
radendron from similar plants found in most species of Dendrophthora and Or- 
yctanthus. Some leafy species of Dendrophtlwra are very much like Phoradendron, 
but the difference in anthers seems to be a consistent distinction between the two 
genera. 

The following account of Phoradendron species is probably the least adequate of 
any genus yet treated for the Flora Costaricensis series. At first it seemed that 
inadequacy of collection, the fragile and fragmentary nature of many specimens 
and unusual within-species variation were responsible for making species delim- 
itation so difficult in Phoradendron. However, occasional collections suggest that 
hybridization between species may be another factor. The illustrations and keys 
are an attempt to characterize the commonly collected material. Neither keys nor 
illustrations are of much help when working with unusual collections that may 
represent variants, hybrids, or species not yet recognized in our flora. Never- 
theless, we need more collections of these plants so that future workers can solve 
some of the problems posed by the material at hand. 

la Branching always dichotomous with the inflorescence solitary and terminal, pairs of 
small scale leaves present just above the branching node and midway between 

leaf-bearing nodes; rare plants of evergreen areas P. dichotomum 

Ib Branching various, dichotomous or not, the inflorescences axillary to leaves. . . . 2a 

2a Leaf-bearing nodes difficult to see because of the slightly expanded leaf bases, 

laminae lanceolate to falcate (curved), narrowed toward the base but widened and 

somewhat auriculate at the stem P. dipterum 

2b Leaf-bearing nodes not obscured by the leaf bases, petioles narrowed to the 

stem 3a 

3a All stems between leaf-bearing nodes with small (1-5 mm) pairs of scale leaves, 
these sometimes just above the node and obscure or not visible on older nodes, stems 

usually terete or only slightly 2- to 4-angled in early stages 4a 

3b Percurrent stems between leafy nodes lacking small pairs of scale leaves, scale leaves 
present on the lateral stems above branching nodes (note that branching nodes may 
occasionally appear to be percurrent when 1 branch fails to develop or is lost), stems 

sometimes flattened or angled in age 9a 

4a Paired scale leaves tubular or splitting, ca. 4 mm long, borne 2-8 mm above the 
branching node; laminae lanceolate to falcate and often acute apically; female 
spikes with the proximal (basal) half of the fertile internode lacking flowers; 

branching usually dichotomous; rare in collections P. acinacifolium 

4b Paired scale leaves short-tubular or a tube not apparent, borne 0-5 mm above 
the node; female spike with flowers throughout most of the length of the fertile 

internodes 5a 

5a Laminae usually somewhat rounded at the apex; branching often dichoto- 
mous; stems between leaf-bearing nodes almost always with only 1 pair of scale 

leaves 6a 

5b Laminae usually acute to acuminate at the apex; branching not usually dichot- 
omous; stems between leaf-bearing nodes occasionally with 2 pairs of scale 

leaves 7a 

6a Laminae usually oblong, mostly rounded at the apex, often emarginate with a 
minute succulent tip, surface slightly rough in life, the plants often grayish or 
olive green; common in deciduous and semideciduous areas, 0-1,000 m 

elevation P. wbustissimum 

6b Laminae usually narrowly ovate to lanceolate, often tapering gradually to the 
blunt apex and rarely emarginate, the surface smooth and lustrous in life, 
entire plant often with a reddish cast; common in eastern areas of the Central 

Highlands, evergreen areas from (0) 1,000-2,000 m elevation P. obliquunt 

7a Venation pinnate, the major veins flat and inconspicuous when the leaves are 



68 FIELDIANA: BOTANY 

dried, the laminae tapering gradually to base and apex, 1-4 (6) cm broad; 
0-1,500 m elevation but most common in the evergreen lowlands 

P. piperoides 
To Venation palmate, the major veins usually becoming raised and prominent 

when dry, the laminae often rounded at the base 8a 

8a Spikes usually borne in the axils of leaves; flowers in 6 longitudinal ranks on 
each internode; the fruit obscuring the rachis and nodes of the spike, pale 
orange-yellow; laminae 2-6 (8) cm broad; 600-2,000 m elevation . . .P. flavens 
8b Spikes not usually borne in the axils of leaves, often in 2-4 groups along the 
stem between leaf-bearing nodes; flowers in 4 longitudinal ranks with 2 alter- 
nate distal flowers on each internode; fruit not usually obscuring the 
rachis, yellowish white; laminae (2) 4-10 cm broad; 0-1,000 (1,500) m elevation 

in evergreen formations P. crassifolium 

9a Laminae lanceolate to linear-lanceolate, to 15 (20) cm long but ra/ely more than 2.5 

cm broad; plants of higher altitudes, (700) 1,000-3,000 m elevation lOa 

9b Laminae elliptic to narrowly ovate or narrowly oblong 12a 

lOa Male flowers in 2 opposite disklike areas on each fertile internode, female 
flowers usually in an annular ring around the fertile internode (a whorl of 
usually 6 1-flowered ranks); leaves rarely curved and often drying dark; plants 

often found on Quercus, 1,500-3,000 m P. annulatum 

lOb Male flowers never found in broad disklike groupings, female flowers with 
at least some ranks of 2 or more flowers, never a whorl of 1-flowered 

ranks lla 

lla Laminae generally curved (falcate), to 20 cm long, but rarely more than 2 cm 
broad; male spikes with 6 ranks (of ca. 10 flowers each) per fertile internode; 
female spikes with usually 4 ranks (of 2 flowers) and 2 alternate distal flowers; 
most commonly found on the Pacific slope, (300) 1,000-2,000 m . .P. tonduzii 

lib Laminae only occasionally curved, never so long and narrow 12a 

12a Laminae usually elliptic to narrowly ovate or lanceolate, usually tapering to an acute 

apex, often more than 8 cm long 13a 

12b Laminae obovate, ovate, to narrowly oblong or very narrowly elliptic, usually 

rounded at the apex, rarely more than 7 cm long 14a 

13a Laminae with pinnate venation, lateral stems with 2 or 3 pairs of scale leaves 
between the branching node and the first leaf-bearing node; (900) 1,100- 

2,500 m P. undulatum 

13b Laminae with palmate venation, lateral stems with a single pair of scale leaves 
about halfway between the branching node and the first leaf-bearing node; 

2,000-3,000 m P. sp. aff. undulatum 

14a Lateral stems with 2 pairs of scale leaves between the branching node and the first 
leaf-bearing node, young stems usually 2-angled or somewhat flattened; 1,000-2,000 

m elevation in western Panama P. corynarthron 

14b Lateral stems with a single pair of scale leaves between the branching node and the 
first leaf-bearing node, young stems usually 4-angled in cross section; plants of 
lowland (0-1,000 m) deciduous and evergreen formations. (Note that specimens 
with rounded stems from above 1,400 m elevation keying to this dichotomy are 

probably plants of the genus Dendrophthora.) 15a 

15a Laminae usually narrowly oblong or elliptical, bluntly rounded at the apex; fruit with 

a smooth or wrinkled surface; common in Costa Rica P. quadrangulare 

15b Laminae usually broadly obovate, with an apical notch or bilobed at the apex (rarely 
rounded); surface of the fruit with small tubercles or projections; rarely collected in 
Central America P. mucronatum 

Phoradendron acinacifolium Eichler, in Martius, Fl. Brasil. 5, pt. 2:117. 
1868. P. robaloense Woodson ex Rizzini, Ann. Missouri Bot. Card. 47:282. 1962. 
Figure 11. 

Shrubs, 1-2.5 m tall, basal stems up to 7 cm in diameter, apparently unisexual, leafy 
internodes 2-10 cm long, 2-6 mm thick, terete, stems usually branching dichotomously 
and percurrent stems absent, 1st lateral internodes with united pairs of scale leaves form- 
ing a tube ca. 4 mm long a little (2-8 mm) above the branching node. Leaves usually 



BURGER: FLORA COSTARICENSIS 69 

asymmetric and slightly curved, petioles 4-15 mm long, lateral ridges continuous with the 
lamina margins; laminae 4-20 cm long, 1.4-5 cm broad, lanceolate to falcate or narrowly 
ovate, tapering gradually to the usually acute (rarely blunt and rounded) apex, sometimes 
with a minute succulent tip, tapering to the attenuate and often unequal base, margin 
entire but undulate on drying, venation palmate with 5-7 primary veins, the major veins 
often obscure. Inflorescences usually 2 (3) per leaf axil, 4-6 per node, the sterile rachis 
(peduncle) usually drying very (1-2 mm) thin; male spikes to 8 cm long, with 3 or 4 fertile 
internodes, each to ca. 2 cm long, male flowers present throughout the length of the 
internode or absent near the base, in 4 longitudinal ranks of 6-10 flowers each; female 
spikes 3-5 cm long, rachis with 3 or 4 fertile internodes bearing flowers only in the distal 
half, each fertile internode 2-15 mm long, female flowers in 4-6 longitudinal ranks of only 
1-3 flowers each. Fruit a large ovate berry with acute apex ca. 8 mm long and 6 mm thick 
but much smaller (5x2 mm) and narrowly ovoid or subcylindrical when dry. 

Branch parasites of evergreen montane forests between 700 and 2,000 m ele- 
vation in Costa Rica; flowering and fruiting collections have been made between 
January and August. The species apparently ranges southward to Paraguay. 

Phoradendron acinacifolium is recognized by the usually dichotomous branching, 
slightly curved somewhat falcate leaves, and slender spikes with the fertile inter- 
nodes (of the female) bearing flowers only in the distal part. Description of the 
male flowers and inflorescences is based on only two collections: Stone 3121 from 
above Tapanti, Cartago, and Stern et al. 1992 from near Boquete, Chiriqui, 
Panama. 

Phoradendron angustifolium(H.B.K.) Nuttall, J. Acad. Nat. Sci. Philadelphia, 
ser. 2, 1:185. 1847. Loranthus angustifolius H.B.K., Nov. Gen. Sp. PI. 3:442. 1820. 
Viscum angustifolium (H.B.K.) DC., Prodr. 4:281. 1830. V. ensifolium Pohl, in DC., 
loc. cit. Phoradendron ensifolium (Pohl) Nuttall, loc. cit. 

In the paper on mistletoes of Panama, P. corynarthron and P. tonduzii are placed 
in synonymy under P. angustifolium (Kuijt, Ann. Missouri Bot. Card. 65:744, 
1978). In the present treatment, both P. corynarthron and P. tonduzii are retained, 
because they are usually easy to recognize and distinguish in Costa Rica, and 
because they do not conform very well with the type description of P. an- 
gustifolium or with a majority of the South American material associated with that 
name. If the broader concept of P. angustifolium proves sound, then the rank of 
subspecies might be considered as appropriate for the two groups of specimens 
here placed under P. corynarthron and P. tonduzii. 

Phoradendron annulatum Oliver, Vidensk Meddel. Dansk Naturhist. Foren. 
Kjoebenhavn 1864:176. 1865. Figure 10. 

Large shrubs 1-2 m tall, probably unisexual, leafy internodes 2-8 cm long, 2-9 mm 
thick, slightly flattened at first but soon terete, drying dark, percurrent stems without 
paired scale leaves, lateral stems with distinct paired scale leaves 5-15 mm above the 
branching node. Leaves symmetrical or somewhat curved and asymmetrical, petioles 5-15 
mm long but gradually merging with the lamina and the lateral ridges continuous with the 
lamina margins; laminae 8-15 cm long, 1-2.5 cm broad, linear-lanceolate to somewhat 
falcate, tapering very gradually to the acute or blunt apex, tapering gradually to the 
attenuate base, margin entire, laminae drying stiffly coriaceous and the margins occa- 
sionally slightly undulate, venation palmate to subpalmate with 3 major veins, venation 
obscure. Inflorescences solitary in the leaf axils (2 per node), very short (1-3 cm) and thick, 
drying dark; male spikes with 4 or 5 very short (4-6 mm) fertile internodes, each fertile 
internode with 2 opposite groups of 10-15 densely crowded flowers, the flowers forming 
a well-defined cushion-like area circular to ovate in outline and without floral ranks or 
seriation; female spikes 1-3 cm long, usually of 4 rounded internodes 3-5 mm long and 



70 FIELDIANA: BOTANY 

each bearing only a single whorl (annulus) of 6 flowers deeply imbedded in the rachis (6 
longitudinal ranks of 1 flower each from a modified 1A arrangement). Fruit not seen, 
fruiting spikes ca. 3.5 cm long. 

Branch parasites of higher montane evergreen forest formations between 1,500 
and 3,000 m elevation; fertile collections have been made in July, August, and 
December. The species, as presently understood, is endemic to the Cordillera de 
Talamanca in Costa Rica and the adjacent highlands of western Panama. 

Phoradendron annulatum is distinguished by its thick linear-lanceolate leaves on 
thick rounded stems, the scale leaves about 1 cm above the base of lateral 
branches, lack of scale leaves on percurrent nodes, the unusual arrangement of 
male flowers in opposite circular areas, and the equally unusual "annulus" of 
flowers on the female spikes. These plants often have long unbranched distal 
stems with short thick internodes (as in Davidson 996 and Evans et al. 202). This 
species is very closely related to P. conzattii Trel. of Mexico, but that species has 
longer, more falcate leaves and the female flowers more numerous in each fertile 
internode. Material ascribed to this species in the Flora of Guatemala was appar- 
ently misidentified (Fieldiana, Bot. 24, pt. 4:69. 1946), as neither P. annulatum nor 
P. conzattii have been collected from the area between Mexico and Costa Rica. 

Phoradendron corynarthron Eichler, in Martius, Fl. Bras. 5, pt. 2:115. 1868, e 
descr. P. davidsoniae Standl., Publ. Field Mus. Nat. Hist., Bot. Ser. 22:17. 1940. 
Figure 9. 

Small shrubs of yellowish brown appearance, leafy internodes 1-5 cm long, 1-3 mm 
thick, somewhat flattened or 2-ridged in early stages but soon becoming terete, scale 
leaves absent on percurrent stems, the 1st lateral internodes with 2 pairs of scale leaves, 
the lowest ca. 1 cm above the base of the lateral branch and the 2nd usually 1-2 cm above 
the 1st. Leaves usually symmetrical and straight (rarely curved), petioles ill defined, 1-5 
mm long, the lateral winglike margins continuous with the lamina margins; laminae 4-8 
cm long, 8-14 mm broad, lanceolate to very narrowly elliptic-oblong, gradually or abruptly 
narrowed at the usually blunt apex, very gradually narrowed at the cuneate to attenuate 
base, margin entire and drying as a rim of thinner slightly differentiated tissue, laminae 
drying very stiffly chartaceous or subcoriaceous but thin, venation palmate, the 3 central 
primary veins reaching the distal half of the lamina but obscure beneath. Inflorescences 
solitary in the axils of leaves, 2 per node, 1-3 cm long or becoming 4 cm long in fruit, 
flowering internodes with a basal sterile rachis 2-8 mm long and ca. 1 mm thick (dry); male 
spikes not seen; female spikes with 2-4 fertile internodes, female flowers in 6 vertical ranks 
of usually 1 or 2 flowers each (ca. 8-14 flowers per internode). Fruit becoming globose and 
white, 3-5 mm in diameter. 

Branch parasites of premontane and lower montane wet forest formations be- 
tween 1,000 and 2,200 m elevation in western Panama; collected with flower or 
fruit between March and July. The species is known only from around Volcan 
Baru (Chiriqui) and the Boquete district in the province of Chiriqui, Panama. 

Phoradendron corynarthron is recognized by the smaller very narrow symmetrical 
leaves, the consistent presence of two pairs of scale leaves on the lateral stems 
above the branching node, solitary spikes in the leaf axils, few-flowered inter- 
nodes with a basal sterile rachis often equaling in length the fertile portion, and 
the restricted mid-elevation habitat. While not known in Costa Rica, it may be 
expected in the eastern part of the Talamanca range. This species is related to P. 
tonduzii; see the discussion under that species and under P. quadr angular e. 
Recently, P. corynarthron has been placed into synonymy under P. angustifolium; 
see the discussion under that species. 



BURGER: FLORA COSTARICENSIS 71 

Phoradendron crassifolium(Pohl ex DC.) Eichler, Fl. Brasil. 5, pt. 2:125. 1868. 
Viscum crassifoliumPoh] ex DC., Prodr. 4:280. 1830. P. crassifolium var. pittieriTrel., 
Gen. Phorad. 145, pi. 215. 1916. Figure 11. 

Shrubs, apparently bisexual, stems usually percurrent, leafy internodes 3-15 cm long, 
(1.5) 2-6 mm thick, terete, percurrent stems with a small pair of scale leaves above the leafy 
node, usually with 2-4 pairs of deciduous scale leaves evenly spaced between the leafy 
nodes. Leaves opposite, articulate at the stem, petioles ca. 5 mm long, difficult to dis- 
tinguish because of the attenuate lamina base, margins of the lamina continuous with the 
lateral ridges of the petiole; laminae 6-16 cm long, (2) 4-10 cm broad, ovate to elliptic- 
ovate, elliptic-oblong, or oblanceolate, tapering gradually to the acute to acuminate apex, 
tapering gradually or abruptly to the cuneate or attenuate base (sometimes rounded 
basally in the broader lamina), margin entire but often undulate on drying, the laminae 
drying stiffly coriaceous, venation subpalmate with the 5 major veins free or united for 1-2 
cm above the base, major veins obscure in fresh material but often raised on both surfaces 
and readily visible when dried. Inflorescences usually in the axils of small scale leaves and 
occasionally in the axils of larger leaves, 1 or 2 (rarely 3) per axil (2, 4, or rarely 6 per node), 
spikes 1-3 cm long, usually with 4-7 small closely spaced fertile internodes, flowerless 
rachis ca. 1.5 mm thick (dry), paired fertile scale leaves ca. 1.5 mm long and 2 mm broad 
(apex to apex), flowers in 4 vertical ranks of only 1 or 2 (3) flowers each, distal flowers in 
the internode may be staminate. Fruit 2-3 mm long, ca. 2.5 mm thick (dry), pale orange- 
yellow when ripe, somewhat ellipsoid, 4-8 fruit per internode, fallen fruit leaving a 
depression 1-2 mm broad with a minutely erase margin. 

Branch parasites of wet evergreen forest formations and known in Costa Rica 
only from the southern half of the Pacific slope (western area of the General Valley 
to Golfo Dulce) from 30 to 800 m elevation, but to 1,500 m in adjacent Panama; 
apparently flowering throughout the year. The species ranges from Guatemala 
southward to Peru and Brazil. 

Phoradendron crassifolium is recognized by the thick leaves, with subpalmate 
venation usually tapering at both apex and base, and the short spikes usually 
borne in the axils of two to four pairs of small scale leaves on the leafless stems 
between pairs of foliage leaves. The species is poorly represented in collections, 
and it may be more widely distributed in Costa Rica than present collections 
indicate. This is the only Central American Phoradendron in which the in- 
florescences arise from the axils of scale leaves (intercallary cataphylls) as well as 
from the axils of leaves or fallen leaves (but not all flowering stems exhibit this 
peculiarity). 

Phoradendron dichotomum (Bert.) Krug & Urban, Bot. Jahrb. 24:48. 1897. 
Viscum dichotomum Bertero, in Sprengler, Syst. 1:488. 1824, non D. Don, Prod. Fl. 
Nepal. 147. 1825. Figure 10. 

Shrubs, bisexual, with slender dichotomizing growth, leafy internodes 3-12 cm long, 
1.5-4.5 mm thick, round or slightly angular in early stages, branching dichotomous 
because of terminal inflorescences (percurrent stems absent), a pair of scale leaves present 
about midway between the leaf-bearing nodes and a pair of scale leaves also present just 
above the leaf-bearing node. Leaves symmetrical or slightly asymmetric, petioles 2-8 mm 
long but gradually merging with the lamina base; laminae 5-12 cm long, 1.7-4 cm broad, 
lanceolate to narrowly ovate, gradually tapering to the acute apex, acute to attenuate at the 
base, margin entire and usually drying undulate, the laminae drying coriaceous but 
relatively thin, venation palmate or subpalmate with usually 5 primary veins, the major 
veins usually obscure. Inflorescences 1 and terminal or occasionally with 2 additional 
lateral spikes on 1 side of the dichotomizing twigs, the spikes 3-6 cm long, with up to 6 
(7) fertile internodes, a sterile basal internode often present, the fertile internodes to 16 mm 
long and apparently bisexual with the male flowers distal, the flowers in 6 longitudinal 



FIELDIANA: BOTANY 

ranks or 4 ranks with 2 alternate distal flowers (IB or less often 1A), flowers borne in deep 
depressions with entire margins. Fruit and undeveloped flowers often present in the same 
areas of the fertile internodes, fruit globose and ca. 3 mm in diameter (dry). 

Apparently rare branch parasites of evergreen forest formations and known in 
Central America from only two collections: Tonduz 13142, near Tucurrique, Car- 
tago, at 635 m altitude, and Williams et al. 29155, from near Sta. Maria de Ostuma, 
Cordillera Central de Nicaragua, at 1,400 m altitude. These collections were made 
in January and February. The species ranges to northern South America and the 
West Indies. 

Phoradendron dichotomum is the only species of the genus in our area with truly 
terminal spikes; however, these may fall off, and paired lateral spikes may be 
found at some nodes. In any event, virtually all the stems exhibit dichotomous 
branching. Scale leaves present in the middle of stems between leaf-bearing nodes 
as well as at the base of all stems and the bisexual(?) fertile internodes of the spikes 
further distinguish this species. 

Phoradendron dipterum Eichler, in Martius, Fl. Brasil. 5, pt. 2:109-110. 1868. 
Figure 10. 

Shrubs, bright green to olive green, bisexual, leafy internodes 2-9 cm long, 2-6 mm 
thick, somewhat flattened or 4-angled in cross section (in ours) or prominently 2- to 
4-winged, becoming terete, percurrent stems without paired scale leaves, 1st lateral inter- 
nodes with a pair of scale leaves at the base just above the branching node. Leaves 
symmetrical or asymmetrical, sessile and the petiole absent; laminae 5-13 cm long, 1.5-3 
(4) cm broad, narrowly lanceolate or falcate to ovate-lanceolate, or narrowly oblong, taper- 
ing gradually or abruptly to the rounded apex, tapering gradually to the obtuse or rounded 
and clasping base, margin at the base usually revolute downward and almost auriculate, 
5-10 mm broad across the base, the lamina edge orange in life, entire or undulate dried, 
venation palmate with 3-5 primary veins slightly raised on the upper surface (dry). 
Inflorescences 1 or 2 in the axils of leaves (2-4 per node), unisexual, male and female at 
different but sometimes adjacent nodes, flowers often irregularly arranged in the fertile 
internodes; male inflorescences to 8 cm long with 4-7 fertile internodes, each fertile 
internode ca. 1 cm long, the flowers usually in 6 longitudinal ranks of 6 or 7 flowers each, 
united pairs of scale leaves (fertile bracts) ca. 2 mm long and 3-4 mm broad apically; female 
inflorescences to 5 cm long with 3-5 fertile internodes, the female flowers usually in 6 
longitudinal ranks of ca. (2-) 5 flowers each. Fruit an orange- tipped white spherical berry 
ca. 2 mm in diameter, flesh transparent. 

Apparently rare branch parasites of partly deciduous and evergreen forest for- 
mations between about 1,000 and 2,000 m elevation in Central America. The 
species is known in Costa Rica only from a single collection (Kuijt 2587} from El 
Alto, Cartago, and flowering in August. The species, as interpreted by Kuijt 
(1964), ranges from southern Mexico to northern Argentina. 

Phoradendron dipterum is recognized by its narrow leaves clasping the stems at 
their base with recurved auriculate-like margins, the palmate venation, the long 
internodes with ridges or wings in early stages, the male and female spikes 
sometimes found at adjacent nodes, and the fertile internodes with usually more 
than 25 flowers. The species is known from only a few collections in Central 
America. Material from Oaxaca, Mexico, under the name P. auriculatum Trelease 
has the stems prominently winged and quadrangular, and the leaves are shorter 
and more ovate-oblong. With so few samples at hand, it is not possible to decide 
at this time the proper status of these northern elements. In most of these col- 
lections, the flowers are deeply imbedded in the rachis, and the edges of the floral 
depressions are minutely erose. 



BURGER: FLORA COSTARICENSIS 73 

Phoradendron flavens (Sw.) Grisebach, Fl. Brit. W. Ind. 313. 1864. Viscum 
flavens Swartz, Prodr. Veg. Ind. 32. 1788. P. quinquenenrium Krause, Notizbl. 
Konigl. Bot. Gart. Berlin 5:264. 1912. P. supravenulosum Trel., Gen. Phor. 154. 
1916. Figure 11. 

Shrubs 1-2 m broad, branch parasites, apparently unisexual, leafy internodes 2-7 cm 
long, 1.3-4 (6) mm thick, terete or somewhat 2- or 4-angIed in early stages, percurrent 
stems with a pair of keeled scale leaves ca. 1 cm above the basal node, the 1st lateral leafy 
internode with a pair of scale leaves near the base and a 2nd pair at ca. Vs the length to 
the next leafy node. Leaves opposite, somewhat articulate at the stem, petioles 1-6 mm 
long, not clearly distinguished and with lateral ridges continuous with the lamina mar- 
gins; laminae 4-11 (14) cm long, 2-6 (8) cm broad, ovate to elliptic-ovate or elliptic, 
occasionally lanceolate or asymmetric and curved, tapering gradually or abruptly to the 
acute to acuminate apex (occasionally obtuse), tapering gradually or abruptly to the atten- 
uate base, margin entire, drying stiffly chartaceous to subcoriaceous, venation palmate or 
subpalmate with 3 or 5 primary veins, the 3 central primaries reaching the distal part of 
the lamina, the major veins often raised on the surface of the dried leaves, secondaries 
obscure. Inflorescences at first solitary but often with 1 or 2 additional developing in leaf 
axils (2-6 per node), the spikes 2-6 cm long, secondary spikes subtended by sterile scale 
leaves, the paired fertile scale leaves ca. 3 mm broad (tip to tip) and 2-3 mm long and 
keeled, sterile portions of the rachis ca. 0.8-2 mm thick (dry), with 6 vertical ranks of 2-7 
flowers each, male spikes with usually 6-15 flowers per internode, the female with 30-50 
flowers. Fruit becoming contiguous and obscuring the rachis, 2-3 mm in diameter, glo- 
bose, yellowish white, pulp viscid and transparent, fertile internodes to 15 mm long. 

Branch parasites of wet evergreen and moist mountain forest formations be- 
tween 600 and 1,900 m elevation on both the Caribbean and Pacific slopes of Costa 
Rica; probably flowering throughout the year, but not collected in July- August or 
October and December. The species ranges from Guatemala and Belize to north- 
ern South America and the southern Caribbean Islands. 

Phoradendron flavens is recognized by the scale leaves present on the often 
slender percurrent stems, leafy nodes often with two older and four younger 
spikes, laminae often narrowed to both apex and base with the palmate venation 
readily apparent when dry, and the flowers usually in six vertical ranks. This 
species is closely related to P. piperoides, but is easy to separate by the obviously 
palmate venation of the usually broader leaves. Typical material of this species is 
distinguished by the ovate to oblong leaves with three primary veins distinctly 
raised above when dried and the succulent fruits becoming contiguous so that the 
nodes are not visible on the spike. 

Phoradendron woodsonii Trelease, discussed by Kuijt (1974) in his recent review 
of the Panamanian species, would key out here if found in the Costa Rican flora. 
This species has two to four pairs of scale leaves on its internodes, and it differs 
from P. flavensin other ways. Phoradendron flavens, P. crassifolium, P. piperoides, and 
P. woodsonii appear to form a closely related group, and it is possible that hybrid- 
ization occurs among them. 

Phoradendron mucronatum (DC.) Krug & Urban, Bot. Jahrb. 24:34. 1897. Vis- 
cum mucronatum DC., Prodr. 4:282. 1830. 

Small shrubs, leafy internodes to ca. 3 cm long and 3 mm thick, usually with 4 promi- 
nent longitudinal ridges and square in cross section, glabrous, percurrent stems without 
scale leaves but often with an articulation just above the node, lateral stems with a pair of 
scale leaves ca. 3 mm long just above the node. Leaves short and broadly rounded, petioles 
1-3 mm long; laminae 1-4 cm long, 1-3 cm broad, broadly obovate to suborbicular, 
abruptly rounded distally and emarginate to bilobed at the apex, abruptly narrowed at the 
base, margins entire, laminae drying yellowish green and subcoriaceous, venation palmate 



74 FIELDIANA: BOTANY 

with the 3 or 5 primary veins often visible on the upper surface. Inflorescence 0.5-3 cm 
long, usually solitary in the axils of leaves or fallen leaves, each fertile internode 2-5 mm 
long, usually with only 1 flower in each of 4 ranks resulting in a whorl of 4 flowers (rarely 
6) per internode. Fruit ca. 2.5 mm in diameter, with persisting and erect perianth lobes ca. 
0.5 mm high, surface covered with small papillae that give a muricate or tuberculate 
appearance. 

A species of evergreen or partly deciduous lowlands often found near man- 
groves, lakes, and rivers in Central America; from sea level to 800 m elevation. 
Rarely collected in Mesoamerica, but ranging from the Yucatan peninsula and the 
West Indies to southern Brazil. 

Phoradendron mucronatum is a very distinctive member of the genus with small 
rounded leaves deeply emarginate or bilobed at the apex, short four-ridged inter- 
nodes, short spikes often with only one whorl of flowers per fertile internode and 
unusual surface of the fruit. Although known from Panama and Guatemala, this 
species has not been collected from Costa Rica; it is likely to occur in the Caribbean 
lowlands. 

Phoradendron obliquum (Presl) Eichler, Fl. Brasil. 5, pt. 2:134. 1868. Figure 11. 

Large shrubs to 2 m in diameter, often pendent, unisexual, the branches often forking 
dichotomously, leafy internodes 2-15 cm long, 2-8 mm thick, young stems slightly flat- 
tened or round and the older terete, percurrent stems rare and with paired scale leaves just 
above the node, lateral stems with paired scale leaves just above the branching node and 
somewhat tubular distally (a second pair of scale leaves rarely present ca. 1 cm above the 
node). Leaves often asymmetric and somewhat curved, petioles to 15 mm long but difficult 
to distinguish from the laminae, the winged margins continuous with the lamina margins; 
laminae 6-15 (23) cm long, 2-7 (9) cm broad, narrowly ovate to lanceolate and sometimes 
slightly curved, tapering gradually to the acute or bluntly rounded apex, rounded or 
gradually to abruptly narrowed at the attenuate base, margin entire but drying undulate, 
the laminae drying stiffly coriaceous, venation palmate, subpalmate, or pinnate with the 
secondaries arising in the lower 4th of the midvein, the major veins usually 5 and only the 
central 3 subparallel, often obscure (dry). Inflorescences 3-5 cm long, the male as many as 
12 per node, the female 2-6; male spikes unknown (see discussion); female spikes with 3 
or 4 fertile internodes with 4 longitudinal ranks of 2-4 flowers each and 2 distal alternating 
flowers. Fruit ellipsoid to somewhat cylindrical, ca. 3-5 mm long and 2-3 mm thick (dry), 
depressions in the rachis to 3 mm in diameter and with an entire edge. 

Branch parasites of evergreen and partly deciduous forest formations between 
sea level and 1,400 m elevation; probably flowering throughout the year. This 
species ranges from Costa Rica to Peru; our material has been collected in the 
Central Highlands and their slopes and southwestern Costa Rica. 

Phoradendron obliquum is recognized by the frequent dichotomous branching, 
scale leaves usually present just above the node on all stems, thick larger leaves 
usually tapering to a narrowed apex and often slightly curved, and flowers 
throughout the length of the fertile internodes. In life, the plants are often char- 
acterized by a reddish color and leaves with a shiny-glossy surface. The latter 
character differentiates this species from the closely related P. robustissimum which 
has rough-surfaced leaves in life. Unfortunately, this character disappears on 
drying, and some specimens may be very difficult to place in one or the other 
species. The two species are very closely related, and intermediate plants or 
populations may exist: see the discussion under P. robustissimum. 

A survey (Kuijt, 1964) of almost 30 plants near the continental divide between 
Tres Rios and Cartago disclosed no staminate plants or spikes. A more intense 
study of plants on the University campus near San Pedro found that male flowers 
are extremely rare (1% to 2%), occurring as the lowest (proximal and last devel- 



BURGER: FLORA COSTARICENSIS 75 

oping) flowers of a floral rank in occasional fertile internodes. The fact that these 
populations were producing fruit suggests that these plants may have been re- 
producing asexually (Kuijt, 1964). 

This species has been the subject of a thesis by R. E. Zurcher: Las Loranthaceae 
que parasitan el laurel, Cordia alliodora, en Costa Rica y sus posibilidad de control 
con inyecciones de hierbicidas al tronco del huesped, Inst. Interamer. Ciencias 
Agric, Turrialba, 1958. 

Phoradendron piperoides (H.B.K.) Trelease, Genus Phoradendron 145. 1916. 
Loranthus piperoides H.B.K., Nov. Gen. & Sp. 3:443. 1820. P. biolleyi Krause, 
Notizbl. Kdnigl. Bot. Gart. Berlin 5:264. 1912. Figure 11. 

Small shrubs, epiphyte-like hemiparasites, bisexual, the stems often trailing, leafy inter- 
nodes 2-8 (10) cm long, 1.5-4 mm thick, terete, percurrent stems with a pair of reduced 
opposite scale leaves just above the node and often difficult to see, the first lateral inter- 
node with 1-5 pairs of scale leaves, 1 pair often near the center of the 1st lateral internode. 
Leaves opposite, petioles 1-4 (7) mm long, 1-2 mm broad, margins of the lamina con- 
tinuous with the wings of the petiole; laminae 3-11 (14) cm long, 1-4.5 (6) cm broad, 
elliptic to oblong or narrowly obovate, acuminate to acute at the apex, usually tapering to 
the acute or attenuate base, margin entire but undulate on drying, the laminae drying 
coriaceous, glabrous and smooth, venation pinnate with 2-3 pairs of major secondary 
veins but these usually obscure. Inflorescences 1-3 per leaf axil (2-6 per node), very rarely 
terminal, the spikes 3-8 cm long with 1-3 sterile internodes near the base, the paired 
fertile scale leaves ca. 2.3 mm broad (apex to apex), sterile portion of the spike ca. 1 mm 
thick (dry), fertile internodes 6-11, usually with 4 longitudinal ranks of 2-4 flowers and 

2 alternate distal flowers, rarely to 28 flowers per internode. Fruit spherical to ellipsoid, ca. 

3 mm in diameter and yellowish to orange when ripe, separate from each other when 
dried. 

Branch parasites of evergreen and partly deciduous forest formations between 
sea level and about 1,500 m elevation on both the Caribbean and Pacific sides of 
Costa Rica; apparently flowering throughout the year, but not collected in October 
and November and with the majority of collections made in February and August. 
The species ranges widely over the American tropics. 

Phoradendron piperoides is recognized by the small paired scale leaves on all the 
slender and usually terete stems, medium-sized laminae tapering to both apex 
and base with usually obscure pinnate venation, and the infloresences usually in 
axillary clusters at leafy nodes. The scale leaves just above the nodes of percurrent 
stems are often difficult to see or are represented only by opposite scars. This is 
one of Costa Rica's most abundant species of Phoradendron, especially common in 
the wet lowlands. It is particularly abundant in the Limon region on cacao and 
shade trees. 

Phoradendron quadrangulare (H.B.K.) Krug & Urban, Bot. Jahrb. 24:35. 1898. 
Loranthus quadrangularis H.B.K., Nov. Gen. & Sp. 3:444. 1818. P. ceibanum Trel., 
Genus Phoradendron 110. 1916. P. rensoniiTrel., loc. cit. 105. P. venezuelenseTrel., 
loc. cit. 111. P. corynarthron var. seibertii Trel., Ann. Missouri Bot. Card. 24:187. 
1937. P. paquitanum Trel., Publ. Field Mus. Nat. Hist., Bot. Ser. 18:405. 1937. P. 
herrerenseTrel., Ann. Missouri Bot. Card. 27:307. 1940. P. sonanumTrel., loc. cit. 
308. P. seibertii (Trel.) Rizzini, loc. cit. 47:285. 1960. Figure 9. 

Small shrubs, bisexual(?), branches usually erect and often branching dichotomously, 
leafy internodes, 1-8 cm long, 1-4 (6) mm thick, with 4 distinct longitudinal ridges but 
becoming rounded in age, often slightly thickened beneath the node, percurrent stems 
lacking fused pairs of scale leaves, 1st lateral stems with a pair of fused scale leaves just 



76 FIELDIANA: BOTANY 

above the branching node. Leaves usually symmetrical and straight, subsessile or with 
poorly defined petioles 0-4 (6) mm long, with lateral ridges continuous with the lamina 
margins; laminae 2.5-6 (7.5) cm long, 1-2.3 cm broad, very narrowly oblong, to narrowly 
elliptic or very narrowly obovate, rounded to bluntly obtuse at the apex, cuneate to 
attenuate at the base, margin entire, the laminae drying very stiffly chartaceous to subcor- 
iaceous and often becoming grayish green, venation palmate with 3 or 5 primary veins, the 
3 central veins reaching the distal part of the leaf, the major veins slightly raised or obscure 
(dry). Inflorescences 1 or less often 3 in each leaf axil (2-6 per node), spikes 1.5-3 (5) cm 
long, peduncle 2-6 mm long, flowering axis with 4-6 fertile internodes, the fertile pairs 
of scale leaves often small and inconspicuous, male and female spikes quite similar, the 
flowers in 4 vertical ranks of 2-4 flowers (very rarely to 7 in male spikes), and 2 alternating 
distal flowers, usually up to 18 flowers per fertile internode. Fruit globose, to 4 mm in 
diameter, yellow to yellow-orange. 

Branch parasites most often found in evergreen and partly deciduous (tropical 
moist and premontane moist) forest formations below 1,000 m in elevation; flow- 
ering throughout the year. The species ranges from southern Mexico to northern 
South America and the West Indies. 

Phoradendron quadrangulare is characterized by the small- to medium-sized 
leaves that are very narrow and abruptly rounded at the tip, the four-angled 
young stems, short slender spikes with few fertile internodes (or the internodes 
difficult to distinguish because of the very small paired scale leaves), and the 
apparent preference for semideciduous lowland habitats. The present circum- 
scription of this species includes considerable variation in inflorescence 
morphology, but the laminae are rather uniform. For example, one of the very few 
collections from the wet Caribbean lowlands (Lent 1926 from Tirimbina, Sarapiqui, 
Heredia) has very narrow stems, distinctly petiolate leaves, and short spikes with 
very few (three to five) flowers per fertile internode. Material from Venezuela 
often has short-cylindrical or ellipsoid fruit, whereas ours appears to be uniformly 
globose as interpreted from the dry collections. 

Several collections from near Tilaran (Standley & Valeria 44983 and 45577, Wil- 
liams, Molina, & Williams 26606) key to this species, but are perhaps more closely 
related to P. corynarthron and P. tonduzii. The leaves of these specimens are a bit 
larger, but of much the same shape, as P. quadrangulare and P. corynarthron. 
However, they lack the angled stems of P. quadrangulare and the second set of scale 
leaves (on lateral stems) of P. corynarthron. These collections also lack the falcate 
leaves and two-ridged stems of P. tonduzii. All three species and the Tilaran 
material have very similar inflorescences and appear to be closely related. Perhaps 
the collections from Tilaran represent an unusual population of mixed parentage. 
The type of P. dodgei (Dodge 6200) from the same area, while having many of the 
characteristics of P. tonduzii, does resemble the specimens referred to above and 
may be intermediate between them and typical P. tonduzii. All these collections 
come from altitudes beneath those at which P. corynarthron and P. tonduzii are 
usually found. 

Phoradendron robustissimum Eichler, in Martius, Fl. Brasil. 5, pt. 2:122. 1868. 
P. falcifolium Trel., Gen. Phorad. 79. 1916. P. pergranulatum Trel., Ann. Missouri 
Bot. Card. 27:308. 1940. Figure 11. 

Shrubs to 1 m or more, dark green or grayish green, unisexual, usually branching 
dichotomously, leafy internodes 2-10 cm long, 2-6 mm thick, usually terete, percurrent 
stems infrequent, both percurrent and lateral stems with a single (rarely 2 or 3) pair of 
united scale leaves ca. 5 mm above the node, 2 spikes often peripheral to the aborted apex 
with vegetative laterals developing axillary to prophylls of the spikes or vice versa. Leaves 



BURGER: FLORA COSTARICENSIS 77 

symmetric or the larger often asymmetric, petioles 2-15 mm long but not easily dis- 
tinguished from the attenuate leaf base, broader than thick and with the lateral margin 
continuous with the lamina margin; laminae 3.5-10 (14) cm long, 2-5 (8.5) cm broad, 
oblong to ovate-oblong or somewhat spatulate, abruptly rounded at the apex, often emar- 
ginate with a minute succulent tip, abruptly narrowed at the attenuate base, margin entire 
with a thin brownish edge, the laminae drying stiffly coriaceous, surfaces with a slightly 
rough texture in life and, when dry, venation palmate to pinnate with the secondaries 
arising from the lower 3rd of the midvein, usually subpalmate, with usually 5 major veins 
and these often obscure. Inflorescences dimorphic, the male much thinner than the fe- 
male, 1 to several per leaf axil or the males as many as 12 on older nodes; male spikes to 
11 cm long, with 4-6 fertile internodes 1-2 cm long, sterile rachis ca. 1-2 mm thick, male 
flowers in 4 (6) longitudinal ranks of ca. 10 flowers each and with 2 alternating terminal 
flowers (1A arrangement) female spikes to ca. 6 cm long with 3-5 fertile internodes, the 
central (longer) internodes 1-2 cm long with 4 ranks of 4 or 5 flowers each and 2 alternate 
terminal flowers (1A arrangement). Fruit elliptic-ovate or cylindric (dry) and about 4 mm 
long and 2 mm thick, yellowish to dusty yellow-green. 

Branch parasites of both evergreen and deciduous lowland forest formations 
below about 1,000 m in Costa Rica; apparently flowering throughout the year. The 
species ranges from southern Mexico to Venezuela. 

Phoradendron robustissimum is recognized by the stiff oblong leaves usually with 
bluntly rounded apices, frequent dichotomous forking of the stems, slender male 
spikes often more than eight at older nodes, and usual restriction to lower (0 to 
500 m) altitudes on the Pacific slope. This species is related to P. oblicjuum and may 
be difficult at times to separate from specimens of that species; see discussion 
under P. obliquum. 

Phoradendron tonduzii Trelease, Gen. Phorad. 67. 1916. P. cooperi Trel. , loc. 
tit. P. dodgeilrel, Publ. Field Mus. Nat. Hist., Bot. Ser., 18:405. 1937. P. novae- 
helvetiaelrel., Ann. Missouri Bot. Card. 27:307. 1940. Figure 10. 

Shrubs, often orange-brown or yellow-brown, to ca. 1 m broad and often pendulous, 
unisexual, leafy internodes 1-10 cm long, 1-5 mm broad, with 2 opposing ridges and 
somewhat flattened in early stages, scale leaves absent on percurrent stems, the 1st lateral 
internode with 1 or rarely 2 pairs of scale leaves near the base. Leaves opposite, articulate 
at the stem, usually asymmetric, petioles 5-20 mm long but not really distinguishable from 
the lamina base; laminae 6-15 (20) cm long, 0.5-2 (3) cm broad, very narrow and usually 
curved (falcate) to narrowly lanceolate, tapering gradually to the acuminate apex, tapering 
gradually to the attenuate base, margin entire or undulate, laminae drying very stiffly 
chartaceous, smooth and glabrous, venation palmate with 3-6 primary veins the 3 central 
primaries subparallel and reaching the distal half of the lamina, slightly raised and usually 
visible (dry). Inflorescences 1-3 in the axils of leaves (2-6 per node), spikes 3-7 cm long, 
usually without basal sterile scale leaves; the male spikes with ca. 4-8 fertile internodes, 
flowerless rachis 0.5-1.5 mm thick (dry), the male flowers usually in 6 ranks, of ca. 20 
flowers each (ca. 70 flowers per internode), the paired scale leaves almost completely 
united and only slightly cleft, 2-2.5 mm broad at the apex; female spikes with 2-5 fertile 
internodes, female flowers usually in 4 ranks of 2-4 flowers with 2 alternate distal flowers, 
ca. 10-20 flowers per internode, the united scale leaves becoming slightly cleft. Fruit ovoid 
to globose, 3-4 mm long, white but becoming orange in the sun, flesh translucent orange. 

Branch parasites of wet evergreen and partially deciduous forest formations 
between (300) 1,000 and 2,000 m elevation and only rarely collected on the Carib- 
bean slope; apparently flowering throughout the year. As here defined, the 
species is endemic to the area between Tilaran, Guanacaste, and western Panama 
(see below). 

Phoradendron tonduzii can often be recognized almost immediately because of the 
long and very narrow curved leaves. The young stems with two opposite ridges, 
lack of scale leaves on the percurrent stems, and male spikes more slender and 



78 FIELDIANA: BOTANY 

with many more flowers than the female further distinguish this species. Among 
our species, the relationships of P. tonduzii are with P. corynarthron and P. quad- 
rangulare. A number of collections from Tilaran may represent an unusual popu- 
lation of P. tonduzii (Kuijt, 1964) or a population of hybrid origin. However, these 
plants are here keyed to and discussed under P. quadmngulare. Recently, P. ton- 
duzii has been placed into synonymy under P. angustifoium; see the discussion 
under that species. 



Phoradendron undulatum Eichler, Fl. Brasil. 5, pt. 2:122. 1868. P. gradlispicum 
Trel., Gen. Phorad. 130. 1916. Figure 10. 

Shrubs, often pendent, bisexual, leafy internodes 1-9 cm long, 2-8 mm thick, with 2 
opposite ridges and somewhat flattened in early stages but becoming terete, percurrent 
stems without paired scale leaves, first lateral internodes with (1) 2 or 3 pairs of scale leaves 
with the distal often in the middle of the internode. Leaves opposite, articulate at the base, 
often slightly asymmetric, petioles 2-10 (16) mm long, with lateral ridges continuous with 
the lamina margins; laminae 5-17 (23) cm long, 1.5-4.5 (6) cm broad, lanceolate to very 
narrowly elliptic-ovate or narrowly elliptic, tapering very gradually to the acute to acu- 
minate apex, abruptly to gradually narrowed at the obtuse to acute base, margin entire or 
undulate when dry, the lamininae drying stiffly coriaceous, venation pinnate with 2 or 3 
pairs of major secondary veins but the secondaries often obscure. Inflorescences 1 or 2 (3 
or 4) in leaf axils (2-8 per node), spikes 1.4-5(7) cm long, with 6-12 fertile internodes 4-10 
mm long, with 4 (-6) longitudinal ranks of 1-3 (4) flowers each, with usually 10-14 flowers 
per internode, terminal internode usually with only 2 flowers; male flowers few and 
usually in an apical position, pairs of fertile scale leaves often forming a distal edge 
perpendicular to the rachis and very slightly erose. Fruit a white globose berry ca. 4 mm 
in diameter, often drying cylindrical, flesh transparent and viscid. 

Branch parasites of wet evergreen montane forest formations between (900) 
1,100 and 2,500 m elevation in Costa Rica; probably flowering throughout the year, 
but collected most often in December and February. The species ranges from the 
Cordillera Central de Nicaragua southward to Bolivia and Brazil. 

Phoradendron undulatum is recognized by the lack of scale leaves above per- 
current internodes, flattened young stems, stiff leaves gradually tapering to the 
apex and with pinnate venation, spikes with short and few-flowered internodes, 
and the montane habitat. Small plants of P. undulatum are easily confused with 
P. piperoides, but that species has paired scale leaves on the percurrent internodes. 



Phoradendron sp. aff. undulatum. Figure 10. 

Shrubs, green, apparently unisexual, branches to ca. 1 m long, leafy internodes 2-5 (7) 
cm long, 1.5-6 mm thick, often with 2 longitudinal ridges and somewhat flattened or even 
quadrangular, older nodes conspicuously thickened, percurrent stems lacking scale 
leaves, lateral stems with 1 (rarely 2) pair of united scale leaves 8-30 mm above the 
branching node. Leaves usually symmetrical, petiole 5-15 mm long but gradually expan- 
ding into the leaf with lateral margins continuous with the lamina margins; laminae 5-11 
cm long, 2-4 cm broad, lanceolate to narrowly ovate, tapering gradually to the acute or 
acuminate apex, gradually or abruptly narrowed to the attenuate base, the larger laminae 
more abruptly narrowed and somewhat asymmetric at the base, the laminae drying thin- 
to rigid-coriaceous with the margin often becoming undulate, venation palmate with 
usually 5 major veins, the venation often obscure. Inflorescences 1-3 from the leaf axils 
(2-6 per node), 2-3 cm long; male spikes with 2-5 fertile internodes, each fertile internode 
with 6 longitudinal ranks of ca. 4 or 5 flowers each; female spikes with 3 or 4 fertile 
internodes, sterile rachis of the fertile internode often as long (2-4 mm) as the fertile 
rachis, sterile rachis 0.6-1 mm thick (dry), female flowers in 6 ranks (4 plus 2) of only 1 or 
2 flowers each. Fruit not seen. 



BURGER: FLORA COSTARICENSIS 79 

Branch parasites of wet evergreen montane forest formations between about 
2,000 and 3,000 m elevation; probably flowering throughout the year. The species 
is known only from the Central Volcanic Highlands and Cordillera de Talamanca 
in Costa Rica. 

Phoradendron species (aff. undulatum) is recognized by the paired scale leaves 
about halfway up the first lateral internodes (to the first leaves), angular stems, 
acute to acuminate laminae, short spikes, and few-flowered female internodes. 
The description of female spikes is based on Kuijt 2469; no other female material 
is known. This species is very similar in overall appearance to P. undulatuni, but 
that species has leaves with pinnate venation, more scale leaves on the lateral 
stems above a branching node, and undulating leaf margins. 

ARISTOLOCHIACEAE 

By Kerry Barringer 

REFERENCES: F. C. Hoehne, Aristolochiaceae, in Fl. Brasil. 15(2):1-141. 1942. 
Howard W. Pfeifer, Revision of the North and Central American hexandrous 
species of Aristolochia. Ann. Missouri Bot. Card. 53:115-196. 1966. O. C. Schmidt, 
Aristolochiaceae, in Engler & Prantl, Nat. Pflanzenfam. ed. 2. 16b:202-242. 1935. 

Lianas, herbs, or shrubs, often aromatic, wood with broad medullary rays; true stipules 
absent, clasping pseudostipules sometimes present. Leaves alternate, simple, petiolate; 
lamina entire or lobed, usually cordate and reniform, often palmately veined, often with 
eglandular pubescence. Flowers solitary or racemose, bisexual; calyx enlarged, petaloid, 
usually tubular, radially or bilaterally symmetrical, the lobes valvate; petals usually absent 
or reduced to scales; stamens 5, 6, or multiples thereof, free or connate, anthers extrorse, 
dehiscing by longitudinal slits; ovary inferior or half inferior, 4- to 6-locular, rarely of free 
carpels; ovules many in each locule, axile or parietal, anatropous. Fruit a septicidal capsule 
or follicle, usually pendent, rarely indehiscent; seeds with copious endosperm. 

A family of seven genera and about 600 species, the Aristolochiaceae previously 
were placed in an order with the Rafflesiaceae and Hydnoraceae. They are now 
generally classified into an order by themselves and are believed to be derived 
from the Magnoliales, with affinities to the Annonaceae. Many authors have 
noted the similarities between the lianoid species of this family and the Di- 
oscoreaceae. Only Aristolochia has been found in Costa Rica. 

ARISTOLOCHIA Linnaeus 

Woody or herbaceous lianas, rarely shrubs or trees; true stipules absent but broad, 
clasping pseudostipules formed by the first leaf of axillary buds often present. Leaves 
alternate, distichous, simple, petiolate, entire or lobed, usually palmately veined with 3-7 
primary veins. Flowers solitary and axillary or in racemose clusters which may be axillary 
or from older parts of the stem, bisexual, variously colored with yellow, brown, and red, 
often fetid smelling; calyx tubular, bilaterally symmetrical due to bending of the tube, 
forming an inflated, ovoid utricle at its base, a narrowed or funnelform tube, and an 
expanded, 1- to 3-lobed, variously structured limb; stamens in multiples of 3 or 5, connate 
into a gynostemium which appears to also function as stigmas; ovary inferior, narrowly 
cylindric, 5- or 6-loculate. Fruit a dry, septicidal capsule, pendent; valves and pedicels 
usually splitting from the base of the capsule, the valves remaining attached at the apex, 
sometimes with persistent, lattice-like septa connecting the valves; seeds compressed, 
often with paired, lateral wings. 

A genus of 400 to 500 species, chiefly pantropical. The Costa Rican species are 
all lianas whose flowers have six stamens and six-loculate ovaries. Little is known 
about the pollination of Aristolochia in the wild. Recent work in Costa Rica indi- 




A. veraguensis 



A. constricta 




Fruit 




ARISTOLOCHIA 
maxima 



A. tonduzii 




A. Translucida 




FIG. 12a. Aristolochiaceae: Aristolochia maxima and its Costa Rican allies; note the un- 
usual fruit. 



80 



A. gigantea 




ARISTOLOCHIA 
odoratissima 




A. grandiflora l 




A pilosa 



A. anguicida 




A. triloba 




FIG. 12b. Aristolochiaceae: six Costa Rican species of Aristolochia, two with large flowers. 



81 



FIELDIANA: BOTANY 

cates that butterfly larvae feed on the leaves of some species, thereby obtaining 
substances which make them distasteful to predators. Extracts of the stems and 
roots have been used against snakebite and to alleviate pain during childbirth. 
Sterile material is sometimes confused with species of Dioscorea, but Aristolochia 
can usually be recognized by the distichous leaf arrangement on young shoots. 

la Pseudostipules rounded, clasping, at the base of leaves 2 

Ib Pseudostipules absent 6 

2a Leaves 3-lobed; calyx limb with a long apical appendage A. trilobata 

2b Leaves entire; calyx limb without apical appendage 3 

3a Leaf blade broadly reniform, glaucous below; flowers bilabiate . . . . A. ringens 
3b Leaf blade triangulate, glabrous or slightly pubescent below; flowers uni- 

labiate 4 

4a Leaf apex rounded; fruit with a prominent beak A. littoralis 

4b Leaf apex acute to cuspidate; fruit without beak 5 

5a Capsule narrowly cylindric, 7-10 cm long; calyx limb peltate, acuminate; leaves 

usually hastate A. odoratissima 

5b Capsule ovoid, 2-3 cm long; calyx limb triangulate, folded; leaves triangulate 

A. anguicida 

6a Plants hirsute with brown septate hairs A. pilosa 

6b Plants glabrous, strigose, or tomentose with white hairs 7 

7a Leaves broadest at base; fruit valves free 8 

7b Leaves broadest at middle; fruit valves usually connected by the persistent, lattice- 
like septa 12 

8a Petioles 10-15 cm long 9 

8b Petioles 2-8 cm long 10 

9a Leaves variegated with yellow or white along veins; flowers in racemose clusters on 

old wood A. veraguensis 

9b Leaves green, not variegated. Flowers solitary on older stems A. grandiflora 

lOa Lower leaf surface white tomentose; petioles 5-7 cm long A. gigantea 

lOb Lower leaf surface glabrous; petioles 2-4 cm long 11 

lla Capsule narrowly cylindric, 7-10 cm long; calyx limb peltate, acuminate; leaves 

usually hastate A. odoratissima 

lib Capsule ovoid, 2-3 cm long; calyx limb triangulate, folded; leaves triangulate 

A. anguicida 

12a Leaves ovate, long acuminate, deeply cordate; fruits 5-6 cm long . . . . A. constricta 
12b Leaves oblong, short acuminate to cuspidate, truncate to shallowly cordate; fruits 

6-10 cm long 13 

13a Leaf base truncate; calyx 5-7 cm long A. maxima 

13b Leaf base shallowly cordate; calyx 8-13 cm long 14 

14a Calyx limb translucent, with green spots A. translucida 

14b Calyx limb opaque, with dark elevated maculae A. tonduzii 

Aristolochia anguicida Jacq., Enum. Syst. PI. 30. 1760. A. loriflora Mast., Bot. 
Jahrb. Syst. 8(1):220. 1887. Figure 12b. 

Herbaceous lianas, younger stems glabrous; pseudostipules often present, rounded, 
clasping, 1.5-2 cm wide. Leaves with petioles 3-4 cm long; laminae triangulate, 5-6.5 cm 
long, 4.5-6 cm wide, acuminate, base cordate with a sinus ca. 1 cm deep, 5 primary veins 
diverging from the base, glabrous. Flowers solitary in leaf axils or on short leafy shoots, 
ovary and pedicel 2.5-3 cm long; utricle horizontal, ovoid, 8-12 mm long, 5-7 mm wide; 
tube erect, funnelform, 15-25 mm long, limb erect, unilabiate, triangulate, folded, 15-25 
mm long. Capsule ovoid, 2-3 cm long, valves 6-8 mm wide, horizontally striate, finely 
pubescent; seeds triangulate, bilaterally winged, 6 mm long, 4 mm wide. 

This species is found along the seasonally dry Pacific slope of Costa Rica and 
into the Meseta Central. It occurs in similar habitats from Peru to Guatemala. 
Flowering material has been collected from December through March, but it 
probably blooms throughout the year. The flowers are similar to those of A. 
linearifolia, a native of Haiti, and of A. bilabiata of the Greater Antilles. 



BURGER: FLORA COSTARICENSIS 83 

Aristolochia constricta Griseb., Abh. Konigl. Ges. Wiss. Gottingen 7:225. 
1857. A. securidata Mast., Bot. Gaz. 33:256. 1902. Figure 12a. 

Woody lianas, older stems with ridged, corky bark, younger stems glabrescent; pseudo- 
stipules absent. Leaves with petioles 3-5 cm long; laminae ovate, 10-20 cm long, 7-13 cm 
wide, long acuminate, bases deeply cordate with sinuses 2-4 cm deep, 5 primary veins 
diverging from the base, glabrous above, glabrescent below. Flowers in axillary racemes; 
utricle horizontal, ovoid, 1 cm long; tube erect, funnelform, 2 cm long; limb erect, uni- 
labiate, 2-3 cm long. Capsules broadly ellipsoid, 5-6 cm long, valves 2 cm wide, horizon- 
tally striate, glabrous, septa persistent, lattice-like, connecting the valves after dehiscence; 
seed cordate, with broad lateral wings, 7 mm long, 12 mm wide. 

Native to Costa Rica, northern Panama, and southern Nicaragua, growing in 
evergreen forests below 1,000 m. Flowering material collected between October 
and May. 

This species can be recognized by its ovate, long-acuminate, deeply cordate, 
glabrous leaves. The species seems to be closely related to A. maxima. The fruits 
have persistent septa which connect the valves of the fruit after dehiscence, 
making the fruit look like a hanging basket. Similar fruits are found in A. maxima, 
A. chapmaniana, A. tonduzii, and probably A. translucida. 

Aristolochia gigantea Mart. & Zucc., Nov. Gen. Sp. PI. 1:75. t. 48. 1824. A. 
sylvicola Standley, J. Wash. Acad. Sci. 15:5. 1925. Figure 12b. 

Woody lianas, older stems with a deeply ridged, corky bark, younger stems glabrous; 
pseudostipules absent. Leaves with petioles 5-7 cm long; laminae ovate to triangular, 
15-16 cm long, 11-16 cm wide, apices acuminate, bases truncate to slightly cordate, with 
5 major veins diverging from the base, glabrous above, villous with white hairs below. 
Flowers borne on older stems; utricle pendent, turbinate, 7 cm long, 3 cm wide; tube 
strongly reflexed, funnelform, 3 cm long, limb erect, peltate, 15-17 cm long, 12-13 cm 
wide, with purple-brown markings between the veins. Capsule cylindric, 13 cm long, 
valves 8-10 mm wide, glabrous, horizontally striate; seeds ovate, without wings, 7 mm 
long, 5 mm wide. 

Currently known from the wet lowland forests from Panama to Amazonian 
Brazil; it is likely that this species will be found in Costa Rica. Flowering material 
has been collected from September to March. 

This species can be recognized by the leaves, which are villous on the lower 
surface, and the broadly peltate calyx limb. The Central American material differs 
from the South American material in having smaller flowers, no pseudostipules, 
and white hairs on the lower leaf surface. The two groups may be distinct taxa, 
but these characters are known to vary within some species. Aristolochia gigantea 
is closely related to A. littoralis. 

Aristolochia grandiflora Swartz, Prodr. Veg. Ind. Occ. 126. 1788. Figure 12b. 

Lianas, older stems with a corky bark, younger stems glabrous; pseudostipules absent. 
Leaves with petioles 10-17 cm long; laminae triangulate, 8-15 cm long, 9-17 cm wide, 
apices acute, bases deeply cordate with sinuses 3-6 cm deep, glabrous. Flowers solitary on 
older stems, fetid; utricle pendent, narrowly ellipsoid, 9-11 cm long, with prominent 
veins, tube strongly bent, 2-3 cm long, bullate at base of limb, limb funnelform, pendent, 
15-20 cm long, with a long caudate appendage to 1 m long at its apex, veins prominent, 
purple-brown on veins within. Capsule cylindric, 10 cm long; seeds triangulate. 

Common in wet lowland forests below 1,000 m along both coasts. Plants have 
been cultivated in San Jose. The species is found from Mexico to Panama and 
throughout the West Indies. 



84 FIELDIANA: BOTANY 

The leaves of this species resemble those of A. veraguensis, but are not varie- 
gated. The flowers are among the largest of any neotropical plant and are ex- 
tremely fetid. The flowers are distinctive because of their size and because of the 
long apical appendage. 

Aristolochia littoralis Parodi, Anales Soc. Ci. Argent. 5:155. 1878. A. elegans 
Mast., Card. Chron. n.s. 34:301. t. 61. 1885. 

Lianas, older stem with a ridged bark, younger stems glabrous; pseudostipules rounded, 
clasping, 1.5-2.5 cm wide. Leaves glabrous, petioles 3-5 cm long; laminae triangulate, 
broader than long, 3-5 cm long, 4-6 cm wide, apex rounded, base cordate with a sinus 1 
cm deep, 5 primary nerves diverging from the base. Flowers solitary in leaf axils; utricle 
horizontal, oblong, 3.5 cm long, tube erect, 3 cm long, limb erect, peltate, 10 cm long. 
Capsule ellipsoid, 4-5 cm long, with a 6 mm long beak at its apex, valves 4-5 mm wide, 
horizontally striate, glabrous; seeds triangulate, slightly winged, 5-6 mm long, 4-5 mm 
wide. 

Native to South America, widely cultivated and escaped in Central America. 
The species flowers through most of the year and appears to set viable seed 
without insect pollinators. 

This species can be recognized by the triangulate leaves with pseudostipules 
and the peltate calyx limb. It is similar to A. gigantea in the structure of the 
flowers, but the flowers of A. gigantea are much larger. The fruit is distinctive due 
to the short beak at its apex. 

Aristolochia maxima Jacq., Enum. Syst. PI. 30. 1760. Howardia hoffmanni 
Klotzsch, Aristoloch. Berl. Herb. 621. 1859. A. maxima var. angustifolia Duchartre, 
in DC., Prodr. 15(1):457. 1864. Figure 12a. 

Woody lianas, older stems with a deeply ridged, corky bark, younger stems glabrescent 
with strigose hairs; pseudostipules absent. Leaves with petioles 1-2 cm long; laminae 
oblong to obovate, 7-15 cm long, 3-7 cm wide, apices acuminate, base truncate to slightly 
cordate, glabrous above, glabrescent beneath. Flowers in loosely branched rhipidia from 
the axils of leaves or from the base of the stem; ovary and pedicel 3 cm long, utricle 
horizontal, ovoid, 2-3 cm long, 1 cm wide, tube bent, funnelform, 2 cm long, limb erect, 
unilabiate, ovate, slightly hooded, 3-5 cm long, purple-brown. Capsule ovoid, 10-15 cm 
long, valves 2 cm wide, glabrous, held together after dehiscence by persistent, lattice-like 
septa; seed triangulate, winged, 1 cm long, 1.5 cm wide. 

In thickets and forests along both coasts below 1,000 m and rarely found in the 
Meseta Central, where it may have escaped from cultivation. The species is found 
throughout Central America and into Colombia and Venezuela. 

The species can be recognized by the oblong leaves which are glabrous when 
mature and which usually have truncate bases. The inflorescences are unusual in 
the genus, not only because of their branching pattern, but also because they may 
appear from the base of the plant. The species is closely related to A. bicolor of 
Colombia. Pittier reported that the young fruits are edible. 

Aristolochia odoratissima L., Sp. PI. 1362. 1763. A. pandurata Jacq., PI. Hort. 
Schoenbr. 4:49. t. 497. 1804. Figure 12b. 

Lianas, glabrous; pseudostipules rarely present, 1-2 cm wide, clasping. Leaves with 
petioles 4 cm long; laminae hastate-triangulate, 10-15 cm long, 8-10 cm wide, apices 
acute, bases cordate with a sinus 5-15 mm deep, with 3 major veins diverging from the 
base, glabrous. Flowers solitary in leaf axils; ovary and pedicel 6-7 cm long, utricle 
pendent, ovoid, 2-3 cm long, 1 cm wide, tube erect, 1-2 cm long, expanding slightly 



BURGER: FLORA COSTARICENSIS 85 

above, limb erect, unilabiate, peltate, 5-10 cm long, 3-5 cm wide, acuminate, dark purple- 
brown. Capsule narrowly cylindric, curved, valves 5 mm wide, glabrous; seeds rhombic 
to triangulate, without wings, 3 mm long, 2 mm wide. 

Widely distributed in wet forests throughout the neotropics. This species shows 
considerable geographic variation throughout its range and has been divided into 
many species in South America. In Costa Rica, plants have been collected near 
Pto. Limon where they seem to bloom throughout the year. 

Aristolochia odoratissima can generally be recognized by the hastate leaves, but in 
cases where the leaf shape is variable, the peltate and acuminate calyx limb is 
distinctive. It is related to the other Aristolochia species with peltate calyx limbs, 
including A. gigantea and A. littoralis. 

Aristolochia pilosa H.B.K., Nov. Gen. & Sp. 2:146. t. 113. 1817. Hawardia 
costaricensis Klotzsch, Aristoloch. Berl. Herb. 614. 1859. A. costaricensis (FQotzsch) 
Duchartre, in DC., Prodr. 15(1):450. 1864. A. costaricensis var. zamorensis Heiron., 
Bot. Jahrb. Syst. 20(Beibl. 49):5. 1895. Figure 12b. 

Lianas, all parts hirsute with brown, septate hairs, older stems with a deeply ridged, 
corky bark; pseudostipules absent. Leaves with petioles 3-7 cm long; laminae deltoid to 
ovate, 10-14 cm long, 8-10 cm wide, apices acute to rounded, margins ciliate, bases deeply 
cordate with sinuses 1-3 cm deep, glabrous above, hirsute on veins and white pubescent 
on areolae below. Flowers solitary in leaf axils; pedicel and ovary to 6 cm long, utricle 
horizontal, ovoid, 15-20 mm long, 10-12 mm wide, tube erect, 15-25 mm long, flaring 
slightly at mouth, limb erect, unilabiate, ligulate, 30-40 mm long, 15-25 mm wide, fim- 
briate to efimbriate, maculate. Capsules broadly ellipsoid, 5-7 cm long, valves 5 mm wide; 
seeds obovate, acute, without wings, 4 mm long, 3 mm wide. 

Plants of the wet lowlands on the Atlantic coast and the Osa Peninsula, from 
sea level to 850 m elevation. Probably blooming throughout the year. This species 
is distributed in wet forests from southern Mexico to the Amazon. 

Aristolochia pilosa is easily recognized by the conspicuous brown pubescence on 
most of the plant; it is variable in leaf shape and in the pigmentation and vestiture 
of the limb. Closer study of the species throughout its range may show it to be a 
group of closely related species. 

Aristolochia ringens Vahl, Symb. Bot. 3:93. 1794. 

Woody lianas, older stems with a ridged, corky bark, younger stems glaucous; pseudo- 
stipules rounded, clasping, 2-3 cm wide. Leaves with petioles 10-11 cm long, glaucous; 
laminae broadly reniform, 9-10 cm long, 13-15 cm wide, apex rounded, base deeply 
cordate with a sinus 3 cm deep, glaucous, with 7 primary veins diverging from the base. 
Flowers solitary in leaf axils; utricle pendent, turbinate, 5-6 cm long, tube bent, fun- 
nelform, 2-2.5 cm long, limb horizontal, bilabiate, the upper lobe spatulate, 8 cm long, the 
lower lobe lanceolate, 8-9 cm long, 2-3 cm wide. Capsules cylindric, 8 cm long, glaucous; 
seeds cordate, bilaterally winged, 12 mm long, 7 mm wide. 

Native to South America and widely cultivated in tropical and subtropical areas. 
In Costa Rica, plants have been grown in San Jose. It is the only bilabiate species 
known from Costa Rica and can be recognized by the broad reniform leaves and 
pseudostipules. The bilabiate aristolochias are a distinctive group within the ge- 
nus; their taxonomy has yet to be satisfactorily worked out. 

Aristolochia tonduzii Schmidt, Repert. Sp. Nov. 23:284. 1927. A. chapmaniana 
Standley, Contr. Arnold Arbor. 5:60. 1933. Figure 12a. 



86 FIELDIANA: BOTANY 

Woody lianas, older stems with a ridged, corky bark, younger stems glabrescent, stri- 
gose; pseudostipules absent. Leaves with petioles 1.5-3 cm long, strigose hairy; laminae 
ovate to oblong, 10-16 cm long, 4-8 cm wide, short acuminate, bases cordate with a sinus 
5-20 mm deep, glabrous above, densely strigose below. Flowers racemose on short axillary 
branches; ovary and pedicel 2-3 cm long, strigose, utricle horizontal, ellipsoid, 3-4 cm 
long, 1.5 cm wide, strigose, tube slightly bent, 1.5-3.3 cm long, strigose, flaring at mouth, 
limb erect, unilabiate, hooded or folded back, 4-6 cm long, 1-2 cm wide, maculate on inner 
surface, purple. Capsule ovoid, 10 cm long, valves 2 cm wide, held together after de- 
hiscence by persistent, lattice-like septa; seeds deltoid, cordate, 9 mm long, 15 mm wide, 
winged. 

This species is found in the wet lowland forests of the Atlantic coast. Flowering 
specimens have been collected from April through July, and fruiting specimens 
have been collected throughout the year. 

The cordate leaf base and strigose lower leaf surface distinguish A. tonduzii from 
A. maxima. The flowers of A. tonduzii are also larger, and the inflorescence is not 
as strongly branched. Aristolochia tonduzii is very closely related to A. schmidtiana, 
native to Amazonian Peru. 

Aristolochia translucida H. W. Pfeifer, Brittonia 28(3):349. 1976. Figure 12a. 

Woody lianas, older stems with a ridged, corky bark, young stems strigose; pseudo- 
stipules absent. Leaves with petioles 2 cm long; laminae oblong-ovate, 10 cm long, 5 cm 
wide, apices slightly acuminate, bases cordate with sinuses to 1 cm deep, with 3 major 
veins diverging from the base, glabrous above, strigose below. Flowers on short axillary 
branches; pedicel and ovary to 4 cm long, utricle horizontal, ovoid, 4 cm long, tube erect, 
funnelform, 2 cm long, limb unilabiate, hooded, translucent, 8-9 cm long, with elevated 
green maculae within. Fruit and seed unknown. 

Known only from the type collection, found growing at "La Selva" in the 
Caribbean lowlands near Puerto Viejo de Sarapiqui. Living material was collected 
without flowers and bloomed later in a northern greenhouse. Aristolochia trans- 
lucida is very similar to A. tonduzii, differing chiefly in the pigmentation of the 
flowers. More collections are needed to determine the variability and range of this 
species. 

Aristolochia trilobataL., Sp. PI. 960. 1753. Figure 12b. 

Woody lianas, young stems glabrous; pseudostipules rounded, clasping, 1-2.5 cm wide. 
Leaves with petioles 3 cm long; laminae 3-lobed, 7-9 cm long, 7-11 cm wide overall, the 
middle lobe 2.5-3.5 cm wide, apex acute to rounded, base truncate to slightly cordate, 
glabrous. Flowers solitary in leaf axils; ovary and pedicel to 6 cm long, utricle horizontal, 
ovoid, 3 cm long, with a 6-lobed, starlike hypanthium at its base, tube bent, erect, 2 cm 
long, limb unilabiate, triangulate, 1.5 cm wide, with a long, pendent, caudate apex, over 
15 cm long. Capsule ovoid, 5 cm long, valves 1.5-2 cm wide, glabrous, horizontally striate; 
seeds triangulate, bilaterally winged, 8 mm wide, 8 mm long. 

A circumcaribbean species found in lowland woods and thickets on the Atlantic 
coast. In Costa Rica, the species has been found near Limon. This is the only Costa 
Rican species which has lobed leaves. Its relationships are obscure, but it is most 
likely not closely related to the other Caribbean species with lobed leaves. 

Aristolochia veraguensis Duchartre, in DC., Prodr. 15(1):458. 1864. Figure 12b. 

Woody lianas, older stems with ridged, corky bark, to 10 cm diameter, younger stems 
glabrous; pseudostipules absent. Leaves with petioles 10-12 cm long; laminae variegated 
with white or yellow along veins, triangulate, 13-17 cm long, 13-15 cm wide, acuminate, 
deeply cordate, with a sinus 3-4 cm deep, glabrous. Flowers in dense, racemose clusters 



BURGER: FLORA COSTARICENSIS 87 

on older stems; ovary and pedicel 5-6 cm long; utricle pendent, ovoid, 1.5-2 cm long, 1 
cm wide, tube strongly bent, 1-1.5 cm long, limb funnelform, 2.5-3.5 cm long, acute, 
yellow with purple marking around the edge. Capsule cylindric, 14-20 cm long, valves 5 
mm wide, glabrous; seeds ovate, without wings, 3 mm long, 1 mm wide. 

Plants of the seasonally dry, lowland forest in Guanacaste, Puntarenas, and San 
Jose. Generally found below 1,000 m, but cultivated at higher elevations. Also 
known from Panama. The plants bloom from December to May. This species is 
very distinctive due to its variegated leaves. It is probably related to A. schippii of 
southern Mexico and Belize. 



HYDNORACEAE 

By Luis D. Gomez 

Parasitic plants on roots of the host, lacking chlorophyll, stems all subterranean, lacking 
leaves and roots, underground stem (rhizome) producing terete or 3- to 6-angled rhizoids 
with numerous, elongated and wartlike protuberances. Flowers solitary or groups borne 
on the rhizome and usually with only the distal part of the flower above the gound, large 
and bisexual, thick-fleshy, perianth of 1 whorl of 3 or 4 valvate sepals (tepals), the fleshy 
perianth united below to form a thick tube and opening distally, the perianth lobes either 
opening and diverging or remaining united at their tips and opening below to form a 
lantern-like structure; stamens borne on the perianth tube, anthers very large and numer- 
ous, united into a ringlike mass on the perianth tube or forming synandria of tightly 
united undulating thecae, the synandria as many as the perianth lobes in Hydnora; ovary 
inferior, of 3 fused carpels with a single locule containing many reduced ovules on placen- 
tas which are leaflike or lamellate, the placentation parietal or pendulous from the apex of 
the large locule, stigma broad and rounded or button-like, sessile. Fruit usually formed 
underground, a large thick-walled fleshy berry; seeds minute, with copious endosperm 
and a verrucose or pitted testa. 

An unusual family of parasites with very large fleshy flowers that remain par- 
tially underground and are pollinated by beetles. The Hydnoraceae are probably 
most closely related to the Rafflesiaceae and Balanophoraceae from which they 
differ in the bisexual flowers. Hydnora, with some six to 10 species in Africa and 
Madagascar, and Prosopanche, with two species in southern South America and a 
newly discovered species in Central America, are the only genera in the family. 



PROSOPANCHE DeBary 

REFERENCE: A. E. Cocucci, Estudios en el genero Prosopanche 1. Revision tax- 
ondmica. Kurtziana 2:53-74. 1965. 

Herbs, completely parasitic, vegetative stem hypogean, a thick mass of tissue from 
which arise the flowers which are its only aerial parts and long underground 4- to 5- (6-) 
angled rhizoids bearing numerous wartlike haustorial rudiments on the aristae. Leaves 
absent. Flowers bisexual, perianth fused at the base to form a tube of variable length, the 
upper edge of which subtends the stamens, tepals (perianth lobes) 3, thick and valvate; 
stamens 3, opposite the tepals, filaments much reduced, more or less deltoid and fused to 
the perianth tube on one side and with an anther at the distal end, anthers with 15-30 
thecae concrescent to form a conical or ovoid synandrium, dehiscing longitudinally, ex- 
trorse; an inner whorl of 3 bilobed interstaminal appendages alternating with the stamens; 
pistil 1 and united with the perianth tube, ovary inferior, 3 carpellate, the solitary locule 
completely filled by numerous lamellar parietal placentae the upper ends of which are 
united to form a button-like stigmatic surface which plugs the upper end of the locule, the 
ovules very reduced, embedded in the placental walls, absent near the stigmatic surface. 
Fruit a fleshy berry; seeds numerous, small, with pitted or verrucose episperm, dark 
brown or black at maturity, very hard. 




FIG. 13. Hydnoraceae. Prosopanche costaricensis; vertical scale at the right is 5 cm high. 



BURGER: FLORA COSTARICENSIS 89 

The genus is represented by P. americana (R. Br.) Baillon, which is parasitic on 
Leguminosae, mainly Prosopis, and P. bonacinae Spegazzini, which parasitizes 
several dicotyledonous families. Both species are found only in the drier parts 
of southern South America. Prosopanche costaricensis is the only species known 
from Central America and northern South America. 

Prosopanche costaricensis Gomez & Gomez-L., Phytologia 49:53. 1981. Fig- 
ure 13. 

Thick-fleshy herbs, found in clumps forming extensive colonies, parasitizing the roots 
of leguminous trees, rhizoids 4- or 5-angular, up to 15 mm thick, with numerous fragile 
haustorial rudiments. Flowers pedicellate, pedicels up to 150 mm long and 15 mm thick, 
the flowers averaging ca. 6 cm long and 2 cm thick when in bud, sepals 3, up to 90 mm 
long and 35-42 mm broad, externally flocose or with lenticel-like warts, inside smooth and 
white, valvate and remaining joined at the tip with the perianth segments forming a 
narrow lantern-like structure when open, perianth tube short (ca. 7 mm), the exterior 
diameter 25-32 mm; synandrium conical, 19-23 (29) mm long, 11-22 mm broad at the 
widest point, anthers white when young, dark brown or black when mature, thecae ca. 
25, dehiscing longitudinally; ovary ca. 50-60 mm long and 40-53 mm in external diameter 
when mature, also flocose-warty on the exterior, stigmatic surface 3-radiate with fewer 
than 12 pairs of lamellae lobes in frontal view. Seeds elliptic, 1-1.3 mm long, 0.6-0.7 mm 
wide, buff when young, black in maturity, testa rugulose-verrucose. 

This species is known only from cacao groves near Siquirres at about 50 m 
elevation at the edge of the Caribbean coastal plain in evergreen wet forest for- 
mations. The plants are parasitic on Inga orstediana and possibly Gliricidia saepium. 
Unlike its South American congeners, this plant inhabits a tropical rain forest 
region. Its closest affinity is with P. americana from which it differs in various 
aspects, particularly size of structures, seed ornamentation, and folds or lobes of 
the stigmatic surface. 

Editor's note: The collection of Prosopancheby Luis D. Gomez and Jorge Gomez - 
Laurito in June 1981 was an exciting find. This is not only a major geographical 
disjunction for the genus, but a new ecological niche. The brown warty flowers 
are easily mistaken for stems and roots on the forest floor. Surprisingly, an earlier 
collection from Costa Rica in Field Museum's fruit collection had been overlooked. 
This specimen was collected by W. R. Hatch on July 22, 1937, identified as Corynea 
crassa, and annotated as Prosopanche by Bertel Hansen in 1976. The only informa- 
tion this collection gives us is the word Reventazon, a river that descends the 
highlands and flows close by Siquirres. 



RAFFLESIACEAE 

By Luis D. Gomez 

REFERENCES: J. Kuijt, The Biology of Parasitic Flowering Plants, Univ. of Califor- 
nia Press, 1969; I. Vattimo, Contribuicao ao conhecimento da tribo Apodanthea R. 
Br. Parte 1, Conspecto das Especies. Rodriguezia 26, no. 38:37-62, 1971. 

Herbaceous parasites, without chlorophyll and without roots, stems short and fleshy or 
absent and flowers emerging directly from the tissues of the host, borne on the aerial 
woody stems or on the subterranean roots of the host. Leaves absent or represented by 
bracts or scales. Inflorescences racemose or the flowers borne directly from the stems or the 
roots of the host, neotropical genera with small (less than 1 cm) to medium size (up to 3.5 
cm in diameter) flowers (Rafflesia with the world's largest flower, ca. 1 m in diameter). 
Flowers radially symmetric, usually unisexual by abortion, rarely bisexual, perianth of 
4-10 imbricate (rarely valvate) or spreading segments or calyx lobes, united at the base to 



90 FIELDIANA: BOTANY 

form a short tube; stamens 5 to many, filaments united into a tube, column or synandrium, 
anthers sessile, arranged in 1-3 whorls around the apex of the column or staminal tube, 
1- or 2-thecous, opening by a longitudinal slit, pollen decussate, acolpate or 3- or 
4-colpate, without sculpturing, sometimes shed in tetrads; pistil superior to inferior, 
carpels 4, 6, or 8, ovary always unilocular, placentae 4, 6-20, or more, placentation parietal 
over the inner wall or toward the distal (apical) portion of the locule (in transection the 
locule appears circular, cruciform, or lamellate, with many parietal projections from the 
wall), ovules very numerous and sessile, stigma solitary, terminal on a slender style or 
stout column, capitate to discoidal, undivided or obscurely lobate. Fruit a fleshy berry with 
many seeds, opening irregularly, often concrescent in Bdallophyton; seeds very small, with 
a hard testa, often with few (8) cells rich in fatty substances. 

This unusual family of parasites, containing about nine genera and 50 species, 
is well represented in the Old World, with the best known examples being Cytinus 
and Rafflesia. In the neotropics, the family is represented by the genera Apodanthes 
and Pilostyles of the Apodantheae, and Bdallophyton and Mitrostemon of the Cy- 
tineae. Bdallophyton is the only genus endemic to the American tropics. The 
biology of the family, which is little known, has been summarized by Kuijt (1969). 
Plants of Apodanthes and Pilostyles are easily passed by since they appear only as 
small flowers on the thicker stems of the host, often only 5 mm high. 

la Parasites on aerial branches of Flacourtiaceae or Leguminosae; flowers solitary and 
terminal, subtended by a short peduncle covered by closely appressed bracts, borne 
directly on the stem of the host, often with scars of previous flowers evident on the 
bark of the host in the immediate vicinity; Apodantheae 2a 

Ib Parasites on the horizontal roots of Burseraceae or Fagaceae; flowers several to many 
in racemose inflorescences; stems evident and single or branched above the tissue of 

the host, stems with leathery foliose or triangular bracts; Cytineae 3a 

2a Locule of ovary cruciform in transection, placentation restricted to the swollen 
longitudinal ribs; flowers subtended by 4 alternate bracts, exserted, 4-segmented, 

subepigynous, not persisting; parasites on Flacourtiaceae Apodanthes 

2b Locule of ovary evenly circular in transection with placentation on the entire inner 
surface; flowers subtended by a wide base covered with imbricate bracts and 
concealed, parasites on Leguminosae Pilostyles 

3a Plants large, up to 25 cm tall, stems well developed and with many foliose bracts, 
these spirally arranged but often with the internodes so reduced as to produce bracts 
in pseudowhorls; flowers axillary on a racemose axis; ovary inferior; parasites on the 
roots of Burseraceae, Ficus and Cochlospermum Bdallophyton 

3b Plants smaller, usually 4-8 cm tall; stems not well developed and often concealed by 
many bracts; ovary superior or subinferior; parasitic on roots of Quercus and perhaps 
Carpinus (Betulaceae) Mitrastemon 

APODANTHES Poiteau 

Very small plants parasitic on the aerial stems of the host (almost always species of 
Flacourtiaceae, especially Casearia), aerial stems very short (less than 5 mm), leaves re- 
duced to small scales, only the cupular stem apex with whorled scale leaves and flower or 
fruit visible on the stem surface of the host. Flowers solitary from a woody cupule borne 
on the bark of the host (but flowers usually occurring in groups on the surface of the host), 
the cuplike stem apex with 3 whorls of imbricate scales, the 1st whorl with 2 free scale 
leaves, the 2nd with 4 scales united at the base, and the 3rd whorl with thinner rounded 
petal-like parts that are deciduous. Flowers unisexual, small, radially symmetrical, the 
male flowers with a central "stylar " column broadened and stigma-like at the top beneath 
which 2 series of many (ca. 20) subsessile stamens are attached; female flowers with a 
partly inferior ovary, 1-locular with many ovules, stylar column cylindrical and narrow 
above, stigma annular. Fruit baccate, subtended by the woody and scaly cup; seeds with 
hard testa. 

Seven species have been reported for the genus, ranging from Mexico to Gua- 
temala and Honduras, Panama, and northern South America. The Mexican plants 



BURGER: FLORA COSTARICENSIS 91 

may all be forms of A. caseariae Poit., while in South America all described 
material may be referable to either A. flacourtiae Karst. or A. tribracteata Rusby. 
Only one species is known from Costa Rica. 

Apodanthes caseariae Poit., Ann. Sci. Nat. (Paris) 3:422. 1824. A. panamensis 
Vatt., nom. nud. Figure 8. 

Small, leafless, parasitic herbs, emerging from bark of trunk and branches of Flacourtia- 
ceae. Flowers solitary. Pistillate flowers white, subtended by a receptacle, 1-2 mm high 
and 2-3 mm wide, formed in the outer bark of the host plant; basal bracts 2, suborbicular 
cucullate, leathery, 2-3 mm long; the upper bracts 4, apically rounded, almost twice as 
long as the basal ones, fused to the lower l /2 or Vs of the ovary and pressed against the 
ovary; calyx segments 4, obovate, imbricate, slightly inequilateral, borne in a shallow and 
small depression near the apex of the ovary, petals lacking; ovary ovoid, creamy white to 
dirty yellow to orange, 3-4 mm long; ovules numerous, parietal on folds or invaginations 
within the unilocular ovary, style thick, 2 mm long, dilated toward the apex, stigma finely 
papillate. Staminate flowers with a short stylar column which subtends 2 series of many 
stamens each, stamens almost sessile. Fruit a berry. 

Only known from the General Valley where it grows abundantly on Caesearia 
nitida. The most evident stage is the fruit, which becomes yellow or orangish in 
maturity and is eaten by Hnaupis birds. The flowers are visited by Trigona bees. 
These parasites have been reported as growing on Burseraceae and Meliaceae, in 
addition to Flacourtiaceae, in northern Central America. On Barro Colorado Is- 
land, Panama, these parasites have been seen only in August and September. 

BDALLOPHYTON Eichler 

This is the only genus of the Rafflesiaceae endemic to the neotropics. The plants 
are parasitic on the roots of Burseraceae, fleshy, with well-developed stems bear- 
ing lanceolate, acute, foliose bracts. Racemose inflorescence often producing con- 
crescent fruit. Two species have been described: B. americanum (A. Br.) Harms and 
B. oxylepis (B. L. Robinson) Harms, the latter of which differs from the former only 
in size of plants, which are slightly smaller, and in the reduced internodes of the 
infructescence which give it the appearance of a small pineapple. I consider the 
genus as monotypic. 

Bdallophyton americanum (A. Br.) Harms, in Engler & Prantl, Nat. Pflanzen- 
fam. ed. 2, 17b:281. 1935, based on Cytinus americanum R. Br., Trans. Linn. Soc. 
(London) 19:246. 1845. B. andreuxiiEichl, Bot. Zeitung. (Berlin) 39:715, t. 8B. 1872. 
B. cerantantherum Eichl. loc. cit. t. 8A, figs. 1-5. B. bambusarum (Liebm.) Harms, 
loc. cit. B. oxylepis (B. L. Robinson) Harms, loc. cit. Figure 14. 

With characters of the genus and those given in the generic key. 

Plants when alive a drab purplish olive green, the pigment dissolving in alcohol 
leaving all parts an opaque olive brown. Anthers sometimes relatively short and 
swollen or elongate and rather narrow (4-5 x as long as wide), horny projections 
straight in the immature flowers, curving outward just before dehiscence of the 
pollen. Pollination carried out by flies, apparently attracted only by the morbid 
color since no odor was perceived at the time of observation. The seed are carried 
around by rodents, the ripe fruit often showing the signs of sharp incisors. 

In Costa Rica, the plants are known only from one locality, the riparian forest 
along the lower course of Rio Calera, Parque Nacional Sta. Rosa, Guanacaste 
Province. Blooms in the months of October to early December. 




Bdallophyton 
americanum (A.Br.) Harms 



FIG. 14. Rafflesiaceae. A H, Bdallophyton americanum: A, habit of female plant showing 
concrescent fruits; B, polar view of 4-colpate pollen grain; C, discoid and lobate stigma; D, 
E, types of anthers and anther appendages; F, young shoot covered by imbricate bracts; G, 
female flower; H, diagrammatic view of transection of ovary. 



92 



BURGER: FLORA COSTARICENSIS 93 

PILOSTYLES Guillemin 

No representatives are so far recorded from Costa Rica, where they may occur 
on the Leguminosae of the tropical dry forest and at middle elevations of the 
northern mountain ranges of the country. Pilostyles thurberi A. Gray and P. globosa 
S. Watts are known from northern Central America. Pilostyles covillei Rose is 
described from Colombia. Like Apodanthes, these plants appear as small (5 mm) 
projections or pustules on the branches of the host. These projections give rise to 
the flowers which are often found in considerable number and give the parasitized 
branch a peculiar warty appearance. 

MITRASTEMON Makino 

Originally described under the name Mitrastemma, Makino later not only 
changed the generic name to its present form, but also transferred the genus from 
Rafflesiaceae to Mitrostemonaceae (in Bot. Mag. [Tokyo] 25:253, 1911), proposing 
also a separate order, Mitrostemonales. Unlike all other Rafflesiaceae, Mitrostemon 
has a subinferior to superior ovary. In other characters, it conforms with the 
family concept. One species, M. matudai Yamamoto, in Matuda (Bull. Torrey Bot. 
Club 74:133, 1947), is described and illustrated from Mexico and Guatemala, 
where it is a parasite on the roots of Quercus (Fagaceae). It might possibly occur 
in Costa Rica in the same habitats as Conopholis (Orobanchaceae), also parasitic on 
Quercus and ranging from the central portions of Mexico southward into northern 
South America. Mitrastemon matudai is the only species in the New World; the 
others are from Japan, Formosa, and southeastern Asia to Borneo. 

BALANOPHORACEAE 

By Luis D. Gomez 

REFERENCE: B. Hansen, Balanophoraceae, Flora Neotropica, Monograph 
23:1-80, 1980. 

Fleshy parasitic herbs devoid of chlorophyll, consisting of a cylindrical tuberous rhi- 
zome, long-creeping and then dichotomously branching or globose and massive, epigeous 
or hypogeus, the surfaces tomentose, squamose or naked, erect stems represented by the 
inflorescence peduncles or absent. Leaves reduced to scales present only on the peduncles 
of the spadices in imbricate spirals, transformed into hexagonal peltate scales which form 
a crustose covering of the spadix and fall before anthesis, or reduced to an annulus of 
leathery laciniate tissue. Inflorescences spadix-like, short to long-pedunculate, flowering 
portion globose to cylindrical or clavate. Flowers small and densely crowded on the surface 
of the spadix (capitulum) or intermixed with a dense mat of filiform paraphyses (hairs), 
unisexual or bisexual. Flowers small and radially symmetrical, unisexual, male flowers 
naked or with a 3- to 8-lobed valvate perianth, stamens generally equal in number to the 
perianth lobes and opposite them, filaments free or connate to form a tubular column, 
anthers free or united, usually 2-thecous, attached by their basal or dorsal surface, de- 
hiscing by a lateral longitudinal slit or by an anterior-apical fissurate pore. Female flowers 
lacking a perianth or the perianth reduced and adnate to the ovary, the free limb small, 
truncate, 2-lobed or tublar, ovary globose-ellipsoid to prismatic-obovoid, 1- to 3-locular, 
styles terminal, 1 or 2, filiform and elongate or short and subclavate, the stigmas simple 
and discoid to capitellate. Fruit small 1-seeded achenes or slightly fleshy and drupelike; 
seeds globose or compressed, testa thin or lacking, endosperm rich in fatty substances. 

A family of about 18 genera and twice as many species in urgent need of more 
intensive study. The relationship of the Balanophoraceae to other families of the 
Santalalean alliance is at best obscure and likely to prove unnatural. The alliance 




FIG. 15. Balanophoraceae. 14, Langsdorffia hypogaea: 1 & 2, inflorescences; 3, female 
flower; 4, male flower. 5- 9, Helosis cayennensis: 5, inflorescence; 6, peltate scale; 7, female 
flower, lateral view; 8, female flower, frontal view; 9, male flower. 10 14, Corynaea crassa: 
10, inflorescence; 11, male flower; 12, peltate scale; 13, paraphysate trichomes, uniseriate 
and crotaliform apices; 14, female flowers. 15 & 16, Corynaea sphaerica: 15, inflorescence; 16, 
peltate scale. Refer to Figure 16 also. 

94 




Fie. 16. Balanophoraceae: see Figure 15 for explanation. 



95 



96 FIELDIANA: BOTANY 

of this family may be with the Gunneraceae. These unusual parasitic plants are 
represented by three genera and perhaps four species in Costa Rica. 

la Peduncle of the inflorescence ensheathed by many stiff imbricate, lanceolate scales to 
3 cm long; rhizome elongate and branched, tomentose or velutinous; flowers not 
imbedded in a mat of filiform hairs; style 1 Langsdorffia 

Ib Peduncle of the inflorescence not covered by large imbricate scales, peduncle of 
variable length or the inflorescence almost sessile, always covered by a crustose layer 
of small peltate scales caducous at anthesis; flowers imbedded in a dense mat of 
filiform hairs (paraphyses); styles 2 2a 

2a Perianth of male flowers with 3-6 tepals, connate in the lower half to form a tube and 
with the lobes always reflexed; stamens free at the apex but connate in the lower half 
(the apex often held together as a unit by an adhesive mucus of the anthers), anthers 
with 3 pollen sacs, 1 anterior and 2 posterior Helosis 

2b Perianth of male flowers completely connate or the parts free in the upper half, the 
perianth lobes never reflexed but the margins always somewhat crenate; stamens 
connate in their entire length to form a tube, anthers with 2 lateral pollen sacs 

Corynaea 

CORYNAEA Hooker f. 

Herbaceous root parasites, rhizomes nodular, globose or very rarely elongate, varying 
in size from a few centimeters to 35-40 cm in diameter. Inflorescence usually monoecious 
and proterogynous, rarely dioecious, peduncle emerging from an annular basal volva 
which disintegrates quickly, glabrous except for occasional annular appendages, capitu- 
lum or spadix globose to cylindrical or claviform, before anthesis covered by a compact 
layer of 6-sided, peltate and umbonate scales under which a substrate of dense filiform 
paraphyses surround the flowers, distal peltate portion of the scales caducous at anthesis, 
the pedicels of the scales forming areolae with male flowers along edges and corners of the 
areolae and female flowers within the areolae around the pedicles of the hexagonal (but 
deciduous) scales. Male flowers with a tubular or subcampanulate perianth, entirely con- 
nate or free in the upper half, perianth lobes 3, always crenate and never reflexed; stamens 
3, exserted, filaments united into a column, anthers each with 2 lateral pollen sacs and 
forming a synandrium of 6 thecae; pollen 3- (5-) colpate, globose; some male flowers have 
a much-reduced pistillode. Female flowers without an apparent perianth or the perianth 
adnate to the pistil and reduced to a low epigynous collar with 2 inconspicuous segments; 
pistil 2-carpellate, ovary compressed, ovules 2, of which only 1 matures, styles 2, filiform 
and divergent, deciduous, stigmas slightly capitate. Fruit a 1-seeded achene with a hard 
epicarp and endocarp. 

A genus of yellowish brown to deep purple root parasites that have not been 
found below 1,000 m elevation. Hansen (1980) considers the genus to be com- 
posed of a single species, Corynea crassa, but Costa Rican material does appear to 
fall into two species. 

la Inflorescences pinkish in color, capitulum globose to ellipsoid or fusiform in 
shape C. crassa 

Ib Inflorescences golden yellowish brown in color, capitulum spherical to globose- 
elongate in shape C. sphaerica 

Corynaea crassa Hooker f., Trans. Linn. Soc. London 22:31. t. 13. 1856. Fig- 
ure 16. 

Inflorescence pink by the concentration of pigments in the glandular apices of the 
paraphysate trichomes which are 1.5-2.4 mm long, uni- or pluriseriate in which case the 
apex is crotaliform. Capitulum globose to elliptical or fusiform, up to 12 cm long and 4 cm 
in diameter, when immature covered by scales 3-4 mm in diameter, peltate on a pedicel 
3-4 mm long. Staminate flowers up to 5 mm long with a 3-lobed perianth, the lobes 3-3.5 
mm long and 1-1.4 mm wide, free in the upper % below which they form a tight tube of 
wide base; stamens 3, connate into a thick and long staminal column, anthers clavate and 
massive; pistillodes absent; pistillate flowers lacking a perianth, ovary obovoid, styles 2, 



BURGER: FLORA COSTARICENSIS 97 

divergent, filiform and tapering at the apex, stigmas subdiscoid-capitate. Fruit obovoid, 
large (up to 1.5 mm long). 

Parasitic on Quercus, Chusquea, and Vitis in the mixed forest at high elevations. 
The inflorescences are visited by many flies and occasionally by Bombus bees; the 
fruit are scattered by staphylinid beetles which forage on the paraphysate tri- 
chomes and also rear their larvae in the outer layers of the rhizome which is of a 
bright cadmium yellow when freshly cut and rapidly oxidizes into a rusty brown. 
Although the rhizomes are often exposed and seem fleshy enough to attract 
herbivores, they contain a bitter principle that probably detracts predation. 

Corynaea sphaerica Hooker f., loc. cit. t. 14. Figure 16. 

Rhizome tuberous, irregularly lobate, often velutinous and not more than 10 cm in 
diameter. Inflorescences bisexual, solitary or rarely 2 per rhizome, peduncles very short 
(less than 1 cm) or almost lacking, emerging from a persistent and thick annular volva, 
capitulum spherical or globose-elongate, up to 6 cm in diameter, when immature covered 
by spirally arranged rows of shortly peltate, wide scales, paraphysate trichomes abundant 
and dense, golden brown, up to 1.5 mm long, mostly uniseriate. Staminate flowers sub- 
immersed, with an obscure perianth of 3 connate lobes forming a campanulate in- 
fundibulum, stamens 3, fused into a tube 2.5 x as long as the width of the perigonial 
funnel, anthers and pollen like those of C. crassa; laterally compressed pistillodes some- 
times present. Pistillate flowers lacking a perianth, styles 2, rather short and parallel, 
stigma discoid, ovules 1. Fruit not seen. 

Parasitic on Chusquea and Euterpe (?) in the high elevations of Talamanca. It 
differs little from the preceding species, the most important character being the 
mixed distribution of male and female flowers and the golden brown color of the 
paraphysate trichomes. 

HELOSIS Richard 

Herbaceous root parasites, rhizomes fleshy, tuberous, emitting elongate hypogean 
branches from which emerge the erect peduncles (flowering stems or spadices). In- 
florescences borne on short or long peduncles that are annulate at the base or higher, 
capitulum broadly ovoid or globose, at first covered with hexagonal peltate valvate scales 
but these deciduous before anthesis, the inflorescences bisexual, the mixed male and 
female flowers in mammillate areoles and subimmersed in a dense mat of slender clavate 
paraphysate trichomes. Male flowers with a cylindrical perianth united near the base and 
with 3 ovate, concave, valvate and strongly reflexed distal lobes; stamens 3, filaments 
connate to form a tube up to 7 mm long, often with the filaments free in the upper third 
and directed outward or the anthers remain joined and the filaments become arcuate 
beneath them, anthers 3, basifixed and united into a 9-thecous synangium (each anther 
3-thecous and cordate); pollen 3-colpate, ca. 30 /im in diameter. Female flowers with 
superior perianth united to form a tube near the base and 2-labiate distally with 2 deltoid 
obtuse lobes; ovary ellipsoid, 1-locular, styles 2, long and filiform, stigmas capitate. Fruit 
a small 1-seeded achene with hard pericarp and oily endosperm. 

Helosis includes only a single species, ranging from central Mexico through 
Central America and northern South America to Brazil and Bolivia. The plants 
range from sea level to 2,000 m elevation. 

Helosis cayennensis(Sw.) Sprengel, Syst. Veg. 3:765. 1826. Cynomorium cayen- 
nense Swartz, Nov. Gen. & Sp. 12. 1788. H. guyanensis Richard, Mem. Mus. Hist. 
Nat. 8:416, t. 20. 1822, nom. illeg. superfl. Caldasia cayennensis (Sw.) Mutis ex 
Steudel, Nom. ed. 2. 1:255. 1840. H. mexicana Liebmann, Forh. Skand. Naturf. 4, 
Mote 1844:181. 1847. H. cayennensis var. mexicana (Liebm.) B. Hansen, Svensk Bot. 
Tidskr. 72:188. 1978. Figures 15 and 16. 



98 FIELDIANA: BOTANY 

Plants whitish, light brown or ferrugineous, glabrous, arising from a coralline tuberous 
rhizome. Peduncles solitary or clustered, erect, up to 10 cm long and 1 cm thick, with or 
without an annular process near the base or higher, capitulum ovoid or ellipsoidal-globose 
up to 6 cm long and 3 cm in diameter, before anthesis covered by peltate (stalk 2 mm) 
umbonate scales 3 mm in diameter which correspond to mammilate areoles densely cov- 
ered by paraphysate claviform trichomes 1-2.5 mm long and densely pigmented. Perianth 
of staminate flowers a tube 2-3 mm long, 3-lobed, lobes ovate, 1-3 mm long, 0.5-1 mm 
wide; stamens 3, filaments connate, free at the apex when mature, anthers forming a 
synandrium 0.5-1 mm long, 0.5-1 mm in diameter. Pistillate flowers with a 2-Iabiate, 
fimbriate perianth, styles 2, 1.5 mm long, caducous, stigmas capitate. Fruit up to 2.25 mm 
long, ca. 0.5 mm broad. 

Plants parasitic on the roots of a number of woody plants, found from the 
lowlands to elevations up to 1,600 m, in Costa Rica. The plant resembles a fungus, 
and like the species of Corynaea, it is called "hongo" by the local residents. Two 
other species have been described under Helosis, but I cannot find consistent 
differences to warrant their segregation. In Standley's Flora of Costa Rica (1937) 
and in Woodson & Schery's Flora of Panama (1960), this plant is cited or described 
as H. mexicana Liebmann, the apparent confusion stemming from the peculiar 
behavior of the staminal tube which may be of connate filaments throughout its 
entire length, have the apices free or the anthers held together, while the imme- 
diate portion of the filaments are free and curved outward like a lantern (cf. 
Howard, Rhodora 61:79-81, 1959; Hansen, 1980). 

Helosis cayennensis has been divided into two varieties by Bertel Hansen (1980); 
both of these varieties have been found in Costa Rica. The following key dis- 
tinguishes them: 

la Peduncle with an involucre of 2-6 minute triangular scales near the base, the length 
of the peduncle divided by the length of the involucre (or annulus) to the base giving 
a value greater than 2.8; plants usually found below 1,000 m var. cayennensis 

Ib Peduncle with the involucre represented by a more or less oblique, slightly swollen, 
ringlike mark (annulus) near the middle, the length of the peduncle giving a value of 
less than 2.8 when divided by the length of the ringlike involucre to the base; plants 
usually found above 1,000 m var. mexicana 

LANGSDORFFIA Martius, in Eschwege 

Herbaceous fleshy root parasites with creeping or upright rhizome-like tubers dichoto- 
mously branched and tomentose-velutinous or glabrescent, stems (peduncles) bearing the 
inflorescences unbranched, surrounded at the base by a short toothed sheath (volva), 
covered by many imbricate stiff scales (scaly leaves). Leaves represented by the imbricate 
scales, ovate near the base and becoming progressively more lanceolate toward the apex 
surrounding the inflorescence. Inflorescences unisexual (rarely bisexual and monoecious) 
the flowering capitulum globose, to ellipsoid, capitate-clavate or ovoid, the male in- 
florescence taller than the female, the female often discoid or hemispherical. Male flowers 
pedicellate, with a perianth of 3 (rarely 2) concave, valvate tepals; stamens as many as there 
are tepals and opposite them, exserted, with short filaments connate into a column; 
anthers united into a synandrium with 6 pollen sacs, 4 at the base and 2 near the apex. 
Female flowers tightly congested, linear-prismatic, the perianth reduced to an obscurely 
2- to 4-lobed collar, pistil solitary and the locule not apparent, ovule 1 and fused to the 
ovary wall, style 1 and caducous, stigma papillate. Fruit a small 1-seeded achene or 
drupaceous with a fleshy epicarp and hard endocarp. 

A genus of yellowish or reddish root parasites resembling Thonningia, with one 
neotropical species ranging from southern Mexico to Brazil and Bolivia and a 
second, recently described, species from New Guinea. The stiff scaly covering of 
the flowering stems (inflorescences) readily distinguishes this genus. 



BURGER: FLORA COSTARICENSIS 99 

Langsdorffia hypogaea Martius, in Eschwege, J. Brasil. 2:179, t. 5. 1818. Fig- 
ure 15. 

Herbaceous and thick-stemmed root parasites with the characters of the genus. Male 
inflorescences with peduncles (stems) up to 7 cm long, entirely covered by scales, the larger 
scales lanceolate, 4 cm long and 1 cm broad, the basal ones smaller and sparsely ciliate and 
stiff, capitulum ellipsoidal, 7-8 cm long and up to 4 cm in diameter; staminate flowers on 
long (10 mm) pedicels, petals 3, connate at the base to form a tube, free above with reflexed 
lobes, glabrous, petals 3-4 mm long and 1.5-2 mm wide; stamens 3 with filaments entirely 
connate, anthers subglobose-cordate dehiscent by slits, pollen 4-colpate, globose, smooth. 
Pistillate inflorescence of smaller dimensions, the capitulum or head discoidal to sub- 
globose; female flowers with a short 2-lobed perianth 1.0-1.5 mm long and up to 0.5 mm 
in diameter, closely appressed to the style, the style up to 1.5 mm long, spirally twisted 
and laterally compressed, stigma subcapitate and minutely papillate. 

Parasitic on the roots of Ficus, Sapium, and Palmae in elevations above 1,500 m 
in the Cordillera Volcanica Central. The pistillate flowers form a mat of coalescent 
structures due to a resinous or waxy secretion which burns easily. 

POLYGONACEAE 

Herbs, shrubs, trees, or climbers, terrestrial or semiaquatic, bisexual or unisexual, gla- 
brous or puberulent, stems often with thickened nodes, internodes solid or hollow; stip- 
ules forming a sheathing tube (the ocrea or ochrea) that surrounds the stem, usually 
deciduous and leaving a scar encircling the stem (absent in Eriogonum of N. America). 
Leaves alternate and simple, in a spiral or distichous (absent in Muehlenbeckia platyclada), 
petiolate, laminae entire or pinnately lobed, usually pinnately veined. Inflorescences usu- 
ally an unbranched axis with alternating fascicles of flowers, less often with the flowers 
solitary, axillary, or cymose, the axes racemose or spikelike but occasionally borne on a 
leafless terminal twig and forming a compound paniculate arrangement, the flower fas- 
cicles usually subtended by a sheathing (ocreate) bract and the flowers subtended by thin 
translucent (ocreolate) bracteoles. Flowers usually radially symmetrical, bisexual or func- 
tionally unisexual, usually small, often borne on articulated pedicels, the perianth 3- to 
6-parted, in 1 or 2 whorls of 2, 3, or 5 parts, the inner and outer whorls often not clearly 
differentiated (tepals), the outer parts often persistent or enlarging in fruit; stamens (4) 
6-9, often in 2 whorls, filaments free or united at the base, borne on the base of the 
perianth or on the edge of a short hypanthium, anthers 2- or 4-thecous, often versatile and 
introrse; gynoecium of a solitary pistil with 1 locule and 1 basal orthotropous ovule, ovary 
superior and often 3-angled or lenticular, stigmas and carpels usually 3 (2-4). Fruit an 
achene with usually smooth hard surface, often tightly enclosed within the persistent and 
expanded outer perianth, the perianth sometimes forming wings, hooks, or tubercles as 
aids to dispersal; seed with a straight or curved embryo and mealy endosperm. 

A cosmopolitan family of about 40 genera and 800 species, well represented in 
the north temperate zone as well as the tropics and subtropics. The unusual 
sh'pular tube leaving an encircling scar around the often thickened node is a 
distinctive vegetative feature. Some Commelinaceae have similar leaf bases, but 
the leaves are never pinnately veined. The small (less than 1 cm) flowers, often 
borne on spikelike axes and subtended by thin scarious bracteoles, are also dis- 
tinctive. 

KEY TO THE GENERA OF POLYGONACEAE IN COSTA RICA 

la Climbing plants with tendrils borne at the ends of inflorescences or leafless shrubs 
with flat ribbonlike stems; usually found in gardens but occasionally escaped; the 
stipules reduced to a thickened line around the stem at the nodes 2a 

Ib Plants with leaves and without tendrils; the stipules usually forming a tube (ocrea) 
around the shoot apex, the ocrea persisting or deciduous and leaving a line around 
the stem. . 3a 



100 FIELDIANA: BOTANY 

2a Climbing plants with tendrils terminating the inflorescence; laminae cordate to 
triangular; plants often growing along fences in gardens, with bright pink (or 

white) sepals Antigonon 

2b Shrubs or very short many-branched trees, the distal green stems 1-3 mm thick 

and 1-2 cm broad with transverse lines Muehlenbeckia platyclada 

3a Plants herbaceous, stems not woody except sometimes near the base; flowers bisex- 
ual or less often unisexual 4a 

3b Plants with woody stems, trees, shrubs, or climbers; flowers unisexual or bi- 
sexual 6a 

4a Leaves with palmate venation; plants grown in gardens for food Rheum 

4b Venation pinnate; plants not cultivated for food 5a 

5a Perianth of 2 whorls of 3 parts, the inner 3 expanding in fruit and often with 
grainlike tubercles, the flowers often in verticels, filaments shorter than 
the anthers, stigmas fimbriate; leaves often dimorphic with broader basal 

leaves Rumex 

5b Perianth of 3-5 subequal parts, not expanding in fruit; filaments longer than the 
anthers, stigmas capitate; leaves rarely dimorphic (in ours); plants often found 

in wet sites Polygonum 

6a Achenes enclosed but not greatly exceeded by a dry or succulent perianth, the 
fruiting perianth without long distal wings, perianth usually 5-parted; trees, shrubs 

or climbers, without spines 7a 

6b Achenes enclosed and exceeded by a thin, dry, expanded perianth, the fruiting 
perianth with 3 conspicuous long thin distal wings; perianth 6- (rarely 3-) parted; 

trees or spine-bearing shrubs 9a 

7a Trees or large erect shrubs, often with thick stems, not growing wild above 
1,000 m in our area; inflorescences with thick (more than 3 mm) axes, flowers 

functionally unisexual and with a cuplike hypanthium Coccoloba 

7b Climbers and scrambling shrubs, growing wild or cultivated above 1,000 m 

elevation in our area; inflorescences with slender axes 8a 

8a Native plants found only above 1,400 m elevation; laminae cordulate and with 
more than 6 pairs of secondary veins; flowers unisexual, pedicels articulated 

beneath the flowers and lacking wings Muehlenbeckia 

8b Cultivated or escaped plants only known from around 1,100 m elevation; 
laminae cordate and with 3-5 pairs of secondary veins; flowers bisexual, pedi- 
cels with wings and articulated at the base Bilderdykia 

9a Fruiting perianth with the wings expanded from the back of the midrib and de- 
current on the pedicel; stems with solid internodes and short terminal spines and 
with small (3 mm) rounded short shoots from which leaves and flowers arise in 
fascicles; laminae less than 8 cm long and with fewer than 7 pairs of secondary veins 

Podopterus 

9b Fruiting perianth with the wings expanded distally and long-spatulate or 
oblanceolate; stems lacking spines, flowers in racemose or paniculate arrange- 
ments lOa 

lOa Internodes hollow and often with biting ants; leaves with more than 12 pairs of major 
secondary veins, 15-35 cm long; achene with 3 sharp ridges and 3 flat or concave 

faces, tightly enclosed within the fruiting perianth Triplaris 

lOb Internodes solid; leaves with fewer than 12 pairs of major secondary veins, 3-18 cm 
long; schene with 3 deep longitudinal sulci separating 3 rounded sides, loosely 
enclosed within the fruiting perianth Ruprechtia 

ANTIGONON Endlicher 

Climbing plants with tendrils borne on the ends of the inflorescences, bisexual, glabrous 
or more often puberulent, stems thin and herbaceous or slightly woody; stipules reduced 
and leaving a small (often obscure) thickened line around the stem. Leaves alternate in a 
spiral, petiolate, laminae cordate to deltoid or sagitate, acute to acuminate at the apex and 
often with the midvein extended to form a small (1-3 mm) mucronate tip. Inflorescences 
basically a single racemose axis with alternating clusters of flowers, solitary and axillary 
but occasionally terminal and forming paniculate arrangements by the failure of sub- 
tending leaves to develop, the flower-fascicles subtended by small floral bracts. Flowers 
bisexual, borne on articulated pedicels, perianth of 5 parts with the outer 3 usually broader 



BURGER: FLORA COSTARICENSIS 101 

than the inner 2, persisting and enlarging in fruit, stamens 8, free from the perianth, the 
filaments united to form a short tube, anthers 4-Iocular, ovary trigonous, styles 3 with 3 
peltate stigmas. Fruit enclosed within the persisting and enlarged perianth parts, achene 
strongly 3-ridged in the upper (distal) part, surface smooth. 

A genus of several poorly defined species, apparently native to Mexico and 
northern Central America. The plants are now widely cultivated because of the 
attractive inflorescences with long-persisting rose red or white perianth parts. The 
climbing habit, tendril-bearing inflorescences, and colorful stiff dry persisting 
perianth parts immediately distinguish this genus. These plants resemble the 
genus Bougainvillea in a superficial way. Collections of Antigonon from Costa Rica 
are few; the species have become naturalized only rarely. 

la Laminae not decurrent on the petiole and not forming conspicuous lateral wings on 

the upper part of the petiole; plants recorded from Costa Rica 2a 

Ib Laminae decurrent on the petiole and forming conspicuous lateral wings (or margins) 
on the petiole; floral bracts small (less than 4 mm) and inconspicuous; plants not 

included in the descriptions 3a 

2a Petioles short (less than 10 mm) and often obscured by the broad basal lobes 
of the lamina; floral bracts ca. 5 mm long and ovate; outer perianth parts be- 
coming 3.5 cm long in fruit, with rounded apex and overlapping cordate basal 

lobes A. guatemalense 

2b Petioles to 30 mm long and usually easily seen within the broad sinus of the 
lamina lobes (in pressed material); floral bracts 1-3 mm long, lanceolate; outer 
perianth parts rarely more than 1.5 cm long in fruit, acute at the apex and 

subcordate at the base A. leptopus 

3a Perianth reddish in color, outer perianth parts becoming 2 cm long in fruit, broadly 

rounded in outline; staminal tube very short (?M- cinarascens Mart. & Gal. 

3b Perianth whitish or yellowish, outer perianth parts becoming 1.3 cm long in fruit, 
acute at the apex; staminal tube half the length of the pistil . . (?)A. flavescens Wats. 

Antigonon guatemalense Meisn., in DC., Prodr. 14:184. 1856. Polygonum gran- 
diflorum Bertol., Fl. Guat. 412. 1840, not P. grandiflorum Willd., 1799. A. grandi- 
florum (Bertol.) Robinson, Proc. Amer. Acad. 44:513. 1909. A. macrocarpum Britton 
& Small, Sci. Surv. Porto Rico and Virgin Isl. 5:266. 1924. Figure 19. 

Climbers, usually in thickets and shrubs to 2 m high, leafy internodes 1.5-15 cm long, 
0.5-4 mm thick, densely short (0.3 mm) brownish puberulent. Leaves with petioles 2-10 
mm long, densely brownish tomentulose, often obscured by the lamina base; laminae 6-15 
cm long, 3.5-10 cm broad, broadly ovate to ovate-triangular, tapering gradually to an acute 
apex, cordate to cordulate at the base with the basal sinus usually narrow and obscuring 
petiole and node, margin entire, laminae drying thin chartaceous, densely soft puberulent 
below, venation pinnate with 3-6 pairs of major secondary veins. Inflorescences solitary 
and axillary with a single axis but occasionally terminal with several axes in a paniculate 
arrangement, to ca. 25 cm long, the alternating flower fascicles 5-25 mm distant on the 
rachis, subtended by conspicuous broadly ovate floral bracts, ca. 5 mm long and with a 
cuspidate apex, puberulent, pedicels 8-25 mm long, densely and minutely (0.2 mm) 
puberulent; flowers with the perianth parts ca. 4 mm long before anthesis, staminal tube 
relatively short and thick. Fruit enclosed within the persisting perianth, the outer perianth 
parts becoming 3.5 cm long, cordate at the base with the basal lobes usually overlapping, 
rounded to emarginate at the apex, venation prominent on the surface of the perianth, fruit 
narrowly ovoid, with 3 sharply defined longitudinal ridges on the upper half, ca. 10 x 5 
mm, lustrous and pale brown or greenish. 

Plants cultivated in gardens or found as escapes in secondary growth between 
(0) 200 and 1,500 m altitude. The species appears to be native in Guatemala and 
is now widely distributed in the tropics and subtropics. 

Antigonon guatemalense is recognized by the usually cordate leaf bases obscuring 
the short petioles and nodes, the generally dense brownish puberulence, the 



meisnenanum 




hydropiperoids 





10 cm hispidum 




acuminatum 





FIG. 17. Polygonaceae: species of Polygonum in Costa Rica. 



102 



RUM EX 
obtusifolius 




5 mm 



'nepalensis 

FIG. 18. Polygonaceae: species of Rumex in Costa Rica. 



103 



MUEHILENBECKIA 
tamnifolia 



ANTIGONON 
leptopus 



BILDERDYKIA 
aubertii 




FIG. 19. Polygonaceae: wild and ornamental climbing plants in the genera Antigonon, 
Bilderdykia, and Muehlenbeckia. 



104 



PODOPTERUS 
mexicanus 



RUPRECHTIA 
costata 




1 cm 



FIG. 20. Polygonaceae: trees and shrubs with winged fruits; species of Podopterus, Ru- 
prechtia, and Triplaris. 



105 



106 FIELDIANA: BOTANY 

broad little floral bracts at the base of the flower clusters, and the large pink 
perianth parts enclosing the fruit. The common names Bellisima, Colacion, Confite, 
Confitillo, and San Andres have been used for these plants in Central America. 

Antigonon leptopus Hook. & Am., Bot. Beechey Voy. 308, pi. 69. 1839-1840. 
A. cordatum Mart. & Gal., Bull. Acad. Roy. Sci. Bruxelles 10, pt. 1:14. 1843. Fig- 
ure 19. 

Climbers to over 10 m high but more often only 1 or 2 m high, leafy internodes 1-10 cm 
long, 1-4 mm thick, sparsely to densely puberulent. Leaves with petioles 4-30 mm long, 
0.5-1.5 mm thick; laminae 3-15 cm long, 2-10 cm broad, broadly ovate to sagitate, acu- 
minate to acute at the apex, subcordate to cordate at the base with a usually broad open 
sinus, margin entire or undulate, laminae drying thin chartaceous, sparsely to densely 
puberulent beneath with small (0.1-0.3 mm) brownish hairs, venation pinnate with 5-9 
pairs of major secondary veins. Inflorescences solitary and axillary with a single axis but 
also terminal and forming a compound panicle, to 25 cm long, flower clusters 5-20 mm 
distant on the rachis, floral bracts 1-3 mm long, lanceolate, sparsely puberulent, the 
pedicels 2-10 mm long; flowers ca. 4 mm long when buds open for anthesis, staminal tube 
ca. half the length of the pistil. Fruit enclosed within the persistent and enlarged perianth 
parts, the perianth parts to 15 mm long and 12 mm broad (rarely? to 25 x 12 mm), acute 
at the apex, subcordate at the base, very sparsely or very minutely (0.5 mm) puberulent, 
the venation raised on the abaxial surfaces when dry, body of the fruit ovoid, 3-angled 
with 3 longitudinal ridges near the apex, ca. 9 x 5 mm, lustrous and pale brown. 

Plants cultivated in gardens or occasionally escaped and climbing over low 
shrubs (especially along river banks), rarely found above 1,000 m altitude in 
Central America. The species is probably native to Mexico, but is now widely 
planted in warmer parts of the world. 

Antigonon leptopus is recognized by the broadly cordate or subcordate leaf bases, 
the inconspicuous floral bracts, the persisting perianth parts which are pink to 
rose or deep rose red, and the usual association with gardens. This species is 
called Bellisima, Confite, Flor de San Miguel, and San Miguel in Central America. 

BILDERDYKIA Dumort 

Woody or herbaceous, climbing or decumbent, slender stemmed; ocreate stipules 
present and persisting. Leaves alternate in a spiral, petiolate, laminae deltate to cordate or 
sagittate, glabrous or very minutely puberulent. Inflorescences solitary, axillary or termi- 
nal, flowers usually in small fascicles subtended by ocreate bracts, on spikelike or raceme- 
like axes that may be part of a paniculate arrangement (as in ours); flowers bisexual and 
regular, borne on articulate pedicels, perianth composed of 5 parts united near the base, 
the 3 outer perianth parts with longitudinal keels or wings on the midrib abaxially, 
stamens 6-9 and borne on the edge of a shallow cup, filaments of 2 lengths, ovary superior 
and free of the cup, styles absent, stigma capitate. Fruit a 3-angled nut, usually included 
in and not exceeding the persisting perianth, perianth becoming pink and the nut black. 

A small genus once included in Polygonum and native to Europe and Asia. 

Bilderdykia aubertii (Henry) Moldenke, Revista Sudamer. Bot. 6:29. 1939. 
Polygonum aubertii Louis Henry, Rev. Hort. 1907:82-83. 1907. P. baldschuanicum 
auct., non Regel. Figure 19. 

Woody climbers to 5 m high, the distal stems thin and pendent, bisexual, leafy inter- 
nodes 1-10 cm long, ca. 2 mm thick, glabrous, drying pale in color and with longitudinal 
ridges; ocreate stipules 2-3 mm long, thick, brown, the basal parts persisting. Leaves 
alternate, petioles 1-4 cm long, slender and glabrous, with 2 adaxial ridges forming a 
narrow sulcus; laminae 2-9 cm long, 1.5-5 cm broad, ovate to ovate-triangular in outline, 
tapering to an acuminate apex, cordate to subcordate at the base and decurrent on the 



BURGER: FLORA COSTARICENSIS 107 

petiole, margin entire, drying chartaceous, smooth and essentially glabrous on both sur- 
faces, venation pinnate or subpalmate with 3-5 pairs of major secondary veins. In- 
florescences solitary and axillary or terminal, to 15 cm long, paniculate with alternate 
racemose branches, flower-bearing rachis slender and with minutely papillate-puberulent 
longitudinal ridges, pedicels ca. 2 mm long, articulate near the base and with 3 wings 
enlarged distally; flowers bisexual, ca. 1.5 mm long (open) and 3 mm broad, the 3 outer 
perianth parts with conspicuous wings that are continuous with the wings of the pedicel, 
inner perianth parts smaller, stamens mostly 8 or 9, ovary strongly 3-angled and with large 
papillate stigmas. Fruit not seen. 

A trailing climber in shrubs about 2.5 m high and apparently growing wild in 
the city of San Jose at 1,100 m elevation; flowering in September. We have no 
other record of this genus and species in Central America. 

Bilderdykia aubertii is recognized by the glabrous cordate leaves on thin hanging 
stems, the small white flowers in open paniculate inflorescences, and the thin 
wings on the back of the outer perianth parts decurrent on the pedicel. This 
species is planted in Europe as an ornamental climber; it is native to western China 
and Tibet. This species also is referred to as Fallopia aubertii (Louis Henry) J. Holub 
or as Polygonum aubertii Louis Henry. English names are "Silver Lace Vine" and 
"China Fleece Vine." 

COCCOLOBA Patrick Browne ex Linnaeus 

REFERENCES: R. A. Howard, Studies in the genus Coccoloba, VII. A synopsis and 
key to the species in Mexico and Central America. J. Arnold Arbor. 40:176-220. 
1959. R. A. Howard, in R. E. Woodson, Jr., and R. W. Schery, Coccoloba in the 
Flora of Panama. Ann. Missouri Bot. Card. 47:340-353. 1960. 

Shrubs or trees, rarely scramblers or lianas (none in Central America), usually unisexual, 
leafy stems usually thick and terete, glabrous to puberulent or with glandular excretions 
resembling small trichomes, often longitudinally striate, the pith solid or the internodes 
sometimes hollow, the nodes usually thicker than the internodes; stipules united to form 
a tube (the ocrea) around the stem, the ocrea initially enclosing and protecting the shoot 
apex and then splitting as the apex develops, the distal sheathing part of the stipule 
usually thin and deciduous, the basal part usually thicker and often persisting, occa- 
sionally extending below the petiole base, glabrous to puberulent, leaving a scar around 
the stem. Leaves alternate and simple, persistent or deciduous, often varying considerably 
in size on the same plant, the leaves of juveniles and adventitious shoots often much larger 
than leaves on distal branches; petiole borne at the base or above the base of the differ- 
entiated stipule enclosing the node, usually canaliculate or sulcate (grooved) above (ad- 
axially); laminae entire or undulate, venation usually pinnate, often quite stiff, glabrous to 
puberulent or with glandular excretions. Inflorescences terminal or terminal on short 
lateral shoots, unisexual, basically a single unbranched axis but occasionally branched near 
the base or the axes in a paniculate arrangement on a short leafless terminal shoot, the 
peduncle (flowerless base) usually very short and not differentiated from the rachis, the 
rachis usually minutely puberulent and with longitudinal ridges, flowers borne singly or 
in fascicles on thickened areas of the rachis, subtended usually by a stiff bract and 1 or 
more thin ocreolate bracteoles, pedicels shorter or longer than the subtending bracteoles, 
the female flowers usually solitary, the male flowers usually several together in a fascicle. 
Flowers functionally unisexual but with organs of both sexes, perianth and staminal bases 
forming a small or distinct cuplike hypanthium, perianth 5- (6-, 7-) parted, imbricate in 
bud, becoming reflexed in male flowers but usually remaining appressed to the ovary and 
succulent in fruit in the female, stamens usually 8, functional stamens of the male flowers 
exserted, filaments free above, staminodes of the female flower included, and pistillode of 
the male flowers remaining included, the functional pistil of female flowers with 3 exserted 
styles and expanded stigmatic surfaces, ovary trigonous. Fruit included within the ex- 
panded and usually fleshy or succulent hypanthium and/or perianth lobes (essentially a 
drupe with loosely enclosed achene); the achene usually trigonous, surface smooth and 
brownish in color, outer wall hard, seed with ruminate endosperm. 



COCCOLOBA 
caracasana 




FIG. 21. Polygonaceae: two species of Coccoloba with larger rounded leaves. 



108 



COCCOLOBA A acapulcensis 



COCCOLpBA 
tuerckheimii 




FIG. 22. Polygonaceae: species of Coccoloba with petioles arising above the base of the 
associated tubular stipule. 



109 



COCCOLOBA 
acuminata 




FIG. 23. Polygonaceae: common species of Coccoloba with petioles arising near the base 
of the associated stipules. 



110 



COCCOLOBA 
belizensis 




FIG. 24. Polygonaceae: rarely collected species of Coccoloba with petioles arising at or 
above the base of the associated stipules. 



Ill 



112 FIELDIANA: BOTANY 

A genus of the American tropics with more than 100 species, best represented 
in the West Indies and South America. Our members of the genus can be recog- 
nized by the shrub or tree habit, ocreate stipules at first enclosing the shoot apex 
and leaving a scar around the stems, the usually thick twigs often with thickened 
nodes, usually stiff entire leaves with pinnate venation, small flowers subtended 
by thin tubular bracteoles and borne on a relatively thick and often unbranched 
axis, and a trigonous achene tightly enclosed within a thin succulent perianth. 
Papaturrois a commonly used name for members of the genus in Central America. 
None of our species grow above 1,000 m elevation in Costa Rica. 

la Petiole arising well above the base of the tubular stipule (ocrea), the diameter of the 
petiole scar smaller than the distance from the base of the petiole scar to the differ- 
entiated stipular base 2a 

Ib Petiole arising at about the same level as the clearly differentiated base of the sheath- 
ing stipule 6a 

2a Inflorescence paniculate; distal internodes covered by the stiff persisting 
ocreae, leafy stems 6-15 mm thick, laminae usually over 18 cm long and 10 cm 

broad; wet evergreen forests below 1,000 m elevation C. tuerckheimii 

2b Inflorescences usually solitary spikes or racemes; distal internodes usually 
visible between the ocreae, leafy stems to 7 mm thick, laminae generally not 

over 18 cm long; found mostly on the Pacific slope in Costa Rica 3a 

3a Flowering and fruiting pedicels 2-15 mm long, the flowers clearly separate 
in early stages on a rachis only 1-2 mm thick; achenes not coronate at the 

apex 4a 

3b Flowering and fruiting pedicels 1-4 mm long, the flowers densely congested 
in early stages, flowering rachis 2-3 mm thick; achenes coronate at the 

apex 5a 

4a Laminae ovate to suborbicular, to 10 cm long, cordate to subcordate or 
peltate near the base, petioles 12-45 mm long, 0.6-1.5 mm thick; rare 
plants of the Pacific slope between ca. 500 and 1,000 m elevation 

C. acapulcensis 

4b Laminae oblong to obovate, to 20 cm long, sometimes rounded at the base 
but never cordate to peltate, petioles to ca. 25 mm long and 1-3 mm thick 
(dry), plants of dry deciduous lowland areas in Guanacaste 

C. guanacastensis 

5a Petioles 8-25 (60) mm long; fruit sessile or short (1-3 mm) pedicellate; laminae 
elliptic to obovate, abruptly narrowed at both apex and base (but never rhom- 
bic); evergreen or partly deciduous formations of the Pacific slope. C. obavata 
5b Petioles 8-11 mm long; fruit clearly pedicellate; laminae usually conspicuously 
and gradually narrowed to both apex and base, often rhombic in outline; low 
elevations around the Caribbean but not recorded from between Honduras and 

Central Panama and not included in the descriptions C. coronata 

6a Inflorescence paniculate; terminal shoot at first enclosed in a spatulate or obovoid 
and bluntly rounded densely tomentulose ocreate stipule 1-4 cm long; laminae 
becoming 50 cm long and 25 cm broad on relatively short petioles; Caribbean 

lowlands C. belizensis 

6b Inflorescence a spike or raceme and these not in a paniculate arrangement; shoot 

apex of terminal shoots not enclosed in a large spatulate covering 7a 

7a Laminae almost as broad as long to broader than long, stiffly subcoriaceous to 

coriaceous, rounded to emarginate at the apex 8a 

7b Laminae usually distinctly narrower than long, usually acute to acuminate at the 

apex (or rounded in C. venosa) 9a 

8a Plants usually found near the sea shore but also planted for ornament; laminae 
usually broader than long and with 3-6 pairs of major secondary veins, 

coriaceous C. uvifera 

8b Plants of seasonally very dry areas along the Pacific slope below 500 m; laminae 
usually narrower than long and with 6-12 pairs of major secondary veins 

C. caracasana 
9a Bracts and bracteoles subtending the flowers very small (less than 1 mm) and incon- 



BURGER: FLORA COSTARICENSIS 113 

spicuous, the flowers usually separate along the rachis and clearly pedicellate with 
the inflorescence racemose, both male and female flowers often solitary; plants 

glabrous and rare in collections lOa 

9b Bracts and bracteoles subtending the flowers usually more than 1 mm long, con- 
spicuous and often obscuring the pedicels and the inflorescence appearing spicate 
(at least in early stages), puberulent, male flowers usually borne in groups of 

2-5 lla 

lOa Flowers 2-4 mm long; laminae with the tertiary venation obscure above 
when dry; trees of evergreen forests of the Pacific slope between sea level and 

1,000 m C. padiformis 

lOb Flowers 4-6 mm long; laminae with the tertiary venation forming a fine (xiO) 
reticulum on the upper surface (dry); plants of the deciduous lowlands of 
Guanacaste C. guanacastensis 

lla Laminae usually broadest above the middle, drying very stiffly chartaceous or sub- 
coriaceous; inflorescences not usually exceeding 14 cm in length, the flowers usually 
closely crowded and the rachis not clearly visible; plants of the deciduous and partly 
deciduous formations of the Pacific slope below 300 m elevation C. venosa 

lib Laminae usually broadest at the middle (occasionally obovate in C. lehmanii), drying 
chartaceous to stiffly chartaceous; inflorescences usually exceeding 14 cm with the 
flowers or flower fascicles separate along the rachis 12a 

12a Inflorescence racemose, pedicels usually clearly visible, bracts usually perpendicular 
to the rachis; laminae broadly elliptic to elliptic-obovate, acute to short acuminate; 
wet evergreen formations, 0-1,000 m C. lehmannii 

I2b Inflorescence spicate, pedicels usually hidden within the bracts, the bracts at an acute 
angle to the rachis; laminae narrowly elliptic and acuminate; evergreen or partly 
deciduous areas, below 300 m elevation C. acuminata 

Coccoloba acapulcensis Standley, Proc. Biol. Soc. Wash. 33:66-67. 1920. C. 
browniana Standl., Trop. Woods 10:4. 1927. C. wercklei Standl., Publ. Field Co- 
lumbian Mus., Bot. Ser. 4:304. 1929. C. cardiophylla Standl., Publ. Field Columbian 
Mus., Bot. Ser. 8:8. 1930. Figure 22. 

Shrubs or small trees 2-6 (8) m tall, glabrous throughout, leafy internodes 0.5-8 cm 
long, 1-4 mm thick, smooth and glabrous, becoming striate, becoming dark brown and 
lenticellate; stipules 1-2 cm long, originating 7-12 mm below the base of the petiole, 
glabrous or very minutely puberulent, drying reddish brown and usually persisting, the 
apex of the ocrea often resembling a ligulate development on the leaf base. Leaves alternate 
in a spiral or distichous, often peltate in younger plants, petioles 10-45 mm long, 0.6-1.5 
mm thick, smooth and drying brown, becoming articulate near the middle of the ocrea; 
laminae 4-14 cm long, 2.5-11 cm broad, ovate to suborbicular, rounded distally and very 
short-acuminate at the apex, rounded at the subcordate or peltate or truncate base, occa- 
sionally peltate with the petiole as much as 15 mm distant from the base of the laminae, 
margin entire or somewhat crenate-undulate, the edge becoming revolute, the laminae 
drying chartaceous pale brown or grayish, smooth and glabrous above and below, with 
4-8 pairs of major secondary veins. Inflorescences terminal on axillary short shoots, 3-8 
cm long, solitary and racemose, rachis 0.5-2 mm thick, glabrous, both male and female 
flowers solitary, bracts and bracteoles ca. 1 mm long; male flowers with filaments 2-3 mm 
long, anthers ca. 0.5 mm long; female flowers not seen. Fruit retained within the succulent 
perianth, about 2 cm long and 1.2 cm in diameter, globose or obovoid, perianth lobes only 
ca. 3 mm long at the apex of the fruit, fruiting pedicels 5-10 (15) mm long; achene difficult 
to remove from the perianth when dry, ca. 16 x 10 mm, rounded-trigonous. 

Plants of the seasonally dry Pacific slope and known in Costa Rica from only 
two collections: Werckles.n. from near El Coyolar, and Brenes 21872 from San Pedro 
de San Ramon, both from the province of Alajuela between 100 and 1,000 m on 
the Pacific slope. The species ranges from Guerrero and Yucatan in Mexico along 
the Pacific slope of Central America to central Costa Rica. 

Coccoloba acapulcensis is recognized by its relatively small rounded (sometimes 
peltate) leaves on slender petioles articulated well above the stipular base, the lack 



114 FIELDIANA: BOTANY 

of pubescence on nearly all parts, small inflorescences with conspicuous pedicels, 
and relatively large fruit. The species is very poorly known in Costa Rica, and it 
may be restricted to the partly deciduous (tropical moist and premontane moist) 
forest formations between 100 and 1,000 m on the Pacific slope. 

Coccoloba acuminataH.B.K., Nov. Gen. 2:176. 1817. Figure 23. 

Shrubs or small slender trees 1.5-5 (8) m tall, leafy internodes (0.2) 1-6 cm long, 1-3 (6) 
mm thick, glabrous or brownish puberulent, usually drying dark and smooth, sparsely 
lenticellate; stipules 3-15 mm long, the free distal portion of the tube truncate at the apex 
and caducous, densely brownish hirsutulous or (less often) very sparsely hirsutulous or 
with reddish brown glandular excretions. Leaves alternate and distichous, petioles 6-15 
mm long, 0.8-1.5 mm thick, slightly sulcate above, hirsutulous or glabrous, arising from 
the base of the ocrea; laminae 716 (24) cm long, 2-6 (8) cm broad, narrowly elliptic to 
elliptic-oblong or lanceolate, gradually tapering to the long-acuminate apex, acute to 
obtuse at the base, margin entire, the laminae drying thin-chartaceous to stiff-chartaceous 
and often dark in color above, smooth and glabrous above or minutely papillate- 
puberulent on the midvein, glabrous below except for tufts of hairs in the axils of the major 
veins, often with small punctate glandular excrescences sparsely distributed over the 
lower surface, with 7-15 pairs of major secondary veins, the tertiary veins very thin and 
inconspicuous, the midvein raised above. Inflorescences terminal and solitary, 15-30 (45) 
cm long, the flower fascicles clearly separate along the slender (0.7-1.5 mm) rachis, 
peduncle 2-5 cm long, the rachis minutely (0.2-1 mm) puberulent to short-hirsute, thick- 
ened below each flower cluster, pedicels shorter than the subtending bracteoles; male 
flowers usually solitary, ca. 3 mm long, fertile pistil ca. 1 mm long with 2 or 3 styles. Fruit 
included within the succulent perianth, becoming globose and 6-8 mm in diameter (dry), 
the perianth parts united only near the base (at first) but the basal areas expanding and the 
lobes finally covering Vz-Va of the fruit, translucent white at maturity and drying black, 
pedicels 1-2 mm long and not exceeding the bracteoles; achene ca. 5-6 mm long and 4 mm 
broad, trigonous with rounded edges, broadest near the base, dark brown to tan, smooth 
and lustrous. 

Plants of the lowland wet evergreen and partly deciduous forest formations 
below 300 m elevation; flowering and fruiting throughout the year, but collected 
most often in March and April. The species ranges from the Caribbean side of 
Guatemala, Honduras, and Nicaragua through Costa Rica and Panama to Peru 
and Brazil. 

Coccoloba acuminata is recognized by the thin narrow acuminate leaves, long- 
pendulous spicate inflorescences with the flower groups clearly separate along the 
slender rachis, short pedicels hidden within the bracteoles (ocreolae) and the wet 
lowland habitat. The leaves resemble those of many tropical wet forest species, but 
differ strikingly from other members of the genus in our area. The species is 
known only from three collections in Costa Rica: Allen 5226 from near the Rio 
Terraba, Puntarenas, Holm & Iltis 710 from the Rio Frio, and Standley 40189 from 
near the Rio Grande de Tarcoles, both in the province of Alajuela. Recently, new 
records for Costa Rica have come from Santa Cruz, Guanacaste, near the Nic- 
araguan border. Despite the paucity of Costa Rican collections, the species ap- 
pears to be common in southeastern Nicaragua and central Panama. 

Coccoloba belizensis Standley, Trop. Woods 16:38. 1928. C. hirsuta Standley, 
Publ. Field Columbian Mus., Bot. Ser. 4:303. 1929. Figure 24. 

Small to large trees, reaching 30 m in height, leafy internodes 1-8 (12) cm long, 4-8 (14) 
mm thick, at first densely short (0.3 mm) hirsute but quickly becoming glabrous, (densely 
puberulent to tomentulose on adventitous and young shoots), the hairs yellowish brown 
to dark brown; stipules 1-4 cm long, forming an unusual spatulate cap over the shoot 



BURGER: FLORA COSTA RICENSIS 115 

apex, rounded at the apex and arising above the petiole base, densely brownish hir- 
sutulous, splitting irregularly as the shoot expands. Leaves alternate, variable in size and 
often quite large, petioles 1.5-5 cm long, 3-8 mm thick, densely brownish hirsutulous 
with hairs 0.1-1 mm long, longitudinally striate and somewhat canaliculate above; lami- 
nae 16-30 (50) cm long, 8-14 (30) cm broad, oblong to broadly ovate, tapering to the 
usually bluntly obtuse apex, obtuse to rounded at the base and often cordulate at the 
petiole in larger leaves, margin entire and revolute on drying, subcoriaceous, quickly 
becoming glabrous and grayish-lustrous above, remaining minutely puberulent on the 
veins beneath (but remaining densely brownish hirsutulous in some), with 6-10 pairs of 
major secondary veins, the midvein raised within a depression above, tertiary veins 
obscure above but prominent and often subparallel beneath. Inflorescences to 20 cm long, 
paniculate terminal arrangements of nearly equal racemose or spicate branches, flower 
fascicles separate on the minutely puberulent and deeply ridged rachis, pedicels not 
exceeding the bracteoles; male flowers several per fascicle, filaments ca. 1 mm long, 
anthers ca. 0.5 mm long; female flowers solitary. Fruit enclosed within the succulent 
f>erianth ca. 7 mm long and 6 mm in diameter, the perianth lobes free for about half the 
length of the fruit; achene ca. 5-6 mm long and 5 mm thick, ovoid to subglobose, weakly 
trigonous with rounded edges, surfaces lustrous brown. 

Trees of the Caribbean lowlands below 800 m elevation; flowering and fruiting 
from May to October. The species, as presently known, ranges from Belize to 
eastern Nicaragua. 

Coccoloba belizensis is easily recognized because of the unusual size and form of 
the ocreate stipules covering the shoot apices, the large leaves with relatively few 
secondary veins, and the paniculate inflorescences. The leaves often dry with a 
very smooth, but not lustrous, upper surface that is pale gray or pale yellowish 
brown. While not yet recorded from Costa Rica or Panama, the species has been 
collected in eastern Nicaragua (Shank 93) and is said to be common along the Rio 
Grande in the Department of Zelaya (Molina 2509). 

Coccoloba standleyana Allen, based on sterile material and described in The Rain 
Forests of Golfo Dulce (1956, pp. 177 & 409), probably belongs under C. belizensis, 
according to Howard (1959, p. 215). 

Coccoloba caracasana Meisner, in DC., Prodr. 14:157. 1856. Figure 21. 

Small- to medium-sized trees 2-12 (20) m tall, often with multiple trunks and rounded 
crown, leafy internodes 0.5-6 (9) cm long, 2-6 (10) mm thick, minutely puberulent to 
hispidulous with brownish hairs 0.1-0.8 mm long, becoming glabrous and pale gray; 
stipules 10-20 (40) mm long, the distal tube membranaceous and deciduous, minutely 
(0.1-0.3 mm) puberulent or with resinous excretions. Leaves alternate and usually di- 
stichous, petioles 8-25 (40) mm long, 1.5-4 mm thick, inserted just above the thickened 
node on the base of the ocrea, densely reddish brown puberulent or glabrescent; laminae 
(5) 8-20 (37) cm long, (4) 6-15 (28) cm broad, broadly ovate to broadly oblong or 
suborbicular, rounded and often emarginate at the apex, rounded and truncate to subcor- 
date at the base, margin entire and slightly undulate, the edge flat, the laminae drying 
stiffly chartaceous to subcoriaceous and dark brown or pale gray, smooth and glabrous 
above, minutely (0.1-0.5 mm) puberulent on the veins beneath or glabrous but with hairs 
in the axils of the major veins, with 6-10 (12) pairs of major secondary veins, the major and 
minor veins slightly raised on the upper surface when dry. Inflorescences terminal on 
short axillary shoots, 15-25 cm long, the rachis densely and minutely puberulent, 1.5-3 
mm thick; male flowers 3-4 per fascicle and the fascicles often crowded on the rachis (but 
the rachis usually visible), filaments ca. 2 mm long, anthers ca. 0.4 mm long; female flowers 
solitary in the fascicles and the fascicles separate along the rachis, perianth lobes 1-1.5 mm 
long on a hypanthium 0.5 mm long. Fruit enclosed in the white semisucculent perianth, 
4-6 mm long and ca. 5 mm in diameter when dry, the perianth lobes free almost to the 
base (covering % of the achene), the fruit borne on short (2-3 mm) pedicels; achenes 3-5 
mm long, strongly 3-angled with 3 distinct longitudinal ridges, broadest near the base, 
becoming dark brown, smooth and lustrous. 



116 FIELDIANA: BOTANY 

Trees of the seasonally very dry and deciduous forest formations along the 
Pacific slope of Costa Rica below 500 m elevation; flowering and fruiting from 
January to June. The species ranges from Chiapas, Mexico, and the Pacific slope 
of Central America to Panama, Colombia, and Venezuela. 

Coccoloba caracasana is recognized by the usually broad stiff leaves rounded at 
both apex and base, the short pedicels that hardly exceed the bracteoles and make 
the inflorescences appear to be spikes, the enlarged perianth lobes covering half 
the fruit, and the seasonally dry forest habitat. There is no evidence of an associ- 
ation with biting or stinging ants in our area. The inflorescences become pen- 
dulous with the fleshy edible white drupes, and it is from these that the common 
name Papaturro Blanco is derived. 

Coccoloba guanacastensis W. Burger, Phytologia 49:387. 1981. Figure 24. 

Trees to over 10 m tall, leafy inter nodes 0-3 cm long, 1.5-4 mm thick, glabrous, be- 
coming pale grayish and longitudinally striate; stipules (ocreae) 4-8 mm long, the distal 
tube 2-3 mm broad, thin and caducous, the basal portion persisting with the leaves and 
extending below the petiole base, glabrous. Leaves often borne close together near the 
ends of branches, deciduous, petioles 1.5-3 cm long, 1-2.5 mm thick, terete except near 
the lamina base, glabrous, becoming articulated 2-6 mm above the differentiated base of 
the ocrea; laminae (7) 9-23 cm long, 3-11 cm broad, broadly oblong to elliptic-oblong, 
obtuse to rounded at the apex and often very short acuminate, obtuse to rounded at the 
base, margin entire or drying undulate, the laminae drying very stiffly chartaceous and 
often pale grayish green in color (the newly expanded leaves drying thin and brown), 
smooth and glabrous on both surfaces, with 6-10 pairs of major secondary veins, the 
tertiary venation forming a very fine (0.2-0.6 mm) reticulum that is slightly raised on both 
surfaces and paler in color than the enclosed leaf areas on the lower surface (dry). In- 
florescences terminal or axillary, 1 or 2 from the same node, 10-15 cm long at anthesis, 
clearly racemose with the flowers usually solitary (rarely 2 together) and separate along the 
thin (0.5-1 mm) glabrous rachis, the rachis longitudinally ridged but not thickened at the 
pedicel bases, the subtending bracts and bracteoles less than 0.5 mm long, deciduous, 
pedicels 2-4 mm long; the flowers appearing to be bisexual, 4-6 mm long and 7 mm broad, 
the hypanthium narrowed for 0.5-2 mm above the articulation with the pedicel, hypan- 
thium 2-3 mm long with perianth lobes 2-3 mm long, filaments 2-3 mm long, anthers ca. 
0.8 mm long, stigmas 3, exserted and thickened. Fruit (immature?) partly enclosed in the 
perianth base (hypanthium), perianth lobes about half the length of the developing fruit, 
free and separate from the upper half of the fruit; achene apparently somewhat turbinate 
with an expanded and rounded apical half. 

Trees of the riparian forest in the seasonally very dry deciduous forest for- 
mations below 200 m elevation on the Pacific slope of northern Costa Rica; flow- 
ering from February to April. This species is known only from the province of 
Guana caste in Costa Rica. 

Coccoloba guanacastensis is recognized by the lack of pubescence, petioles articu- 
late well above the base of the stipular sheath, minute and deciduous floral bracts, 
and relatively large and long-pedicellate flowers. This species appears to be closely 
related to C. padiformis and is known only from deciduous forest formations near 
Canas, Bagaces, and Santa Rosa National Park. 

Coccoloba lehmannii Lindau, Bot. Jahrb. Syst. 49:6-7. 1895. C. changuinolana 
Standl., Publ. Field Columbian Mus., Bot. Ser. 8, pt. 1:9. 1930. C. williamsii 
Standl., Field Mus. Nat. Hist., Bot. Ser. 11, pt. 5:148. 1936. C. allenii Lundell, 
Contr. Univ. Michigan Herb. 6:8. 1941. Figure 23. 

Small trees to 10 (rarely? 20) m tall, leafy internodes 2-7 cm long, 1.8-4.5 mm thick, 
glabrous or with resin-like excretions resembling short hairs, becoming longitudinally 



BURGER: FLORA COSTARICENSIS 117 

striate (dry) and grayish or pale brown; stipules 5-15 (20) mm long, 1-3 mm thick, with 
or without glandular excretions, arising above the petiole base, caducous. Leaves alternate 
and distichous, petioles 8-15 (25) mm long, 1-3 mm thick, narrowly sulcate above (cana- 
liculate) above near the lamina base, minutely puberulent, resinous punctate or glabrous; 
laminae (6) 9-18 (26) cm long, (3) 4.5-9 (16) cm broad, broadly elliptic to elliptic-obovate, 
abruptly narrowed to the acute or short acuminate apex (occasionally rounded distally), 
obtuse or slightly rounded at the often unequal base, margin entire or slightly undulate, 
drying stiffly chartaceous, smooth and glabrous above and below or minutely puberulent 
on the midvein, with longer crooked hairs in the axils of major veins, with 5-10 pairs of 
major secondary veins, the tertiary venation often subparallel and slightly raised on both 
surfaces when dry. Inflorescences terminal and solitary, often on short axillary shoots, 
8-22 (35) cm long, peduncle 1-3 cm long, flower fascicles separate along the rachis or 
closely approximate but not congested, rachis 0.5-2 (3) mm thick, prominently ridged, 
very minutely papillate puberulent and brownish, pedicels equaling the bracteoles in 
length; male flowers in groups of 2-4, filaments to 2 mm long, pistil 1.5 mm long with 3 
styles. Fruit enclosed in the succulent perianth, 5-7 mm long and 4-5 mm in diameter, the 
perianth lobes free almost to the base of the fruit, borne on pedicels to 6 mm long that 
clearly exceed the bracteoles; achenes 5-7 mm long, ca. 5 mm in diameter, broadest near 
the base and ovate in outline, strongly trigonous, pale brown to light tan and lustrous. 

Trees of the wet evergreen forests of both the Caribbean and Pacific slopes 
between sea level and 1,000 m elevation; flowering collections have been made 
from March to June, and fruiting collections have been made between March and 
August in our area. The species ranges from central Costa Rica through Panama 
and Colombia to Venezuela and Peru. 

Coccoloba lehmannii is recognized by its usually broad thin leaves, the stipule 
usually completely caducous to leave only a small scar on the stem, the relatively 
long racemes of close or separate (but not congested) flowers, and the evergreen 
lowland habitat. The species is known in Costa Rica from only three collections: 
Dunlap 467 from along the Rio Sixaola valley, Lent 2464 along the Rio Parismini, 
both in the province of Limon, and A. Jimenez 2444 from near Golfito in southern 
Puntarenas province. An interesting collection with more narrowly obovate leaves 
has recently been made by Luis Poveda (1105) near Bijagualito-Tarcoles on the 
Pacific slope. This collection lacks flowers and fruit, so it is not possible to say 
whether it is an unusual representative of this species or perhaps a new and 
closely related species. 

Coccoloba obovata H.B.K., Nov. Gen. 2:176. 1817. C. riparia Lundell, Contr. 
Univ. Michigan Herb. 6:11. 1951. Figure 22. 

Shrubs or trees 3-8 (15) m tall, leafy internodes 0.5-5 cm long, 2-4 (7) mm thick, 
glabrous and terete, becoming grayish or reddish brown and often splitting longitudinally 
when dry; stipules 5-10 (20) mm long, 3-6 mm broad, appressed and with the thin distal 
tube deciduous or persisting, longitudinally striate, originating 2-8 mm below the petiole 
and the lower portion usually persisting. Leaves alternate and distichous, petiole 0.8-4 (6) 
cm long, 1-3 mm thick, minutely puberulent or glabrous, striate when dry, becoming 
articulate 2-8 mm above the differentiated (stipular) ocrea; laminae (5) 12-22 (24) cm long, 
(3) 5-14 cm broad, elliptic to elliptic-obovate or occasionally ovate, tapering or occasionally 
rounded to the short acuminate apex, narrowed or rounded to the obtuse, truncate, or 
cordulate base, often unequal at the petiole with 1 side or lobe larger than the other, entire, 
drying chartaceous to stiffly chartaceous and usually dark above, smooth and glabrous 
above and below but sometimes minutely puberulent in the axils of the major veins, with 
4-9 pairs of major secondary veins, tertiary veins slightly raised on both surfaces (dry), 
often with minute (0.1 mm) circular peltate scales on the lower surface. Inflorescences 
solitary and terminal, on tips of branches or short axillary shoots, 8-25 cm long, spicate 
or racemose and the flower fascicles densely crowded, subtended by bracteoles ca. 1.5 mm 
long, rachis ca. 2 mm thick, and minutely papillate-puberulent to short pilose; male 



118 FIELDIANA: BOTANY 

flowers borne on pedicels not exceeding the bracteoles, filaments ca. 1 mm long, anthers 
0.3-0.4 mm long; female flowers on inflorescences to 17 cm long, pedicels becoming 
exserted only in fruit, ovary with 3 styles. Fruit included within the appressed succulent 
perianth, globose, or somewhat turbinate, 8-10 mm in diameter, developing thick longi- 
tudinal ribs, the free perianth lobes covering only the distal 2-3 mm of the fruit, borne on 
pedicels to 3 mm long and 0.5 mm thick (dry); achene difficult to separate from the 
enclosing perianth when dry, trigonous, tan to dark brown. 

Plants of the seasonally dry partly deciduous or evergreen forest formations 
between sea level and 1,000 m elevation; flowering and fruiting throughout the 
year, but collected most often between June and September. The species ranges 
from the Pacific side of central Costa Rica to Panama and Colombia. 

Coccoloba obovata is recognized by the petiole arising well above the base of the 
stipular tissue surrounding the node, the thin often obovate and glabrous leaves, 
densely flowered spikes becoming racemose in fruit, and seasonally dry but 
mostly evergreen habitats of the Pacific slope between the Bay of Nicoya and 
Chiriqui, Panama. 

Coccoloba padiformis Meisner, in DC., Prodr. 14:166. 1856. Figure 24. 

Trees to 30 m tall, leafy internodes 2-6 cm long, 2-4 (6) mm thick, terete and glabrous, 
becoming pale gray; stipules 6-18 mm long, 2-5 mm broad, acute at the apex, glabrous, 
persisting or deciduous, becoming stiff basally, arising at about the level of the petiole 
attachment. Leaves alternate and usually distichous, apparently deciduous and produced 
in flushes, petioles 8-18 (26) mm long, 1-3 mm thick, glabrous, with a shallow adaxial 
groove above (canaliculate), becoming articulate at or 1-2 mm above the base of the ocreate 
stipule; laminae 6-18 (26) cm long, 2-8 (12) cm broad, elliptic-ovate to elliptic-oblong, 
tapering or rounded to the short-acuminate apex (sometimes acute or obtuse), rounded to 
obtuse at the base, the margin entire or slightly undulated, the edge becoming slightly 
revolute, the laminae drying stiffly chartaceous to subcoriaceous and often grayish or 
pinkish in color, smooth and glabrous on both surfaces, with 4-9 (11) pairs of major 
secondary veins, arcuate ascending near the margin, tertiary venation usually flat on both 
surfaces and obscure above. Inflorescences axillary (or terminal on very short axillary 
shoots?), 1-3 together, 3-8 cm long, racemose, both the male and female flowers sub- 
tended by very short (1 mm) bracts and bracteoles (ocreolae), rachis ca. 1 mm thick with 
minute (0.2 mm) reddish hairs; male flowers 1 or 2 per fascicle, pedicels 2-3 mm long, the 
hypanthium narrowed at the base (above the pedicel articulation), filaments ca. 2 mm 
long, anthers ca. 0.5 mm long; female flowers solitary, pistil ca. 2 mm long. Fruit included 
within the succulent perianth, ca. 9 mm long and 7 mm thick, free perianth lobes covering 
only 2-3 mm at the top of the fruit, fruiting pedicels 3-5 mm long; achene ca. 8 mm long 
and 6 mm in diameter, ovoid to subglobose, weakly trigonous, lustrous pale brown. 

A poorly known species of evergreen or partly deciduous forests of the Pacific 
below 1,000 m elevation in southern Costa Rica; collected with flowers and fruit 
between February and April. The species ranges from the Golfo Dulce area of 
Costa Rica to Colombia and Venezuela. 

Coccoloba padiformis is recognized by the glabrous vegetative parts, stiff leaves 
drying pale tan and with obscure tertiary venation (above), short racemose in- 
florescences that are usually axillary, and distinctive pedicels subtended by very 
small bracts and bracteoles. Included here are two collections of Paul Allen (5944 
and 5964) that are said to form small stands at the heads of valleys on the summits 
of high (300-800 m) hills above Palmar Norte. These trees were listed under the 
name C. roseiflora Standl. & L. Wms. (never validly published) in Allen's book, 
The Rain Forests of Golfo Dulce, 1956, p. 177. 

Coccoloba tuerckheimii Donnell Smith, Bot. Gaz. 37:213. 1904. Figure 22. 



BURGER: FLORA COSTARICENSIS 119 

Trees 7-15 (20) m tall, leafy internodes 0.5-4 on long, 6-15 mm thick, often obscured 
by the persisting stipules, becoming striate and glabrous; stipules 2-5 cm long, over- 
lapping near the apex of the stem, to 25 mm broad, stiffly chartaceous and striate, thicker 
near the base and arising below the petiole attachment, persisting with the leaves. Leaves 
usually clustered near the ends of branchlets, petioles 5-45 mm long, 1.5-8 mm thick, 
sulcate or canaliculate above, very minutely brownish puberulent or glabrescent, be- 
coming striate or deeply ridged, borne and becoming articulate on the ocrea 6-15 (25) mm 
above the stipular base; laminae (13) 20-45 (70) cm long, (7) 10-25 (40) cm broad, obovate 
to broadly elliptic-oblong, abruptly narrowed at the short-acuminate apex, gradually 
narrowed at the acute or rounded base, decurrent or subtruncate at the petiole, margin 
entire or slightly undulate, the laminae drying stiffly chartaceous, and often dark brown, 
smooth and glabrous on both surfaces or minutely puberulent beneath, the axils of the 
major veins often with tufts of hairs, with 6-10 pairs of major secondary veins, tertiary 
venation slightly raised beneath and not usually subparallel (between the secondaries). 
Inflorescence a paniculate arrangement of 10-20 racemes of nearly equal length, terminal 
on axillary short shoots, 20-40 cm long, the common peduncle and main axis less than 5 
cm long, peduncles of the racemes less than 1 cm long, rachis very minutely (0.1 mm) 
puberulent and with longitudinal ridges, 1-2 mm thick and drying dark brown; male 
flowers in fascicles of 4-8, bracts and bracteoles 0.5 mm long or less, pedicels 2-3 mm long, 
filaments 1.5-3 mm long, anthers ca. 0.5 mm long; female flowers solitary, functional pistil 
3 mm long. Fruit enclosed within the succulent perianth, 11-14 mm long and 6-9 mm in 
diameter, ovoid, the free perianth lobes covering only the apex of the fruit, the base 
constricted into a stalk 1-2 mm long above the pedicel articulation, fruiting pedicels 1-3 
mm long; achene obtusely trigonous, dark brown. 

Plants of the wet evergreen forest formations below 1,000 m elevation; fertile 
collections have been made in July and August. The species ranges along the 
Caribbean side of Central America from Guatemala to central Panama and is 
found in the evergreen forests of the Pacific slope in southern Puntarenas Prov- 
ince. 

Coccoloba tuerckheimii is very distinctive because of the unusually large leaves 
borne on large striate ocreae enclosing the nodes on thick brownish stems and the 
paniculate arrangement of long racemose inflorescence branches. Very few flow- 
ering or fruiting collections have been made of this species. 

Coccoloba uvifera(L.) L., Syst. Nat. ed. 10:1007. 1759. Polygonum uviferaL., Sp. 
PI. 365. 1753. Figure 21. 

Shrubs or short widely branching trees 2-8 (15) m tall, the trunk not usually straight, 
leafy internodes 0.3-4 (10) cm long, 2.5-10 mm thick, very minutely puberulent or 
sparsely glandular but quickly becoming glabrous, longitudinally striate, pale brown to 
gray; stipules 3-12 mm long, beginning just beneath the petiole base, very minutely 
puberulent to pilose, splitting as the shoot expands and becoming reddish brown. Leaves 
usually distichous and broader than long, petioles 5-15 mm long, 3-7 mm thick, arising 
just above the stipular base and becoming articulate on the ocrea, minutely papillose in 
ours; laminae 6-15 (18) cm long, 8-20 (27) cm broad, reniform to broadly transversely 
elliptic or suborbicular, often with the lateral halves unequal in area, rounded to emar- 
ginate at the apex, rounded to the cordulate or subcordate base, 1 basal lobe often extend- 
ing around the petiole, margin entire, often slightly undulate with the edge revolute, the 
laminae thick, fleshy, and pale green when alive but drying pinkish gray and coriaceous, 
smooth and essentially glabrous above and below but with minute (0.05 mm) hairs on the 
major veins beneath and with larger hairs in the axils of the major veins, with 3-5 pairs 
of major secondary veins, the tertiary venation minutely reticulate or obscure, minutely 
punctate on both surfaces. Inflorescences usually solitary and terminal (rarely branched at 
the base), 15-30 cm long, racemose, the rachis ca. 3 mm thick and minutely puberulent, 
flower fascicles subtended by small (1-1.5 mm) bracts and bracteoles, the flower fascicles 
separate and not closely crowded along the rachis; male flowers in groups of (1) 2-7, 
pedicels 1-2 mm long, filaments 2-4 mm long, anthers 0.5-0.8 mm long; female flowers 
solitary, perianth 3-4 mm long. Fruit included within the succulent perianth, ca. 2 cm long 



120 FIELDIANA: BOTANY 

and 1.5 cm in diameter, narrowed at the base above the pedicel articulation, obpyriform 
to obovoid, the perianth lobes remaining free only at the top 2-4 mm of the fruit; achene 
difficult to separate from the perianth when dry, black at maturity. 

Plants of the sandy seashore vegetation just above and behind the high water- 
line on both the Pacific and Caribbean coasts in Costa Rica; probably flowering and 
fruiting throughout the year, but with very few collections made in January or in 
May and June. The species ranges from Mexico and southernmost Florida 
(U.S.A.) through the West Indies and Central America to northern South Amer- 
ica. This species is occasionally grown in gardens as an ornamental tree. 

Coccoloba uvifera is distinguished by its thick stiff leaves, usually broader than 
long on very short petioles, thick stems with ocreae covering the nodes, long 
racemose inflorescences, and sandy coastal (or garden) habitats. Because the spe- 
cies is so characteristic of seaside vegetation and so easily recognized, it is only 
occasionally collected and hence poorly represented in herbaria. The plants are 
known as Uva, Uva de Playa, Papaturro, and Sea Grape in Central America. The 
juicy fruit is edible with a slightly acid flavor and has been used to make an 
alcoholic beverage in the West Indies. The hard heavy wood has been used in 
making furniture and for charcoal. 

Coccoloba venosa L., Syst. Nat. ed. 10:1007. 1759. Campderia floribunda Ben- 
tham, Bot. Voy. Sulphur 159, tab. 52. 1846. Campderia mexicana Meisner, in DC., 
Prodr. 14:171. 1856. Coccoloba floribunda (Benth.) Lindau, Bot. Jahrb. 13:217. 1890. 
Coccoloba mohnaeStandl. & L. Wms., Ceiba 3:198. 1952. Figure 23. 

Shrubs or small trees 4-7 (10) m tall, often with a twisted trunk and thick spreading 
crown of many branches, leafy internodes 0-3 cm long, 2-6 mm thick, at first very 
minutely papillate-puberulent but quickly glabrescent, becoming pale grayish and longi- 
tudinally striate, sometimes resinous punctate, becoming lenticellate, the nodes con- 
spicuously thicker than the internodes; stipules 5-15 mm long, originating at or just below 
the petiole attachment, glabrous or very minutely puberulent, deciduous or persisting 
with the leaves. Leaves alternate, often borne on short shoots, distichous on the long 
shoots, petioles 3-10 (15) mm long, 1-2.3 mm thick, glabrous or minutely puberulent, 
often reddish punctate or reddish brown throughout, often borne above the thickened 
base of the node or on the differentiated base of the ocreate stipule; laminae 5-14 (20) cm 
long, 2.5-7 (10) cm broad, obovate or obovate-oblong, acute to obtuse or rounded at the 
apex, obtuse to rounded at the base, often with small (3 mm) and unequal cordulate lobes 
at the petiole, entire, drying undulate and very stiffly chartaceous to subcoriaceous, 
smooth and glabrous above and below (in ours) except for the presence of crooked hairs 
in the axils of the major veins, with 5-8 pairs of major secondary veins, tertiary venation 
often slightly raised above and below when dry. Inflorescences usually solitary, terminal 
or (apparently axillary) on short axillary shoots, (4) 6-12 (16) cm long, the flowerless 
peduncle less than 5 mm long, flower fascicles densely crowded and the rachis often 
difficult to see, the rachis 1-2.5 mm thick, very minutely puberulent or glabrous, usually 
reddish brown and deeply ridged, basal bracts of each fascicle 1-2.5 mm long, dark and 
stiff, the thin bracteoles 2-3 mm long, pedicels ca. 2 mm long; male flowers several per 
fascicle, filaments 1-2 mm long, anthers 0.3-4 mm long; female flowers solitary, flower 
buds ca. 2 mm long. Fruit enclosed within the persistent slightly succulent perianth, to 6 
mm long, perianth lobes separate almost to the base, narrowed at the base above the 
articulation with the petiole; achenes 4-5 mm long to 4 mm broad, strongly trigonous, 
broadest near the base and ovate or trangular in outline, dark brown and lustrous. 

Plants of the seasonally very dry deciduous (tropical dry and tropical moist 
transition) forest formations below 200 m elevation in Costa Rica; probably flow- 
ering sporadically throughout the year, but fertile collections have been made 
primarily in January and February and in July and August. The species ranges 
from central Mexico to the northwestern Pacific lowlands of Costa Rica, and from 



BURGER: FLORA COSTARICENSIS 121 

Hispaniola and Puerto Rico southward through the Lesser Antilles to Trinidad 
and Venezuela. 

Coccoloba venosa is recognized by the short-petiolate obovate-oblong leaves 
borne on thick grayish stems with thickened nodes, compact spikes with densely 
crowded flowers, and deciduous lowland habitat. The species is occasionally 
found near the seashore. Common names that have been used for the species in 
our area include Papaturro, Papaturro de Playa, Papaturro Negro Macho, Papaturro 
Rastero, and Gateador. 



MUEHLENBECKIA Meisner 
Nomen Conservandum 

Small shrubs, slender climbers, or lianas, unisexual or bisexual, stems mostly glabrous 
and longitudinally striate; stipules united to form a thin tube (ocrea) surrounding the 
stem, deciduous or persisting. Leaves alternate and simple, sessile or petiolate; laminae 
entire, glabrous. Inflorescence basically fasciculate and axillary, often racemose or spike- 
like with the fascicles alternating along leafless stems or the stems branched and pan- 
iculate, the flowers occasionally borne directly from the axils of persisting leaves; fascicles 
subtended by thin stipule-like (ocreolate) bracts. Flowers unisexual (in ours) or bisexual, 
borne on short pedicels articulate at the base of the perianth, perianth usually deeply 
5-lobed (rarely 4- or 6-lobed), segments subequal, united near the base to form a shallow 
cup, stamens 8 (9), inserted on the perianth cup, filaments free, anthers introrse, stami- 
nodes present or absent in the female flowers, a pistillode present or absent in the male 
flowers; ovary 3-angled, style 3, short, stigmas fimbrillate to capitate. Fruit remaining 
enclosed in the persistent perianth, the perianth becoming somewhat larger and slightly 
succulent in many species; achenes trigonous, the edges rounded or acute, the surface 
often dark and lustrous. 

A genus of about 20 species best represented in montane and southern South 
America, New Zealand, and Australia. The genus is characterized by woody 
climbing or clambering stems (or subshrubs of high mountains), very small flow- 
ers in small fascicles, and five tepals that enlarge just enough to enclose the fruit 
and become slightly fleshy. 

la Distal stems flat and ribbon-like; leaves usually absent; flower fascicles borne alter- 
nately along the edges of the phyllodes just above transverse lines; cultivated orna- 
mentals or occasional escapes M. platyclada 

Ib Stems terete or angular; leaves always present 2a 

2a Large shrublike plants with clambering or climbing stems to over 3 m long; leaves 
often cordulate at the base, to 12 cm long; flower fascicles in spikelike or paniculate 
arrangements; 1,500-3,000 m M. tamnifolia 

2b Small subshrubs with stems less than 80 cm long; leaves elliptic, to 10 mm long; 
flowers solitary or fasciculate in the leaf axils; plants of high montane paramo vegeta- 
tion above 3,000 m M. volcanica 

Muehlenbeckia platyclada (F. v. Muell.) Meisner, Bot. Zeitung 23:313. 1865, as 
platydados. Polygonum platycladum . v. Muell., Trans. & Proc. Philos. Inst. Victoria 
2:73. 1858. Homalocladum platycladum (F. v. Muell.) Bailey, GentesHerb. 2:58. 1929. 

Shrubs, 0.5-3 m tall, with many closely crowded branches, glabrous, unisexual, basal 
and primary stems terete, the distal stems flat and straplike, less than 1 mm thick (dry) and 
5-15 mm broad, with distinct transverse lines ca. 1-2 cm distant and demarking the 
nodes, the surface with closely parallel ribs 0.2-0.5 mm apart; stipules (ocreae) repre- 
sented by a transverse line across the flattened stem. Leaves usually absent, sessile; 
laminae 2-5 cm long and 0.5-1.5 cm broad, cuneate to hastate at the base, narrowly 
lanceolate distally, acute at the apex, glabrous, quickly caducous. Inflorescences small 
flower fascicles borne alternately along the edges of the stems just above the transverse 



122 FIELDIANA: BOTANY 

lines, pedicels ca. 1 mm long; flowers small and unisexual, perianth ca. 2 mm long. Fruit 
included within the sweet red succulent perianth, ca. 5 mm long; achene ca. 3 mm long. 

Unusual plants native to the southwestern Pacific and adjacent areas. These 
plants are often grown in gardens and in pots for their dense branching and 
unique stems. They escape and grow in the wild on occasion, but do not appear 
to persist in our area. The flat stems with transverse line and small flower fascicles 
alternating along the edges of the distal phyllodes distinguish this species from 
virtually all other terrestrial plants. The species is often called Solitaria or Tenia in 
Spanish and "Ribbon Bush" or "Tapeworm Plant" in English. 

Muehlenbeckia tamnifolia (H.B.K.) Meisner, Gen. PI. 2:227. 1840. Polygonum 
tamnifolium H.B.K., Nov. Gen. & Sp. 2:180. 1817. Figure 19. 

Woody vines or lianas, scrambling or climbing to 15 m high, often forming dense 
masses, unisexual or bisexual, glabrous, leafy internodes 0.5-3 (8) cm long, 0.8-4 mm 
thick, often with 2 or 4 longitudinal ridges, drying reddish brown and striate; stipules 
tubular (ocrea), thin and translucent, 5-15 mm long but often deciduous, entire distally, 
leaving a distinct scar around the stem. Leaves alternate and usually distichous, slightly 
succulent when alive, glabrous, petioles 4-16 (20) mm long, with 2 adaxial ridges con- 
tinuous with the lamina margins; laminae 3-9 (12) cm long, 1-4 (6) cm broad, elliptic- 
oblong to elliptic-ovate or elliptic, tapering gradually or abruptly to the acute or acuminate 
apex, usually rounded near the base and auriculate or cordulate with a relatively wide 
sinus or the laminae sometimes gradually tapering to an obtuse or acute base (rarely 
auriculate and acute on the same plant), margin entire, usually drying thin chartaceous, 
venation pinnate with 7-14 pairs of major secondary veins, the basal secondaries often 
dichotomizing halfway to the margin. Inflorescences 1-3 from the axils of leaves, simple 
and racemose or spikelike or branched and paniculate (sometimes with reduced leaves), 
unisexual or bisexual, very variable (2-15 cm) in length, flowers in alternating fascicles 
subtended by a number of ocreolate bracts 1-3 (5) mm long, rachis 0.3-0.6 mm thick, 
pedicels 0.5-3 mm long and articulate beneath the perianth. Flowers unisexual, small, pale 
yellowish to greenish white, the perianth usually 5-parted, united near the base, ovate; 
male flowers ca. 2 mm long, stamens 8 (10), borne on the lower half of the tepals, ca. 1 mm 
long, anthers ca. 0.5 mm long, a pistillode present or absent; female flowers 1.5-3 mm 
long, ovary 3-angled, styles 3 and spreading, stigmas fimbrillate, staminodia usually 
present. Fruit loosely enclosed within the persistent perianth, perianth enlarging slightly 
to cover the fruit; achenes bluntly 3-angled, 2.5-3.5 mm long, 2-3 mm broad, dark and 
lustrous. 

Vinelike plants of evergreen moist and wet montane forest formations, from 
(1,400) 1,800 to 2,900 (3,100) m elevation in Costa Rica; probably flowering 
throughout the year, but collected most often between September and March. 
This species is known from southern Mexico and Guatemala, central Costa Rica 
to western Panama, and western South America. 

Muehlenbeckia tamnifolia is recognized by the clambering stems with annular 
scars left by the ocreate stipules, thickened nodes with reddish brown surfaces, 
glabrous leaves often cordulate at the base, and the small fasciculate flowers in 
spikelike or panicle-like inflorescences. Plants placed under this name exhibit an 
interesting polymorphism as regard the shape of the leaf base. In Costa Rica, about 
one-third of the collections have an acute or obtuse leaf base, while the majority 
have a slightly auriculate or cordulate leaf base. The latter often have a con- 
spicuous (2-5 mm) basal bract with dark midvein subtending the flower fascicles, 
whereas plants with acute leaf bases seem to lose these bracts early or to have 
them less well developed. The plants with acute leaf bases also seem to have their 
inflorescences more often branched. A closer examination of these differences in 
the field might prove rewarding. 



BURGER: FLORA COSTARICENSIS 123 

Muehlenbeckia volcanica(Benth.) Endlicher, Gen. PI. Suppl. 4:51. 1847. Po/y- 
gonum volcanicum Bentham, PI. Hartweg. 81. 1841. 

Small shrubs or dwarf shrubs, 5-50 cm tall, stems to 75 cm long, usually prostrate or 
pendent, leafy internodes with conspicuous ridges, very minutely puberulent; stipules 
with a tube 1-2 mm long. Leaves alternate, closely spaced, petioles 0-3 mm long; laminae 
3-10 mm long, 2-5 mm broad, elliptic to rhombic-elliptic, tapering gradually to both acute 
apex and attenuate base, drying coriaceous. Flowers axillary, solitary or in fascicles, 
pedicels very short, flowers 2-3 mm long, greenish white. Fruit fleshy and black, loosely 
enclosed in a calyx 3-4 mm long; seed an ovoid-trigonous achene. 

Plants found only on Costa Rica's highest mountains above 3,100 m elevation, 
but ranging from 2,400 to 4,000 m in Guatemala. The species ranges from southern 
Mexico to Guatemala, Costa Rica and Colombia to Bolivia. 

Muehlenbeckia I'olcanica is recognized by its very small stature, tubular ochreate 
stipules, very small leaves, and high altitude habitat. Arthur Weston's careful 
collecting on Chirripd in 1976 first disclosed the presence of this species in Costa 
Rica. 

PODOPTERUS Humboldt & Bonpland 

Shrubs or small trees, bisexual, branches usually terminating in stiff spines, leaves and 
inflorescences usually borne on small rounded short shoots (spur shoots or brachyblasts); 
ochreate stipules small, caducous. Leaves alternate in a spiral or in fasciculate clusters on 
small axillary short shoots, deciduous and the plants leafless for much of the year, lamina 
thin and entire, venation pinnate. Inflorescences fascicles of flowers borne on small axil- 
lary short shoots, pedicels articulate. Flowers bisexual and regular, small, perianth of 2 
whorls of 3 parts, united near the base, the outer 3 perianth parts larger and each with a 
longitudinal keel along the midrib that quickly expands to form a thin wing decurrent on 
the pedicel, the inner smaller perianth whorl with flat erect parts enlarging slightly in fruit; 
stamens 6, free, filaments filiform, anthers ovate; ovary trigonous, styles 3, stigmas cap- 
itate, ovule basal and subsessile. Fruit a trigonous achene, included within the persisting 
and enlarged perianth, each of the 3 outer perianth parts with a thin expanded longi- 
tudinal wing arising from the back (abaxial) side of midrib, the wing rounded near the 
apex of the perianth part and long-decurrent on the pedicel. 

A genus of three species previously known only from Mexico, Belize, and 
Honduras. The genus has a number of unusual characters, including spiny 
branches with small rounded short shoots, deciduous leaves usually borne in 
fascicles, flowers and fruits also in fascicles borne on the rounded short shoots, 
and fruit with persisting perianth and unusual wings that are decurrent on the 
pedicels. The genus is only found in deciduous formations with a severe dry 
season. 



Podopterus mexicanus Humboldt & Bonpland, PI. Aequin. 2:89. 1812. Fig- 
ure 20. 

Shrubs or small trees, 2-5 (8) m tall, usually branched near the base of or with a short 
trunk, stems straight or angled and with short rounded spur shoots and terminal spines, 
leafy internodes 0.3-2 cm long, 1.5-5 mm thick, smooth and usually dark gray in color, 
glabrous; ochreate stipules not usually apparent, stipule scars encircling the young stems 
often difficult to see, older stems with the stipule scars obscure except near the leaf base. 
Leaves usually borne in fascicles of 2-5 on short shoots ca. 3 mm long, deciduous, petioles 
(3) 5-20 mm long, ca. 0.6 mm thick, minutely puberulent with very short (0.1-0.2 mm) 
straight hairs; laminae 2-7 cm long, 1.5-4.5 cm broad, broadly elliptic to obovate, rounded 
to bluntly obtuse at the apex, gradually narrowed to the cuneate base, margin entire, 
laminae drying stiffly chartaceous, smooth on both surfaces, glabrous or very minutely 
puberulent along the midvein beneath, the 3-6 pairs of major secondary veins arising at 



124 FIELDIANA: BOTANY 

an angle of ca. 50 from the midvein. Inflorescences fascicles of flowers borne on short (3-4 
mm) thick short shoots (brachyblasts) alternate along the stems, with 5-20 flowers per 
fascicle, pedicels articulate near the base; flowers small and said to be green but becoming 
white and with the 3 outer perianth parts soon developing longitudinal wings along their 
midribs. Fruit borne within the thin whitish to pale brown or yellowish pink perianth 
parts, 2-3 cm long including the pedicel, wings of the outer 3 perianth parts 2-3 mm broad 
and 10-15 mm long, decurrent on the pedicels for 5-10 mm, the wings thin and trans- 
lucent, achene ca. 5 mm long and 3 mm broad, with 3 narrow longitudinal ribs, the surface 
pale brown and lustrous. 

Trees and shrubs of the dryest seasonally deciduous woodlands and scrub 
formations along the Pacific side of Central America between sea level and 700 m 
elevation; fruiting collections have been made from late December to March. The 
species ranges from central Mexico through western Guatemala and Honduras 
and has recently been collected in northwestern Costa Rica. 

Podopterus mexicanus is recognized by the spine-tipped branches with alternat- 
ing rounded short shoots (spur shoots), small fasciculate leaves rounded at the 
apex and cuneate at the base, the small fasciculate white flowers, and the fruit 
with outer perianth parts bearing broad thin wings that are long-decurrent on the 
pedicel. The restriction to seasonally very dry areas and the (often obscure) stipule 
scars further distinguish these plants. They are called Escambron and Escambron 
negroin Honduras. This species was not known from Costa Rica until early Decem- 
ber 1977, when Daniel Janzen collected it growing near the swamp at Palo Verde, 
Guanacaste. A collection by William Haber (74) from the same locality was made 
on March 17, 1977. 

POLYGONUM Linnaeus 

Herbs, climbers or rarely shrubs, annual or perennial, bisexual, often growing in or near 
water, stems often with thickened nodes and longitudinal ridges, glabrous to strigose and 
occasionally with gland-tipped hairs; stipules and leaf base developed into a tubular leaf 
sheath that surrounds the stem and is called an ocrea, the ocrea often with cilia or stiff 
awns on its distal margin. Leaves alternate and simple, some species articulate above the 
leaf sheath, subsessile to short-petiolate; laminae linear to ovate and occasionally cordate 
to sagittate or hastate, margins entire, glabrous or puberulent, usually pinnately veined, 
often glandular or pellucid punctate. Inflorescences basically fasciculate, the flowers in the 
axils of leaves or leaflike bracts but more often subtended by ocrea-like bracts that are borne 
close together on a raceme-like or spikelike axis, the flowering axes solitary or several in 
a panicle-like arrangement, terminal or axillary near terminal leaves, flowers borne on 
pedicels articulated near their apex. Flowers bisexual or occasionally functionally uni- 
sexual, radially symmetrical, small, perianth of 4-6 subequal tepals in 1 or 2 whorls, the 
inner often smaller and of thinner texture, perianth united near the base, green to white 
or pink and red in color, imbricate in bud and persisting in fruit; stamens (3) 5-8 (9), often 
unequal in length, included or protruding on filaments free or adnate to the perianth near 
the base, anthers small, introrse, usually isodiametric and versatile (appearing peltate); 
ovary superior, lenticular or trigonous, styles 2 or 3 and united near the base, stigma small 
and capitate, locule 1 with an erect basal ovule. Fruit an achene, lenticular or trigonous, 
ovate to orbicular in outline, usually included in the dry persisting perianth, the apex often 
beaked with a persistent style base, surface of the fruit often dark and lustrous. 

A genus of about 150 species often growing in open wet habitats and with the 
great majority of species in the North Temperate Zone. With the exception of the 
common Polygonum punctatum, the Costa Rican species of the genus are poorly 
represented in collections. This is probably due to the fact that most live in wet 
habitats that collectors have difficulty working in. Additionally, populations are 
quite variable, and delimitation of species is often difficult. The genus is seriously 



BURGER: FLORA COSTARICENSIS 125 

in need of monographic revision, and one suspects that a great many species will 
have to be redefined as much broader concepts than those currently in use. 

Most of our species of Polygonum are easily recognized by their herbaceous 
habit, narrow alternate pinnately veined leaves, flowers in spikelike or raceme-like 
inflorescences, and the very unusual stipular structure (ocrea) enclosing the node. 
Some Commelinaceae have similar stipular developments, but their leaves are not 
pinnately veined. 

la Flower groups borne on long (1.5-15 cm) spikelike or raceme- like axes; common 

plants 2a 

Ib Flowers in small groups in the axils of leaves or on short (0.5-1.5 cm) raceme-like or 

spikelike groups at the ends of much longer slender flowerless peduncles; plants 

rarely collected in Costa Rica 6a 

2a Outer perianth parts and/or the ocreate bracts subtending the flowers with dis- 
tinctive minute (0.1 mm) disklike gland dots; flower fascicles often somewhat 
separate on the flowering rachis; leaves gradually narrowed to apex and base; a 
common species P. punctatum 

2b Outer perianth parts and ocreate floral bracts lacking disklike gland dots; flower 
fascicles often crowded on the floral rachis; less common species 3a 

3a Distal margins of the ocreae (stipular tube above the leaf base) with very short 
(1-2 mm) setae or ciliate awns or these lacking; plants rarely with conspicuous 
hairs, pubescence often confined to leaf margins and midveins, stems often slen- 
der; leaves usually narrow and tapering gradually to apex and base 4a 

3b Distal margins of the ocreae with long (2-20 mm) stiff setae, plants often 
conspicuously pubescent, lower stems often more than 1 cm thick; fruit 

lenticular 5a 

4a Distal branches of the inflorescence lacking minute gland-tipped hairs, 
flower fascicles often somewhat separate on the flowering rachis; fruit lentic- 
ular or trigonous; mostly from the Caribbean lowlands (in ours) 

P. hydropiperoides 

4b Distal branches of the inflorescence with minute gland-tipped hairs, flower 
fascicles usually crowded; fruit lenticular with 2 flat faces P. segetum 

5a Stems and inflorescence branches with longer strigose hairs and minute gland- 
tipped hairs; green leaflike flanges often present on the distal margin of the 
ocreate stipules; laminae somewhat rounded near the base P. hispidum 

5b Stems and inflorescence branches with appressed ascending strigose hairs, 
gland-tipped hairs absent; stipules with setae to 25 mm long but lacking flanges; 
laminae tapering gradually to the base P. acuminatum 

6a Laminae broadly ovate to triangular and deeply cordate, petioles usually more 
than 1 cm long; introduced vining weeds of open sites, naturalized in a few areas 
in Panama but not recorded from Costa Rica and not included in the species 
descriptions P. convolvulus 

6b Laminae never broadly ovate or deeply cordate, (rarely subcordate to hastate), 
petioles less than 5 mm long; plants erect or clambering but not vines 7a 

7a Laminae 5-15 cm long; flowers clustered in fascicles at the ends of long slender 
inflorescence branches; native plants of swamps and marshes, 0-1,800 m 

P. meisnerianum 

7b Laminae 0.5-4 cm long; flowers in fascicles in the axils of leaves; introduced 
weeds of short (less than 0.5 m) stature, 1,500 m and above P. aviculare 

Polygonum acuminatum H.B.K., Nov. Gen. & Sp. 2:178. 1817. P. guatemalense 
Gandoger, Bull. Bot. Soc. France 66:225. 1919. Figure 17. 

Herbs to 1.5 (rarely 2) m tall, usually erect, leafy internodes 2-4 (12) cm long, 4-8 (15) 
mm thick, with appressed ascending strigose hairs but soon becoming glabrous; stipules 
14 cm long with a usually dense covering of slender ascending hairs 1-4 mm long, distal 
margin with 10 or more stiff setae (awns) 10-25 mm long; leaves alternate in a spiral, 
subsessile or with petioles 1-15 mm long, lateral margins of the petioles continuous with 



126 FIELDIANA: BOTANY 

the lamina margins, appressed strigillose; laminae 8-23 (30) cm long, 1.5-3.5 (5) cm broad, 
narrowly lanceolate to linear-lanceolate, occasionally curved and falcate, tapering gradu- 
ally to the acuminate or acute apex, gradually tapering to the base and abruptly decurrent 
on the petiole, margin entire and densely strigillose, laminae drying chartaceous and 
smooth to the touch, the surfaces usually covered with appressed hairs distally oriented 
and 0.1-1 mm long, the hairs often more dense along the midvein and margins, venation 
pinnate with 13-25 pairs of major secondary veins. Inflorescences terminal or axillary from 
near-terminal leaves, to 30 cm long, raceme-like or spikelike with a single axis or with 1-3 
branches and paniculate, primary peduncle (2) 4-7 cm long, appressed strigose, branches 
of the inflorescence 6-16 cm long with the flowering portion (1) 3-11 (14) cm long, ca. 1 
cm in diameter at full anthesis, fascicles of flowers closely crowded and partly overlapping, 
bracts of the fascicles 2-3 mm long and with distal cilia 0.5-2 mm long, pedicels exceeding 
the bracts by 1-2 mm; flowers ca. 3-4 mm long, whitish or pink, perianth united only near 
the base, usually 4-parted, stamens usually 6 and becoming exserted beyond the perianth, 
anthers ca. 0.5 mm long, versatile, styles 2, 2-3 mm long. Fruit a thick lenticular achene 
2-2.5 mm long, ovate in outline and with convex faces, dark brown or black, lustrous. 

Plants of swamps, streamsides, wet depressions, and dense aquatic (rooted or 
floating) vegetation from sea level to about 1,500 m elevation; probably flowering 
throughout the year in Central America. The species ranges from southern Mexico 
and the West Indies to southern South America. 

Polygonum acuminatum is characterized by the often robust stems, general pres- 
ence of thin ascending appressed (strigillose) hairs, long-setose stipules, ciliate 
floral bracts, crowded flower fascicles, and thick lenticular fruit. The species is 
known from only two collections in Costa Rica: Brenes 14353 from near San 
Ramon, Alajuela, and Standley 48465 from near Cairo, Limon province. 

Polygonum aviculareL., Sp. PL 362. 1753. 

Annual herbs, prostrate or decumbent-ascending, simple or much branched, often 
densely leafy with short internodes, leafy internodes 0-10 (30) mm long, 0.5-1.5 (3) mm 
thick, smooth and glabrous, often ridged or angled and becoming longitudinally striate 
when dry; stipules forming short (2-5 mm) tubular ocreae, the ocreae very thin and 
translucent, smooth and lustrous, becoming lacerate distally. Leaves alternate in a spiral, 
often bluish green in color, glabrous, clearly articulate just above the sheathing ocreate 
base, subsessile or very short (0-3 mm) petiolate; laminae 0.5-3 (4) cm long, 1.5-5 (8) mm 
broad, very narrowly elliptic to narrowly elliptic-oblong, bluntly acute at the apex, acute 
and decurrent on the base, margin entire, laminae drying stiffly chartaceous, venation 
pinnate with 3-5 pairs of major secondary veins. Inflorescences of fasciculate flowers in the 
axils of leaves or leaflike bracts, 1-5 flowers per fascicle, pedicels to 2 mm long; flowers 2-3 
mm long, perianth greenish white to pinkish or white, tepals rounded at the apex, fruit 
a 3-angled achene, ovate in outline, dark brown, dull or slightly lustrous. 

A weed of roadsides and open ground originally from north temperate areas but 
now naturalized at higher altitudes in the tropics. The species is known in Costa 
Rica from only three collections, all from the southern slope of Volcan Irazu near 
Tierra Blanca, Cartago. 

Polygonum aviculare is recognized by its small narrow leaves, many-branched 
and often procumbent stems, translucent ocreae on the leaf bases, articulate small 
narrow leaves, flowers in axillary fascicles and usually open weedy habitat. This 
species has become naturalized in Guatemala, where it probably does not persist 
below 1,500 m elevation; it is not likely to be found in our area below 1,500 m. 

Polygonum hispidumH.B.K., Nov. Gen. & Sp. 2:178. 1817. Figure 17. 

Herbs, 0.5-1.5 m tall, perennial and often with robust viscid stems to 2 cm thick, leafy 
internodes 1-8 cm long, 3-10 mm thick, usually densely strigose to hispid with stiff 
pale-colored hairs 2-6 mm long and minute (0.2-0.5 mm) reddish gland-tipped hairs; 



BURGER: FLORA COSTARICENSIS 127 

stipules forming a narrow tube 2-20 mm long with setae on the distal margin 2-5 mm long 
and often with distal rounded reflexed or spreading flanges, long ascending and minute 
gland-tipped hairs covering the surface. Leaves alternate in a spiral, petioles 1-6 cm long 
with lateral ridges continuous with the lamina margins, strigose-hispid and with gland- 
tipped viscid hairs; laminae 7-30 cm long, 3-12 cm broad, ovate- triangular to narrowly 
ovate-elliptic or broadly lanceolate, tapering gradually to the acute or acuminate apex, 
abruptly rounded near the base but gradually decurrent on the petiole, margin entire and 
strigose, the laminae drying thin chartaceous, smooth to the touch but strigose-hispid 
along the veins above and below, usually glabrous between the veins on older leaves, 
venation pinnate with 10-25 pairs of major secondary veins, the lower surface punctate. 
Inflorescences to 30 cm long, usually paniculate with 3 flowering branches, the primary 
peduncle 5-10 (15) cm long and ca. 3.5 mm thick, branches 4-16 cm long and bearing 
flowers over more than half their length, flowerless axes of the inflorescence with strigose 
hairs 1-2 mm long and minute gland-tipped hairs, flower fascicles congested or closely 
approximate, spikelike and raceme-like, 6-18 mm thick, fascicles subtended by ocreate 
bracts 3-4 mm long, bracts usually with few hairs on the back and a ciliate margin of stiff 
hairs 0.5-1 mm long, pedicels becoming slightly longer than the bracts; flowers 3-5 mm 
long, deep pink to dark red (rarely greenish), perianth lobes 5, stamens 5, filaments 1.5-2 
mm long, styles 2 and ca. 2 mm long, united for half their length. Fruit a lenticular achene, 
3-4 mm long, ovate to orbicular in outline, with 2 flat or slightly concave faces, becoming 
black or very dark brown, lustrous, style persisting and ca. 1 mm long. 

Plants growing in and along streams and in seasonally wet swampy sites from 
sea level to 1,500 m elevation; flowering throughout the year in Central America, 
but collected most often in August. The species ranges from Guatemala and the 
West Indies to southern South America. 

Polygonum hispidum is recognized by the combination of larger strigose or hispid 
and minute gland-tipped hairs, the unusual herbaceous flanges on the stipule- 
margins (not always developed), the larger laminae rounded above an attenuate 
base, the colorful flowers, and the lenticular fruit. In living material, the stems and 
leaves are usually viscid. Virtually all the Central American collections come from 
the Pacific slope, but the species has not yet been collected in Costa Rica. The 
plants are called Tobacon and Tobaquillo in Honduras. 

Polygonum hydropiperoides Michaux, Fl. Borealis 1:239. 1803. Figure 17. 

Herbs, to ca. 1 m tall, lower stems usually slender and often rooting at the nodes, leafy 
internodes 0.5-6 cm long, 1-4 mm thick, glabrous or with a few minute strigillose hairs, 
becoming longitudinally striate when dry; stipules forming a narrow tube 8-20 mm long, 
the distal margin entire or with small (1-2 mm) thin setae (ciliate awns). Leaves alternate 
in a spiral, petioles 2-5 mm long and not clearly differentiated from the lamina; laminae 
5-12 (15) cm long, 0.4-1 (1.5) cm broad, very narrowly elliptic or elliptic-lanceolate to 
linear-lanceolate, tapering very gradually to the acute apex, tapering very gradually to the 
attenuate base, margin entire and minutely strigillose, laminae drying chartaceous and 
smooth to the touch, minutely (0.1-0.5 mm) strigillose on the midveins and margins and 
often glabrous between, venation pinnate with 10-18 pairs of major secondary veins, 
pellucid-punctate in transmitted light. Inflorescences to ca. 15 cm long, paniculate or 
unbranched, the spikelike or raceme-like flowering portions 1-5 cm long and 0.5-1 cm in 
diameter, ocreate bracts subtending the fascicles 2-3 mm long; flowers 2-3 mm long, 
pedicels becoming ca. 1 mm longer than the subtending bract; flowers 2-3 mm long, 
usually 5-parted, the outer perianth lobes 1.5-2 mm long, white or pink, stamens usually 
8, anthers less than 0.5 mm long, ovary trigonous or lenticular, styles 2 or 3. Fruit a 
3-angled or lenticular achene (mostly lenticular in Costa Rica), 2-3 mm long and ca. 1.5 
mm broad, ovate in outline, brown to black, becoming lustrous. 

Plants of river edges, wet depressions, and sandy or gravelly soils near water; 
flowering throughout the year, but seen most often during the wet season. Al- 
though these plants grow from sea level to 1,500 m elevation on the Pacific side 
of northern Central America (El Salvador, Honduras, and Guatemala), they have 



128 FIELDIANA: BOTANY 

only been collected from below 200 m on the Caribbean slope in Costa Rica and 
Panama. The species ranges from the southern United States to South America, 
where it appears to merge with P. persicarioides. 

Polygonum hydropiperoides is recognized by the almost glabrous aspect of the 
plants, the slender stems, the narrow leaves tapering gradually to both apex and 
base, slender inflorescences with flower fascicles not closely crowded, and fruit 
that may be either lenticular or trigonous. As used here, P. hydropiperoides includes 
Central American material previously identified as P. persicarioides H.B.K. Speci- 
mens placed here may include individuals of P. punctatum lacking the character- 
istic gland dots on perianth and floral bracts. Likewise, specimens of P. segetum 
lacking gland-tipped hairs may find themselves placed under this name. The use 
of P. hydropiperoides as something of a catchall is, I believe, justified by the very 
poor state of our knowledge of these semiaquatic plants in Central America. James 
S. Wilson has annotated specimens of this species as P. persicaria L. in the herbar- 
ium of the University of Wisconsin; a Linnean epithet may be the ultimate 
repository for this material. 

Polygonum meisnerianum Cham. & Schlecht., Linnaea 3:40. 1828. Figure 17. 

Herbs, to ca. 1m tall, decumbent or somewhat scandent, leafy internodes 1-5 (8) cm 
long, 1.2-3 mm thick, glabrous or with stiff retrorse barbs or prickel-like hairs (these often 
at the base of the node), occasionally with gland-tipped hairs; stipules narrow and tubular, 
8-30 mm long, distally with short (1-2 mm) setae or entire, glabrous or with strigose or 
glandular hairs. Leaves alternate in a spiral, sessile or with petioles 1-4 mm long, retrorse 
hairs covering the petiole or only along the adaxial ridges continuous with the lamina 
margins; laminae 5-15 cm long, 0.6-1.6 (2) cm wide, linear lanceolate, tapering very 
gradually to the acute apex, abruptly narrowed at the base (very rarely subcordate or 
hastate at the base in Central America), margin entire and with minute (0.1-0.2 mm) 
ascending and/or glandular hairs along the edge, the laminae drying thin-chartaceous, 
with stiff curved retrorse or ascending hairs to 1 mm long on the midvein beneath or 
occasionally scattered over the leaf surface, venation pinnate with 15-30 pairs of major 
secondary veins. Inflorescences terminal, panicles 5-20 cm long, primary peduncles 2-8 
cm long, glabrous or with minute gland-tipped hairs, usually branching dichotomously, 
usually with 2-5 thin branches 1-8 cm long and bearing flowers only in the distal 10-16 
mm, branches of the inflorescence subtended by minute small ocreate bracts and with few 
to many minute gland-tipped hairs; flowers ca. 3-4 mm long, borne on pedicels not 
exceeding the floral bracts, perianth lobes less than 2 mm long, usually white. Fruit ca. 3 
mm long, 3-angled, ovate in outline, lustrous pale brown, with a short (0.2 mm) beak. 

Plants of lake edges, swamps, and marshes from 500 to 1,800 m elevation in 
Central America and apparently flowering throughout the year. The species 
ranges discontinuously from central Mexico to Brazil and the West Indies. 

Polygonum meisnerianum is distinctive because of its open few-branched panicles 
with relatively few (1-5) flower-fascicles at the ends of long thin secondary pe- 
duncles. The glandular hairs usually found on the secondary peduncles and the 
stiff retrorse hairs on leaves and nodes further distinguish this species. Only two 
collections have been seen from Costa Rica; one from Lago Arena!, Guanacaste (A. 
Jiminez 2699), and the other from Canas Gordas, Puntarenas (Pittier 11089). The 
aquatic habitat of this species probably accounts for the fact that so few collections 
have been made in our area. 

Polygonum punctatum Elliott, Sketches Hot. S. Carol. & Georgia 1:445. 1817. 
P. acreH.B.K., Nov. Gen. & Sp. 2:179. 1817. Figure 17. 



BURGER: FLORA COSTARICENSIS 129 

Herbs to ca. 1 m tall, annual or perennial, often with creeping stems, leafy internodes 
0.5-2 (4) cm long, 1.3-10 mm thick, glabrous or rarely with ascending appressed strigose 
hairs, longitudinally ridged when dry, partly included in the tubular stipule of the pre- 
vious node; stipules tubular and narrow, (5) 12-25 mm long, glabrous or rarely with 
appressed hairs, the distal margin setose ciliate with hard yellowish setae (bristles or 
awns) 2-8 mm long (rarely smaller). Leaves alternate in a spiral, petioles 1-10 (15) mm 
long, gradually merging with the sheathing ocreate (stipular) base and enclosing the stem; 
laminae (2) 4-10 (17) cm long, (0.5) 1-2 (4) cm broad, very narrowly elliptic to lanceolate 
or linear-lanceolate, tapering gradually to the acute or acuminate apex, decurrent on the 
petiole, margin entire and minutely (0.3 mm) strigose, the laminae drying chartaceous and 
slightly rough to the touch, usually glabrous above except for the margins and midvein, 
glabrous below or with appressed ascending (strigose) hairs on the major veins, hairs ca. 
0.2-0.5 mm long, venation pinnate with 5-15 (25) pairs of major secondary veins, the 
lamina pellucid punctate when viewed by transmitted light. Inflorescences solitary or less 
often 2-3 from the axils of near-terminal leaves, spikelike or raceme-like with a single 
major axis or occasionally with 1 or 2 branches and paniculate, 5-20 cm long, flowering 
portion 2-10 (15) cm long and ca. 0.5 cm thick, flower fascicles separate along the axis and 
not closely crowded, fascicles subtended by tubular ocreate bracts ca. 2-3 mm long, entire 
or awned apically, usually glandular punctate; flowers exserted from the bracts on slender 
(0.2 mm) pedicels, ca. 4 mm long and articulate at the apex, flowers ca. 34 mm long, 
gradually narrowed to the base, perianth lobes ca. 2 mm long, glabrous but with raised 
pellucid dots, white to pale greenish in color, the 3 larger outer parts imbricate and 
including the 2 inner perianth parts; stamens usually 8, filaments 1-1.5 (2) mm long, 
anthers less than 0.5 mm in diameter, subglobose, ovary trigonous, style ca. 1 mm long, 
connate basally. Fruit a 3-angled achene (in ours), ovate in outline, 2.5-4 mm long, 1.5-2 
mm broad, dark brown to black and lustrous, beak inconspicuous. 

Herbs of wet depressions in open areas, moist forest edges, and stream sides 
from sea level to 2,000 m altitude; flowering throughout the year in Costa Rica, but 
with most of the collections made between December and April and in July and 
August. This species ranges from southern Canada to Argentina and is found in 
Asia. 

Polygonum punctatum is readily recognized among our species by the pellucid 
punctate perianth and floral bracts. The species is further distinguished by the 
narrow leaves tapering gradually to both apex and base and the inflorescences 
with flower fascicles never closely crowded. This is the most commonly encoun- 
tered species of Polygonum in Central America and often referred to as Chile de 
perro in Costa Rica. This species is very similar to P. hydropiperoides among our 
species; P. hydropiper L. of north temperate areas is a closely related species. 
Polygonum punctatum is variable over its wide range, and a number of varieties 
have been proposed (see Norman Fassett, The variations of Polygonum punctatum, 
Brittonia 6:363-393, 1949). 

Polygonum segetumH.B.K., Nov. Gen. & Sp. 2:177. 1817. P. mexicanum Small, 
Bull. Torrey Bot. Club 19:256. 1892. Figure 17. 

Herbs to ca. 1 m tall, mostly annuals, sometimes decumbent, leafy internodes (0.5) 2-9 
cm long, 1.3-6 (10) mm thick, smooth and glabrous or rarely with gland-tipped hairs, 
somewhat longitudinally striate when dry; stipules tubular and narrowly enclosing the 
stem, 5-35 mm long, glabrous, entire or with a few short (1 mm) cilia distally. Leaves 
alternate in a spiral, petioles 2-15 mm long, with lateral margins continuous with the 
lamina margins, sparsely short-strigose; laminae 5-16 cm long, (0.5) 1-2.5 cm broad, linear 
to lanceolate, occasionally curved and falcate, tapering very gradually to the acute or 
acuminate apex, tapering gradually to the base and decurrent on the petiole, margin entire 
but with appressed ascending minute stiff hairs along the edge, laminae drying char- 
taceous, usually with minute (0.1-0.4 mm) appressed ascending stiff hairs on the major 
veins, margins and near the tip, glabrous and minutely punctate between the veins, 



130 FIELDIANA: BOTANY 

venation pinnate with 10-30 pairs of major secondary veins. Inflorescences solitary or less 
often 2 or 3 from the axils of near-terminal leaves, spikelike or raceme-like with a single 
major axis or occasionally with 1 or 2 branches and paniculate, to 20 cm long, flower- 
bearing rachis 1-6 cm long, 8-18 mm thick, primary peduncle and inflorescence branches 
usually with minute (0.1-0.3 mm) gland-tipped hairs, flowers in crowded fascicles sub- 
tended by ocreate bracts 2-4 mm long, bracts entire distally or with very short (1 mm) thin 
cilia, glabrous or minutely gland punctate, pedicels equaling or slightly exceeding the 
bracts; flowers 3-4 mm long, to 5 mm in fruit, pale pink or white, outer perianth lobes 
2-2.5 mm long, ovary lenticular, styles 2. Fruit (2) 3-4 mm long, 2-3 mm broad, orbicular 
in outline, lenticular with 2 flat faces, pale brown becoming very dark brown or black, 
lustrous. 

Aquatic or semiaquatic plants of lake edges, wet depressions, seasonally 
flooded land or occasionally forming floating mats on open water; between sea 
level and 1,500 m elevation and probably flowering throughout the year, but 
collected most often in November and from January to March. The species ranges 
from Mexico to Colombia and the Greater Antilles. 

Polygonum segetum is distinguished by the glandular hairs on peduncles, flowers 
often closely grouped on the floral axes, lenticular fruit, narrow leaves that taper 
gradually to apex and base, and preference for aquatic and temporarily flooded 
habitats. Specimens lacking the distinguishing gland-tipped hairs will key out to 
P. hydropiperoides, and that species may prove to be a catchall for a variety of 
atypical material. Vegetatively, the plants are also similar to P. punctatum, with 
appressed ascending hairs usually confined to the major veins and margins of the 
leaves. 

Polygonum mexicanum is placed under P. segetum following C. D. Adams in the 
Flowering Plants of Jamaica (1972). The plants placed here are also closely related 
to P. pennsylvanicum L. of the eastern United States. 

RHEUM Linnaeus 

Herbs, with thick woody rhizomes, aerial stems short (1 m) or lacking; stipules thin and 
loose, without cilia. Leaves often large, petiolate, the laminae palmately veined, often 
sinuately dentate or palmately lobed. Inflorescences panicles with small clusters of flowers; 
the flowers bisexual or functionally male, perianth 6-parted, subequal or the outer whorl 
smaller, not enlarging in fruit; stamens usually 9, anthers ovate; ovary trigonous, styles 3, 
short and recurved. Fruit an achene, narrowly or broadly 3-winged, embryo straight. 

A genus of about 30 species best represented in eastern Asia and originally 
ranging to eastern Europe. A few are cultivated for their large showy leaves and 
one (Rheum rhabarbarum) is widely grown as a vegetable for its succulent petioles 
which are used with sugar as a vegetable or a filling for pies. 

Rheum rhabarbarum L., Sp. PI. 372, 1753. 

A large perennial herb, most of the leaves borne from the base of the rhizome and lacking 
a prominent stem but producing inflorescences to 2 m tall. Leaves to 1 m long, the petiole 
thick and succulent, often reddish in color; laminae broadly ovate to suborbicular, 50-80 
cm broad, deeply cordate at the base, the margin undulate, glabrous, venation palmate 
with usually 5 primary veins. Inflorescences 1-2 m tall, a narrowly pyramidal leafy pan- 
icle, flowers small and pale green to white, on slender articulated pedicels, similar to those 
of Rutnex. 

Rhubarb (Ruibarbo) is cultivated at middle elevations in Costa Rica; the reddish 
succulent petioles are often seen in vegetable markets of the Meseta Central. The 
name Rheum rhaponticum L. has been used for this species, but refers to a species 
of Bulgaria that is little cultivated. 



BURGER: FLORA COSTARICENSIS 131 

RUMEX Linnaeus 

REFERENCE: K. H. Rechinger, Die siid- und zentralamerikanischen Arten der 
Gattung Rumex. Ark. Bot. 26, no. 3:1-58. 1934. 

Perennial herbs, rarely annual or woody shrubs, unisexual or bisexual, glabrous or 
sparsely puberulent, stems often longitudinally striate and hollow; stipules united to form 
a sheathing tube (ocrea) around the stem, usually very thin and translucent, persistent but 
lacerate and withering. Leaves alternate, simple, often dimorphic with basal or lower 
cauline leaves differing from those near the inflorescences, early leaves often forming basal 
clusters, petioles sheathing the stem at their base and united with the ocreae; laminae 
entire or minutely dentate, often slightly succulent. Inflorescences racemose or paniculate 
but basically composed of flower fascicles borne along an unbranched axis (and these axes 
usually in panicle-like arrangements), the fascicles at first enclosed in stipule-like (ocre- 
olate) bracts, the flowers sometimes numerous within the fascicle and appearing to be 
verticillate or whorled, the flowers borne on simple or articulate (ebracteolate) pedicels. 
Flowers bisexual or unisexual, mostly wind-pollinated, radially symmetrical, the perianth 
of 6 parts in 2 whorls of 3 each, the outer whorl usually smaller than the inner whorl and 
reflexed, remaining small, the inner 3 perianth parts usually larger and often enlarging in 
fruit, both whorls persisting in fruit, stamens 6, free, filaments very short, anthers 
2-thecous, narrowly oblong, usually longer than the filaments; ovary 3-angled (trigonous), 
styles 3 and spreading or reflexed, stigmas fimbriate or penicillate, locule and ovule 1. Fruit 
usually enclosed within the stiff dry persisting perianth parts of the inner whorl, in some 
species at least 1 of the enlarged perianth parts develops a grainlike tubercle on the back 
(abaxially) of the midrib; fruit a 3-angled achene, the 3 longitudinal ribs usually acute, the 
surface smooth and lustrous or rough and dull. 

A genus of perhaps 200 species, most of which grow in the Northern Hemi- 
sphere. The genus is recognized by the very thin stipules encircling the stem, the 
leaves often varying in form on the same stem, the small flowers often in verticel- 
like groups along the inflorescence branches, perianth parts in two whorls of three 
with the parts persistent and closely enclosing the fruit. In some species, at least 
1 of the inner perianth parts enclosing the achene develops a grainlike tubercle on 
the back of the midrib. This remarkable and conspicuous (pale colored) structure 
may serve as a seed-mimic and reduce predation on the achenes. Of the four 
species represented in Costa Rica, three are widely naturalized weeds recognized 
by Linnaeus over 200 years ago, while the fourth species is a unique high- 
mountain endemic that may include the tallest plants known in the genus. 

la Flowers borne on pedicels becoming 3 cm long; plants regularly becoming more than 
2 m tall, stems to 10 cm thick at the base; usually found only in moist protected sites 
above 2,800 m elevation R. costaricensis 

Ib Flowers borne on pedicels usually less than 1 cm long; plants rarely becoming more 
than 1.5 m tall 2a 

2a Small plants only occasionally becoming 50 cm tall; leaves 1-5 cm long, basal leaves 
often with divergent lobes (hastate); flowers unisexual, 2 mm long or less; fruiting 
perianth without grainlike tubercles on the back of the midrib; 1,500-3,500 m elevation 

R. acetosella 

2b Larger plants regularly becoming 50 cm or more tall, leaves 2-40 cm long, basal leaves 
never hastate; flowers bisexual, usually more than 2 mm long; fruiting perianth often 
with a grainlike tubercle developed on the back of the midrib 3a 

3a Enlarged sepals (valves) with entire margins in fruit, without sharp projections or 
spines, flowers and fruit often crowded on the inflorescence axis; largest basal leaves 
usually less than 4 cm broad, rarely truncate or subcordate; common weeds, 1,000- 
2,000 m R. crispus 

3b Enlarged sepals with spine-like projections along the edge in fruiting stages; flowers 
and fruits often in separate verticels along the flowering rachis; larger leaves com- 
monly truncate to cordate; uncommon weeds, 1,000-2,800 m elevation 4a 

4a Enlarged sepals with a few straight spines along the margin; larger leaves usually more 



132 FIELDIANA: BOTANY 

than 5 cm broad, broadest below the middle, laminae margins arising at about the 

same level on the petiole R. obtusifolius 

4b Enlarged sepals with distinctly hooked (uncinate) spines along the margins; larger 
leaves 2-10 cm broad and often broadest at the very base of the laminae, margins 
usually arising 1-5 mm distant along the apex of the petiole R. nepalensis 

Rumex acetosella L., Sp. PI. 338. 1753. Figure 18. 

Perennial herbs 10-40 (60) cm tall, usually branched only at the inflorescence and near 
the base, spreading by slender rootstocks, usually unisexual, glabrous, leafy internodes 
0-3 cm long, with 6-9 distinct longitudinal ribs; stipules 0.5-1 cm long, thin and trans- 
lucent, lacerate. Leaves often dimorphic with basal and distal leaves of different form, 
petioles weakly differentiated from the laminae, 4-40 mm long, with lateral margins 
continuous with the laminae margins; upper (distal) laminae 1-3 cm long, 1-4 mm broad, 
very narrowly elliptic and tapering gradually to both apex and base, lower (basal) laminae 
1-5 cm long, often with divergent basal lobes (hastate), lanceolate or narrowly elliptic to 
obovate above the basal lobes and 2-12 mm broad, acute to obtuse at the apex, usually 
attenuate on the petiole below the divergent lobes, margins entire, the laminae drying 
chartaceous, (often slightly succulent and with a pleasant sour taste in life), venation 
subpalmate with usually 3 major veins. Inflorescence usually a panicle of spicate branches 
(a simple spikelike or raceme-like axis on small plants), usually unisexual, the flowers 
borne in fascicles resembling verticels on the inflorescence branches, each fascicle sub- 
tended by an ocreate (stipule-like) bract and with 1-6 (9) flowers, the flowers borne on 
slender pedicels 0.5-3 mm long. Male flowers 1-2 mm long, perianth of 3 narrow outer 
parts and 3 inner slightly broader parts, a pistillode absent. Female flowers 0.5-1.5 mm 
long, outer perianth parts small and narrow, the inner perianth parts broader and expand- 
ing in fruit, ovary strongly 3-angled, the fimbriate stigmas ca. 0.5 mm long. Fruit included 
within the persistent perianth, larger perianth parts ca. 1.5 mm long and closely appressed 
to the fruit, entire; achene 1-1.5 mm long, 3-angled, surfaces flat or convex, ovate to 
orbicular in outline, smooth, dull or slightly lustrous, brown. 

Introduced weeds of open and disturbed sites at higher elevations. In Costa 
Rica, the plants are commonly found between 2,200 and 3,500 m elevation and 
occasionally down to 1,500 m; flowering and fruiting throughout the year. The 
species, a native of Europe and Asia, is now widely naturalized. 

Rumex acetosella is recognized by its often hastate basal leaves that are usually 
slightly succulent and have a pleasant sour taste. The small stature, very small 
reddish flowers and fruit, and open weedy high-altitude habitats further dis- 
tinguish this species. The plants are often called Ruibarbilloin Central Ameria. This 
species and its close relatives have sometimes been placed in a separate genus, 
Acetosella. 

Rumex costaricensis Rechinger, Repert. Sp. Nov. 40:300. 1936. Figure 18. 

Large single-stalked herbs 2-5 (7) m tall, bisexual, glabrous, the main stems usually 
unbranched below the flowering nodes, leafy internodes to 15 cm long, 5-10 cm thick, 
hollow, longitudinally striate, glabrous and smooth; stipules (ocreae) to 18 cm long and 
surrounding the stem (at upper nodes), thin and translucent, pale reddish brown, with 
many subparallel veins. Leaves alternate in a spiral, somewhat polymorphic with the 
upper leaves on the plant attenuate to the stem and the lower leaves petiolate and rounded 
near the base, petioles 0-3 cm long near the inflorescence and 2-12 cm long lower on the 
stem, 3-10 mm broad, with lateral margins continuous with the laminae margins; laminae 
20-60 cm long, 5-15 cm broad, narrowly elliptic, tapering gradually to the acute or 
acuminate apex, gradually tapering to the attenuate base (distal laminae near the in- 
florescence) or abruptly rounded at the base (more basal cauline leaves), margin entire 
(sometimes very slightly undulate), the laminae drying thin chartaceous, smooth and 
glabrous above and below, venation pinnate with 20-40 pairs of major secondary veins. 
Inflorescence paniculate, terminal or 1-3 from the axils of leaves, bisexual, flowers borne 
in fascicles of 10 or more, separate and distant along the flowering axes, inflorescences 



BURGER: FLORA COSTARICENSIS 133 

usually with many male and few female flowers; the flowers unisexual and glabrous, borne 
on long (to 3 cm) slender pedicels. Male flowers 4-7 mm long, the outer tepals 1.5-2 mm 
long, inner tepals 4-6 mm long, stamens with very short filaments, anthers 2.5-3.3 mm 
long, a small pistillode present. Female flowers ca. 2-3 mm long, inner perianth whorl ca. 
2 mm long, ovary ca. 1 mm long with fimbriate styles 0.5-1 mm long. Fruit loosely 
enclosed within the persisting perianth, larger perianth parts becoming 4-6 mm long, and 
2-5 mm wide, emarginate; achene ca. 3 mm long (immature?), strongly 3-angled, with 
convex faces ca. 2 mm broad and broadly ellipsoid in outline, becoming dark greenish 
brown. 

Unusual plants apparently restricted to partly open sites on moist slopes and 
stream edges in areas protected from strong winds and found only from (2,200?) 
2,800 to 3,400 m elevation; probably flowering throughout the year, but collected 
with flowers and fruit only from December to March and in June and July. The 
species is endemic to Costa Rica and known only from the Cerro de las Vueltas 
(Heredia) and on the Cerro de la Muerte (along the Interamerican Highway 
bordering the provinces of San Jose and Cartago). 

Rumex costaricensis is recognized by its tall single-stalked habit, hollow thin- 
walled stems, large leaves with many veins, large tissue-thin stipules, and pan- 
iculate inflorescences to 50 cm long. This is one of Costa Rica's most unusual 
high-mountain endemics and seems to be restricted to very moist areas subject to 
wet Caribbean winds. This species apparently attains the largest size known for 
the genus and is closely related to R. peruanusRech. and R. tolimensis Wedd. of the 
high Andes of northern South America. 

Rumex crispusL., Sp. PL 335. 1753. Figure 18. 

Erect perennial herbs 0.3-1.5 m tall, with a thick taproot, the stems usually unbranched 
below the inflorescence, bisexual, leafy internodes 1-5 (10) cm long, 3-10 mm thick, 
glabrous, longitudinally striate, hollow; stipules 0.5-5 cm long, thin and translucent. 
Leaves quite variable on the individual plant, often forming dense clusters at the base of 
the plant, petioles 1-5 cm long (to 10 cm on basal leaves); clasping the stem at the base; 
laminae 3-25 cm long, 0.5-4 cm broad, linear-lanceolate to narrowly oblong or linear- 
oblong, acute at the apex, attenuate at the base (rounded or cordate on basal leaves), 
margin undulate and crisped, minutely crenate-dentate, the laminae drying chartaceous, 
smooth and glabrous above and below, venation pinnate with 10-20 pairs of major second- 
ary veins. Inflorescences terminal and paniculate with racemose branches or axillary and 
racemose, the flowers in verticil-like fascicles on the flowering axes, the verticils (whorls) 
closely approximate, and subtended by ocrea-like bracts, flowers borne on slender pedicels 
1-5 (12) mm long; flowers bisexual, outer tepals 1-2 mm long and not expanding in fruit, 
oblong, inner tepals ovate to cordate and becoming 3-5 mm long in fruit, stamens 6 with 
filaments less than 0.5 mm long, anthers 1-3 mm long, ovary 3-angled, stigmas fimbriate. 
Fruit tightly enclosed within the persisting perianth, the perianth parts 3-5 mm long and 
ca. 3 mm broad in fruit, entire, often with an expanded ellipsoid tubercle ("grain") on the 
base of the midrib abaxially becoming 3 mm long and 1.5 mm broad; achene 1.5-3 mm 
long, ca. 1.3 mm broad, 3-angled with 3 flat or slightly convex faces, ovate to orbicular in 
outline, lustrous dark brown. 

Introduced weeds from Europe and naturalized in areas of extensive agricultural 
and similar activity. The species has only been collected in the Central Highlands 
(around the Meseta Central) between 1,000 and 2,000 m in Costa Rica; flowering 
and fruiting material has been collected from December to May and in August. 
The species is now naturalized in many parts of the world. 

Rumex crispus is recognized by the densely flowered inflorescences, undulate 
and obscurely dentate leaves, and the entire perianth parts which (in the inner 
whorl) enlarge in fruit and often have a grainlike development on their back 
(abaxially). The young leaves are eaten after cooking in the United States, but this 



134 FIELDIANA: BOTANY 

practice is not recorded from Central America. The plants are called Lengua de vaca, 
Lengua de caballo, and Lechugon in Guatemala. 

Rumex nepalensis Sprengel, Syst. Veg. ed. 16, 2:159. 1825. Figure 18. 

Herbs, 0.3-1 m tall (in ours), leafy internodes 0-10 cm long, 1.5-6 cm thick, glabrous, 
longitudinally ribbed; stipules thin and soon tearing off. Leaves basal or cauline but not 
differing greatly in form, petioles 1.5-10 cm long; laminae 5-15 (21) cm long, 1.5-5 (10) cm 
broad, ovate-oblong to narrowly triangular and broadest at the base, acute to bluntly 
obtuse at the apex, truncate to cordate or somewhat hastate at the base, margins entire and 
usually arising 1-5 mm distant on the petiole, laminae drying thin-chartaceous with 9-15 
pairs of major secondary veins. Inflorescences terminal or axillary, 10-50 cm long, the 
flower fascicles 5-12 mm distant on the deeply ridged glabrous rachis, the fascicles form- 
ing verticil-like (whorled) clusters with short (1-4 mm) pedicels articulated near the base; 
flowers ca. 2 mm long at anthesis. Fruit enclosed in valves (enlarged sepals) 3-5 (6) mm 
long and with numerous hooked (uncinate) spines 1-3 mm long on the margins, the 
tubercles (grains) on the abaxial surface poorly developed or absent but the venation 
prominent. 

An apparently recently introduced weed collected only in San Jose (Godfrey 
67336) and on the grounds of the University (Croat 593 and 959), both in 1965. 
These specimens are smaller in almost every respect than those seen from other 
parts of the world, but the valves with their hooked spines are diagnostic. 

Rumex obtusifoliusL., Sp. PI. 335. 1753. Figure 18. 

Erect perennial herbs, 0.5-1.5 m tall, often forming dense colonies, bisexual, leafy 
internodes 0-8 cm long, 2-8 mm thick, longitudinally striate, glabrous; stipules (ocreae) 
to 5 cm long, very thin, pale yellowish and translucent. Leaves often polymorphic on the 
same plant, the basal leaves often in dense clusters and long-petiolate, petioles 1.5-15 cm 
long, 0.5-3 mm broad, clasping the stem at their base; laminae 4-25 (40) cm long, 1-10 cm 
broad, tapering gradually to the acute apex, the upper (distal) laminae elliptic to lanceolate 
or ovate-elliptic and tapering to the obtuse base, the lower (basal) laminae much larger and 
oblong to ovate-oblong, truncate to cordate at the base, margin entire or crisp-undulate 
and minutely crenate-dentate in larger leaves, the laminae drying thin-chartaceous, 
smooth and glabrous above, minutely (0.2 mm) puberulent on the veins beneath (the 
trichomes rather thick and irregular), venation pinnate with 4-14 pairs of major secondary 
veins. Inflorescences racemose or paniculate, the flowers borne in somewhat separate 
verticil-like fascicles, the fascicles subtended by ocreate bracts, the flowers borne on 
articulate pedicels to 8 mm long. Flowers bisexual, 2-3 mm long, the 3 outer perianth parts 
ca. 0.5 mm broad, the inner parts broader (1-1.5 mm) and longer (2-3 mm), enlarging and 
developing unusual lobes in fruit, anthers ca. 1.5 mm long, stigmas fimbriate. Fruit tightly 
enclosed in the persisting and enlarged perianth, inner perianth parts (valves) 3-7 mm 
long, with narrow or teethlike lobes along the margin, an ellipsoid tubercle (grain) 2-3 mm 
long often developing on the back of the midrib; achene 2-3 mm long, strongly 2-angled 
with 3 convex faces, ovate or elliptic in outline, lustrous brown, the perianth becoming 
reddish. 

Introduced weeds of open sites in montane habitats between 1,200 and 2,800 m 
elevation; probably flowering primarily in the wet season and early part of the dry 
season (June to February). Native of Europe and Asia and now widely naturalized. 

Rumex obtusifolius is recognized by the raceme-like inflorescences, with separate 
whorls (actually fascicles) of flowers, articulate pedicels, unusual teeth and thick- 
ened "grains" on some of the fruiting perianth parts, and the long-petiolate basal 
leaves. The stems are said to be eaten for stomach ailments in Costa Rica. 

RUPRECHTIA Meyer 

REFERENCE: A. E. Cocucci, Revision del Genero Ruprechtia, Kurtziana 1:217-269. 
1961. 



BURGER: FLORA COSTA RICENSIS 135 

Trees or shrubs, unisexual (dioecious), stems solid; stipules forming a tube around the 
stem (ocrea), small and thin, caducous or evanescent. Leaves alternate and simple, decid- 
uous, petiolate, the laminae pinnately veined, glabrous or puberulent. Inflorescence race- 
mose or of racemose axes in a paniculate arrangement on a leafless terminal twig, the 
flowers borne in fascicles subtended by several thin ocreolate bracts, the flowers pedi- 
cellate (in ours), flowers very small at anthesis. Male flowers with 3 sepals, free or united 
at the base, usually obtuse and membranaceous, the 3 inner petals (tepals) similar to the 
sepals and alternate with them; stamens 9, the outer whorl with 6 stamens in pairs 
alternating with the petals and the inner whorl of 3 stamens opposite the petals, a disk 
usually present, a pistillode absent. Female flowers with 3 sepals, free or united and with 
or without a conspicuous tube, greatly enlarging in fruit, 3 petals alternate with and much 
smaller than the sepals, glabrous or pilose, 9 very small staminodes usually present; ovary 
with 3 short styles and 3 globular or linear stigmas. Fruit retained within the persisting 
perianth, the sepals always enlarging in fruit, often with 3 long narrowly spatulate wings, 
stiffly chartaceous in texture; achene with 3 deep longitudinal sulci separating the rounded 
faces of the fruit, narrowly ovoid to ellipsoid and narrowed to the persisting styles and 
stigmas, seed deeply 3-sulcate. 

A New World genus of 17 recognized species, with several species in Mexico 
and a majority in southern South America. These separate centers of diversity 
probably reflect the fact that most of the species are restricted to seasonally dry 
and deciduous habitats. These plants are recognized by the small flowers in 
fasciculate groups subtended by ocreolate bracts, the unusual three-winged fruit 
very similar to those in Triplaris, and the restriction to seasonally very dry areas 
of northwestern Costa Rica. In addition to the differences listed in the key, 
Ruprechtia differs from Triplaris in chromosome number (n = 14 in Ruprechtia and 
11 in Triplaris) and the much smaller stipules that are often difficult to see. 

Ruprechtia costata Meisner, in DC., Prodr. 14:180. 1857, sensu lato. R. deamii 
Robinson, Proc. Amer. Acad. Sti. 43:51. 1907. R. kellermanii Donn. Smith, Bot. 
Gaz. 47:260. 1909. Figure 20. 

Medium-sized to tall trees, 2-10 (25) m tall, trunk to ca. 35 (60) cm in diameter, uni- 
sexual, leafy internodes 0.3-1.5 (5) cm long, 0.7-2 (5) mm thick, at first with thin ascending 
hairs ca. 0.5 mm long, soon becoming glabrous and gray, lenticellate; stipules forming a 
short (1 mm) thin tube around the stem and leaving a very obscure ring around the stem. 
Leaves usually distichous, articulate at the base (below the ocrea), petioles 2-6 mm long, 
with lateral margins continuous with the lamina margins; laminae 3-11 (18) cm long, 1.5-5 
(8) cm long, elliptic or slightly elliptic-obovate to elliptic ovate, tapering to a short- 
acuminate apex (in ours), acute to obtuse at the base, margin entire or slightly undulate- 
crenate, the laminae drying chartaceous (in ours) or subcoriaceous, glabrous above and 
with few thin ascending hairs on the midvein beneath, the midvein prominent above and 
below, venation pinnate with 5-7 (11) pairs of major secondary veins. Inflorescences 
racemose, 1-3 from the axils of leaves or fallen leaves, occasionally in paniculate arrange- 
ments on leafless stems, flower fascicles subtended by small (1 mm) thin-translucent 
ocreolate bracts, flowering axes to ca. 3 cm long in ours (to 10 cm in others). Male flowers 
on puberulent pedicels 1-2 mm long, perianth ca. 2 mm long, filaments ca. 3 mm long, 
anthers ca. 0.6 mm long; female flowers not seen. Fruit enclosed within the enlarged dry 
perianth and borne on pedicels 2-4 mm long, pedicel and perianth with thin erect hairs 
0.2-0.5 mm long, fruiting perianth 2-4 cm long, (only 2-2.5 cm long in ours with wings 
ca. 15 mm long and 34.5 mm wide), pale rose brown when dry; achene becoming 1 cm 
long, 3-4 mm thick with 3 deep longitudinal sulci separating the 3 rounded sides of the 
fruit, narrowly ovoid to ellipsoid and usually puberulent on the upper half. 

Trees of the seasonally very dry deciduous (tropical dry) forest formations of 
Guanacaste province below 300 m elevation; flowers and fruit have only been 
collected in January, February, and March. The species ranges from Guatemala to 
the Pacific lowlands of northern Costa Rica and central Panama. 



136 FIELDIANA: BOTANY 

Ruprechtia costatais recognized by its distinctive 3- winged fruiting perianth with 
the texture of stiff paper and basal tube loosely enclosing the 3-furrowed achene. 
The ocreate stipules are very small and difficult to see, while the male in- 
florescences are densely (though often minutely) puberulent, with the flower 
fascicles subtended by a cluster of small thin ocreolate bracts. The fruiting peri- 
anth resembles that of Triplaris, but does not enclose the fruit so tightly. 

The current usage of the name Ruprechtia costata, following Cocucci, includes 
specimens of diverse aspect. Specimens from Guatemala with subcoriaceous 
leaves to 18 cm long, with long male inflorescences and fruiting perianth to 4 cm 
long are quite different from the Costa Rican material with thin leaves, male 
inflorescences usually only about 2 cm long, and fruit becoming only 2.5 cm long. 
In addition, our material has foliage with fewer secondary veins. There are Gua- 
temalan collections that appear to be intermediate between these extremes; more 
collections are needed to ascertain the importance of these variations. Our mate- 
rial from Guanacaste is closely matched by specimens from Mexico identified as 
R. pringlei Greenman, a species not treated in the recent monograph. (Earlier, our 
material had been placed under the name of a South American species, R. cum- 
ingii Meissn.) 

TRIPLARIS Loefling 

Trees, unisexual (dioecious), distal stems and branches hollow and often populated by 
fiercely stinging or biting ants, young stems densely strigose to glabrescent; stipules united 
and forming a cap over the shoot apex (as in Ficus), leaving a raised annular scar around 
the stem at each node, the annular ridges often present on older stems (5-10 cm in 
diameter), the stipular structure (ocrea) united to the petiole only at the base, deciduous. 
Leaves alternate and usually distichous, folded (plicate) in bud, short-petiolate, the lami- 
nae generally elliptic to ovate or oblong, often unequal at the base, entire, strigose or 
sericeous to glabrescent, venation prominent beneath, the younger leaves often with 
longitudinal striae or folds reflecting the development within the bud. Inflorescence basic- 
ally an unbranched axis (spicate or racemose), the spikes or racemes in groups of 1-8 in 
the axil of a leaf or undeveloped leaf, often in alternate groups on a terminal twig on which 
the leaves fail to develop or are soon deciduous and thus forming a panicle-like compound 
inflorescence, the flowers usually in fascicles (male) or solitary (female), at first enclosed 
in ocrea-like bracts (ocreolae), the bracts opening along the adaxial side and soon decid- 
uous, the flowers unisexual, subsessile to short-pedicellate, often densely sericeous or 
strigose on the outside, regular. Male (staminate) flowers 1-5 per fascicle, tepals 6, linear 
to ovate, uniseriate and equal or subequal, stamens 9, exceeding the tepals on slender 
filaments, anthers versatile, introrse, 4-thecous, a pistillode absent. Female (pistillate) 
flowers pedicellate and mostly solitary, perianth of 2 very different series, an outer sepa- 
loid series of 3 broad thin parts that are united to form a distinct tube in the lower Vz-Vi, 
the inner series of 3 very narrow stiff perianth parts free or partly adnate to the tube and 
equal to or only slightly exceeding the length of the tube, the perianth strongly accrescent 
in fruit with the 3 outer lobes becoming spatulate to oblanceolate paperlike wings, stami- 
nodes absent or forming an annular disk (rarely with functional stamens), ovary strongly 
3-angled with acute edges, styles 3 with stigmatic areas on their inner faces, locule 1, ovule 
1. Fruit an achene included within the persistent and enlarged 3- winged perianth tube, the 
achene usually 3-angled and ovate in outline, the surfaces lustrous or dull, occasionally 
verrucose or pustulate. 

A neotropical genus with probably fewer than 20 species, most of which are 
confined to South America. These trees are quite distinctive, with large colorful 
compound inflorescences, fruit enclosed in a three- winged papery perianth, stip- 
ules capping the shoot apex and leaving raised scars around the stems, and the 
frequent presence of aggressive ants. Several species of the genus are planted as 
ornamental trees. 



BURGER: FLORA COSTARICENSIS 137 

Variability of the populations, apparent intergradation of what have been called 
species, and lack of monographic study in the last 100 years have made this a 
particularly difficult genus. I have simplified the Costa Rican situation by adapt- 
ing Duke's excellent treatment for the Flora of Panama and assuming that T. 
cumingiana finds its northern limit in westernmost Panama. Since no specimen 
from Costa Rica can be unambiguously keyed to T. cumingiana (following Duke), 
the decision to exclude that species from our account is, I believe, justified. Our 
material will probably prove to be the northern element of a more broadly circum- 
scribed species, such as T. cumingiana. 

Triplaris melaenodendron (Bertol.) Standley & Steyermark, Publ. Field Mus. 
Nat. Hist., Bot. Ser. 23:5. 1943, Velasquezia melaenodendron Bertoloni, Fl. Guatem. 
40. 1840. T. macombii Donn. Sm., Bot. Gaz. 19:257. 1894. Figure 20. 

Trees, 5-15 (25) m tall, unisexual, trunk with circular annular rings in early stages, the 
bark flaking off in broad flat patches, biting or stinging ants often present in the hollow 
distal stems, leafy internodes 1-4 (8) cm long, 3-10 mm thick, with thin appressed and 
ascending strigose hairs but soon becoming glabrous, often reddish brown in color, longi- 
tudinally striate; stipules 1.5-3.5 (5) cm long, densely strigose on the outer surfaces, 
leaving an annular scar around the stem, caducous. Leaves usually distichous, articulate 
at the base, longitudinally folded in bud, petioles 4-20 mm long, 2-5 mm thick, strigose 
abaxially and along the 2 lateral margins, glabrous in the upper (adaxial) shallow sulcus; 
laminae 15-35 cm long, 6-18 cm broad, ovate-elliptic to ovate-oblong, acute or very short 
acuminate at the apex, rounded to the obtuse and often unequal base, entire, the laminae 
drying chartaceous to stiffly chartaceous, smooth or very slightly scabrous above, glabrous 
or sparsely strigose above, strigose beneath with thin stiff hairs 1-2 mm long on the major 
and minor veins, venation pinnate with (12) 14-20 pairs of major secondary veins. Male 
inflorescences spikelike, 1-8 from the axil of a leaf or fallen leaf, often panicle-like when 
leaves have fallen or are undeveloped on terminal twigs bearing spikes, the spikes 10-25 
cm long, flowers borne in fascicles at first enclosed in narrowly ellipsoid or narrowly ovoid 
bracts borne spirally on the rachis of the spike, rachis and bracts usually densely yellowish 
brown strigose, the primary floral bracts deciduous and each fascicle producing several 
flowers; male flowers ca. 5 mm long, perianth of 3 linear and 3 narrowly deltoid tepals 
united near the base, filaments to 7 mm long, anther 0.5-1 mm long. Female inflorescence 
basically a compact raceme, solitary or paired, usually borne in leafless axils on a terminal 
twig and paniculate in form, the spikelike racemes 5-20 cm long, the compound terminal 
inflorescence to 40 cm long, the flowers solitary and at first enclosed in narrowly ovoid 
bracts (resembling the stipules), bracts and rachis densely strigose with yellowish brown 
hairs 1-2 mm long, bracts ca. 1 cm long and narrowed at the base, deciduous, flowers 
solitary from within the bract on short pedicels; female flowers 10-15 mm long at early 
anthesis, pedicels and outer perianth surface densely strigose or sericeous, ovary ca. 3 mm 
long, strongly 3-angled. Fruit an achene tightly enclosed and united near the base to the 
dry persisting long-winged perianth, fruiting perianth 4-6 cm long, perianth tube ca. 14 
mm long and 8 mm thick, the wings 3-5 cm long, oblanceolate, 6-10 mm broad, thin 
chartaceous, venation pinnate and raised on both surfaces, the 3 wings usually parallel 
and not spreading, the inner perianth parts adnate to the tube for 4-7 mm from the base; 
achene ca. 11 mm long and 7 mm broad, ovate in outline and strongly 3-angled, the faces 
slightly convex (deeply concave when undeveloped) and lustrous dark brown, tightly 
enclosed by the perianth tube (especially near the base) and difficult to free from the tube, 
style short, style branches usually breaking off. 

Trees of both the seasonally very dry deciduous forest formations and the wet 
evergreen formations of the Pacific slope from near sea level to 300 (850) m 
elevation in Costa Rica; usually flowering in January and February and with fruit 
in February and March. The species, as presently defined, ranges from central 
Mexico to southernmost Costa Rica; however, these plants will probably prove to 
be the northern representatives of a more broadly defined South American species 
(see below). 



138 FIELDIANA: BOTANY 

Triplaris melaenodendron is readily recognized by its large panicle-like compound 
inflorescences, bright pinkish red or reddish brown fruit with three long papery 
wings, the hollow distal stems usually inhabited by aggressive little ants, the 
shoot apex at first enclosed in a stipule that leaves a prominent scar around the 
stem, the rather large leaves with numerous secondary veins, and the bark on 
older trees breaking off in flakes or strips. This species appears to intergrade with 
T. cumingiana Fischer & Meyer, and some of our collections may be intermediates 
between the two (A. Jiminez 3799, Molina et al. 18245, Skutch 4242; all from the 
General Valley). Triplaris cumingiana differs in having somewhat narrower leaves 
with a greater number of secondary veins and with the inner perianth parts 
adnate for only 2-5 mm on the pistillate perianth tube. All these plants will 
probably prove to be subspecific elements of more broadly defined species. Con- 
sidering the present state of knowledge, I believe it best to follow Duke's treat- 
ment in the Flora of Panama (Ann. Missouri Bot. Card. 47:353-359, 1960); see also 
the remarks by Standley & Steyermark in the Flora of Guatemala (Fieldiana, Bot. 
24, pt. 4:136-137. 1946). 

Common names used in Central America for these trees are Canilla de Mula, 
Callito, Hormigo, Mulato, Tabaco, Tabaco de Monte, Tabacon. The name Mulato refers 
to the patchy, variously colored bark. The Brunka name is Turi-Svan-Kra. Many 
of our collections come from along streams and in flood plains, but it may be that 
these individuals have more accessible lower branches than those growing in 
forests. Included among the collections placed here is a form (Allen 5923 and 6022) 
with larger fruiting perianth and whitish trunk; see the remarks in Paul Allen's 
book, The Rain Forests of Golfo Dulce (1950, p. 348). 



CHENOPODIACEAE 

Herbs (in ours), shrubs, or rarely small trees, bisexual or unisexual, glabrous or puber- 
ulent, sometimes with inflated or flattened hairs, the stems frequently semisucculent, 
often with anomalous anatomy; stipules absent. Leaves alternate, less often opposite or 
whorled, simple, often becoming conspicuously smaller and narrower on distal stems, 
often slightly succulent (reduced to scales in some genera), sessile or petiolate, margin 
entire to lobed or with conspicuous teeth. Inflorescences often of condensed cymes of few 
closely approximate or appressed flowers (glomerules), the glomerules often borne on 
distal axillary or terminal unbranched (spikelike) or branched (panicle-like or thyrselike) 
stems, glomerules often subtended by reduced leaves, the flowers often subtended by a 
bract and bracteoles; flowers bisexual or unisexual, usually small and radially symmetrical, 
perianth of 1 whorl and calyx-like, thin or semisucculent, of 2-5 parts (rarely absent or 1), 
free or united near the base, persisting in fruit, stamens as many as the perianth parts or 
fewer, opposite the perianth parts, free or united at the base to the perianth or to a disk, 
filaments flattened to filiform, bent inward in bud, anthers dorsifixed and introrse, 2- or 
4-thecous, pollen polyporate; ovary superior or united at the base to the perianth or disk, 
1-locular, with 1 basal ovule borne on an erect funicle. Fruit a utricle, often tightly enclosed 
within the persisting perianth or bracts, indehiscent (rarely circumscissle); seed variously 
oriented within the fruit, and with much endosperm, embryo strongly curved, annular to 
hippocrepiform (circular to horseshoe-shaped), rarely spiral or conduplicate. 

A large family well represented in deserts, semideserts, and saline environ- 
ments of the Northern Hemisphere, especially common in eastern Europe and 
western Asia. The family is poorly represented in the tropics, and none of its 
species seem to be members of Costa Rica's indigenous flora. The slightly succu- 
lent or edible alternate leaves, small greenish flowers with stamens borne at the 
base of the sepals, lack of petals, sessile stigmas, solitary locule with ovule borne 
on a basal funicle, and smooth lenticular seeds help distinguish our species. The 



BURGER: FLORA COSTARICENSIS 139 

strongly curved embryo surrounding much endosperm is a characteristic of the 
order Centrospermae, also called the Chenopodiales or Caryophy Hales. Our spe- 
cies are easily confused with members of the Aizoaceae and some Ama- 
ranthaceae. 

la Plants growing wild, herbaceous weeds of open sites; basal and lower leaves rarely 
more than 10 cm long; flowers not subtended by bracts or bracteoles; fruit loosely 
enclosed in the dry slightly enlarged and separate perianth parts Chenopodium 

Ib Plants cultivated for food and ornament; basal leaves often exceeding 15 cm in length; 
flowers subtended by small bracts; fruits tightly enclosed within the united perianth 
parts or bracts 2a 

2a Flowers bisexual; plants cultivated for the edible root, edible leaves or colorful leaves; 
fruit enclosed by the hard and woody perianth, bracts and bracteoles remaining free 
(Acelga, Remolacha) Beta 

2b Flowers unisexual, plants cultivated for the edible leaves; fruits enclosed in a nut- 
like structure formed by the 2 subtending bracts and often with spines 
(Espinaca) Spinacia 



BETA Linnaeus 

Herbs, annual, biennial or perennial, roots often thick and fleshy. Leaves whorled or in 
a rosette at the base, alternate on the stems, laminae entire or sinuate, venation pinnate. 
Inflorescences small clusters of flowers, solitary in leaf axils or terminal, often on distal 
spikelike or paniculate branches, a bract and 2 bracteoles subtending each flower; flowers 
bisexual, small, greenish or reddish, perianth urceolate and 5-lobed, united at the base to 
the ovary and to other flowers, becoming stiff in fruit, stamens 5, borne on the side of the 
ovary, anthers oblong, ovary united to perianth and stamens near the base and appearing 
to be sunken into a disk, with 3 (2-5) short stigmas. Fruit enclosed within the hardened 
and nearly closed perianth, often the product of several flowers united together, pericarp 
free of the seed and united to the perianth at the base; seed horizontal (with the long axis 
at right angles to the floral axis), orbicular to reniform, embryo annular or subannular. 

A genus of about 12 species native to northern Africa, Europe, and Asia. This 
genus includes the many cultivated varieties of beets grown for their nutritious 
roots, the leaves used for green vegetables, and, in some varieties, the colored 
foliage for ornamental plantings. 



Beta vulgarisL., Sp. PI. 222. 1753. 

Herbs, annuals, stems to 1.3 m tall and usually produced in the 2nd growing season, 
sparsely puberulent with thin whitish hairs. Leaves dimorphic, the basal leaves to 50 cm 
long, with long petioles and broad laminae abruptly narrowed at the base, leaves of the 
stem becoming progressively smaller upward on the stem. Inflorescences (glomerules) 
subtended by lanceolate leaves on distal stems; perianth parts narrowly oblong to spat- 
ulate, often keeled on the back. 

An important root and vegetable crop, grown at higher elevations in the tropics. 
Generally referred to as Acelga and Remolacha, the species can be divided into two 
general groups of cultivars: 

Cicla group: Includes the leafy vegetable and ornamental varieties, such as the leaf 
beet, spinach beet, chard, and Swiss chard. The root is not greatly thickened, 
the leaves become as much as 25 cm broad and often have a thick midrib. The 
ornamentals often have reddish leaves. 

Crassa group: Includes those grown for the root, such as the garden beet, red beet, 
yellow beet, and sugar beet. The root may be short or long, but is thick, from 
white or yellow to dark wine red. 



140 FIELDIANA: BOTANY 

CHENOPODIUM Linnaeus 

Herbs or subshrubs, annual or perennial, erect or procumbent, often much branched, 
often with minute scurfy or inflated farinose hairs. Leaves alternate and simple, often 
larger near the base and becoming progressively smaller on the distal branches, the larger 
laminae with petioles, laminae entire to pinnatifid, usually gradually narrowed at the base 
and decurrent on the petiole, gland dots or pale whitish farinose scales often present. 
Inflorescences basically of small groups of flowers (glomerules) solitary or congested 
together, axillary or terminal, often subtended by reduced leaves, the axillary or distal 
flowering stems often spicate or paniculate in form, the flowers lacking both bracts and 
bracteoles; flowers bisexual or unisexual, radially symmetrical, perianth of (3) 5 parts, free 
or united near the base, broadly imbricate, white or greenish, drying thin; stamens 3-5, 
often variable in number on the same plant, filaments short and flat, free or united at the 
base, anthers introrse, ovary superior and subglobose, style short or none, stigmas 2-5, 
fimbriate to subulate. Fruit an indehiscent utricle, subglobose to ovoid, the pericarp mem- 
branaceous or fleshy, free or adherent to the seed, perianth persisting and loosely en- 
closing the fruit; seed usually cochleate-lenticular, held vertically (with long axis parallel 
to the floral axis) or horizontally (with long axis at right angle to the floral axis), embryo 
coiled into a ring (annular) around the central endosperm. 

A chiefly temperate genus with perhaps 100 species, best represented in north- 
ern North America. Most species are weedy, and a few are now distributed 
around the world. Our representatives seem not to be native, and the key includes 
a species not yet recorded but likely to be introduced. Plants of the genus are 
sometimes used as green vegetables; the seeds and inflorescences of C. quinoa 
Willd. provide a grain for the Andean people of Ecuador and Peru. Some are used 
for condiments, and one of our species is used as a vermifuge; see the treatment 
of this genus in the Flora of Guatemala (Fieldiana, Bot. 24, part 4:139-143, 1946). 

la Plants strongly aromatic, with minute yellowish glands on the undersides of leaves, 
not farinose; seeds black and lustrous, ca. 0.7 mm broad, embryo not completely 
encircling the endosperm, seeds both vertical and horizontal within a glomerule of 
flowers; inflorescences paniculate or spikelike, flowers and glomerules mostly sessile; 
occasional in Costa Rica, 1,000-2,600 m elevation C. ambrosioides 

Ib Plants not strongly aromatic, yellowish gland dots absent, with gray or whitish in- 
flated hairs and appearing farinose (as if dusted with flour); seeds more than 1 mm 
broad, dull or lustrous, horizontal, embryo completely encircling the endosperm; rare 
or unrecorded in Costa Rica 2a 

2a Seed with a blunt edge, 1-2 mm in diameter, testa with radial furrows, the pericarp 
easily removed from the seed; inflorescences to 10 cm long and leafless distally; stems 
often reddish; a recent introduction C. album 

2b Seed with a sharp edge, 1.2-1.5 mm in diameter, testa surface with rounded pits, 
pericarp difficult to remove from the seed; inflorescences to 5 cm long, often branched, 
leafless except at the base; unrecorded from Costa Rica and not included in the 
descriptions: C. murale L. 

Chenopodium album L., Sp. PI. 219. 1753. 

Herbs to 1.5 m tall, usually much branched, stems often with longitudinal stripes of pale 
yellow and green (dry), leafy internodes 0.5-10 cm long, minutely puberulent with 
crooked whitish hairs but becoming glabrous. Leaves very variable on the same plant with 
the distal leaves becoming linear-oblong, petioles with thin lateral margins; larger laminae 
2-8 cm long, 1-5.5 cm broad, broadly rhombic-ovate to narrowly oblong, margins entire 
or with up to 10 shallow teeth on each side, upper surface smooth and glabrous, lower 
surface with minute (0.1 mm) translucent or whitish oblong scales (inflated hairs) and 
farinose in appearance, venation pinnate or subpalmate with a prominent pair of basal 
secondaries. Inflorescences of axillary stems with alternate sessile flower clusters and 
spikelike or with some flower clusters (glomerules) stalked and panicle-like, distal flower 
clusters without subtending reduced leaves; flowers 1-1.5 mm broad, perianth with fari- 
nose scales, ovary with 2 stigmas. Fruit with pericarp easily removed from the seed, seed 



BURGER: FLORA COSTARICENSIS 141 

1.2-1.6 mm in diameter, circular or slightly ovate in outline, thick-lenticular and with a 
rounded edge, dull or shiny black. 

A weedy species of worldwide distribution, but only recently collected in Costa 
Rica by J. M. Orozco near Cartago and by J. Gdmez-Laurito at Faldas del Irazu; 
both collections were made in June. The species is recognized by the grayish 
coloring and scales. In the area near Faldas del Irazu, it is found as a weed in 
potato fields and is called Mejicano. 

Chenopodium ambrosioidesL., Sp. PI. 219. 1753. C. anthelminticum L., Sp. PI. 
220. 1753. Figure 38. 

Herbs, upright or leaning over other plants, 0.1-1.5 (2) m tall, annual or perennial, 
usually much branched, stems often with longitudinal pale-colored ridges, leafy inter- 
nodes 0.5-30 mm long, 0.5-4 mm thick, glabrous or very minutely and sparsely puber- 
ulent, strongly aromatic with a sharp unpleasant odor. Leaves very variable in size and 
shape on the same plant, the distal stems with smaller (6-15 mm x 1-4 mm) narrowly 
oblanceolate laminae, petioles 1-10 mm long, with narrow lateral margins continuous 
with the laminae margins; larger laminae 2-7 (10) cm long, 1-2.5 (4.5) cm broad, elliptic 
to obovate in general outline, acute at the apex, gradually narrowed to the base and 
decurrent on the petiole, margins entire in small laminae but with 2-6 short teeth or lobes 
on each side of the larger leaves, sometimes pinnatifid, laminae drying thin and char- 
taceous, smooth and glabrous above, usually glabrous and glandular punctate beneath but 
the small gland dots often difficult to see on dried material, venation pinnate with 3-6 
pairs of secondary veins. Inflorescences spikelike or paniculate, solitary, axillary or termi- 
nal, usually made up of an unbranched rachis with clusters (glomerules) of sessile or 
subsessile flowers often subtended by reduced linear leaves, flowering rachis minutely and 
sparsely puberulent with thin whitish hairs less than 0.4 mm long; flower buds small and 
globose or somewhat flattened distally, 0.6-1.5 mm in diameter, bisexual and male flowers 
found on the same plant, perianth 3- to 5-parted, greenish, rounded; anthers ca. 0.3 mm 
long, stigmas 3 or 4. Fruit with pericarp easily removed from the seed, seed cochleate- 
orbicular in outline, lenticular with rounded edges, smooth and lustrous, black. 

A weedy species of open early secondary vegetation. Collected only in the 
highlands (1,000 to 2,600 m) in Costa Rica and probably flowering throughout the 
year, but with fertile collections made only in January, March, August, and 
October. This species ranges widely as a weed in both the tropics and subtropics, 
but may be native to North America. 

Chenopodium ambrosioides is recognized by its unpleasant odor, alternate leaves 
that vary from toothed to entire and become smaller and narrower as they 
progress up the stem, small flowers in small clusters of three to eight often on 
spikelike stems, and restriction to open weedy habitats. Despite its strong odor, 
this species is used for flavoring food in Guatemala. The species has been used 
effectively as a medicinal plant for the removal of intestinal parasites. 

SPINACIA Linnaeus 

Herbs, annual, erect, unisexual (dioecious). Leaves alternate, petiolate, laminae usually 
broadest at the base, often with lobes or teeth on the base and lower half, triangular to 
hastate, becoming entire and lanceolate distally. Flowers small, rarely bisexual; male flow- 
ers in terminal spikes or panicles, perianth 4- or 5-lobed, stamens 4 or 5; female flowers 
mostly axillary, subtended by 2 bracts which become thick and united in fruit, ovary with 
4 or 5 exserted stigmas. Fruit enclosed within the thick united bracts; seed vertical. 

A genus of five species, originally from western Asia and growing best in cooler 
climates. This is the species referred to as Espinaca or Spinach in Europe, but these 
names are also used for Tetragonia tetragonioides of the Aizoaceae (q,v.) which 
grows better in warm climates. 



142 FIELDIANA: BOTANY 

Spinacea oleraceaL., Sp. PI. 1027. 1753. 

Herbs to 0.8 m tall, glabrous. Leaves dimorphic, basal and in a rosette or cauline and 
alternate, laminae broadly ovate and with basal lobes to oblong or narrowly obovate, 
becoming smaller and narrower up the stem, lanceolate in the distal flowering branches 
(inflorescences), glabrous, venation pinnate. Fruit enclosed in the thickened carpel-like 
bracts, occasionally with spines, capsule-like. 

AMARANTHACEAE 

Herbs, shrubs or clambering plants, rarely small trees, bisexual or rarely unisexual, 
puberulent or glabrous, stems often marked with reddish coloring; stipules absent. Leaves 
alternate or opposite, petiolate, simple and entire (rarely somewhat crenate or serrate), the 
lamina often decurrent on the petiole, midvein often extending beyond the lamina as a 
small mucronate tip, venation usually pinnate. Inflorescences axillary or terminal, solitary 
or several, the flowers usually borne in congested fascicles or small condensed cymose 
glomerules and these often arranged in heads or spikes, the flowers usually subtended by 
a basal bract and 2 lateral bracteoles, these usually stiff and dry and sometimes colorful, 
glomerules occasionally with sterile flowers modified to aid protection or dispersal. Flow- 
ers bisexual or unisexual, generally small and radially symmetrical, sessile or subsessile, 
perianth (1-3) 4 - or 5-parted in 1 or 2 whorls, usually stiff, dry and imbricate, usually 
narrow, greenish to whitish, pink or reddish; stamens usually as many as the perianth 
parts and opposite them (rarely 1-3), straight in bud, filaments free or united to form a 
short or long tube, the tube often with appendages (pseudostaminodia) between the 
anther-bearing filaments, anthers 2- or 4-thecous, medially attached and introrse; ovary 
superior and 1-locular, 2- or 3-carpellate, with 1 (more rarely several to many) ovules 
pendulous from long erect funicles from a basal placenta, styles 2 or 3 (1-8), stigmas 
capitate or filiform. Fruit a 1-seeded utricle or nut, less often a several-seeded capsule or 
berry, often with circumscissle dehiscence, sometimes indehiscent, the fruit usually in- 
cluded within the persisting bracts, bracteoles, and perianth parts; seed lenticular or 
reniform, often cochleate-orbicular in outline, often lustrous and smooth, embryo annular 
or U-shaped, with perisperm. 

The Amaranthaceae probably exceed 60 genera and 900 species in number, 
ranging throughout the tropics and warm temperate areas. They are especially 
well represented in Africa and the .Americas. The family is closely related to the 
Chenopodiaceae, but that family is often succulent, with the perianth more sepal- 
oid and the filaments bent inward in bud. The Amaranthaceae are usually easy to 
recognize because of their simple entire estipulate leaves, small flowers, stiff dry 
grasslike floral bracts and perianth parts, stamens opposite the perianth parts, 
and basal ovule(s) often producing shiny lenticular seeds with curved embryo. 
Most of our species are weeds of recently cleared soil or early secondary 
vegetation. Some species of Amaranthus, Celosia, Gomphrena, and Iresine are used 
in ornamental plantings and in dried flower arrangements because of their col- 
orful, often long-persisting, inflorescences. Several species are used as potherbs, 
and the grain amaranths (Amaranthus spp.) have been an important source of food 
in some cultures. For a recent review of their use as vegetables, see: Vegetables for 
the Hot Humid Tropics, Part 6, Amaranthus and Celosia (1979), available from the 
Mayaguez Institute of Tropical Agriculture, P.O. Box 70, Mayaguez, Puerto Rico, 
00708. 

KEY TO THE GENERA OF AMARANTHACEAE IN COSTA RICA 

la Leaves alternate along the stem; stigmas 2-8; fruit a 1-seeded utricle or capsule or a 
many-seeded capsule or berry, the fruit loosely enclosed within persisting perianth 
and bracts 2a 

Ib Leaves opposite along the stem (but sometimes alternate within the inflorescences); 
stigma 1-3; fruit 1-seeded, usually a thin- walled utricle or indehiscent 5a 



BURGER: FLORA COSTARICENSIS 143 

2a Fruit a many-seeded capsule (or occasionally berry-like); ovary with several to 
many ovules, stigmas 2-8 and usually exerted beyond the perianth parts; fil- 
aments united to form a tube or a shallow cup 3a 

2b Fruit a 1-seeded utricle; ovary with a single basal ovule, stigmas 2 or 3 and 
exerted or included within the perianth; filaments free or united for ca. Va their 

length to form a cup 4a 

3a Capsule or utricle larger than the perianth parts, the perianth parts often 
reflexed; seeds usually more than 10, stigmas 2-8 and equal to or longer 
than the style; inflorescences paniculate arrangements of racemes; leaves 

usually ovate; shrubs of evergreen forest formations Pleuropetalum 

3b Capsules or utricles not exceeding the erect persisting perianth parts; seeds 
usually fewer than 9, stigmas 2 or 3 and shorter than the style; inflorescences 
spicate (or terminal and broadly flattened or folded and brightly colored in 
some horticultural forms); leaves usually lanceolate; herbs of open second- 
ary growth or grown in gardens Celosia 

4a Erect or prostrate herbs of open secondary vegetation or sometimes cultivated 
for the colorful inflorescences (densely flowered spikes in terminal paniculate 
arrangements) or for the small edible grains; bracts equal to or larger than the 
perianth; flowers mostly unisexual, filaments free; seeds 0.5-1.5 mm broad 

Amaranthus 

4b Vining or clambering shrubs of primary and secondary vegetation; bracts much 
shorter than the perianth parts; flowers bisexual, filaments united at the base, 

seeds 1.5-2.5 mm broad Chamissoa 

5a Inflorescences elongate (5-20 cm) spikes with the fruiting flowers or flower clusters 
(glomerules) becoming reflexed (pointing backward toward the base) on the spike; 
fruit tightly enclosed within perianth and bracts, bracts and bracteoles usually with 

spine tips; anthers 2- or 4-thecous, style 1 with a capitate stigma 6a 

5b Inflorescences of short congested spikes or heads or racemes, often in paniculate 
arrangements, flowers or glomerules not strongly reflexed on the inflorescence axis 
or branches; fruit loosely or tightly enclosed within the bracts and perianth, bracts 
and bracteoles rarely with spine tips (in Alternanthera spp.); anthers 2-thecous, styles 

1-3, stigmas filiform, cylindrical, or capitate 7a 

6a Spine tips of perianth and bracts straight, not becoming hooked in fruit, flowers 
solitary and not borne in glomerules or fascicles together with sterile (modified) 
flowers; perianth parts without prominent ribs; seeds 0.8-1.2 mm 

broad Achyranthes 

6b Spines of some perianth parts and bracts becoming hooked at the apex in late 
stages, glomerules composed of fertile and sterile flowers; perianth parts with 

prominent longitudinal ribs abaxially; seeds 1-2.5 mm broad Cyathula 

7a Leaves mostly linear and succulent, clasping the stem at their base (amplexicaul) and 
lacking a well-defined petiole; usually procumbent succulent plants growing at the 
seashore; filaments united at the base to form a short tube, style with 2 stigmatic 

branches Philoxerus 

7b Leaves neither linear nor succulent, with well-defined petioles and not clasping the 

stem; plants mostly erect 8a 

8a Inflorescences of spikes in paniculate arrangements; flowers unisexual or bisexual, 
with a conspicuous tuft of whitish hairs developing from under the fruit or from 

under the fruiting perianth; stigmas 1-3 and filiform 9a 

8b Inflorescences spikes or gloermules, the spikes and glomerules solitary or in few- 
branched cymes or corymbs; flowers bisexual, a tuft of hairs not produced under 

flower or fruit in late stages; stigmas 1 or 2 and filiform to capitate lOa 

9a Flowers bisexual, stigma solitary and 2-lobed; outer 3 perianth parts much 
broader than the inner, basal hairs arising from within (adaxially to) the peri- 
anth; clambering shrubs Pf a fft 

9b Flowers unisexual or bisexual, stigmas 2 or 3 and filiform to deltoid; perianth 
parts subequal, basal hairs arising from the outside (abaxial) base of the peri- 
anth; erect herbs or clambering shrubs, often common in secondary growth and 

with conspicuous whitish inflorescences Iresine 

lOa Stigma 1, capitate or short-cylindric, anthers borne on slender filaments; bracts and 
bracteoles much shorter than the perianth parts, bracteoles lacking dorsal (abaxial) 
crests or ridges Alternanthera 



144 FIELDIANA: BOTANY 

lOb Stigmas 2 and filiform, anthers sessile on the staminal tube; bracts and bracteoles 
equaling or exceeding the perianth parts, usually with crenate or serrate crests on the 
back (abaxially) of the distal half of the bracteoles (in our species) Gomphrena 

ACHYRANTHES Linnaeus 

Herbs or subshrubs, annuals or perennials, usually becoming woody at the base, erect 
or decumbent, puberulent or glabrous; stipules absent. Leaves opposite and simple, pet- 
iolate, laminae entire and pinnately veined, usually puberulent. Inflorescence solitary, 
terminal or axillary, a spike or spikelike raceme, the flowers on very short pedicels and 
becoming reflexed on the inflorescence, flowers subtended by a bract and 2 bracteoles, the 
bracts and bracteoles of similar size, often with 1 or 2 stiff straight sharp spines, the 
bracteoles with the spine far exceeding the thin translucent lobes (in ours), flowers bisex- 
ual, essentially radially symmetrical, sepals 4 or 5, free, subequal, narrow and concave, 
longitudinally ribbed, glabrous or puberulent, becoming stiff and dry, persisting but not 
enlarging in fruit, stamens usually as many as the perianth parts and opposite them (rarely 
2 or 3), united near the base to form a short tube, the tube with pseudostaminodial 
appendages, anthers 2- or 4-thecous, opening introrse, ovary ovoid and often narrowed 
at the base, 1-locular, the solitary ovule borne from the basal placenta on a long funicle, 
style and stigma 1. Fruit an indehiscent utricle (or like an achene when the fruit wall is 
stiff), tightly enclosed by bracts and perianth, usually reflexed and appressed against the 
axis of the inflorescence; seeds somewhat flattened, the embryo curved. 

A weedy genus of probably five to 10 species with two species now widely 
naturalized in the neotropics. The genus is thought to have been confined to the 
Old World until recently. These plants are characterized by the opposite leaves, 
long spikelike inflorescences with flowers and fruit becoming reflexed and ap- 
pressed on the rachis, the bracts with stiff straight spines, and the utricles rightly 
enclosed within perianth and bracts. 

la Larger laminae ovate to elliptic and with acuminate apices; sepals 5-7 mm long; 

0-1,200 m A. aspera 

Ib Larger laminae broadly obovate to obovate-orbicular, abruptly rounded or truncated 

at the apex; sepals ca. 4 mm long; 0-400 m A. indica 

Achyranthes aspera L., Sp. PI. 204. 1753. Centrostachys aspera (L.) Standl., J. 
Wash. Acad. Sci. 5:75. 1915. Figure 25. 

Herbs or subshrubs, 0.4-1.5 (2) m tall, woody in the lower parts and usually erect, leafy 
internodes (1) 2-15 cm long, 2-5 mm thick, puberulent with whitish ascending sericeous 
hairs ca. 1 mm long, longitudinally striate and brown when dry, usually terete. Leaves 
opposite and decussate, often quite variable on the same plant, petioles 3-30 (40) mm long, 
densely sericeous, with lateral margins forming an adaxial sulcus near the base and 
continuous with the lamina margins distally; laminae 2-18 (25) cm long, 1-8 (10) cm broad, 
ovate to elliptic or slightly obovate, apically obtuse on the smaller leaves but acuminate on 
the larger leaves, obtuse to attenuate at the base, margin entire or obscurely crenate (dried) 
and decurrent on the petiole, the laminae drying thin- to stiff-chartaceous, smooth on 
both surfaces, sparsely to densely sericeous to strigillose with the lower surface more 
densely puberulent than the upper, with 3-7 pairs of major secondary veins arising at 
angles of 40-60. Inflorescence usually solitary and terminal, spikes 10-40 cm long, 6-14 
mm broad, the flowers at first closely crowded and divergent but soon becoming separate 
and reflexed, bracts and bracteoles with 1 or 2 sharp stiff spines, 2-4 mm long, pedicels 
0.1-0.5 mm long; flowers essentially subsessile and becoming reflexed on the spike, sepals 
5-7 mm long, lanceolate, very stiff. Fruit enclosed by the tightly appressed bracts and 
perianth, reflexed and appressed against the axis of the spike, utricle ca. 3 mm long and 
1 mm thick, cylindrical with a truncated apex and rounded base, difficult to separate from 
the enclosing perianth. 

Plants of open weedy sites and early successional stages from sea level to about 
1,200 m elevation in both evergreen and seasonally very dry deciduous areas; 



BURGER: FLORA COSTARICENSIS 145 

flowering and fruiting collections have been made from November to April in our 
area. The species appears to be an introduction from the Old World. 

Achyranthes aspera is recognized by the long slender spikes with retrorse flowers 
and fruits enclosed in spine-bearing bracts and stiff perianth parts, the thin 
acuminate leaves, and open-branched growth habit. The larger leaves with acute 
or acuminate apices and the perianth parts always 5 mm long or more are consis- 
tent traits that distinguish this species from A. indica in our area. The spines on 
the bracts and bracteoles are an effective aid in dispersal. The plants are called 
Rabo de Chanco, Mosotillo, and Mozote. 

Achyranthes indica (L.) Miller, Card. Diet. ed. 8, no. 2. 1768. A. aspera ft indica 
L., Sp. PI. 204. 1753. Centrostachys indica (L.) Standl., J. Wash. Acad. Sci. 5:75. 
1915. Figure 25. 

Herbs or subshrubs, to 1 m tall (rarely taller), woody at the base, leafy internodes (1) 
3-15 cm long, 1-4 mm thick, puberulent with thin whitish ascending hairs 0.2-1 mm long, 
grayish and longitudinally striate when dry, terete or angular. Leaves opposite and decus- 
sate, petioles 1-8 (15) mm long, poorly differentiated from the lamina, with lateral margins 
continuous with the lamina margins, densely sericeous; laminae 1.5-6 (8) cm long, 1-4 cm 
broad, broadly obovate to obovate-orbicular or rhombic-orbicular (broadly elliptic in small 
leaves), rounded or abruptly obtuse at the apex with a small acute tip, usually cuneate at 
the base, margin entire and decurrent on the petiole, the laminae drying thin- to 
stiff-chartaceous, smooth to the touch and puberulent on both surfaces, densely sericeous 
beneath with thin ascending whitish hairs ca. 0.3 mm long, with 5-8 pairs of major 
secondary veins. Inflorescences terminal (often terminal on short axillary shoots), 10-30 
cm long, 5-10 mm broad, axis of the spike with spreading thin whitish hairs, flowers at 
first crowded and divergent but soon becoming separate and reflexed, bracts and bracte- 
oles with stiff spines 2-3 mm long; flowers subsessile, perianth parts ca. 4 mm long, 
lanceolate, pale green, tightly enclosing the fruit. Fruit tightly enclosed within the spinose 
bracts and the stiff dry perianth parts, reflexed on the flowering axis, utricle some- 
what cylindrical, ca. 2 mm long and 1 mm thick, difficult to separate from the enclosing 
perianth. 

Plants of open bare soils and early successional vegetation below 400 m el 
evation in both evergreen and seasonally very dry deciduous formations in Cen- 
tral America; probably flowering throughout the year, but with collections in our 
area only from December through March, July, and August. The species is proba- 
bly an introduction from the Old World. 

Achyranthes indica is recognized by its long slender spikes with retrorse flowers 
and fruits tightly enclosed in spine-bearing bracts and stiff dry perianth parts, 
puberulent leaves with blunt rounded apices, and short stature in open or recently 
disturbed sites. The bluntly rounded leaves and shorter perianth parts consis- 
tently distinguish these plants from A. aspera in our area. The two taxa were 
treated as varieties in the Flora of Panama (Ann. Missouri Bot. Card. 48:24, 1961), 
but they seem to behave like two different species in Central America. 

ALTERNANTHERA Forsskal 

Herbs or small subshrubs, annuals or perennials, prostrate, erect or clambering, bisex- 
ual, usually puberulent in early stages. Leaves opposite, petioles present, poorly differ- 
entiated or absent; laminae simple and essentially entire, puberulent or glabrous, venation 
pinnate. Inflorescences axillary or terminal, 1-3 at a node, sessile or pedunculate, capitate 
or spicate, each flower usually with a subtending bract and 2 lateral bracteoles, the bracts 
and bracteoles similar or differing in size and shape. Flowers bisexual, radially sym- 
metrical, sessile or subsessile, perianth 5-parted, the perianth parts free with the inner and 
outer whorls similar or differing in size and form, usually concave, dry and stiff, ovate to 



ACHYRANTHES 

indica 




A aspera 



FIG. 25. Amaranthaceae: Costa Rican representatives of Achyranthes and Cyathula. Note 
the hooked hairs of Cyathula. 



146 



BURGER: FLORA COSTARICENSIS 147 

lanceolate and usually acute at the apex, longitudinal ribs often thickened on the abaxial 
side, whitish to purple or pale yellowish, persisting but not enlarging in fruit; stamens 3-5, 
united in the lower part to form a tube, usually with staminode-like projections on the 
tube between the anther-bearing filaments, anthers oblong and 2-thecous, introrse; ovary 
superior and globose to ovoid or obovoid, usually laterally flattened, 1-locular with 1 ovule 
borne on an elongate funicle from a basal placenta, style short or long, stigma solitary. 
Fruit a thin-walled utricle, indehiscent, tightly or loosely enclosed within the persisting 
perianth; seeds cochleate-reniform to orbicular or ellipsoid in outline, usually lenticular in 
cross section, smooth and lustrous, embryo annular. 

A genus of perhaps 100 species best represented in the Neotropics, but with 
many species now widely ranging as weeds in tropical and subtropical to warm- 
temperate areas. Our species are distinguished by their small whitish heads 
(except in A. costaricensis) , densely crowded little flowers subtended by usually 
similar bracts and bracteoles, longitudinal ribs on the back of the outer perianth 
parts often thickened, both bracts and perianth parts often terminating in sharp 
spinelike tips, and preference for open early secondary growth habitats (except in 
A. costaricensis). This genus is very similar to Gomphrena (q.v.), and the nomen- 
clature of the two genera has been badly confused (see J. A. Mears in Proc. Acad. 
Nat. Sci. Philadelphia 129:1-21, 1977, and in Taxon 29:85-95, 1980). This treat- 
ment is based on the annotations and identifications of our material by James 
Mears. 

la Inflorescences pedunculate, not subtended by leaves; internodes often more than 5 cm 

long, leaves usually 4-14 cm long, plants usually erect; seeds lustrous black 2a 

Ib Inflorescences sessile in the axils of leaves, less than 12 mm long (except in A. cos- 
taricensis); plants erect, clambering or prostrate; seeds lustrous brown or reddish 

brown 5a 

2a Perianth parts sparsely puberulent or glabrous, inflorescences rarely more than 1 
cm long, floral bracts 1-1.5 mm long and often with a sharp tip; 1,000-2,200 m 

altitude A. lanceolata 

2b Perianth parts densely puberulent or ciliate, inflorescences often more than 1 cm 

long, floral bracts more than 2 mm long 3a 

3a Floral bracts 4-6 mm long with an erose or ciliate margin and often with very 
short (0.5 mm) stiff white hairs; seed ellipsoid, ca. 1.8 mm long; 0-1,000 m but 

rarely collected in southern Central America A. brasiliana 

3b Floral bracts 2-4 mm long, with an entire margin; 0-1,500 m 4a 

4a Perianth with long (4 mm) thin whitish hairs; seeds ca. 0.7 mm long; leaves 
lanceolate to very narrowly elliptic; common in Costa Rica in wet evergreen 

formations A. laguroides 

4b Perianth with short (0.5 mm) hairs; seeds ca 1.5 mm long; leaves elliptic to 
elliptic-ovate; rare in Costa Rica and usually found in seasonally deciduous 

areas A. pubiflora 

5a Plants usually prostrate, laminae rarely exceeding 2.5 cm in length; plants rarely 
collected in Costa Rica; fruit truncated at the apex and with the style usually persis- 
ting 6a 

5b Plants erect,clambering, or occasionally forming low mats; laminae often exceeding 2.5 

cm in length; fruit rounded or emarginate (notched) at the apex 7a 

6a Perianth with thin hairs minutely hooked (*25) at the ends; fruit tightly enclosed 

within the persisting perianth; floral bracts ca. 3 mm long A. caracasana 

6b Perianth with thin white hairs lacking very minute hooks at the tip; fruit easily 
removed from the persisting perianth; floral bracts 1-2 mm long 

A. paronychioides 

7a Plants erect or clambering on others and forming mats; often found in open sunny 
early secondary sites, common wild plants in evergreen and partly deciduous 
areas . . . . 8a 



148 FIELDIANA: BOTANY 

7b Plants erect; found in gardens or in deep forest shade 9a 

8a Laminae to 9 cm long and 4 cm broad; floral bracts 2 mm long, perianth ca. 4 mm 
long; fruit tightly enclosed within the persisting perianth; suborbicular 

A. tenella 

8b Laminae to 6.5 cm long and 2 cm broad; floral bracts 0.5-1 mm long, perianth 
ca. 2 mm long; fruit loosely enclosed by the perianth, lenticular, notched at the 

apex A. sessilis 

9a Laminae 7-16 cm long; inflorescences 1-4 cm long and drying brownish, perianth 
parts to 8 mm long; rarely collected plants of wet forest interiors below 1,000 m 

elevation A. costaricensis 

9b Laminae to 6 cm long, often purplish or marked with varied colors; inflorescences less 
than 1 cm long, perianth parts ca. 3 mm long; common ornamental plants of parks and 
gardens A. bettzichiana 

Alternanthera bettzichiana (Regel) Voss, in Steb. & Voss, Vilmorin's Blu- 
mengartnerei 869. 1896. Telanthera bettzichiana Regel, Gartenfl. 11:178. 1862. 
Achyranthes bettzickiana (Regel) Standl., N. Amer. Fl. 21:138. 1918. Alternanthera 
bettzickiana (Regel) Standl., Publ. Field Columbian Mus., Bot. Ser. 3:254. 1930. 
Figure 26. 

Cultivated herbs or subshrubs of small (20-80 cm) stature, with many lateral branches 
and bushlike in form, leafy internodes 0.5-4 cm long, 0.7-3 mm thick (dry), becoming 
sparsely puberulent, ridged or longitudinally sulcate on drying but succulent in life, with 
tufts of thin whitish hairs in the leaf axils. Leaves opposite, often with reddish or purple 
coloring, petioles poorly differentiated from the lamina, 6-25 mm long, ca. 0.5 mm thick 
when dry, with lateral margins continuous with the lamina margins; laminae 0.5-4 cm 
long, 0.5-2 cm broad, obovate to oblanceolate, obtuse at the apex, gradually narrowed at 
the base and decurrent on the petiole, margins entire, the laminae drying stiffly char- 
taceous, sparsely puberulent or glabrous, with 2-4 pairs of major secondary veins. In- 
florescences solitary and axillary, capitate, 48 mm long, floral bracts 1-2 mm long, stiff 
and with a thickened midrib extending to form a sharp tip; flowers with the outer perianth 
parts ca. 3 mm long, with 3 longitudinal ribs thickened abaxially, sharply acute at the apex, 
with thin whitish hairs on the back. Fruit suborbicular, 1-1.5 mm long; seeds 0.8-1.2 mm 
broad, cochleate-orbicular, lenticular in cross section, shiny reddish brown. 

Widely cultivated and perhaps occasionally escaping plants of open sunny sites; 
to be expected between sea level and about 2,000 m altitude. This taxon may be 
unknown as a truly wild plant; it is commonly cultivated from the southern 
United States to Brazil and Peru in the New World and in many areas of the Old 
World. 

Alternanthera bettzichiana is distinguished by its variably colored foliage (from 
reddish and purplish to green marked with yellow or white), short succulent bush 
habit, small sessile axillary whitish heads, and general restriction to gardens and 
cultivated plantings. The dense branching and variously colored foliage make 
these plants especially suitable for planting in rows or dense groups to achieve 
masses of color irf formal gardens and parks. These plants have been called 
Colchdn de nino in Honduras, Coqueta in Belize, Monte negro in Nicaragua, and 
Perico in El Salvador. This species is closely related to A. tenella Colla. 

Alternanthera brasiliana (L.) O. Kuntze, Rev. Gen. 1:537, 1891. Gomphrena 
brasilianaL., Cent. PI. 2:13. 1756. Achyranthes brasiliana (L.) Standl., J. Wash. Acad. 
Sci. 5:74. 1915. 

Herbs, annual or perennial, erect or prostrate, leafy internodes 3-10 (18) cm long, 0.7-3 
mm thick, strigose with thin white ascending hairs 0.5-2 mm long. Leaves opposite, 
petioles 3-10 mm long, with narrow lateral margins continuous with the lamina margins; 



GOMPHRENA 
serrata 



ALTERNANTHERA 
bettzichiana 




ALTERNANTHERA 
paronychioides 



A caracasana 



FIG. 26. Amaranthaceae: species of Alternanthera with sessile inflorescences and a com- 
mon species of Gomphrena. The arrow denotes the dorsal crest on the floral bract of 
Gomphrena serrata. 



149 



150 FIELDIANA: BOTANY 

laminae 2-10 cm long, 1-6 cm broad, elliptic to ovate-elliptic or lanceolate, tapering 
gradually or abruptly to the acute or short-acuminate apex, rounded to obtuse at the base 
and decurrent on the petiole, margins entire, the laminae drying thin-chartaceous, puber- 
ulent on both surfaces with whitish appressed-ascending hairs 0.2-1.5 mm long, venation 
pinnate with 3-6 pairs of major secondary veins. Inflorescences solitary, usually terminal, 
compact spikes or capitula 10-20 mm long and 8-14 mm thick, white or yellowish, borne 
on slender peduncles 2-16 cm long, with slender ascending stiff hairs, floral bracts 4-6 mm 
long, the distal margin erase or cilliate, midrib obscure, glabrous or minutely puberulent; 
flowers sessile or subsessile, perianth parts 3-6 mm long and often obscured by the bracts 
and bracteoles, ovate-lanceolate, with 3 longitudinal ribs prominent on the basal half, 
stamens and pistil hidden within the persisting perianth and bracts. Fruit included within 
the persisting perianth and bracts; seed ellipsoid, ca. 1.8 mm long, lustrous black. 

Herbs of open sunny sites often in sandy soils below 1,000 m elevation and 
flowering throughout the year. Known from a single collection in Nicaragua and 
to be expected in Costa Rica; the species is native to Venezuela, the Guianas, 
Brazil, and eastern lowland Peru. 

Alternanthera brasiliana is recognized by the opposite leaves with conspicuous 
hairs, long internodes, terminal and solitary white or yellowish heads on long 
peduncles, and large floral bracts. The species has recently been collected near 
Esteli in Nicaragua (Molina 23058), but it has not been recorded from Costa Rica 
or Panama. 



Alternanthera caracasanaH.B.K., Nov. Gen. & Sp. 2:206. 1818. Figure 26. 

Densely branched usually prostrate herbs, 5-25 cm tall, leafy internodes 0-4 cm long, 
0.7-2 mm thick (dry), densely sericeous or villous with thin whitish hairs 1-2 mm long. 
Leaves opposite and small, often clustered at the nodes, petioles 1-5 mm long, with lateral 
margins continuous with the lamina margins; laminae 0.5-2 cm long, 3-12 mm broad, 
elliptic to obovate, abruptly obtuse or rounded at the apex, gradually narrowed to the 
attenuate base, margins entire, the laminae drying chartaceous, sparsely puberulent, 
venation often obscure, with 1-3 pairs of secondary veins. Inflorescences solitary and 
sessile in the axils of leaves, short spikes 5-10 mm long, floral bracts ca. 3 mm long, the 
prominent midvein short-cuspidate at the apex, broadly ovate and thin-translucent, 
mostly glabrous; flowers tightly clustered, outer perianth parts ca. 3 mm long, often 
obscured by the bracts, the midrib prominent and often extended to form a short (1 mm) 
apical spine, 2 lateral longitudinal ribs often thickened near the base, puberulent on the 
back (abaxially) with thin whitish hairs that are minutely hooked at the tip. Fruit tightly 
enclosed within the persisting perianth; 1.5-2 mm long, truncate at the apex and with a 
persisting style; seeds ca. 1.5 mm long, cochleate-ovoid, lenticular in cross section, lus- 
trous brown. 

Prostrate plants of open early secondary habitats, known only as weeds near 
large urban centers in Costa Rica between 1,000 and 1,500 m elevation. The species 
flowers throughout the year in northern Central America and ranges from about 
500 to 2,500 m elevation (rarely collected below 500 m in Guatemala). The species 
ranges from Mexico (in both low and higher altitudes) through Central America 
and the West Indies to northern and western South America as far as Bolivia. 

Alternanthera caracasana is recognized by its prostrate habit, small leaves and 
small sessile inflorescences, and by the unusual "grappling hook" hairs on the 
back of the outer perianth parts. These small hairs have very minute terminal 
hooks that are quite difficult to see with a 10 x hand lens and are sometimes 
interspersed with hairs lacking the hooks. Most of our Central American material 
of this species was previously placed under the name A. repens (L.) Kuntze. The 
species appears to be quite rare in Costa Rica. 



BURGER: FLORA COSTARICENSIS 151 

Alternanthera costaricensis O. Kuntze, Rev. Gen. 2:538. 1891. Achyranthes cos- 
taricensis (Ktze.) Standl., J. Wash. Acad. Sci. 5:74. 1915. Achyranthes megaphylla 
Standl., North Amer. Fl. 21:141. 1917, ex char. Figure 27. 

Herbs or subshrubs 20-80 cm tall, apparently perennial, erect and usually unbranched, 
leafy internodes 1-9 cm long, 1-3.5 mm thick, with thin usually straight appressed- 
ascending yellowish hairs 0.5-1 mm long, stems becoming dark brown and glabrous. 
Leaves opposite, petioles 5-10 mm long, puberulent with appressed-ascending hairs, 
usually becoming glabrous; laminae 7-16 (17.5) cm long, 2-5 (7.5) cm broad, narrowly 
elliptic to narrowly ovate-elliptic or ovate-oblong, tapering gradually to a sharply acu- 
minate or acute apex, acute to obtuse at the base, margins entire, the laminae drying 
thin-chartaceous, smooth above and below, with scattered thin straight ascending hairs 
above and (more densely) below, the 7-10 pairs of major secondary veins arising at angles 
of 50-70. Inflorescences sessile or subsessile in the axils of terminal or distal leaves, 
solitary and spicate, 1-4 cm long, ca. 1 cm thick, greenish in life but drying yellowish 
brown or brown, floral bracts 3-4 mm long, ovate but narrowed to a sharp tip ca. 1 mm 
long, with a single midrib, rachis visible between the flowers and bracts, densely pilose; 
flowers with the outer perianth parts 6-8 mm long, with 3 or 5 prominent longitudinal 
ribs, tapering gradually to the sharply acute apex, puberulent at the base. Fruit and seed 
not seen. 

Rare plants in the understory of wet evergreen forests and known only from 
near sea level to 1,100 m altitude on the Caribbean slopes and lowlands; flowering 
collections have been made between late March and November. The species has 
not been found outside Costa Rica and is presently known from as far north as 
Bijagua (Alajuela) and as far south as Siquirres (Limon). 

Alternanthera costaricensis stands apart from all our other species of Alternanthera 
because of the elongate inflorescences with very stiff, relatively large, dull brown- 
ish perianth parts, deep forest habitat, and relatively large thin leaves. The in- 
florescences give the impression that this species may be more naturally situated 
in another genus. The original description of Kuntze states that the spikes are 
borne on peduncles and, indeed, Kuntze's collection from eastern Costa Rica (NY) 
gives this impression. However, on closer inspection, the "peduncles" appear to 
be terminal internodes, with the distal leaves having fallen off. Note added in 
proof: Specimens of this species returned to Field Museum in September 1982 have 
been annotated Jamesbondia costaricensis (Ktze.) Mears by Mears. 

Alternanthera laguroides (Standl.) Standley, in Standl. & Calderon, Lista PI. 
Salvador. 74. 1925. Achyranthes laguroides Standl., Contr. U.S. Natl. Herb 18:90. 
1916. Figure 27. 

Herbs or subshrubs, erect or clambering, to over 2 m high or 3 m long, older nodes 
slightly thickened, leafy internodes 5-15 (20) cm long, 0.5-4 mm thick, at first densely 
sericeous with thin ascending whitish hairs ca. 1 mm long but soon becoming glabrescent, 
older stems longitudinally striate. Leaves opposite, petioles 1-4 (6) mm long, slightly 
expanded at the base and with tufts of hairs in the axils; laminae (2) 4-11 (14) cm long, (0.4) 
1-2.5 (3.5) cm broad, lanceolate to narrowly elliptic or very narrowly elliptic-oblong, acute 
at the apex and with a slender sharp tip 1-2 mm long, acute at the base and decurrent on 
the petiole, margins entire, smooth and sericeous on both surfaces with thin appressed- 
ascending whitish hairs ca. 1 mm long, the 3-6 pairs of major secondary veins arising at 
angles of 30- 50. Inflorescences compact heads or short spikes 4-14 mm (20) mm long, 
borne on simple (rarely branched) peduncles 1-4 cm long, solitary or 3 together, axillary 
or terminal, leaves subtending the inflorescences sometimes reduced and the terminal 
stems and spikes producing panicle-like arrangement, floral bracts 2-4 mm long, with a 
single midrib and acute tip; flowers sessile, perianth 4-5 mm long, with long (4 mm) thin 
whitish hairs from the base of the perianth, each perianth part with only a single promi- 



V C W?', PFAFFIA grandiflora 



A. pubiflora 
A laguroides 




ALTERNANTHERAT costaricensis 

FIG. 27. Amaranthaceae: three species of Alternanthera and a species of Pfaffia. 



152 



BURGER: FLORA COSTARICENSIS 153 

nent longitudinal midrib, stamens and pistil hidden within the perianth. Fruit hidden 
within the persisting perianth and bracts; seeds ca. 0.7 mm broad. 

Plants of moist evergreen forest formations on both the Caribbean and Pacific 
sides of Costa Rica from sea level to 1,500 m elevation; flowering collections have 
been made from January to June. The species, as presently known, ranges from 
central Nicaragua to central Panama. 

Alternanthera laguroides is distinguished by its clambering habit, long inter- 
nodes, pedunculate heads or short spikes, and the relatively long straight whitish 
hairs borne from the base of the outer perianth parts (abaxially). The plants have 
been called Botoncillo in our area. The species is well represented by collections 
from Costa Rica, but only a very few A. laguroides are from Nicaragua and Panama. 

Alternanthera lanceolata (Benth.) Schinz, in Engler & Prantl., Naturl. Pflanz- 
enfam. ed. 2, 16O75. 1934. Brandesia lanceolata Bentham, PI. Hartweg. 247. 1846. 
Alternanthera lehmannii Hieron. , Bot. Jahrb. Syst. 20, beih. 49:8. 1895. Achyranthes 
lehmannii '(Hieron.) Standl., J. Wash. Acad. Sci. 5:74. 1915. Achyranthes panamensis 
Standl., Contr. U.S. Natl. Herb. 18:89. 1916. Achyranthes stenophylla Standl., loc. 
cit. 18:90. 1916. Alternanthera panamensis (Standl.) Standl., Publ. Field Columbian 
Mus., Bot. Ser. 8:9. 1930. Alternanthera stenophylla (Standl.) Standl., loc. cit. 

Herbs, 0.3-1 m tall, erect or decumbent, leafy internodes (0.5) 3-15 cm long, 0.7-3 mm 
thick, at first densely puberulent with thin ascending hairs 0.5-1 mm long but soon 
becoming glabrescent. Leaves opposite, petioles 2-10 mm long, slender and with very 
narrow lateral ridges continuous with the laminae margins; laminae 2-8 (15) cm long, 
0.5-3 (5) cm broad, elliptic to elliptic-ovate, gradually narrowed to the acuminate apex, 
acute to obtuse and somewhat decurrent at the base, margin entire, the laminae drying 
thin chartaceous, sparsely puberulent with thin hairs 0.5-1.8 mm long on both surfaces, 
with 4-6 pairs of major secondary veins. Inflorescences capitate or very short spikes, 3-10 
mm long, solitary or rarely 2-3 on slender (0.3 mm) peduncles (0.5) 2-10 cm long, terminal 
or axillary, sparsely puberulent, floral bracts 0.5-2 mm long, cuspidate, with broad thin 
translucent margins; flowers 3-4 mm long, subsessile or sessile, perianth parts ca. 3 mm 
long, glabrous or very sparsely puberulent, with 3 weakly defined longitudinal ribs, 
stamens and pistil included within the persisting perianth. Fruit tightly enclosed within 
the persisting perianth, the seeds 1.2-1.5 mm broad, reniform-rounded, lustrous black, 
smooth or wrinkled when dry. 

Weedy herbs of open and shaded sites in moist and wet evergreen forest for- 
mations from 1,000 m to about 2,200 m elevation in Costa Rica; collected with 
inflorescences from August through January. The species occasionally forms a 
ground cover along stream and brook beds and appears to be restricted to areas 
subjected to the very wet Caribbean winds between San Ramon and the Rio 
Grande de Orosf drainage in Costa Rica; the species ranges from Guatemala to 
Colombia. 

Alternanthera lanceolata is recognized by the long slender internodes, usually 
solitary capitate inflorescences on long peduncles, long hairs on the upper leaf 
surfaces, perianth parts with weakly developed ribs, and the restriction to cloud 
forest habitats between 1,000 and 2,200 m (in Costa Rica). 

Alternanthera paronychioides St. Hil., Voy. Brasil, 2 (2):43. 1833. Gomphrena 
ficoidea L., Sp. PI. 1:225. 1753, non A. ficoides Beauv. 1818. Figure 26. 

Herbs, usually prostrate, stems much branched, up to 1 m long and often rooting from 
the nodes, leafy internodes 1-5 cm long, 0.5-2 mm thick (dry), at first densely sericeous- 
tomentulose but soon becoming glabrous. Leaves opposite, occasionally somewhat dimor- 
phic in size, petioles 1-15 mm long, with lateral margins continuous with the lamina 



154 FIELDIANA: BOTANY 

margins; laminae 0.6-3 cm long, 0.5-1.5 cm broad, obovate to elliptic, abruptly obtuse to 
rounded at the apex, gradually narrowed to the attenuate base and decurrent on the 
petiole margins, entire, the laminae drying thin-chartaceous, very sparsely puberulent, 
with 2 or 3 pairs of major secondary veins. Inflorescences solitary and sessile in the axils 
of leaves, capitate or short spikes 4-10 mm long, white, floral bracts 1-2 mm long, thin, 
obtuse to acute at the apex, with a single thickened midrib; flowers with the outer perianth 
parts 3-4 mm long, 3 longitudinal ribs prominent on the lower half of the abaxial side, 
acute and entire, with thin white hairs, anthers 5. Fruit loosely enclosed in the persistent 
perianth, obovoid and usually truncate at the apex with the base of the style persisting, 
1.2-1.8 mm long and equally broad or broader; seeds 0.8-1.2 mm broad, cochleate- 
orbicular, lenticular in cross section, dark brown and lustrous. 

Prostrate weeds of open, usually damp, sites from near sea level to about 1,500 
m elevation; probably flowering throughout the year, but most often collected in 
the wet season. The species ranges from northern Mexico to southern South 
America. These plants are often found near the seashore and brackish (salty) 
water. 

Alternanthera paronychioides is distinguished by its prostrate habit, profuse 
branching, small sparsely puberulent leaves, small sessile inflorescences, and fruit 
easily removed from the persisting perianth and bracts. This species appears to be 
quite rare in southern Central America; I have seen only a single specimen from 
Costa Rica: Maxon & Harvey 8750 from near Puntarenas, close to sea level. While 
very similar to Alternanthera caracasana, this species lacks the unusual grappling- 
hook hairs (20 x) on the back of the outer perianth parts, and the fruit is not rightly 
enclosed within the fruiting inflorescence. Standley reported Golondrina as a com- 
mon name for this species in Costa Rica, but this species is quite rare and the name 
may be misapplied here. Central American specimens of this species have often 
been placed under the name A. polygonoides (L.) R. Br. (as in the Flora of Gua- 
temala, Flora of Panama, and Flora of Costa Rica), but Mears considers the Lin- 
naean basonym a nomen obscurum. 

Alternanthera pubiflora (Benth.) O. Kuntze, Rev. Gen. 2:538. 1891. Brandesia 
pubiflora Bentham, Bot. Voy. Sulph. 157. 1846. Achyranthes williamsii Standley, 
Contr. U.S. Natl. Herb. 18:89. 1916. Alernanthera williamsii (Standl.) Standley, J. 
Wash. Acad. Sci. 15:458. 1925. Figure 27. 

Herbs, erect, procumbent, or clambering, 0.5-1.5 (2) m tall, leafy internodes 2-11 cm 
long, 0.8-5 mm thick, densely strigilose with small (0.2-0.8 mm) whitish ascending or 
appressed hairs, becoming glabrescent with age. Leaves opposite, petioles 2-10 (14) mm 
long, the lateral edges continuous with the lamina margins; laminae 412 cm long, 1.5-4 
(5) cm broad, elliptic to elliptic-ovate, acute to short acuminate at the apex, gradually 
narrowed to the obtuse or acute base and decurrent on the petiole, margins entire, the 
laminae drying thin to stiffly chartaceous, smooth and with thin whitish hairs ca. 0.5 mm 
long on both surfaces, venation pinnate with 3-6 pairs of major secondary veins. In- 
florescences short spikes or capitate, 6-15 mm long, 1-3 borne in the leaf axils or terminal, 
peduncles slender and sericeous, (0.5) 1-8 cm long, floral bracts 2-3 mm long, ovate- 
lanceolate, acute at the apex and with a single midrib, bracteoles often with the midrib 
prolonged and caudate; translucent white, flowers sessile, perianth parts ca. 6 mm long, 
with 3 prominent longitudinal ribs, and stiff little white hairs on the back (abaxially), 
stamens and pistil included within the perianth. Fruit enclosed within the persisting 
bracts, bracteoles and perianth; seed ca. 1.5 mm long, reniform-oblong, lustrous black. 

Weedy plants of open and partly shaded sites in the seasonally dry and decid- 
uous or partly deciduous formations between sea level and 800 (1,400) m elevation 
along the Pacific slope in southern Central America and collected in flower and 



BURGER: FLORA COSTARICENSIS 155 

fruit from December to June. The species ranges from Nicaragua and primarily 
along the Pacific slope in South America to Chile, Bolivia, and Argentina. 

Alternanthera pubiflara is recognized by its larger elliptic leaves, sericeous pubes- 
cence on many parts, 3-ribbed perianth parts, smaller bracts and bracteoles, and 
long-peduncled inflorescences that arise either from the leaf axils or are terminal. 
The terminal inflorescences are sometimes followed by paired axillary shoots that 
produce dichotomous branching. While collected quite often in Nicaragua, this 
species is apparently rare in Costa Rica. 

Alternanthera sessilis(L.) R. Br., Prodr. 417. 1810. Gomphrena sessile L., Sp. 
PI. ed. 2, 300. 1762. Figure 26. 

Small herbs, erect or decumbent, 10-50 cm tall and to 1 m long, stems usually with only 
a few lateral branches, leafy internodes (0.5) 1-8 cm long, 0.5-3 mm thick, very sparsely 
puberulent with minute crooked hairs usually confined to 2 narrow longitudinal depres- 
sions on opposite sides of the stem, leaf axils often with longer (0.5 mm) whitish hairs, an 
interpetiolar ridge usually joining the leaf bases. Leaves opposite, petioles poorly differ- 
entiated from the laminae, 0-5 mm long, with lateral margins continuous with the lamina 
margins; laminae (1) 1.4-6.5 cm long, 4-14 (20) mm broad, very narrowly elliptic to 
oblanceolate, bluntly acute (obtuse) at the apex, tapering gradually to the base and de- 
current on the petiole, margins entire, the laminae drying thin-chartaceous and usually 
greenish, smooth and glabrous above and below or with a few minute hairs along the 
midvein, with 3-6 pairs of major secondary veins. Inflorescences solitary and sessile or 
subsessile in the axils of leaves, capitate, 3-5 mm long, whitish or slightly pink, floral 
bracts less than 1 mm long, broadly triangular, thin translucent; flowers sessile, outer 
perianth parts ca. 2 mm long, thin translucent and with only the midrib thickened. Fruit 
a utricle 1.5-2 mm long and not tightly enclosed by the persisting perianth, pale yellowish 
brown, emarginate at the apex and broadly obovate in outline with the style sessile in the 
apical notch, lenticular in cross section; seeds ca. 1 mm long, pale brown. 

Pioneer weeds in open sites, often in wet depressions and river margins, occa- 
sionally growing partly submerged in water, from near sea level to 1,200 m 
elevation in our area; flowering throughout the year, but collected most often from 
February to August in Costa Rica. The species appears to be uncommon in the 
seasonally very dry areas of Guanacaste. A pantropical species, ranging from 
Guatemala and Belize through Central America and the West Indies to Peru and 
Brazil in the New World. 

Alternanthera sessilis is distinguished by its small white sessile inflorescences, 
unusual fruit that is usually visible within the persisting perianth, the laminae 
tapering gradually to the petiole, and the usually wet habitats. The unusual fruit 
and the ease with which it can be removed from the dry flowers set this species 
well apart from its congeners in Central America. 

Alternanthera tenella Colla, Mem. Reale Accad. Sri. Torino 33:131. 1829. Fig- 
ure 26. 

Herbs, erect or clambering over other small vegetation, stems to 1 m long, leafy inter- 
nodes 1-10 cm long, 0.8-3 mm thick, densely puberulent at first with thin or basally 
thickened whitish hairs ca. 0.5 mm long, soon becoming glabrous, often with tufts of hairs 
in the leaf axils, the hairs often barbed near the base. Leaves opposite, petioles 1-8 mm 
long, with lateral margins continuous with the laminae margins; laminae (1.5) 2-9 cm 
long, (0.5) 1-4 cm broad, elliptic to ovate-elliptic, obtuse to bluntly acute at the apex, 
tapering gradually to the obtuse or acute base and decurrent on the petiole, margin entire, 
laminae drying thin-chartaceous, smooth, becoming glabrous or with a few small (0.1-0.5 
mm) hairs along the midvein, with 3-6 pairs of major secondary veins. Inflorescences 



156 FIELDIANA: BOTANY 

solitary and sessile in the axils of leaves, capitate or very short spikes 4-10 mm long, 3-6 
mm in diameter, whitish, floral bracts ca. 2 mm long, with a sharp aristate tip and 
translucent margins; flowers sessile, outer perianth parts ca. 4 mm long, stiff and with a 
sharp tip, with 3 (5) strongly raised longitudinal ridges on the back and short (0. 1-0. 5 mm) 
stiff hairs near the base, the hairs occasionally minutely hooked. Fruit a suborbicular 
utricle tightly enclosed within the persisting perianth, seed cochleate-oblongoid, 1 mm 
long, lustrous dark reddish brown. 

Plants of open sunny early secondary growth, from near sea level to about 500 
m elevation in both moist evergreen and in seasonally deciduous areas (but appar- 
ently very rare in seasonally very dry Guanacaste); flowering throughout the year 
in our area, but collected most often between November and February. The 
species ranges from southern Mexico and the Yucatan peninsula through Central 
America and the West Indies to Bolivia and southern Brazil. 

Alternanthera tenella is recognized by the small sessile heads or spikes, the stiff 
sharp-tipped perianth parts with prominent longitudinal ribs and thin straight 
hairs, lack of hairs on older parts, and low-altitude habitats. Most of our material 
had been identified as A. ficoidea (L.) R. Br. until Mears recently determined that 
the Linnaean basonym, Gomphrena ficoidea, belongs to the species now known as 
Alternanthera paronychioides. 

AMARANTHUS Linnaeus 

Herbs, rarely perennial, erect or less often prostrate, bisexual or rarely unisexual 
(dioecious), glabrous or minutely puberulent, often marked with red or purplish coloring, 
unarmed or with spines in A. spinosus; stipules absent. Leaves alternate and simple, 
petioles often long and variable in length on the same plant, laminae entire, usually 
thin-textured, venation pinnate with the midvein usually extending slightly beyond the 
lamina to form a slender mucronate tip. Inflorescences basically of small flower clusters 
(glomerules of condensed cymes) in the axil of a bract, glomerules solitary or more often 
congested on an unbranched rachis and spicate, the spikes solitary in distal leaf axils or 
terminal and near-terminal to form a compound paniculate arrangement of spikes, the 
terminal spikes often twice as long as lateral spikes, each flower subtended by a bract and 
2 lateral bracteoles, bracts and bracteoles usually similar in form and size. Flowers small, 
mostly unisexual, the male and female often borne on the same spike with the male 
flowers borne distally and the female near the base, sessile or subsessile, perianth (1- to 
3-) 5-parted, free, equal or subequal, thin and stiff, stamens usually the same number as 
the perianth parts, filaments slender and free, anthers said to be 2-thecous but dehiscing 
by 4 slits, ovary 1-locular, the solitary ovule from a basal placenta, style very short, stigmas 
2 or 3, slender. Fruit loosely enclosed within the persisting bracts and perianth parts, 
usually a thin-walled utricle or capsule with circumscissle dehiscence or indehiscent; seed 
solitary, usually cochleate-orbicular and lenticular in cross section, often dark colored and 
very lustrous, smooth, embryo annular. 

A genus of about 50 species in both tropical and temperate areas of the world. 
Most of the species are pioneers on bare soil or in early successional vegetation and 
many have become widespread weeds. The young leaves of a number of species 
are used as pot herbs, and the grain amaranths (see under A. hybridus) have been 
an important source of food in some cultures (cf. J. D. Sauer in Ann. Missouri Bot. 
Card. 37:561-632, 1950). Forms with larger deeply red or purple colored in- 
florescences have been used for ornamental planting and in floral arrangements. 
Members of the genus are usually recognized by the short-lived weedy growth 
habit, unusual paniculate grouping of spikes at the apex of the plant (in most 
species), dense clusters of flowers and bracts, fruit loosely enclosed in the persist- 
ing perianth and bracts and usually opening by having the distal half fall away, 
and the small shiny lenticular seeds. The name Bledo is often used in Central 
America to refer to species of Amaranthus. 



BURGER: FLORA COSTARICENSIS 157 

la Plants bearing paired straight spines (5- 15 mm long) from some of the leaf axils; seeds 
0.7-1 mm broad; widespread plants from sea level to 1,600 m elevation 

A. spinosus 

Ib Plants lacking spines in the leaf axils 2a 

2a Fruiting perianth broadest above the middle and becoming partly reflexed with the 
distal half rotate; seeds ca. 0.9 mm broad; seasonally dry areas of the Pacific slope 
below 900 m elevation A. scariosus 

2b Fruiting perianth not broadest above the middle and not becoming reflexed in 
fruit 3a 

3a Fruit indehiscent and with a rugose yellowish brown surface; perianth 3-parted, 
stamens 3, floral bracts 0.5-1 mm long; rachis often visible on the spikes. .A. viridis 

3b Fruit usually circumscissely dehiscent and with a smooth surface; perianth 5-parted, 
stamens usually 5, floral bracts 1.5-4 mm long; rachis usually obscure in the spicate 
inflorescences 4a 

4a Floral bracts up to twice as long as the perianth parts and usually with conspicuous 
spine tips; seeds more than 1 mm broad; plants of waste places near habitations or 
cultivated for the seed or colorful inflorescences, common on the Meseta Central, 
1,000-2,000 m A. hybridus 

4b Floral bracts equaling the perianth in length; seeds ca. 1 mm broad; weedy plants of 
the Caribbean lowlands A. dubius 

Amaranthus dubius Martius ex Thellung, Mem. Soc. Sci. Nat. Cherbourg 
38:203. 1912. A. tristis Willd., Hist. Amaranth 21. 1790, not A. tristis L., 1753. 
Figure 28. 

Herbs, 0.2-1 (1.5) m tall, unisexual, branches ascending, leafy internodes 0.5-6 cm long, 
1-6 mm thick, at first minutely puberulent with thin curled or scurfy hairs ca. 0. 2 mm long, 
becoming glabrous and longitudinally ridged or sulcate. Leaves alternate, petioles 1-10 cm 
long, sulcate above with 2adaxial ridges continuous with the lamina margins; laminae 3-8 
(12) cm long, 2-6 (8) cm broad, ovate-rhombic to ovate-oblong or ovate elliptic, the smaller 
leaves elliptic, bluntly obtuse at the apex and often with a thin 1-2 mm mucronate 
extension of the midvein, obtuse to acute at the base and attenuate on the petiole, margin 
entire or slightly crenulate, laminae drying thin-chartaceous, sparsely and very minutely 
(0.1 mm) puberulent on the veins beneath or glabrescent, midvein impressed above, the 
4-12 pairs of major secondary veins prominent beneath. Inflorescences solitary in the leaf 
axils or in terminal paniculate arrangements, flower clusters densely aggregated along the 
flowering rachis forming spikes 4-9 (12) mm in diameter, terminal spikes to 15 (25) cm 
long, lateral spikes 0.5-6 cm long, floral bracts 1.5-2.5 mm long and usually equalling the 
flower in length, ovate to lanceolate and ending in a sharp tip; flowers unisexual with the 
male less common than the female, perianth 1.5-2 mm long, stamens 5, stigma 3. Fruit 
loosely enclosed within the subequal and loosely persisting bracts, bracteoles, and peri- 
anth, utricle 1.5-2.5 mm long with circumscissle dehiscence; seeds cochleate-orbicular 
and lenticular in cross section, 0.8-1.1 mm broad, dark brown or black and very lustrous. 

Plants of open early successional sites at altitudes below 1,000 m and flowering 
throughout the year. The species is a common weed in the Caribbean area and 
ranges from Mexico to southern South America. The species has become estab- 
lished in Europe and Africa. 

Amaranthus dubius is recognized by its open weedy lowland habitat, floral bracts 
equalling the flowers in length, and the almost circular, lenticular seeds about 1 
mm broad. This species has only been collected from the Caribbean Coastal Plain 
in Costa Rica and may not occur above 200 m elevation in our area. 

Amaranthus hybridus L., Sp. PI. 990. 1753. A. hypochondriacusL., loc. cit. 991. 
1753. Figure 28. 

Herbs, 0.3-1.5 (2) m tall, erect and often much branched, bisexual, leafy internodes 
0.5-3 cm long, 1-5 mm thick, sparsely puberulent with minute (ca. 0.2 mm) thin crooked 
hairs in early stages, becoming glabrescent and longitudinally ridged or sulcate when dry. 



3 mm 





A. hybrid us 




hybrid us 





scanosus 





dubius 




spinosus 





cruentus 





viridis 
AMARANTH US 

FIG. 28. Amaranthaceae: species of Amaranthus, after Sauer. 



158 



BURGER: FLORA COSTARICENSIS 159 

Leaves alternate, petioles 1-8 (12) cm long, sulcate above with 2 adaxial ridges continuous 
with the lamina margins, sparsely and minutely puberulent; laminae (2) 4-10 (15) cm long, 
1-7 (10) cm broad, ovate to rhombic or narrowly ovate-elliptic in smaller leaves, bluntly 
obtuse in larger leaves or acute in smaller leaves, with a thin 2-mm extension of the 
midvein beyond the lamina, margins entire or slightly crenulate, lamina drying char- 
taceous, glabrous or very sparsely puberulent with thin crooked hairs only 0.1-0.2 mm 
long, midvein impressed above, the 6-10 pairs of major secondary veins pale in color and 
prominent beneath. Inflorescences terminal and axillary, spicate or the spikes in terminal 
paniculate arrangements, 1-18 cm long, the individual spikes 5-15 mm thick, flower 
clusters closely congested and the rachis usually obscure, bracts subtending the flower 
clusters 2-4 mm long with almost half the length of the bract made up of a distal stiff spine, 
bracts mostly twice as long as the perianth parts; flowers unisexual or bisexual, perianth 
5-parted, 1.3-2.3 mm long, thin, stamens 5, stigmas 3. Fruit loosely enclosed in the small 
persisting perianth and larger stiff bracts, a thin-walled utricle with circumscissle de- 
hiscence near the middle; seeds 1-1.4 mm broad, cochleate-orbicular in outline and thick- 
lenticular in cross section, edge with a weakly defined ridge, dark reddish brown to black, 
lustrous. 

Plants of open fields, roadsides, and early successional habitats and now natu- 
ralized throughout the world in both tropical and temperate areas. In Costa Rica, 
the species has only been collected between 1,000 and 1,700 m elevation near the 
towns and cities of the eastern part of the Meseta Central (San Pedro de Puriscal 
to San Jose and Cartago); probably capable of flowering at any time of the year in 
our area. 

Amaranthus hybridus is recognized by the spine-tipped bracts often twice as long 
as the perianth parts, the minute puberulence of younger parts and leaves, long 
petioles, and the dark shiny seed usually more than 1 mm broad. The plants are 
often marked with pink, red, or purple and seem to be collected only near the 
more densely populated or well-traveled areas of Central America. 

Amaranthus hybridus subsp. cruentus (L.) Thellung (in Asch. & Graebn., Synop- 
sis 5:243, 1914), more often referred to as Amaranthus cruentus L. and also placed 
under A. caudatus L., is the commonly cultivated grain amaranth of northern 
Central America. These plants are grown for ornament, are occasionally used as 
pot herbs, and are an important grain in some areas. They differ in having more 
reddish coloring in the floral bracts, the larger utricle exceeding the perianth parts, 
the shorter floral bracts, and the lateral spikes of the terminal panicle being more 
divergent than those in plants of typical A. hybridus. The two entities, whether 
species or subspecies, are very closely related and, though extensively cultivated 
in Guatemala, we have seen no authentic material of subspecies cruentus from 
Costa Rica. 



Amaranthus scariosus Benth., Bot. Voy. Sulph. 158, pi. 51, 1844. Figure 28. 

Herbs, 0.5-1.5 (2) m tall, erect and usually much branched, unisexual, leafy internodes 
0.5-4 cm long, 1.2-6 mm thick, glabrous or the new growth with minute puberulence, 
stems often pink in life, terete. Leaves alternate, petioles 2-10 cm long, sulcate above with 
adaxial ridges continuous with the lamina margins; laminae 2-9 (12) cm long, 1-5 cm 
broad, ovate to rhombic or elliptic-ovate (ovate-lanceolate in smaller leaves), tapering to an 
obtuse apex, the midvein extended less than 1 mm beyond the lamina, obtuse to cuneate 
at the base and slightly decurrent on the petiole, margins entire, the laminae drying 
membranaceous to very thin-chartaceous, smooth and essentially glabrous above and 
below, midvein impressed above, the 7-12 pairs of major secondary veins pale in color and 
prominent beneath. Inflorescences terminal or axillary, small spikes to paniculate arrange- 
ments of spikes, 0.5-25 cm long, often densely clustered on the distal part of the stem, 
floral bracts 2-4 mm long, subulate-lanceolate and sharp-tipped, green along the midrib, 
slightly exceeding the flowers; flowers unisexual, female perianth parts 5, ca. 3 mm long 



160 FIELDIANA: BOTANY 

and 1.5 mm broad, obovate and broadest above the middle, with a green midrib and broad 
translucent margins, rounded apically, stamens 5, stigmas 3. Fruit loosely enclosed within 
bracts and perianth, the perianth parts becoming partly reflexed and rotate in form, utricle 
shorter than the tubelike base of the perianth; seed ca. 0.9 mm broad, orbicular or 
cochleate-orbicular, thick-lenticular in cross section, smooth and very lustrous, dark 
brownish black. 

Weedy plants of open fields and forest edges on the seasonally very dry Pacific 
slope of northern Costa Rica below 900 m elevation; flowering and fruiting mate- 
rial has been collected from late December through February. The species ranges 
from southwestern Mexico along the Pacific lowlands to Guanacaste Province in 
Costa Rica. 

Amaranthus scariosus is recognized by its unusual female perianth parts which 
are broadest above the middle and become reflexed above the middle to form a 
tubelike lower basal part and a rotate distal part. The general lack of pubescence, 
long-petioled leaves, and restricted habitat in seasonally deciduous areas further 
distinguish this species. The species probably occurs in northernmost Puntarenas, 
but has not been collected outside of Guanacaste in Costa Rica. It is interesting 
that a plant of weedy early successional habitats has such a restricted geographical 
range. 

Amaranthus spinosusL., Sp. PL, 991. 1753. Figure 28. 

Herbs, 0.5-1.5 (2) m tall, erect and with spreading branches, bisexual, leafy internodes 
0.3-5 (8) cm long, 0.7-4 mm thick (dry), smooth and glabrous or sparsely and very 
minutely puberulent in early stages, often reddish or purplish in life and becoming irreg- 
ularly longitudinally striate when dry, paired sharp spines 8-15 mm long and ca. 1 mm 
thick at the base often arising from the leaf axils and oriented ca. 90 from the stem, sulcate 
adaxially. Leaves alternate, often variable in size on the same stem, petioles 0.5-6 (8) cm 
long, less than 1 mm broad (dry), slightly sulcate above with 2 adaxial ridges continuous 
with the laminae margins; laminae 1-10 (12) cm long, 0.6-3.5 (5) cm broad, narrowly 
elliptic to elliptic-lanceolate or ovate-elliptic, bluntly to sharply acute and rounded at the 
tip, often with a slender terminal spine 1-3 mm long, acute or obtuse at the base and 
decurrent on the petiole, margin entire, the laminae drying thin-chartaceous or mem- 
branaceous, smooth and glabrous, midvein impressed above with 4-7 pairs of major 
secondary veins drying pale in color and prominent beneath. Inflorescences terminal or 
from the axils of distal leaves, varying (often on the same plant) from small axillary 
fascicles or glomerules ca. 10 mm in diameter to densely flowered spikes 1-8 (14) cm long 
and 5-10 mm thick, the spikes often subtended by paired spines 3-6 mm long, bracts 
variable and often resembling the spines, 2-5 mm long, ovate to subulate; flowers uni- 
sexual with the male flowers at the tips of spikes and the female in the lower (proximal) 
glomerules, perianth 5-parted, 2-2.5 mm long in the male and ovate-oblong, 1.5-2.5 mm 
long and oblong-spatulate in the female, scarious, the midvein green and margins trans- 
lucent, stigmas slender, papillate-puberulent, to 1.5 mm long. Fruit loosely enclosed in the 
persisting perianth, utricle ca. 1.5 mm long, pale brown with circumscissle dehiscence or 
indehiscent; seed cochleate-orbicular, lenticular in cross section, 0.7-1 mm broad, dark 
brown and very shiny lustrous. 

Plants of open sites and early secondary growth from sea level to 1,600 m 
elevation on both the seasonally dry Pacific slope and in the evergreen Caribbean 
formations; probably flowering throughout the year in Costa Rica, but collected 
primarily in June and July; collections from the deciduous lowlands of Guanacaste 
have been made primarily between June and January. This species is now wide- 
spread in the warmer parts of the world. 

Amaranthus spinosus is recognized by the paired spines arising from the leaf 
axils, generally glabrous parts, and small seeds. An unusual collection by John 
Taylor (4432 NY) with the floral bracts considerably more spiny than usual and 



BURGER. FLORA COSTARICENSIS 161 

collected on Volcan Irazu at 3,200 m elevation is included here. However, it is 
unlikely that populations of this species persist above 2,000 m elevation in Costa 
Rica. 

Amaranthus viridisL., Sp. PI., ed. 2, 1405. 1763. A. gracilis Desf., Tabl. Bot. 43. 
1804. Figure 28. 

Herbs to ca. 1 m tall, erect or decumbent, bisexual, leafy internodes 0.2-3 (5) cm long, 
0.84 mm thick, glabrous or very sparsely and minutely puberulent in early stages. Leaves 
alternate, petioles very slender (dry), 0.3-10 cm long, often very variable in length on the 
same plant, slightly sulcate above with adaxial margins continuous with laminae margins; 
laminae 0.5-5 (7) cm long, 0.3-3 (4) cm broad, ovate to bluntly triangular or rhombic, 
elliptic or elliptic-ovate, rounded at the bluntly obtuse apex and emarginate at the tip with 
the midvein extended less than 1 mm beyond the lamina, abruptly narrowed or rounded 
at the obtuse to subtruncate base, decurrent on the petiole, margin entire or slightly 
crenulate when dry, the laminae drying very thin-chartaceous, smooth and glabrous, with 
4-8 pairs of major secondary veins prominent below. Inflorescences usually solitary, 
terminal or in the axils of distal leaves, spikelike with clusters of flowers borne on an 
unbranched axis, spikes 1-8 (12) cm long, 3-7 mm thick, flower clusters often separate and 
the rachis visible, floral bracts and bracteoles subequal, 0.5-1 mm long, thin and scarious; 
flowers unisexual, longer than the bracts, perianth 3-parted, 1-1.5 mm long, stamens 3, 
stigmas 3. Fruit a rugose utricle clearly exceeding the persisting perianth and bracts, ca. 
2 mm long, indehiscent, pale yellowish brown; seed 0.9-1 mm broad, cochleate-orbicular 
in outline, thick-lenticular, very dark brown or black, moderately lustrous, with a weakly 
defined ridge around the margin. 

Small weedy plants of open sandy and gravelly soils and often seen as pioneers 
on bare soil from near sea level to 1,500 m elevation; probably capable of flowering 
throughout the year in our area. This species is a pantropical weed. 

Amaranthus viridis is recognized by its very small stature, glabrous parts, small 
bracts and bracteoles, 3-parted perianth, and indehiscent fruit with rugose sur- 
face. These plants are often found as pioneers on open soil, but they appear to be 
quite rare in our area, with only a few collections from Guanacaste and the eastern 
side of the Meseta Central. 



CELOSIA Linnaeus 

Annual or perennial herbs or subshrubs, erect (in ours) to sarmentose or climbing, 
bisexual, glabrous to sparsely puberulent. Leaves alternate, often decurrent on the stem, 
petioles often with lateral margins gradually expanding into the lamina margins; laminae 
entire and pinnately veined. Inflorescences usually dense spikes (heads), axillary or termi- 
nal, solitary, or variously disposed in paniculate arrangements, the spikes usually sub- 
sessile, the panicles sessile or pedunculate, the axes bearing the spikes usually un- 
branched in our species, each flower subtended by a bract and 2 lateral bracteoles. Flowers 
bisexual, sessile or subsessile, perianth of 5 free and equal or subequal parts, scarious, 
longitudinally ribbed and slightly convex, persisting but not enlarging in fruit, stamens 5, 
the filaments united at the base to form a cup shorter than the ovary, anthers 4-celled, and 
introrse, ovary globose to ellipsoid, 1-locular, with several to many ovules on a basal 
placenta, style short to long, with 2 or 3 stigmas. Fruit a capsule, usually with circumscissle 
dehiscence, loosely included within the persisting bracts and perianth parts; seeds (1) 2 to 
many, usually cochleate-lenticular to reniform, smooth and usually lustrous, brown to 
black, the embryo annular. 

A genus of about 40 species, mostly in Asia and Africa with only the following 
two species to be expected in southern Central America. Young leaves and shoots 
of C. argentea are sometimes used as vegetables, though the plants are mostly 
cultivated for ornament. The native species of the genus are apparently quite local 
or rare in Central America. 



162 FIELDIANA: BOTANY 

la Plants grown for ornament, rarely escaping; inflorescences colorful white to rose red 
or magenta spikes, 5-25 cm long and 1.5-3 cm thick, flowers ca. 8 mm long 

C. argentea 

Ib Plants known in Costa Rica only from the deciduous forest formations of northeastern 
Guanacaste Province; inflorescences of small greenish spikes, 0.5-3 cm long, often 
borne in paniculate arrangements, flowers ca. 5 mm long C. virgata 

Celosia argentea L., Sp. PI. 205. 1753. C. cristate L., loc. cit. Figure 29. 

Annual herbs, erect, 0.2-1 (rarely 2) m tall, branched or unbranched, leafy internodes 
0.5-9 cm long, 1-7 (12) mm thick, glabrous, becoming longitudinally ridged or grooved. 
Leaves alternate in a spiral, petioles 4-30 mm long, with lateral margins that expand 
gradually to the lamina margins, decurrent on the stem; laminae 3-15 cm long, 0.5-6 cm 
broad, ovate to ovate-elliptic or narrowly lanceolate, acute to acuminate at the apex, 
tapering gradually or abruptly to the base and decurrent on the petiole, margins entire, the 
laminae drying stiffly chartaceous, glabrous, the 5-8 pairs of major secondary veins 
strongly ascending. Inflorescence usually terminal and solitary or a few clustered together, 
usually a densely flowered thick (1-2 cm) spike, 1.5-15 (25) cm long, occasionally with 
abnormal (fasciated) growth patterns and broadly expanded or divided at the apex, pe- 
duncles glabrous, 0.3-12 cm long, floral bracts ca. 6 mm long, lanceolate, lustrous whitish 
to pinkish, decurrent on the rachis, carinate and mucronate; flowers 8-10 mm long, 
subsessile to short (2 mm) pedicellate, perianth thin and dry (scarious), lustrous, silvery 
white to deep rose red, 6-9 mm long, persisting in fruit, style 3-6 mm long, usually 
exceeding the perianth. Fruit a circumscissile capsule, 3-4 mm long, hidden within the 
persisting perianth and bracts, with (1) 3-9 seeds per fruit; seeds 1.5-2 mm broad, 
cochleate-lenticular, very lustrous, black or dark reddish brown. 

Plants grown in gardens for their colorful inflorescences and only rarely escap- 
ing (especially along streams); flowering throughout the year and rarely encoun- 
tered above 1,400 m elevation in Central America. The species is of uncertain 
origin and is now widely cultivated throughout the tropics. 

Celosia argentea is recognized by its alternate leaves with laminae decurrent on 
the petioles, glabrous parts, and thick colorful spikes with stiff dry persisting 
bracts and perianth parts. The long-lasting lustrous white to deep rose red in- 
florescences make these plants very useful for floral arrangements. In some plants, 
the inflorescences develop a broad flattened form that may be digitate or ruffled. 
This form is often called variety cristate (L.) Voss, the "Garden cockscomb." 
Among the names associated with these plants in Central America are Abanico, 
Amaranto, Amor seco, Boria, Cresta de gallo, Flor de mano, Mano de leon, Mono, Mono 
de reina, Rabo de gato, and Terciopelo. 

Celosia virgata Jacq., Coll. Bot. 2:279. 1788, or a closely related species. Fig- 
ure 29. 

Erect herbs, 0.5-1.5 m tall, leafy internodes 5-80 mm long 1-4 mm thick, glabrous or 
minutely (0.5-2 mm) puberulent with thin crooked hairs, quickly becoming glabrous. 
Leaves alternate in a spiral, decurrent on the stems, petioles 1-8 cm long, with lateral 
margins gradually expanding to the lamina base; laminae 3-15 cm long, 1-6 cm broad, 
ovate to ovate-ellitpic or the smaller leaves often lanceolate, acute to short-acuminate at 
the apex, often with a sharp tip 1-3 mm long, acute to obtuse at the base and decurrent 
on the petiole, margin entire, drying thin-chartaceous, laminae essentially glabrous, with 
5-7 pairs of major secondary veins. Inflorescences basically of short (8-20 mm) spikes, 
solitary and axillary to terminal and variously clustered, the paniculate clusters usually 
with a single primary axis 5-20 cm long and with separate or congested spikes alternating 
along the axis (our material differs from all other collections of the species in having 
slender peduncles or with a 2-5 cm long spike-free basal portion on the inflorescence axis, 
similar peduncles in other collections rarely exceed 2 cm), bracts and lateral bractets 
subequal, 2-3 mm long, cuspidate with a single midvein and thin hyaline margins, nar- 



CELOSIA 
argentea 



CHAMISSOA 
altissima 



5 mm 




PLEUROPETALUM 
sprucei 

FIG. 29. Amaranthaceae: Costa Rican representatives of the genera Celosia, Chamissoa, 
and Pleuropetalum. 



163 



164 FIELDIANA: BOTANY 

rowly triangular to lanceolate; flowers subsessile, ca. 5 mm long, perianth parts with 3-7 
abaxially prominent longitudinal ribs in the basal half, oblong-lanceolate. Fruit with (1) 
3-8 seeds, utricle shorter than the perianth parts; seeds 0.7-1 mm broad, cochleate- 
lenticular, black, lustrous. 

Uncommon herbs found in both moist evergreen and in seasonally very dry 
deciduous formations, from near sea level to 700 m elevation (rarely to 1,200 m); 
flowering and fruiting collections have been made from September to March in 
Central America. The species ranges from central Mexico through Guatemala, El 
Salvador, Honduras, and has recently been collected near Santa Rosa in north- 
western Guanacaste Province, Costa Rica. 

Celosia virgata (in a wide sense) is characterized by its short stature, alternate 
leaves with laminae decurrent on the petiole, general lack of pubescence, in- 
florescences composed of short spikes often aggregated on unbranched axes, 
single-veined translucent bracts, stiff multiple-ribbed perianth, and small dis- 
tinctive shiny seeds. A single recent Costa Rican collection by Ronald Liesner 
(4303) is tentatively placed here. It differs from most specimens of the species in 
a number of ways: The leaf axils do not have the little axillary leaves usually found 
in the species, the inflorescences of the Costa Rican collection have clearly defined 
peduncles, and there are apparently fewer but slightly larger seeds in each fruit. 
Nevertheless, stature, leaves, bracts, and flowers are virtually identical to those of 
typical Mexican and Guatemalan collections. It may be that the plants from near 
Santa Rosa are worthy of subspecific recognition. 



CHAMISSOA Humboldt, Bonpland & Kunth 

REFERENCE: S. H. Sohmer, A revision of Chamissoa. Bull. Torrey Hot. Club. 
104:111-126, 1977. 

Shrubs, subshrubs, or lianas, usually climbing or clambering over adjacent vegetation, 
stems glabrous or puberulent, terete; stipules absent. Leaves alternate and simple, pet- 
iolate, entire or slightly undulate, pinnately veined, glabrous or sparsely puberulent. 
Inflorescences terminal or axillary, solitary, leaves of the upper (distal) nodes often un- 
developed and the inflorescence a compound panicle, the flowers borne in small cymules 
of 2-20 flowers, the cymules usually on unbranched axes and in arrangements of spicate 
branches, the flowers subsessile or very short-pedicellate and subtended by a bract and 2 
lateral bracteoles, bract and bracteoles subequal, persistent and becoming stiff and dry; 
flower small and radially symmetrical, bisexual or functionally unisexual, perianth of 5 
ovate-lanceolate imbricate parts, stiff and persisting but not enlarging in fruit, stamens 5, 
united near the base to form a short tube, pseudostaminodial appendages absent, pistil 
with 1 locule and 1 ovule from a basal placenta, style 1 with 2 slender stigmas. Fruit a 
thin-walled capsule opening by circumscissle dehiscence near the top (a pixidium);. seeds 
lenticular, black or marked, embryo small with much endosperm. 

A genus of two species ranging from Mexico through the West Indies and 
Central America to nearly all of South America excepting Chile and southern 
Argentina. The alternate leaves, unusual fruit, and dense inflorescences made up 
of racemose or spicate arrangements of cymules help distinguish the genus. 

la Plants clambering or climbing, often becoming lianas over 2 m high; seeds enclosed by 
2-valved arils; flowers bisexual or female, ovary over 2 mm long, tubular or oblong in 
form; common lowland plants C. altissima 

Ib Plants erect or clambering over others, up to 2 m tall but never becoming lianas; 
seeds with minute and inconspicuous arils; flowers always bisexual, ovary usually less 
than 2 mm long, ovate to globose in form; plants only rarely collected in Central 
America . . . .C. acuminata 



BURGER: FLORA COSTARICENSIS 165 

Chamissoa acuminata Martius, Nov. Actorum Acad. Caes. Leop. -Carol. Nat. 
Cur. 13:286. 1826. 

Herbs or subshrubs, erect or clambering, 1-2 m tall, leafy internodes ca. 3-6 cm long, 
slender and glabrescent in ours. Leaves alternate, petioles 1-3 (7) cm long, slender; lami- 
nae 3-11 (14.5) cm long, 1-4 cm broad, narrowly ovate to lanceolate, tapering gradually 
to the acute or acuminate apex, rounded to obtuse at the base, margins entire, glabrous or 
puberulent, with 3-7 pairs of major secondary veins. Inflorescences terminal or axillary, 
1-6 (30) cm long, usually simple and spikelike, sometimes compound and paniculate, 
glomerules with 3-7 flowers, bracts and bracteoles 1.5-2.5 mm long, perianth and bracts 
greenish white or yellowish, perianth 5-parted, 2.4-4 mm long, ca. 1 mm broad; stamens 
5; ovary ovate to globose, 1.5-2.3 mm long, style 0.5-1.5 mm long, dilated at the base, 
stigmas shorter than the style. Fruit a capsule, usually opening by a circular lid; seed 
1.5-2.5 mm long, black and lustrous. 

Though ranging from southern Mexico to Bolivia and Paraguay, this species has 
not been collected in Costa Rica. The type collection of C. acuminata var. swansonii 
Sohmer comes from Bocas del Toro, Panama (Wedel 1695), and our plants should 
be identical. 

Chamissoa acuminata is very similar to C. altissima, but does not become a liana 
and differs in floral structure. In addition, the flowers seem to be less robust, and 
the stems usually are more slender. 

Chamissoa altissima (Jacq.) H.B.K., Nov. Gen & Sp. 2:197, pi. 125. 1817. Celosia 
paniculata L., Sp. PI. ed. 2, 298, not L., 1753. Achyranthes altissima Jacquin, Enum. 
PI. Carib. 17. 1762. Chamissoa macrocarpa H.B.K., Nov. Gen. & Sp. 2:197. 1817. 
Figure 29. 

Clambering shrubs to 2 m tall or woody vines to over 10 m long, leafy internodes 2-10 
cm long, 1-4 mm thick, very sparsely puberulent with minute (0.1-0.5 mm) hairs, be- 
coming longitudinally striate when dry. Leaves alternate and usually in a spiral, petioles 
0.5-3 (7) cm long, 0.5-1.5 mm broad, very sparsely and minutely puberulent, sulcate 
above with adaxial ridges continuous with the laminae margins; laminae 3-15 (19) cm 
long, 1.5-7 (9) cm broad, narrowly ovate to broadly ovate or lanceolate, tapering gradually 
to the acute or acuminate apex, acute to obtuse or truncate at the base, often rounded and 
truncate in larger laminae, margins entire or slightly undulate, somewhat decurrent on the 
petiole, the laminae drying thin to stiff chartaceous, smooth on both surfaces, very 
sparsely puberulent with minute whitish hairs with 3-6 pairs of major secondary veins. 
Inflorescences basically small cymules densely clustered on a spikelike rachis 1-15 cm 
long, the spikelike axes solitary and axillary or in complex terminal paniculate arrange- 
ments formed by the failure of distal leaves to develop, the cymules short (1-3 mm) 
pedunculate and bearing 2-8 (20) flowers, flowers very short pedicellate and subtended by 
a bract and 2 lateral bracteoles; flowers yellowish to white or greenish white to rose, 
perianth parts 2-3 (5) mm long, stamens with filaments 2-3 mm long, anthers very small 
(0.2 mm) in functionally female flowers, to 1 mm long in functionally male flowers, pistil 
2-3 mm long in functionally female flowers, style 0.4-1 mm long, the 2 linear stigmas 
minutely papillose. Fruit 3-4 mm long, 1.5-2 mm broad, somewhat ellipsoid with trun- 
cated apex and base, opening with a circular lid near the top; seeds lenticular, orbicular 
in outline, ca. 2 mm broad, black and lustrous. 

Climbing or clambering plants of both the evergreen wet and seasonally very 
dry deciduous formations from sea level to 1,500 m elevation, but most common 
below 300 m; while occasional flowering plants have been found from May to 
November, the majority of flowering and fruiting collections have been made 
from December to April. The species ranges from Mexico through Central Amer- 
ica and the West Indies to northern Argentina. 

Chamissoa altissima is recognized by the vining or clambering sparsely puber- 
ulent stems with alternate thin-petioled leaves, spicate or paniculate arrange- 



166 FIELDIANA: BOTANY 

ments of densely or loosely aggregated flower clusters, flowers with stiff persisting 
pale-colored perianth and bracts, and the thin- walled fruit that opens by a circular 
lid near the top bearing a short style and 2 stigmas. Plants with flowers pinkish 
red to dark purple or with reddish ovaries often having three stigmas have been 
designated as variety rubella by Sohmer. 

CYATHULA Loureiro 

Herbs or subshrubs, annual or perennials, erect, prostrate, or decumbent, usually devel- 
oping a woody base and often with long internodes, bisexual; stipules absent. Leaves 
opposite and simple, petiolate, laminae entire and pinnately veined. Inflorescences termi- 
nal or axillary, solitary or 3 at terminal nodes, spicate with a single unbranched axis 
bearing very short-pedunculate flower fascicles (glomerules), the fascicles with 1 to several 
fertile bisexual flowers and perianth parts and bracts of highly modified sterile flowers, the 
fascicles spicate or capitate and usually subtended by a bract and several bracteoles of 
similar size, bracts and bracteoles usually aristate, parts of the sterile flowers developing 
elongate spines or bristles ending in sharp hooks as the fruit develop; functional flowers 
bisexual, small and radially symmetrical, perianth of 5 free subequal, imbricate parts, stiff 
and persisting but not enlarging in fruit, with 1-5 longitudinal ribs, stamens 5, united at 
the base to form a tube with small pseudostaminodial appendages, anthers 4-thecous, 
dehiscing introrse, ovary ovoid to obovoid, 1-locular, the solitary ovule pendulous from 
a long funicle arising from a basal placenta, style 1 with capitate stigma. Fruit an inde- 
hiscent utricle, tightly enclosed by the stiff persisting perianth; seeds reniform-oblong to 
cochleate-orbicular, testa lustrous brown. 

A genus of about 20 species probably native to the tropics of Asia and Africa, 
with two species introduced into the neotropics. Our members of the genus are 
recognized by their small weedy habit, opposite sparsely sericeous leaves and long 
spikelike inflorescences with unusual flower fascicles that become reflexed on the 
spike and develop elongate spines with hooked tips in later stages. These plants 
resemble and are closely related to Achyranthes. 

la Fruiting fascicles developing 5-15 hooked spines to 4 mm long, perianth parts ca. 
4 mm long; seeds to 2 mm long; terminal spikes becoming 1-2 (4) x as long as the 
subtending leaves; larger laminae usually over 6 cm long, narrowly elliptic and long 
acuminate C. achyranthoides 

Ib Fruiting fascicles developing over 20 hooked spines to 2 mm long; perianth parts 2-3 
mm long; seeds 1-1.5 mm long; terminal spikes becoming 2-10 x as long as the 
subtending leaves, larger laminae usually less than 7 cm long, usually rhombic and 
obtuse to acute at the apex C. prostrata 

Cyathula achyranthoides (H.B.K.) Moq., in DC., Prodr. 13, pt. 2:327. 1849. 
Desmochaeta achyranthoides H.B.K., Nov. Gen. & Sp. 2:210. 1817. Figure 25. 

Herbs or subshrubs to 1 (2?) m tall, erect or decumbent and rooting at the lower nodes, 
leafy internodes 2-18 cm long, 1-4 mm thick, sparsely puberulent with thin ascending 
sericeous hairs, more densely puberulent at the nodes. Leaves opposite and decussate, 
petioles 2-6 (10) mm long, appressed puberulent, with lateral margins continuous with the 
lamina margins; laminae 3-15 (20) cm long, 1.5-5 (7) cm broad, the larger laminae elliptic 
to narrowly elliptic and tapering gradually to both apex and base, the smaller laminae 
more abruptly tapering and often rhombic-ovate, acuminate to acute at the apex (in larger 
laminae) acute or obtuse to attenuate at the base, margin entire or slightly undulate and 
decurrent on the petiole, laminae drying thin- to stiff-chartaceous, smooth to the touch 
above and below, sericeous with thin whitish appressed-ascending hairs 0.5-2 mm long 
on both surfaces but usually more dense beneath, with 4-7 pairs of major secondary veins. 
Inflorescences terminal or axillary, spicate, 5-20 cm long, 5-10 mm broad, peduncle 0.5-8 
cm long with thin whitish hairs ca. 0.5 mm long, bracts subtending the flower fascicles 
(glomerules) 1.5-3 mm long, thin-translucent and broadly lanceolate, mucronate or aris- 



BURGER: FLORA COSTA RICENSIS 167 

late, each fascicle borne on a very short (0.5 mm) peduncle and becoming reflexed, the 
flower fascicles tending to remain closely adjacent even in fruit, the fascicle or glomerule 
usually with 1 fertile flower and 1 sterile flower, the hooked (uncinate) spines 1-4 mm long 
and often exceeding the perianth; flower with the perianth parts ca. 4 mm long and 1.5 mm 
broad, strongly ribbed and sparsely puberulent with thin whitish hairs. Fruit very difficult 
to separate from the enclosing perianth, utricle ovoid and operculate, 1.5-2.5 mm long; 
seeds somewhat oblongoid, reniform to cochleate-orbicular, 1.5-2 mm long, ca. 1 mm 
thick, lustrous brown. 

Plants of open or partly shaded sites in both moist evergreen and seasonally 
very dry formations, from sea level to 1,000 m elevation but rarely collected above 
700 m; flowering and fruiting throughout the year in Costa Rica, but collected 
most often from November to May. In seasonally very dry Guanacaste, the col- 
lections are primarily from December and January. The species ranges from Mex- 
ico and the West Indies to Brazil and throughout much of central Africa. 

Cyathula achyranthoides is recognized by the spikelike inflorescences with 
densely crowded flower fascicles (glomerules) that become reflexed on the spikes 
and develop five to 15 stiff hooked spines. The plants are usually found in recently 
disturbed areas or early secondary growth in both open and shaded sites. The 
plants are most common in the Caribbean lowlands (0 to 200 m). 

Cyathula prostrata (L.) Blume, Bijdr. Ned. Ind. 549. 1826. Achyranthes prostrata 
L., Sp. PI. ed. 2, 296. 1762. Figure 25. 

Herbs or subshrubs, 0.2-0.8 (1) m tall, erect or procumbent, leafy internodes 2-15 cm 
long, 0.6-3 mm thick, sparsely puberulent with thin spreading or ascending whitish hairs 
0.3-1.5 mm long, stems 4-angled or with 4 longitudinal ridges. Leaves opposite and 
decussate, petioles 2-12 mm long, with narrow lateral margins continuous with the lamina 
margins, sparsely puberulent; laminae 1-6 (8) cm long, 0.8-4 cm broad, broadly elliptic to 
rhombic, obtuse to acute at the apex and rounded or obtuse at the base, margin entire and 
decurrent on the petiole, the laminae drying thin to stiff chartaceous, smooth on both 
surfaces, sparsely strigillose above and below with thin usually straight ascending hairs 
0.3-1 mm long, with 3-5 pairs of major secondary veins. Inflorescences terminal or 
axillary, solitary or 3 at a terminal node, spicate, 5-20 (30) cm long, 4-8 mm broad, 
elongating in fruit, peduncles 2-5 cm long, the flower fascicles (glomerules) at first tightly 
congested and spreading but becoming separate and reflexed on the narrow (1 mm) 
sparsely puberulent rachis, the flower clusters borne on short (0.2-1 mm) peduncles and 
subtended by short (1 mm) lanceolate hyaline bracts, usually with 3 bisexual flowers and 
2-4 mm long, hooked (uncinate) awns developing as the fruit matures, 1-2 mm long and 
not usually exceeding the fascicle in length, often more than 20 per fascicle; flowers with 
perianth parts 2-3 mm long, composed of 5 scarious subequal parts. Fruit tightly enclosed 
within the stiff persisting perianth parts, utricle ovoid, 1-2 mm long, inconspicuously 
operculate; seeds slightly flattened and reniform to cochleate-orbicular, ca. 1 mm long. 

Weedy plants of open or shaded sites in disturbed areas, stream beds, and early 
successional vegetation in wet and moist evergreen formations between sea level 
and 1,000 m elevation; probably flowering throughout the year, but with no 
collections having been made from July to October. The species (probably intro- 
duced) has a discontinuous range from Mexico and the West Indies to Brazil; the 
species ranges widely across central Africa, tropical Asia, and Oceania. 

Cyathula prostrata is recognized by the long spicate inflorescences, with fascicles 
of flowers that become separate and reflexed on the rachis, and the later devel- 
opment of many short hooked spines in each flower fascicle. The small stature of 
the plants, their angled stems, small opposite leaves, and the short stiff perianth 
that protects the fruit are also characteristic. The plants are often found along 
stream edges in evergreen formations in our area. 



168 FIELDIANA: BOTANY 

GOMPHRENA Linnaeus 

REFERENCE: J. A. Mears, The Linnaean species of Gomphrena L. Taxon 29:85-95, 
1980. 

Annual or perennial herbs, prostrate or erect, stems sometimes slightly thickened at the 
nodes, usually puberulent with thin unbranched multicellular hairs. Leaves opposite, 
sessile or petiolate, simple and entire, often with a small spine at the lamina apex, usually 
puberulent. Inflorescences terminal or axillary, solitary or less often clustered, sessile, 
heads or short thick spikes, the bracts, bracteoles, and flowers densely crowded together, 
each flower subtended by a single abaxial bract and 2 lateral bracteoles, the bracteoles 
usually much larger than the bracts, bracteoles concave and often with a wing or crest 
developed from the dorsal (abaxial) side of the midrib, flowers bisexual, sessile, perianth 
of 5 equal or subequal perianth parts, wooly (lanate) hairs usually borne on the base of the 
perianth and enlarging in fruit, stamens 5, filaments completely united to form a tube with 
the anthers sessile near the apex of the tube, 2-lobed pseudostaminodia usually present 
at the apex of the tube between the anthers, ovary superior, locule 1, ovule solitary, style 
1 with 2 slender stigmas. Fruit an indehiscent utricle, usually tightly included within the 
persisting bracteoles and perianth; seeds cochleate-orbicular, smooth, embryo annular. 

A pantropical genus of nearly 100 described species. Our species of Gomphrena 
are easily recognized by their dense heads and spikes subtended by two small 
leaves and by the unusual dorsal crests on the upper half of each of the paired 
lateral bracteoles. These dorsal (abaxial) crests are serrate or crenate along their 
margins. A similar species, G. filaginoides Mart. & Gal., with small (1 to 3 cm) 
leaves and white heads almost 2 cm broad, has recently been collected in Hon- 
duras and Nicaragua. Gomphrena elegansMart. and G. t uerckheimii (Vatke) Uline & 
Bray have been reported from Guatemala and Honduras, but not Nicaragua. 
These last two species are quite similar, with terminal heads that are not sub- 
tended by small leaves and bracteoles that do not obscure the flowers or bear 
conspicuous dorsal crests. These last two species look very much like some of our 
species of Alternanthera (q.v.). 

la Flower heads not subtended by a pair of small opposite leaves, the paired lateral 
bracteoles lacking conspicuous dorsal crests, tips of the flowers usually visible within 
the bracteoles. Weedy plants of northern Central America but not yet collected 
from Costa Rica. See the discussion under the genus and compare with species of 
Alternanthera. 

Ib Flower heads of spikes subtended by a small pair of leaves, the paired lateral bracteoles 
with conspicuous serrate to crenate dorsal crests, flowers hidden within the bracteoles 
both in flower and fruit 2a 

2a Plants commonly grown in gardens and used in floral arrangements; heads of spikes 
ca. 2 cm thick, often bright pink or magenta, flowers and bracteoles long-persisting 

G. globosa 

2b Plants native weeds of open sunny sites below 1,300 m elevation; floral heads or spikes 
ca. 1 cm thick, usually white, older flowers and bracteoles deciduous and only the 
smaller (3 mm ) floral bracts persisting on the lower portion of older inflorescences 

G. serrata 

Gomphrena globosa L., Sp. PI. 1:224. 1753. 

Erect or ascending annual herbs to 1 m tall. Leaves opposite, laminae 2-10 cm long, 
0.5-4 cm broad, narrowly elliptic to elliptic-oblong, acute at the apex with a small spine 
tip, with thin ascending appressed hairs on both upper and lower surfaces. Inflorescences 
solitary and terminal or rarely paired and axillary, globose heads or thick (2 cm) short (2-4 
cm) spikes, the heads or spikes subtended by small (0.5-2 cm) ovate leaves, the primary 
floral bracts small (3 mm) and hidden by the much larger (7-12 mm) lateral bracteoles, the 
paired lateral bracteoles with broad dorsal crests arising from the upper half of the midrib 
(abaxially), the crests irregularly crenate-serrate. Flowers hidden within the bracteoles, 



BURGER: FLORA COSTARICENSIS 169 

perianth parts 5-8 mm long, stamens forming a tube 4-8 mm long. Fruit an indehiscent 
utricle tightly enclosed within the persisting perianth and bracteoles; the seed cochleate- 
orbicular, flattened on the sides, 1.5-2 mm broad, reddish brown. 

Plants commonly grown as ornamentals in Central America and flowering 
throughout the year. The species is not known to have become naturalized in 
Costa Rica. The flower heads vary from pink and white to magenta or pink-purple 
in color, and because they persist long after flowering, retaining both their color 
and form, they are often used in floral arrangements. Common names are Amor 
seco, Baton, Inmortal, San Diego, and Siemprevivain Central America. "Batchelor's 
button" and "Globe amaranth" are common English names. This species is widely 
cultivated in the tropics and subtropics. 



Gomphrena serrataL., Sp. PI. 224. 1753. G. decumbens]acq., PI. Hort. Schoenbr. 
4:41, t. 482. 1804. G. dispersa Standl., Contr. U.S. Natl. Herb. 18:91. 1916. Fig- 
ure 26. 

Small herbs 10-50 (80) cm tall, prostrate or erect, annual or perennial, leafy internodes 
1-15 cm long, 0.6-2 (3) mm thick, sparsely to densely sericeous with thin ascending 
multicellular whitish hairs 1-3 mm long. Leaves opposite, often subsessile, somewhat 
articulate at the base, petioles 2-6 mm long, ca. 1 mm broad, little differentiated from the 
lamina, with 2 lateral margins continuous with the lamina margins; laminae 1.5-5 (7) cm 
long, 0.5-2 cm broad, narrowly elliptic to elliptic or ovate-elliptic, obtuse to acute at the 
apex, often with a short (0.5-1 mm) sharp stiff tip, the lamina decurrent on the petiole, 
entire, drying chartaceous, sparsely to densely sericeous above and below with thin 
ascending hairs 1-3 (4) mm long, venation pinnate with 2 or 3 pairs of major secondary 
veins. Inflorescences terminal and solitary (rarely 2), usually subtended by a pair of small 
(5-15 mm) leaves, internode below the inflorescence and its subtending leaves (peduncle 
if the leaves are considered bracts) 1-10 cm long, heads or becoming spikes as much as 3 
cm long with the earlier basal flowers and their lateral bracteoles deciduous but the smaller 
(2-3 mm) bracts persisting, the smaller bracts thin whitish translucent with thickened 
midrib forming a sharp mucronate tip, bracteoles 46 mm long, stiff whitish (rarely 
pinkish) with an apically broadened serrate crest on the back (abaxially) of the midrib; 
flowers equaling or somewhat smaller than the bracteoles and included within them, 
perianth parts ca. 4 mm long and very narrow above the base, with a dense mass of 
villous-lanate hairs on the lower third, ovary tightly enclosed within the perianth. Fruit 
enclosed within the persisting bractlets and tightly enclosed within the thin stiff perianth 
parts, the lanate hairs becoming 3 mm long; seed lenticular with flattened sides, cochleate- 
orbicular in outline, ca. 1.3 mm long, lustrous brown, with an apical notch. 

Common weedy plants of open secondary sites in both wet evergreen areas and 
in seasonally dry deciduous formations from sea level to 1,200 m elevation in 
Costa Rica; flowering throughout the year, but collected infrequently in the dry 
season (February to May). The species ranges from the southern United States 
through Central America and the West Indies to Bolivia and Argentina. 

Gomphrena serratais recognized by its short (sometimes prostrate) habit, slender 
thin ascending hairs on almost all parts, small opposite leaves with sharp tips, 
dense whitish heads and spikes with characteristic bracts and larger lateral brac- 
teoles with dorsal serrate crests, and the flowers with a dense woolly covering of 
cotton-like hairs. These are common weedy plants of open sunny sites not col- 
lected from above 1,200 m elevation in our area. The distinctions used to separate 
G. serrata and G. dispersa do not appear to be consistent or important in collections 
seen from southern Central America. These plants resemble some of our species 
of Alternanthera, but the large paired lateral bracteoles with dorsal crests immedi- 
ately distinguish this species. 



170 FIELDIANA: BOTANY 

IRESINE P. Browne 

Herbs, shrubs, lianas, or rarely trees, erect or often clambering over other vegetation, 
unisexual or bisexual, internodes terete or strongly ridged, usually puberulent in early 
stages, an interpetiolar line or ridge often present and the nodes usually thickened in age. 
Leaves opposite or subopposite but often becoming alternate in the inflorescence, petioles 
with adaxial ridges continuous with the lamina margins; laminae simple and entire or 
rarely denticulate, usually decurrent on the petiole, venation pinnate, surfaces smooth and 
rarely completely glabrous. Inflorescences terminal on the main stem or terminal on distal 
axillary shoots, paniculate, usually large and with several orders of open distant branch- 
ing, basal branches often subtended by small narrow leaves, whitish or pale yellowish, the 
flowers usually borne in small bracteate puberulent spikes, each flower subtended by a 
basal bract and 2 lateral bracteoles, bracts and bracteoles equal or dissimilar, puberulent 
or ciliolate. Flowers bisexual or unisexual, monomorphic or dimorphic, sessile or sub- 
sessile, perianth of 5 equal imbricate parts, narrowly oblong to lanceolate, often puberulent 
distally, stamens usually 5 (4, 3) united near the base to form a shallow cup, ovary 
narrowed at the base, style short with 2 or 3 slender or deltoid stigmas. Fruit an inde- 
hiscent utricle loosely or tightly enclosed by the persisting perianth and bracteoles, con- 
spicuous tufts of whitish hairs often developed from the base of the perianth abaxially; 
seed cochleate-orbicular, thin- or thick-lenticular in cross section, smooth, pale to very 
dark in color, often shiny-lustrous. 

Iresineis a genus of perhaps 40 species closely allied to Pfaffia and greatly in need 
of revision. The often unisexual flowers and the variation in size, arrangement, 
and pubescence of inflorescences, floral bracts, and floral parts all contribute to 
making specific delimitation difficult. The tufts of hairs in female and fruiting 
flowers develop from between the base of the perianth parts and the floral bracts, 
not from the interior of the perianth as in Pfaffia. Two species, /. diffusa (formerly 
/. celosia) and /. calea, are very common in secondary growth throughout Central 
America. 

KEY TO THE SPECIES OF Iresine 

la Flowers unisexual and only 0.5-1.5 mm long, whitish, subtended by bracts 0.3-1 mm 
long; inflorescences to over 50 cm long but usually less than half as broad, branches 
of the inflorescences mostly alternate, very common herbs or weak shrubs of ever- 
green and partly deciduous formations from near sea level to 2,600 m elevation 

/. diffusa 

Ib Flowers 1.2-2 mm long, unisexual or bisexual, subtended by bracts 0.3-2 mm long; 

breadth of the inflorescence usually more than half the length, distal branches of the 

inflorescence opposite or alternate; herbs, shrubs, clambering shrubs or lianas . . . 2a 

2a Spikes and flower clusters densely puberulent, branches of the inflorescence densely 

sericeous, usually opposite throughout 3a 

2b Spikes and flower clusters sparsely puberulent, branches of the inflorescence glabrous 
to sparsely and minutely puberulent, usually alternate on the primary divisions of the 

inflorescence; stigmas slender 4a 

3a Common plants of the Pacific slope and Central Highlands from 0-1,800 m 
elevation; inflorescences usually with opposite branching; flowers unisexual and 
dimorphic, whitish, stigmas linear; laminae with 4-8 pairs of major secondary 

veins /. calea 

3b Rare plants of wet forests formations at middle elevations; inflorescence- 
branching strictly opposite; flowers apparently bisexual, drying pale yellowish 
brown, stigmas rounded; laminae with 7-12 pairs of major secondary veins 

/. costaricensis 

4a Leaves linear-lanceolate to ovate-lanceolate, with 3-8 pairs of major secondary veins; 
flowers bisexual; slender stemmed herbs and subshrubs (rarely clambering), on the 

seasonally dry Pacific slope below 800 m elevation /. angustifolia 

4b Leaves ovate to ovate-lanceolate, with 6-13 pairs of major secondary veins; flowers 
functionally unisexual; clambering shrubs and vines of wet forest formations between 
ca. 1,000 and 2,000 m elevation . . . . /. arrecta 



IRESINE 
diffusa 




IRESINE 
arrecta 



FIG. 30. Amaranthaceae: some species of Iresine. 



171 



172 FIELDIANA: BOTANY 

Iresine angustifolia Euphrasen, Beskr. St. Barthel. 165. 1795. /. elatior Rich., in 
Willd., Sp. PI. ed. 4, 766. 1805. Figure 30. 

Herbs or shrubs with slender stems, usually erect, 0.5-1.5 (2) m tall, bisexual, leafy 
internodes 1-14 cm long, 1-4 mm thick, glabrous or very sparsely and minutely puber- 
ulent, usually with 4 or 6 longitudinal ridges, the older nodes often thickened and some- 
times with tufts of hairs in the leaf axils. Leaves opposite or subopposite, petioles 5-25 mm 
long, 0.5-1 mm thick, with adaxial ridges continuous with the lamina margins, glabrous; 
laminae 2-12 (17) cm long, 0.5-3.5 (6) cm broad, linear-lanceolate to lanceolate or narrowly 
ovate-lanceolate, tapering gradually to the acute or acuminate apex, tapering gradually to 
the acute or obtuse base, margins entire and decurrent on the petiole, the laminae drying 
thin chartaceous, smooth, glabrous or sparsely puberulent with short very thin and incon- 
spicuous hairs, with 3-8 pairs of major secondary veins. Inflorescences terminal on the 
main stem or axillary from distal branches, paniculate, 10-50 cm long, branches of the 
inflorescence usually subtended by progressively smaller leaves, the flowers borne on 
small pedunculate spikes or in small subsessile fascicles, flower-bearing rachis puberulent, 
basal bracts ca. 0.5 mm long, lateral bracteoles ca. 1.5 mm long and broadly ovate, trans- 
lucent and drying pale yellowish brown, slightly mucronate; flowers bisexual, sessile, 
perianth parts 1.0-1.8 mm long, acute at the apex. Fruit loosely enclosed in the persisting 
perianth, long (3-4 mm) white hairs often developed from between the base of the peri- 
anth parts and bracteoles; seed cochleate-orbicular, 0.6-0.8 mm in diameter, lenticular in 
cross section, black or very dark brown, shiny-lustrous. 

Uncommon plants of secondary growth, forest edges, and open sites, from near 
sea level to 500 (800) m elevation on the seasonally dry Pacific side of Costa Rica; 
possibly flowering throughout the year, but with most all of our collections made 
from January to April. The species ranges from Mexico and the West Indies to 
northern South America. 

Iresine angustifolia is recognized by the open much-branched inflorescences with 
flowers closely congested in quite separate pedunculate spikes, the broad lateral 
bracteoles twice as large as the basal bracts and equaling the perianth in length, 
the very narrow leaves both within and beneath the inflorescences, and the 
restriction to our seasonally dry Pacific lowlands. This species has been collected 
only a few times in Costa Rica in the areas around the Gulf of Nicoya and near 
the border with Nicaragua. 

Iresine arrecta Standley, Publ. Field Mus. Nat. Hist., Bot. Ser. 18:1550. 1938. 
Figure 30. 

Clambering shrubs or woody lianas to 7m high, apparently unisexual, leafy internodes 
3.5-18 cm long, 1.5-7 mm thick, very minutely (0.2 mm) puberulent but soon becoming 
glabrous, longitudinally striate with usually more than 8 poorly defined longitudinal 
ridges, terete or obscurely 4-angIed in cross section, nodes thickened in age and with an 
interpetiolar line or ridge. Leaves opposite or subopposite, petioles 6-30 mm long, 1-1.5 
mm thick, broadly sulcate above with 2 adaxial ridges continuous with the lamina margins; 
laminae (4) 7-18 cm long, (1) 2-8.5 cm broad, ovate to ovate lanceolate, or lanceolate (and 
alternate) in the inflorescence, tapering gradually to the acute or less often acuminate apex, 
rounded and obtuse to subtruncate at the base, slightly decurrent on the petiole, margins 
entire, the laminae drying thin-chartaceous to chartaceous and smooth, very sparsely and 
minutely (0.2 mm) puberulent or glabrous, the midvein prominent above with 6-13 pairs 
of major secondary veins. Inflorescences terminal on the main axes or terminal on distal 
axillary shoots that often arise at right angles from the main stem, paniculate with numer- 
ous but distant glabrous or sparsely and minutely puberulent branches, to 30 cm long, the 
flowers in small (3-10 mm) sessile or very short-pedunculate spikes, bracts of the spikes 
and flowers sparsely puberulent, floral bracts 1-1.5 mm long, broadly ovate cuspidate, 
lustrous and translucent; male flowers with perianth 1.3-2 mm long, anthers ca. 0.5 mm 
long, elliptic, pistillode well developed but lacking stigmas; female flowers with perianth 
1.2-1.6 mm long, ovary turbinate or obovoid, ca. 1 mm long, style very short with 2 long 



BURGER: FLORA COSTARICENSIS 173 

(0.5 mm) stigmas. Fruit closely enclosed by the persisting perianth, subtended by tufts of 
villous or lanate whitish hairs 1-3 mm long arising from the base of the perianth abaxially; 
seed cochleate-orbicular, ca. 0.8 mm broad, lenticular in cross section, very dark brown 
and highly lustrous. 

Rarely collected clambering or climbing plants of wet evergreen montane 
(premontane and lower montane rain) forest formations between 1,200 and 1,800 
m elevation; flowering material has been collected from late November to early 
March. The species is known only from central Costa Rica. 

Iresine arrecta is distinguished by its climbing habit, long slender petioles, thin 
leaves often rounded at the base and with numerous secondary veins, and 
separate little spikes of functionally unisexual sparsely puberulent flowers. The 
species is similar in some respects to /. costaricensis (q.v.) and /. argentata (Mart.) 
Dietr. of northern South America, but both of those species have densely seri- 
ceous inflorescence branches with bisexual flowers. Presently, /. arrectais known 
only from near Zarcero, Alajuela (A. Smith A 617 and H 249, the type), near El 
Muneco, Cartago (Standley & Torres 51090), and above San Isidro del General, 
(Skutch 2563). 

Iresine calea (Ibariez) Standley, Contrib. U.S. Natl. Herb. 18:94. 1916. Gom- 
phrena latifolia Mart. & Gal., Bull. Acad. Roy. Sci. Bruxelles 10, pt. 1:349. 1843. 
Achyranthes calea Iba'nez, Naturaleza 4:79. 1879. /. latifolia Benth. & Hook., Gen. 
PL 3:42. 1880, not Dietr. 1839. Figure 30. 

Shrubs or clambering and vinelike, 1.5-4 (5) m tall, unisexual, leafy internodes 2.5-13 
cm long, 1.5-5 mm thick, sparsely or more often densely short (0.2-0.5 mm) hirsutulous 
with whitish or very pale yellowish brown hairs, becoming glabrous and the nodes thick- 
ened, irregularly longitudinally striate when dry, the interpetiolar line or ridge usually 
obscure (sometimes absent). Leaves opposite, petioles 4-15 mm long, sulcate above with 
2 adaxial ridges continuous with the lamina margins: laminae 1.5-8 (11) cm long, 1-4 
(7) cm broad, ovate or occasionally ovate-lanceolate, tapering to an acute apex, usually 
rounded or obtuse at the base, margins entire and decurrent on the petiole, laminae drying 
chartaceous and smooth, usually densely hirsutulous or sericeous beneath with thin 
whitish hairs ca. 0.5 mm long and more sparsely puberulent above, midvein prominent 
above and with 4-8 pairs of major secondary veins. Inflorescence paniculate, 10-50 cm 
long, the open divergent branches densely puberulent, the spikes separate (2-10 mm) 
along the rachis and sessile or pedunculate, the male and female spikes quite different in 
appearance; male spikes with floral bracts ca. 0.5 mm long and clearly exceeded by the 
narrow perianth, the perianth parts 1.5-2 mm long, narrowly oblong, blunt and puber- 
ulent apically, often lustrous in the lower half abaxially, stamens united only at the base 
and not forming a conspicuous cup, pistillode usually slender and translucent; female 
spikes with the flowers hidden by much larger (1-1.5 mm) broadly ovate bracts, with 
dense tufts of tomentulous hairs from the bottom of the perianth further obscuring the 
flowers, perianth parts ca. 1.5 mm long and narrowly lanceolate, ovary ca. 0.7 mm long, 
style with 2 slender stigmas ca. 0.5 mm long. Fruit apparently tightly enclosed within the 
persisting perianth and bracts; seeds not seen. 

Shrubs or clambering plants of low second growth and thickets from near sea 
level to 1,300 (1,800) m elevation on the Pacific slope and Central Mountains in 
Costa Rica; flowering in the dry season, from December through April. This 
species ranges from Mexico to the eastern edge of the Meseta Central in Costa 
Rica along the Pacific slope and Central Highlands of Central America. 

Iresine calea is distinguished by its generally shrubby habit, dense whitish 
puberulence on young stems, undersides of leaves, and inflorescences, and the 
rather different bracts subtending the morphologically distinct male and female 
flowers. The different appearance of male and female spikes and the difficulty 



174 FIELDIANA: BOTANY 

of finding female flowers among bracts and hairs are also noteworthy. This 
species has not been collected from the Caribbean slope below 1,200 m elevation; 
it appears to prefer the seasonally dry habitats of the Pacific side of Central 
America and is especially common in the Meseta Central. Names applied to this 
species in central and southern Central America include: Algodoncillo, Chivito, 
Chivo, Comenternero, Coyontura, Flor de corona, Siete Pellejos, and Tacuquelite, 

Iresine completa Uline & Bray (Bot. Gaz. 21:349, 1896) was originally described 
from San Pedro Sula, Honduras, and is distinguished by its larger (2.5 mm) 
bisexual short-pedicellate flowers and narrow elliptic-lanceolate leaves glabrous 
on the upper surface except above the midrib. I have seen no authentic material 
of this species nor any specimens from our area which clearly fit the description. 
See the discussion by Duke in the Flora of Panama (Ann. Missouri Bot. Card. 
48:33, 1961). This species is related to /. costaricensis and /. hassleriana on the basis 
of the short thick stigmas. 

Iresine costaricensis Standl., Contrib. U.S. Natl. Herb. 18:94. 1916. Figure 30. 

Clambering shrubs and lianas to 15 m high, bisexual, leafy internodes (1.5) 5-12 cm 
long, 2-6 mm thick, terete, densely sericeous with short (0.5 mm) appressed-ascending 
brownish hairs, becoming glabrescent and the nodes thickened, stems often becoming 
contracted above the node and interpetiolar line after drying. Leaves opposite, petioles 
6-17 mm long, sulcate above, with adaxial ridges continuous with the lamina margins; 
laminae 7-18 on long, 3-7.5 cm broad, elliptic-ovate, to elliptic-oblong or broadly elliptic, 
short-acuminate (in the type) to long-acuminate, with a narrow apex 4-10 mm long, 
obtuse at the base and decurrent on the petiole, entire but drying slightly undulate, the 
laminae drying stiffly chartaceous, and smooth, sparsely puberulent above and more 
densely below with thin straight appressed hairs ca. 0.5 mm long, with 7-12 pairs of major 
secondary veins. Inflorescences terminal on the main stem or on lateral branches, pan- 
iculate to 50 cm long and with strictly opposite branching, the flowers in small (3 mm thick) 
densely strigilose spikes or clusters, the flower cluster sessile or less often pedunculate, 
bracts at the base of the spike ca. 1 mm long, these and some of the floral bracts (ca. 0.5 
mm) densely hirsutulous-strigilose, bracteoles subtending the flowers ca. 1 mm long and 
glabrous abaxially, very broadly ovate, tufts of long (1-2 mm) straight white hairs devel- 
oping from the base of the flower within the bracteoles; flowers sessile, apparently bisex- 
ual, perianth parts ca. 1.5 mm long, oblong, obtuse at the apex, puberulent, filaments 
slender and united near the base to form a short cup, style very short with a thickly lobed 
stigma. Fruiting material not seen. 

Rarely collected lianas or shrubs from wet evergreen montane forests and 
presently known only from the Caribbean slope at about 625 m elevation and 
above the General Valley at 1,800 m elevation; flowering material has been 
collected in December and March. The species is only known from central Costa 
Rica. 

Iresine costaricensis is recognized by its stiff leaves with up to 12 pairs of major 
secondary veins, the inflorescences with consistently opposite divisions, young 
flower buds covered with a dense tomentum of pale yellowish brown hairs, and 
the short capitate stigmas. The very broad, almost glabrous bracteoles are usu- 
ally only found with well-developed flowers. Iresine costaricensis was originally 
known only from two collections made by Adolfo Tonduz (12919 and 13183, the 
type) near Tucurrique, Cartago. These two collections appear to have been from 
woody climbing plants. A recent collection (Burger & Liesner 7057) from an erect 
shrub from above San Isidro del General is tentatively placed here. This latter 
collection has narrow elliptic-oblong leaves that are short-acuminate and the 
inflorescences, bracts, and perianth parts are not as puberulent as those in the 



BURGER: FLORA COSTARICENSIS 175 

Tonduz collections. Both collections have the unusually short thick stigmas. 
This species is closely related to I. hassleriana Chodat, originally described from 
Paraguay. Our material has smaller perianth parts, a shorter staminal tube, and 
a shorter more rounded stigma than do the flowers of type material of /. has- 
sleriana (Hassler 3429 F). The illustration of /. hassleriana in Flora of Panama is 
somewhat intermediate, but closer to the material from Paraguay. At present, it 
seems best to maintain /. costaricensis as a separate and distinct species closely 
related to /. hassleriana. 



Iresine diffusa Humboldt & Bonpland ex Willd., Sp. PL ed. 4, 4:765. 1806, 
CelosiapaniculataL., Sp. PL 1:206. 1753. Iresine celosia L., Syst. Veg. ed. 10,1291. 
1759, nomen illeg. /. celosioides L., Sp. PL ed. 2, 2:1456. 1763, nomen illeg. /. 
paniculata (L.) O. Ktze., Rev. Gen. 2:542. 1891, not /. paniculata Poir. Figure 30. 

Herbs, subshrubs, or shrubs to 3 (5) m tall, unisexual, the rootstock and lower stem 
usually becoming woody, stems erect or clambering, leafy internodes 1-15 cm long 1-6 
mm thick, occasionally glabrous but more often sparsely puberulent with short (0.1-0.5 
mm) thin crooked hairs, internodes usually with 4 or 6 longitudinal ridges, the nodes 
slightly thickened below the leaf base and with an interpetiolar line or puberulent ridge, 
stems often narrowed just above the leaf bases when dried. Leaves opposite or sub- 
opposite, petioles 0.4-5 (8) cm long, sulcate above with 2 narrow adaxial ridges continuous 
with the lamina margins; laminae 2-16 cm long, 1-10 cm broad, elliptic ovate to broadly 
ovate or lanceolate (small and linear on the inflorescence), tapering gradually to an acu- 
minate or acute apex, acute to obtuse or rounded at the base and decurrent on the petiole, 
margins entire, the laminae drying thin chartaceous and smooth to the touch, usually 
sparsely puberulent beneath with short (0.1-1 mm) thin hairs, the midvein prominent 
above with 3-9 pairs of major secondary veins arising at angles of 40- 70. Inflorescences 
extremely variable in form and size, essentially terminal on the main or lateral axes, 
paniculate arrangements with the ultimate divisions made up of short spikes with 5-35 
crowded flowers (becoming separate in fruit) the distal inflorescence branches usually 
alternate and often subtended by small lanceolate to linear leaves becoming short-linear or 
bractlike near the ultimate branches, the overall inflorescence from 5-50 cm long and 
whitish in color, the flowers subtended by subequal bracts and bracteoles 0.3-1 mm long, 
broadly ovate and concave, mucronate, translucent to pale yellowish or white; flowers 
sessile, unisexual, the perianth 0.7-1.5 mm long, stamens 5, united near the base to form 
a short tube, ovary obovoid, style very short with 2 (3) slender stigmas. Fruit loosely 
enclosed within the persisting perianth, long (1-2 mm) straight hairs sometimes formed 
between the bracts and the perianth; seeds cochleate-orbicular, lenticular in cross section, 
0.5-0.8 mm long, very dark brown and lustrous. 

Plants of secondary growth in open sunny or partially shaded sites in both 
very wet evergreen formations and, less commonly, in seasonally very dry 
deciduous formations from near sea level to 2,600 m elevation; in Costa Rica, 
some plants can probably be found in flower throughout the year, but almost all 
of our fertile collections have been made between October and May, with a great 
majority of the collections made in December, January, February, and March. 
The species ranges throughout the American tropics. 

Iresine diffusa, formerly called Iresine celosia, is one of Costa Rica's most com- 
mon and conspicuous weeds. The species is recognized by the usually large, 
white, many-branched paniculate inflorescences with very small unisexual 
white flowers, stems with longitudinal ridges and unusual nodes, and thin 
opposite leaves. The plants are most often collected in evergreen and partially 
deciduous formations below 1,500 m elevation. There is considerable variation 
regarding the size and arrangement of flowers and bracts in the material placed 
under this name. It may be that more than one specific entity is included under 



176 FIELDIANA: BOTANY 

the broad interpretation adopted here. Material previously placed under the 
name I. acicullarisStandl., I. frutescenceMoq., and 1. spiculigeraSeub. is included 
here, following James Duke in the Flora of Panama (Ann. Missouri Bot. Card. 
48:35, 1961). Common names used in central and southern Central America 
include: Adorno de nino, Camron, Coyontura de polios, Hierba de goto, Siete pellejos, 
Taba de gueguecho, Velo de gueguecho, and Velo de princesa. 

PFAFFIA Martius 

REFERENCE: O. Stutzer, Die Gattung Pfaffia. Repert. Spec. Nov. Regni Veg. 
Beih. 88:1-46. 1935. 

Herbs, shrubs, or climbers, densely puberulent to glabrescent, stems often with long 
internodes (in ours) and interpetiolar ridges or lines, often with a tuft of hairs in the leaf 
axil; stipules absent. Leaves opposite and simple, petiolate or sessile, entire and pinnately 
veined. Inflorescences varied, heads, fascicles, or solitary flowers often on opposing spike- 
like axes on terminal stems that bear reduced leaves forming compound panicles; flowers 
bisexual or sometimes reduced and nonfunctional, radially symmetrical, small and sessile, 
subtended by a bract and 2 lateral bracteoles, bract and bracteoles subequal, puberulent, 
flowers often with an unpleasant odor, greenish white, perianth of 5 subequal parts, often 
with 3 prominent longitudinal veins on the outer perianth parts, usually puberulent and 
with tufts of straight whitish hairs from the base within, persisting but not enlarging in 
fruit, stiff and dry, stamens 5, united below to form a short cup, the cup and filaments with 
or without appendages, anthers 2-thecous, ovary ovoid to obovoid, 1-locular, with 1 ovule 
borne on an elongated funicle from a basal placenta, style very short and bearing a thick 
2-lipped stigma. Fruit a thin- walled capsule (utricle), usually obscured by the persisting 
perianth, bracts, and tufts of hairs; seeds lenticular, reniform to cochleate-orbicular, red- 
dish brown (in ours). 

A poorly defined neotropical genus of probably fewer than 20 species, closely 
related to Iresine and Gomphrena and intermediate between them in some re- 
spects. The relatively few collections and their distribution in Costa Rica may 
indicate that our species has been introduced. Our plants are recognized by their 
clambering or climbing stems with long internodes and stiff opposite entire 
leaves and compound inflorescences with puberulent little flowers with a stiff 
dry perianth that bears tufts of whitish hairs from the base adaxially (between 
the perianth and the sexual parts). This species and other members of the genus 
are easily confused with species of Iresine, especially I. arrecta and /. costaricensis, 
in our flora. 



Pfaffia grandiflora (Hook.) R. E. Fries, Ark. Bot. 16, no. 12:10. 1921. Iresine 
grandiflora Hooker, Icon. PI. 2; tab. 102. 1837. Gomphrena paniculatavar. hookeriana 
Seub., in Martius, Fl. Brasil. 5, pt. 1:192. 1875. Hebanthe hookerianus Hemsley, 
Biol. Cent. Amer. 3:19. 1882. Pfaffia hookeriana (Hemsl.) Greenman, Publ. Field 
Columbian Mus., Bot. Ser. 2:330. 1912. P. hookeriana forma glabriuscula 
Suesseng., Repert. Spec. Nov. Regni Veg. 35:332. 1934. Figure 27. 

Woody climbers to 3 m long, leafy internodes 2-15 cm long, 1-5 mm thick, sparsely 
puberulent to glabrescent with slender ascending hairs 0.5-1.5 mm long, more densely 
puberulent at the nodes and in the leaf axils. Leaves opposite, petioles 3-15 mm long, with 
lateral margins often forming an adaxial sulcus in the lower half; laminae 3-12 cm long, 
1.5-6 cm broad, ovate to lanceolate or elliptic, acute to acuminate at the apex, rounded to 
obtuse at the base, margin entire or slightly undulate, decurrent on the petiole, the 
laminae drying very stifly chartaceous and pale or dark in color, smooth above and below, 
with stiff slender appressed (strigose) hairs on both surfaces, with 3-5 pairs of major 
secondary veins. Inflorescences usually compounded panicles at the ends of branches or 



BURGER. FLORA COSTARICENSIS 177 

lateral stems, made up of spikelike axes 1-5 cm long, the axes often opposite and sub- 
tended by small leaves, the flowers usually solitary, sessile and subtended by a bract and 
2 bracteoles 1-2 mm long and 1-2 mm broad at the base; flowers bisexual or nonfunctional, 
perianth of 5 subequal parts, 2-3.5 mm long, 1-2 mm broad, with short thin whitish hairs 
on the outer surface and thin silky hairs 3-8 mm long borne from the base of the inner 
surface, stamens 1.5-2.5 mm long, forming a short (0.5 mm) tube at the base and with 
anthers ca. 0.5 mm long; pistil with short style and broad 2-lobed stigma. Fruit a utricle 
ca. 2 mm long, included within the persisting perianth and bracts and obscured by the 
long thin whitish hairs from the interior of the perianth parts; seeds lenticular, reddish 
brown, ca. 1.5 mm broad. 

Uncommon climbing or clambering plants of wet or seasonally dry evergreen 
formations and collected in flower and fruit in February, March, and April in 
Costa Rica. Most all of our collections come from between 900 and 1,400 m 
elevation around the Meseta Central with only a very few from lower areas. The 
species ranges from Mexico through Central America to Peru and the Guianas. 

Pfaffia grandiflora is recognized by the clambering stems with opposite thin 
entire leaves, compound inflorescences with sessile flowers, and long silky hairs 
from within the perianth which obscure stamens, pistil, and fruit. 

PHILOXERUS R. Brown 

Perennial herbs or subshrubs, prostrate, procumbent, or erect, bisexual, glabrous or 
puberulent; stipules absent. Leaves opposite and simple, sessile and often clasping the 
stem at their base, entire and pinnately veined, usually semisucculent. Inflorescences 
solitary, terminal or axillary, short- to long-pedunculate, often subtended by a pair of 
small leaves, the flowers sessile or subsessile and densely crowded in short spikes or 
capitula, flowers subtended by a bract and 2 bracteoles, the bract and bracteoles char- 
taceous and subequal; flowers bisexual and radially symmetrical, with 5 imbricate sub- 
equal perianth parts, the inner 2 usually narrower than the outer 3, acute at the apex, 
stamens 5, united near the base to form a very short tube, the tube lacking pseudo- 
staminodial appendages, anthers 2-thecous, with introrse dehiscence, ovary with 1 locule 
and 1 ovule borne on a long funicle, style short and with 2 (3) stigmas. Fruit an orbiculate 
indehiscent utricle; seed lenticular to cochleate-orbicular, smooth, the embryo annular. 

The genus is most distinctive among our Amaranthaceae, with its very narrow 
semisucculent leaves, short dense spikes, and prostrate habit near seashore 
environments. Here considered part of the genus Philoxerus, our species has 
been placed in the genus Caraxeron Vaillant ex Rafinesque by Mears (Taxon 29:88, 
1980). 

Philoxerus vermicularis (L.) R. Br., Prodr. 416. 1810. Gomphrena vermicularis 
L., Sp. PI. 224. 1753. Caraxeron vermicularis (L.) Rafinesque, Fl. Telluriana 3:38. 
1837. Figure 39. 

Semisucculent herbs from a woody base, usually procumbent or prostrate and some- 
times forming loose mats, leafy internodes 1-8 cm long, 1-4 mm thick (dry), terete but 
becoming longitudinally ridged when dry, glabrous but with thin whitish hairs in the axils 
of the leaves, succulent and greenish in life. Leaves opposite and decussate, semi- 
succulent, clearly differentiated from the stem at the base but not articulate, a petiole not 
clearly differentiated and the lamina narrowed to a clasping base; laminae (1) 2-5.5 (8) cm 
long, 2-8 (14) cm broad, linear to narrowly oblanceolate, usually broadest above the 
middle, rounded to obtuse at the apex but often with a small mucronate tip, gradually 
narrowed to the base, slightly expanded at the base and clasping the stem, margin entire, 
smooth and glabrous above and below, venation obscure. Inflorescences solitary and 
terminal or less often axillary, short-spicate to capitate, usually very short (0.5-1 cm) 
pedunculate above a reduced pair of foliage leaves, flowering portion of the spike 6-18 (28) 
mm long, 8-10 mm thick, rachis obscured by the flowers and bracts but with thin whitish 



178 FIELDIANA: BOTANY 

hairs, flowers sessile or subsessile, subtended by a short (1 mm) abaxial bract and 2 lateral 
narrow bracteoles ca. 2 mm long; flowers with the perianth 3-3.5 mm long, dull white in 
life and becoming pale straw colored when dry. 

A species of sandy and rocky seashores on both the Pacific and Caribbean 
shores of Central America; probably flowering throughout the year in our area. 
The species ranges from Florida, Texas, and Mexico, through Central America 
and the West Indies to Ecuador and Brazil; this species is also found on the west 
coast of Africa. 

Philoxerus vermicularis is immediately distinguished by its seaside habitat, 
succulent prostrate stems, very narrow opposite leaves, and dense spikes with 
scarious whitish bracts. These plants appear to be quite uncommon on the 
beaches of Central America. Only three collections are known from our area: 
Pittier 12692 from Puerto Limon, /. Leon 494 from Caldera, Puntarenas, and von 
Wedel 1948 from Bocas del Toro, Panama. 

PLEUROPETALUM Hooker f. 

Herbs or shrubs, the stems sometimes climbing, plants bisexual, stems glabrous or 
sparsely and minutely puberulent and becoming glabrous; stipules absent. Leaves alter- 
nate in a spiral or occasionally distichous, simple and petiolate, pinnately veined, thin in 
texture. Inflorescences mostly solitary, terminal or axillary, racemes or compound pan- 
iculate arrangements usually made up of racemose branches and often with reduced 
foliage leaves, glabrous or minutely puberulent; flowers bisexual and radially symmetrical, 
pedicellate to subsessile, subtended by 1 bract and 2 bracteoles, these often close together 
beneath the perianth and simulating a second smaller perianth whorl, the bracts and 
perianth parts often with the same stiff texture and color, perianth of 1 whorl of 5 free 
oblong somewhat concave subequal sepals (tepals), imbricate in bud, stiff and persisting 
in fruit but not enlarging, green to yellowish or red in fruit, stamens 5-8, united near the 
base to form a short filament-tube or cup, free portion of the filaments slightly flattened, 
anthers 4-thecous, pistil 1, ovary subglobose, 1-Iocular with many ovules on slender stalks 
from a central basal placenta, style 1 and very short with 3-8 small stigmas. Fruit at first 
slightly succulent and berry-like but becoming dry and capsule-like, opening irregularly 
or with circumscissle dehiscence in the lower half, subtended by the stiff perianth parts; 
seeds laterally flattened and somewhat lenticular, cochleate-orbicular to reniform- 
orbicular in outline, borne on slender funicles, the testa lustrous black; embryo annular. 

A neotropical genus of perhaps three species ranging from central Mexico to 
Peru and with an endemic species on the Galapagos Islands. These plants are 
distinguished by their thin leaves on slender petioles, the flowers with what 
appear to be two whorls of stiff straw-colored (dry) perianth parts, the stamens 
forming a short cup at their base, the slightly fleshy capsule-like fruit that often 
opens around the middle or lower half, and the shiny black seeds borne on 
slender stalks from a basal placenta. The distinctive perianth becomes very stiff 
when dry, pale yellowish brown and with many longitudinal ridges, resembling 
the glumes of grasses. 

la Seeds 1.5-2.5 mm long, larger perianth parts usually 3-4 mm long, inflorescence a 
compact panicle with rounded contours; plants erect and few-branched, 500-1,900 m 

P. sprucei 

Ib Seeds 1-1.5 mm long, larger perianth parts usually 4-5 mm long, inflorescences open 
racemes or open panicles with racemose branches; plants often climbing or clam- 
bering over others, 0-900 m elevation P. pleiogynum 

Pleuropetalum pleiogynum (O. Ktze.) Standley, J. Wash. Acad. Sci. 13:369. 
1923. CelosiapleiogynaO. Kuntze, Rev. Gen. 541. 1891. P. standleyi Suessenguth, 
Repert. Spec. Nov. Regni Veg. 44:41. 1938. Figure 29. 



BURGER: FLORA COSTARICENSIS 179 

Shrubs, erect or arching over other plants, to 3 m tall or climbing to 5 m high, leafy 
internodes 2-6 cm long, 1-4 mm thick, glabrous, weakly longitudinally ridged. Leaves 
alternate in a spiral, glabrous, petioles 0.6-2 (4) cm long, about 1 mm thick, with a narrow 
adaxial sulcus in the basal half, decurrent on the stem; laminae (3) 5-15 cm long (1) 2-5 
cm broad, elliptic-ovate to narrowly elliptic, narrowly elliptic-oblong or lanceolate, gradu- 
ally narrowed to the acuminate (acute) apex, attenuate at the base, margins entire and 
decurrent on the petiole, the laminae drying chartaceous and usually dark in color, 
smooth and glabrous on both surfaces, with (3) 4-6 (8) pairs of major secondary veins. 
Inflorescences racemes or panicles of racemes, axillary or terminal, to 30 cm long, the 
individual racemes 1-6 cm long, the rachis often with a zigzag form, glabrous or very 
minutely puberulent, pedicels 0.5-2 mm long, becoming 5 mm long in fruit, subtended by 
an ovate bract 1-2 mm long with thin membranous edges; flowers ca. 4-6 mm long, 
subtended by short (2 mm) broad-based bracteoles, perianth ca. 4 mm long, with usually 
more than 20 longitudinal ribs, pale yellow to red, ovary usually with 5 or 6 stigmas. Fruit 
a capsule 5-7 mm long, opening by circumscissle dehiscence, upper part cream and the 
lower part orange in color; seeds 1-1.5 mm long, lustrous black, usually more than 30 per 
capsule. 

Plants of forest edges and stream sides in wet evergreen formations from near 
sea level to 900 m elevation, but only rarely found above 500 m in Costa Rica; 
flowering and fruiting collections have been made mostly between August and 
April. The species ranges from western Costa Rica to central Panama. 

Pleuropetalum pleiogynutn is recognized by the open racemes or panicles of 
flowers with stiff persisting perianth parts, the many longitudinal ridges on the 
perianth, and the circumscissle dehiscence of the slightly succulent capsule. The 
arching, clambering, or climbing stems in partly open sites further distinguish 
this species. 

Pleuropetalum sprucei (Hook, f.) Standl., N. Amer. Fl. 21:96. 1917. Melano- 
carpum sprucei Hook, f., in Benth. & Hook., Gen. PI. 3:24. 1880. P. costaricense 
nom. nud., in Hemsl., Biol. Centr. Am. Bot. 3:12. 1882. P. costaricense Wendl. ex 
Hook, f., Bot. Mag. pi. 6674. 1883. P. tucurriquenseDonn. Sm., Bot. Gaz. 61:387. 
1916. P. calospermum Standl., J. Wash. Acad. Sci. 13:368. 1923. Figure 29. 

Small shrubs, (0.5) 1-2 (3) m tall, few-branched and erect, leafy internodes 0.5-5 cm 
long, 1.2-6 mm thick, glabrous or minutely and very sparsely puberulent, becoming 
longitudinally ridged. Leaves alternate in a spiral, petioles 1-4 (6) cm long, ca. 1.5 mm 
broad, with 2 adaxial ridges producing a slight sulcus above, short-decurrent on the stem; 
laminae 5-20 (28) cm long, 2-8 (12) cm broad, elliptic to elliptic-oblong or narrowly 
elliptic-ovate to lanceolate, tapering gradually to the acuminate apex, tapering gradually 
to the attenuate base, margin entire and decurrent on the petiole, the laminae drying thin 
chartaceous and usually dark in color, smooth and glabrous above and below or with a few 
minute strigillose hairs along the veins, with 7-10 pairs of major secondary veins. In- 
florescences terminal or axillary, solitary, usually compact panicles of short racemose 
branches, often somewhat flat-topped or a tight convex group (corymbose), 3-9 cm long, 
peduncles 1-4 cm long, secondary peduncles and rachis minutely (0.1 mm) and densely 
brownish puberulent, pedicels subtended by broad-based bracts ca. 1 mm long, pedicels 
1-4 mm long, 2 or 3 small bracteoles usually subtending the flower just beneath the 
perianth; flowers ca. 4 mm long, perianth of a single whorl but appearing as 2 whorls 
because of the subtending bracteoles, perianth parts free, ca. 3 mm long and 1-1.5 mm 
broad, with usually fewer than 20 longitudinal ribs (striations), yellowish green to reddish 
at the base, fleshy in life, stamens ca. 2.5 mm long, ovary with usually 3 or 4 stigmas. Fruit 
ca. 6 mm long and 5 mm thick, becoming reddish to dark purple, dehiscing irregularly or 
circumscissle in the lower half; seeds 1.5-2.2 mm long, usually fewer than 30 per capsule. 

Plants of shaded evergreen forest formations from 500 to 1,900 m elevation on 
both the Caribbean and Pacific slopes in Costa Rica; probably flowering and 
fruiting throughout the year, but with very few collections made in May and 



180 FIELDIANA: BOTANY 

June and in October and November. The species ranges from central Mexico to 
Peru. 

Pleuropetalum sprucei is characterized by its usually short erect habit, flowers 
usually borne in small dense corymb-like panicles, and relatively large seeds. 
The persisting perianth that dries stiff and with many longitudinal ribs and 
is subtended by two or three small bracteoles with similar texture is quite 
distinctive. 

NYCTAGINACEAE 

Herbs, shrubs or trees, erect or scandent, bisexual or unisexual, glabrous or puberulent, 
with or without spines, sometimes with viscid hairs, the nodes often somewhat thick- 
ened, often with dichotomous branching; stipules absent. Leaves alternate, subopposite, 
opposite or whorled, simple, petiolate, laminae entire and often with short-linear raphides 
visible as projections on the dried surfaces. Inflorescences solitary or several, terminal or 
axillary, variously branched but usually with the distal flowers in cymose groupings, with 
1-3 bracts or bracteoles subtending each flower, these sometimes resembling a perianth 
whorl; flowers bisexual or functionally unisexual, radially symmetrical (in ours), with 1 
perianth whorl but often appearing to have 2 whorls because of the sepaloid or petaloid 
bracts (as in Bougainvillea) or because of the differentiation between lower sepaloid and 
upper corolla-like parts of the perianth (as in Boerhavia), perianth united to form a broadly 
campanulate, urceolate to narrowly cylindrical tube, 5-lobed (rarely 3- to 7-lobed) at the 
apex or with 5 (3-7) small teeth, involute-plicate in bud or the lobes valvate, base of the 
perianth persisting in fruit, distal portion of the perianth persisting or deciduous; stamens 
1-10 (many), filaments usually unequal in length and united at the base to form a short 
tube or united to the base of the pistil, anthers dorsifixed near the base, included within 
the perianth or exserted at anthesis; pistil solitary, often narrowed near the base or 
stipitate, ovary with 1 locule and 1 basal stalked ovule, style long to short or absent, stigma 
solitary, globose to fimbriate. Fruit usually enclosed within the persisting and protective 
perianth to form what is called an anthocarp, becoming fleshy, coriaceous or woody, the 
fruit a thin-walled nut that is not usually separable from the enclosing perianth; embryo 
strongly curved. 

A family of tropical and subtropical plants with most of its species and genera 
found in the New World. The flowers and their bracts differ greatly in different 
genera, and they are often difficult to recognize as members of the same family. 
The perianth tube that is persistent and adherent around the fruit, the often 
stipitate ovary with single basal ovule and solitary stigma, the stamens united 
at the base to form a short tube, and the occasional elaboration of bracts to 
resemble either calyx or corolla are helpful in recognizing this family. The stalked 
basal ovule that produces a strongly curved or folded embryo are important 
features shared by other members of the Centrospermae (Caryophy Hales). Ex- 
cept for a few important ornamentals, the family is of no economic importance; 
a number of species have become pantropical weeds. 

Two genera of small weedy species with opposite leaves (Allionia with lentic- 
ular fruit and dentate winglike margins and Commicarpus with terete fruit with 
longitudinal ranks of stipitate glands) are known from Mexico and Guatemala 
and in South America, but have never been reported or collected in the regions 
between these areas. 

Cephalotomandra fragrans Karsten and Triana (including C. panamensis Standley) 
looks very much like some of our larger leaved specimens of Neea. However, in 
Cephalotomandra, the male perianth forms an open cup and there are more than 
20 stamens in each male flower. The genus is not known from Costa Rica, and 
considerable doubt exists that a specimen with a collection label from Panama 



BURGER: FLORA COSTARICENSIS 181 

was actually collected in Panama (see Woodson's treatment in Ann. Missouri 
Bot. Card. 48:55-56, 1961). 



KEY TO THE GENERA OF NYCTAGINACEAE 

la Leaves alternate along the stem, none opposite 2a 

Ib Leaves opposite along the stem, a few subopposite or alternate leaves occasionally 

present 3a 

2a Herbs, erect; flowers subtended by small green bracts; uncommon lowland plants 

Salpianthus 

2b Woody climbers or shrublike; tubular flowers attached to broad brilliantly colored 
red, purple, or orange bracts, usually in groups of 3; widely planted for ornament 

Bougainvillea 

3a Herbs, woody only at the base 4a 

3b Trees, shrubs or subshrubs 5a 

4a Bracts subtending the flowers inconspicuous; perianth tube with a distinctly 
differentiated calyx-like base and corolla-like upper portion, the perianth 1.5-5 

mm long Boerhavia 

4b Bracts united near the base of the flower to form a 5-parted calyx-like whorl; 
perianth tube 1-5 cm long, uniformly corolla-like and brightly colored 

Mirabilis 

5a Stems frequently armed with spines (but not all stems have spines); small shrubs, 
trees, climbers or woody lianas; fruit often borne on very long stalks, with longi- 
tudinal ranks of viscid-tipped glands Pisonia 

5b Stems never with spines; small shrubs or trees but not climbers; fruit sessile or 
stalked, lacking stalked viscid glands 6a 

6a Male flowers campanulate with the stamens well exserted from the broad perianth 
opening, female flowers with the stigmas exserted at anthesis and the pistil borne on 
a short stalk; fruit becoming dark purple or black, longitudinally ridged when dry; 
laminae rarely more than 15 cm long, drying dark in color; small to large trees (rarely 
shrubs); evergreen forests of the Pacific slope including the Nicoya peninsula, Meseta 
Central, General Valley, and Talamanca mountains, 0-2,000 m elevation . . . Guapira 

6b Male flowers tubular to ellipsoid, the stamens included within the perianth tube, 
female flowers with the stigmas only rarely exserted, pistil sessile or narrowed at the 
base; fruit becoming yellow, orange or purple, occasionally longitudinally striate 
when dry; laminae to 30 cm long, drying pale or dark; small subshrubs to small trees 
(rarely more than 8 m tall); from the highlands and deciduous formations of northern 
Costa Rica to the western edge of the Meseta Central, common in the Caribbean 
lowlands and less so on the Caribbean slope and Osa Peninsula (apparently absent on 
the Talamanca mountains and in the General Valley), 0-1,600 m elevation . . . .Neea 

BOERHAVIA Linnaeus 

Herbs, annual or perennial, often with a woody base, bisexual, erect or prostrate, often 
much branched, stems often with viscous areas on the internodes, gland-tipped hairs 
often present. Leaves opposite or subopposite, opposing leaves of a pair often very un- 
equal, petiolate, entire or sinuate, raphides often visible as surface irregularities when 
dried. Inflorescences terminal, paniculiform to racemeiform with the flowers in small 
umbellate, cymose, capitate or racemose arrangements (rarely solitary), 1-3 slender brac- 
teoles present beneath each flower. Flowers bisexual, radially symmetrical and very small, 
perianth of a single whorl united to form a calyx-like base and a thinner petal-like distal 
limb that is shallowly 5-lobed, the upper and lower areas of the perianth tube divided by 
a constriction, stamens 1-5, filaments slender and united at the base to form a very short 
tube or cup, pistil stipitate, ovary unilocular, style slender, stigma peltate or capitate, 
usually exserted. Fruit an anthocarp formed by the tight enclosure of the ovary within the 
perianth tube, obovoid to obpyramidal, 3-5 angled (rarely winged), glabrous or glandular- 
puberulent. 

A genus of weedy plants ranging widely over the tropics and subtropics. Their 



MIRABILIS 
violacea 




FIG. 31. Nyctaginaceae: a cultivated form of Bougainvillea and two species of Mirabilis. 



182 



SALPIANTHUS 
pupurascens 




BOERHAVIA coccinea 

FIG. 32. Nyctaginaceae: three species of Boerhavia and a species of Salpianthus. 



183 




(deciduous f PISONIA ___ ^ 

forest tree) r aculeata (evergreen forest liana) 1 



FIG. 33. Nyctaginaceae: a species of Guapiraand two species of Pisonia. Note the different 
leaf form and habit in P. aculeata. 



184 



NEEA delicatula 



from deciduous 
Guanacaste Prov. 




NEEA 

psychotrioides 

sensu stricto 

(common form) 



FIG. 34. Nyctaginaceae: Costa Rican representatives of the Neea psychotrioides species- 
group. These are part of a polymorphic assemblage that may not be reducible to species. 



185 



NEEA pittieri 



A. montane form 
(Zarcero, 1500 m) 




NEEA amplifolia 
(sensu stricto) 



FIG. 35. Nyctaginaceae: Costa Rican representatives of the Neea amplifolia species-group. 
These are part of a polymorphic assemblage that may not be reducible to species. 



186 



BURGER: FLORA COSTARICENSIS 187 

distribution patterns in Costa Rica give the impression that these plants are not 
native elements of the flora. The genus is recognized by its opposite to sub- 
opposite leaves which often are very different in size at the same node, the 
frequent presence of gland-tipped hairs or viscous areas on the internodes, the 
perianth tube that is calyx-like beneath and corolla-like distally, slender fil- 
aments united at the base, capitate stigma and fruit resembling an inferior ovary 
and broadest near the apex. The following key and species concepts are based 
on the treatment of C. D. Adams in the Flowering Plants of Jamaica (1972, pp. 
260-261). 

la Fruit glabrous and not at all viscid; distal perianth white to pink or lavender; stems and 
leaves minutely puberulent or glabrous, the internodes often with glutinous patches 
and the leaves usually pellucid-punctate beneath; inflorescence with many vertical 
branches and usually lacking leafy bracts; erect plants from a woody rootstock 

B. erecta 

Ib Fruit minutely viscid puberulent; distal perianth red to dark purple; stems and leaves 
minutely puberulent to densely viscid, lacking glutinous patches on the internodes 
and pellucid dots on the laminae beneath; inflorescence with spreading branches and 
usually with leafy bracts; decumbent to ascending plants 2a 

2a Flowers in distal clusters of 3-12, the inflorescences usually small and few branched, 
leaves and stems usually densely viscid puberulent B. coccinea 

2b Flowers in distal clusters of 2-5, the inflorescences often large and much branched; 
leaves and stems often with minute (0.1 mm) and longer (to 1 mm) thin hairs, not 
densely viscid puberulent B. diffusa 



Boerhavia coccinea Miller, Card. Dictionary ed. 8, Boerhavia no. 4. 1768. B. 
caribaea]acq., Obs. Bot. 4:5. 1771. 

Decumbent or clambering herbs from a strong rootstock, to 0.8 m tall or ca. 1.2 m long, 
leafy internodes 2-12 (15) cm long, 1-5 (8) mm thick (dry), usually densely puberulent 
with slender viscid multicellular hairs 0.2-0.8 mm long. Leaves opposite and subequal, 
petioles 2-40 mm long, usually densely viscid puberulent; laminae 1.5-5 cm long, 0.7-3.5 
cm broad, ovate to ovate-rhomboid or suborbicular, bluntly acute to obtuse or rounded at 
the apex, obtuse to cuneate or truncate and rounded at the base, margin entire or slightly 
sinuate (undulate), laminae drying thin- to stiff-chartaceous, and usually dark in color on 
the upper surface (dry), obscurely and very minutely (0.1 mm) to densely and con- 
spicuously viscid puberulent (occasionally almost glabrous), with 3-5 major pairs of sec- 
ondary veins. Inflorescences terminal on short lateral branches or terminal on the many- 
branched and leafy apex of the plant, flowers in small (3-10 mm broad) clusters of 3-12 
on slender ultimate peduncles 3-15 mm long, glabrous to densely viscid puberulent. 
Flowers 2-3 mm long, rose-purple to deep red or red-purple, stamens 2, anthers ca. 0.3 
mm long. Fruit 3-4 mm long, narrowly obcvoid, ca. 1 mm thick at the thickest part, with 
5 prominent longitudinal ribs, surfaces very minutely (0.1 mm) viscid puberulent. 

Herbs of recently disturbed or open sandy sites in the lowlands of both the 
Caribbean and Pacific coastal plains, ranging to 600 m elevation in northern 
Central America; probably flowering throughout the year, but fertile collections 
have been made only from June to August and from November to February in 
our areas. The species ranges throughout the American tropics to Africa and 
Asia. 

Boerhavia coccinea is recognized by the small brightly colored flowers tightly 
clustered in small groups of usually 4-10, the very short viscid pubescence on 
the fruit and usually on other plant parts as well, and the decumbent growth 
habit. These plants are frequently found near the seashore and in disturbed sites; 
their present distribution in Costa Rica makes it appear that they were not a 
native element of the flora. These plants are often placed under B. diffusa. 



188 FIELDIANA: BOTANY 

Boerhavia diffusaL., Sp. PI. 3. 1753. B. paniculata L. Rich., Actes Soc. Hist. 
Nat. Paris 1:105. 1792. 

Herbs to ca. 1 m tall, prostrate, decumbent or short-ascending, usually much-branched, 
leafy internodes to 20 cm long, sparsely puberulent with very small (0.1 mm) hairs and 
longer slender multicellular hairs to 1 mm long, often becoming glabrous. Leaves opposite, 
opposing leaves of the same node very different in size, small leaves on short axillary 
shoots often present at the widely separate nodes, petioles 3-15 mm long; laminae 1.5-6 
cm long, 1-5 cm broad, ovate to ovate-oblong or ovate-rhomboid, bluntly obtuse to 
rounded at the apex, obtuse to truncate and rounded at the base, margin undulate-sinuate, 
drying chartaceous and with the lower surface often much paler in color than the upper 
surface, sparsely and minutely puberulent on both surfaces or with scattered longer hairs 
to 1 mm long, often puberulent along the edge, with 3-5 pairs of major secondary veins. 
Inflorescences on the open and diffusely branching terminal stems of the plant, small (1 
cm or less) leaflike bracts subtending the major inflorescence branches, ultimate peduncles 
with 1-5 flowers, very variable in length, glabrous to minutely puberulent. Flowers ca. 2 
mm long, pinkish to deep red or purplish in color. Fruit 3.5-4 mm long, narrowly obovoid 
to narrowly obtriangular, thickest ( 1 mm) near the apex, with 5 prominent longitudinal 
ridges, minutely (0.2 mm) viscid puberulent. 

Plants of open recently disturbed weedy sites and sandy or gravelly situations 
in open sun on both the Caribbean and Pacific sides of Costa Rica from sea level 
to 1,200 m elevation; probably flowering throughout the year (no fertile col- 
lections have been made in May, September, October, or December in our area). 
The species ranges throughout the American tropics. 

Boerhavia diffusa is recognized by the small clusters of red flowers on an open 
diffusely branched inflorescence, small viscid fruit thickest near the apex, leaves 
of very different size at the same node (both cauline leaves and those of axillary 
shoots), and the short stature. Often found along the sides of roads, in vacant 
lots in towns, and near the ocean shore, these plants give the impression of being 
recent arrivals in Costa Rica. This species is very closely related to B. coccinea, and 
it may be that the two are conspecific, but they seem to segregate themselves 
quite clearly in our area. 

Boerhavia erectaL., Sp. PI. 3. 1753. 

Herbs 0.3-1.2 m tall, erect, woody at the base, leafy internodes 2-15 cm long, 2-5 (8) 
mm thick, very minutely (0.1 mm) puberulent or becoming glabrous, occasionally with a 
viscid area on the internode, nodes with an interpetiolar line or ridge. Leaves opposite, 
petioles 2-40 (60) mm long, very minutely puberulent; laminae 1-5 (8) cm long, 0.5-5 (7) 
cm broad, ovate to broadly elliptic or triangular, obtuse to bluntly acute at the apex, 
abruptly obtuse to truncate or rounded at the base, margin irregularly sinuate, smooth, 
sparsely and very minutely puberulent on both surfaces, drying much paler in color 
beneath, dark glandular dots often present on one or both surfaces, with 3-5 pairs of major 
secondary veins. Inflorescences to 40 cm long, with many slender (0.5 mm dry) opposite 
branches, the flowers variously arranged in groups of 2-5, sessile or sometimes an individ- 
ual flower on a slender pedicel, inflorescence branches and pedicels glabrous or obscurely 
(0.05 mm) puberulent; floral bracts ca. 1 mm long, linear-lanceolate. Flowers 1.5-2.2 mm 
long, with a greenish calyx-like base ca. 1 mm long and a thin corolla-like distal portion 
0.8-1.2 mm long, pale greenish white to white tinged with pink or pale lavender. Fruit 
narrowly obpyramidal, 3-4 mm long and 1.3 mm broad at the apex, tapering gradually to 
the narrow base, strongly 5-angled in cross section with 5 longitudinal ridges and grooves, 
essentially glabrous. 

Weedy plants of open early secondary vegetation in both seasonally very dry 
areas and in evergreen formations from just behind the ocean shore to 600 (rarely 
to 1,200) m elevation; probably flowering throughout the year, but with most 
collections having been made between February and August in Costa Rica. 



BURGER: FLORA COSTARICENSIS 189 

Widespread in the tropics and subtropics of the Western Hemisphere and in 
Africa. 

Boerhavia erecta is recognized by the distinctive little glabrous fruit, the diffuse 
many-branched inflorescence (in larger specimens), the opposite leaves often 
unequal at a node and with irregular outline, and the little flower with a peri- 
anth tube that appears to be divided into calyx and corolla. The viscid areas on 
the stems and the gland dots on the leaves are also noteworthy, but not always 
apparent. This species is very common in our Pacific lowlands, but uncommon 
in the Caribbean lowlands where it has been collected only in the general vicin- 
ity of Limon. 

BOUGAINVILLEA Commerson 
REFERENCE: W. T. Gillis, Bougainvilleas of cultivation. Baileya 20:34-41. 1976. 

Woody vines, sometimes forming shrubs or small trees, bisexual, glabrous or puber- 
ulent, stems often armed with short spines. Leaves alternate and petiolate, laminae entire 
and pinnately veined. Inflorescences solitary, borne on modified axillary shoots, usually 
consisting of a group of 3 flowers, each flower subtended by a large leaflike bract, the 
pedicel of the flower adnate to the midrib of the bract on the inner (adaxial) side and the 
bracts surrounding the flowers, the bracts usually 2-4.5 cm long and brilliantly colored. 
Flowers bisexual and radially symmetrical, perianth of a single whorl united to form a long 
narrow tube with a small star-shaped distal 5-Iobed limb, perianth tube terete or 5-angled, 
yellowish to whitish or less often the same color as the bracts; stamens 8-10, filaments 
slender and unequal in length, united near the base, anthers included in the tube or a few 
exserted; pistil borne on a short stalk, ovary narrowly ellipsoid and unilocular, ovule 
solitary, style straight or curved, stigma long and papillose, included within the perianth 
tube. Fruit an anthocarp formed by the perianth tube tightly enclosing the fruit and seed, 
narrowly ellipsoid, with 5 longitudinal ribs. 

A genus of probably 10 to 15 species native to central and southern South 
America. These plants are recognized by their woody usually climbing stems, 
alternate entire leaves, and brilliantly colored leaflike bracts in groups of three 
that include three narrowly tubular flowers. The brilliant bracts which remain 
colorful for months and the woody climbing habit which allows the plants to be 
grown in a variety of forms over various supports have made these plants 
important ornamentals in frost-free areas. The plants rarely set seed and are 
propagated vegetatively. Because of their popularity, they are known by a vari- 
ety of names: Bogambilla, Bombilla, Bugambilla, Buguenvitia, Flor de Verano, Lus- 
trosa, Manto de Jesus, Napoleon, Pomonce, Pompilla, Pritnavera, Santa Rita, Sempre 
Lustrosa, Ires Marias, Trinitaria, and Veranera. 

These plants are not known as escapes in our area, and because of propagation 
by vegetative means, it is difficult to establish species limits. Species descrip- 
tions are not provided here (see fig. 31), but the following key, based on Gillis 
1976, should be helpful. For a thorough discussion of the cultivars, see L. H. 
MacDaniels' article on this subject in Baileya 21:77-100, 1981. 

la Perianth tube distinctly angled with longitudinal ribs and with spreading straight 
hairs to 1 mm long; stems and leaves villous; rare in Central America 

B. spectabilis Willd. 

Ib Perianth tube with distinct longitudinal ribs and with upward curving hairs to 0.5 mm 
long; stems and leaves glabrous to puberulent; commonly planted in Central 
America 2a 

2a Leaves broadly ovate, becoming smaller below the inflorescence; bracts deep red or 
orange and with obtuse apices, not crinkled; flowers closely grouped; stems with 
straight thorns B. buttiana Holtrum and Standley 



190 FIELDIANA: BOTANY 

2b Leaves narrowly ovate to elliptic, not becoming smaller below the inflorescence; bracts 
magenta to purple and with acute apices, often crinkled; flowers usually separate; 
stems with curved thorns or thorns absent B. glabra Choisy in DC. 

GUAPIRA Aublet 

Trees and shrubs, functionally unisexual (dioecious), puberulent in early stages but 
often becoming glabrous. Leaves opposite, whorled or occasionally subopposite, often 
very variable in size on the same plant or at the same node, petiolate, entire, pinnately 
veined. Inflorescences terminal, 1-3, with a single primary peduncle and rachis and 
opposite or subopposite branching, densely and minutely brownish or reddish puber- 
ulent, becoming succulent in fruit, flowers usually in groups of 2 or 3 on the ultimate 
inflorescence branches, and subtended by 1-3 minute bracts. Male flowers obconic, to 
campanulate or funnel-shaped, the 5 small distal lobes valvate in bud, green to white or 
yellowish, stamens usually 8 (5-10), filaments slender and unequal, united at the base to 
the stipe of the pistillode, anthers versatile and exserted well beyond the floral cup. Female 
flowers tubular to tubular-campanulate, staminodes with large sterile anthers and in- 
cluded within the perianth tube, pistil narrowly ovoid and with a basal stipe adnate to the 
filament tube, locule 1, style 1, stigma penicillate or fimbriate. Fruit an anthocarp formed 
by enclosure of the ovary within the succulent perianth tube, drupaceous, the free distal 
portion of the perianth tube usually persisting (in ours), becoming red or black, longi- 
tudinally striate when dry. 

A genus of perhaps 50 species ranging from Mexico through Central America 
and the West Indies to northern South America, Brazil, Paraguay, and Bolivia 
(apparently absent along the Pacific side of South America). These plants are 
recognized by their opposite or whorled leaves, terminal inflorescences with 
small flowers that appear to be bisexual but are functionally unisexual, perianth 
tube subtended by one to three minute bracts, exserted stamens and stigma, and 
drupaceous fruit that may appear to be the product of an inferior ovary. These 
plants resemble certain members of the Rubiaceae family, but lack stipules, two 
perianth whorls, and an inferior ovary. The genus Torrubia has been united with 
Guapira, and it is more than likely that Neea should also be submerged under 
Guapira. 

We have very few collections of this genus from Costa Rica. While our material 
appears to represent a single species, there is some question if it is specifically 
distinct from G. linearibracteata (Heimerl) Standley of northern Central America 
and Mexico (with smaller leaves but larger flowers) and G. standleyanum as 
interpreted by Croat in the Flora of Barro Colorado Island (said to grow to 35 m 
in height and with puberulent fruit). Considering the perplexing variability in 
our material of Neea, it would not be surprising to find similar problems in 
Guapira. 

Guapira costaricana (Standl.) Woodson, Ann. Missouri Bot. Gard. 48:62. 
1961. Torrubia costaricana Standley, Contr. U.S. Nat. Herb. 13:385. 1911. 

Small trees 5-10 m tall (rarely shrubs), unisexual, leafy internodes 1-5 (8) cm long, 1.3-4 
mm thick with slender brownish multicellular hairs, stems quickly becoming glabrous and 
pale grayish in age, little or obscurely lenticellate. Leaves opposite and subequal to very 
unequal at a node, often with a whorl of 4 leaves at flowering or branching nodes, usually 
drying dark in color, petioles 5-15 (25) mm long, with 2 lateral or adaxial ridges continuous 
with the laminae margins; laminae 4-15 (18) cm long, 2-6 cm broad, narrowly elliptic to 
elliptic or elliptic-oblong, (occasionally ovate to obovate in the short leaves) tapering to an 
acute or short-acuminate apex, acute to obtuse at the base (rounded at the base on the 
broad little laminae), entire, smooth on both surfaces, glabrous or becoming glabrous 
above and below, drying thin-chartaceous, with 6-10 pairs of major secondary veins, the 
venation often somewhat obscure. Male inflorescences 5-10 cm long, primary peduncle 



BURGER: FLORA COSTARICENSIS 191 

2-6 cm long, peduncle and inflorescence branches minutely brownish puberulent, male 
flowers sessile or subsessile, subtended by minute (0.5 mm) bracts, floral cup 2-3 mm long 
and 2-3 mm broad at the campanulate apex (dry), filaments unequal, anthers ca. 0.6 mm 
long and exserted up to 3 mm beyond the perianth. Female inflorescences to 15 cm long 
in fruit, becoming red in color, minutely puberulent; female flowers 2-3 mm long, tubular, 
subtended by minute (0.5 mm) bracts, stigmas exserted 0.5-1 mm at anthesis. Fruit 
becoming broadly ellipsoid to subglobose, 8 mm long and 5 mm thick (dry), becoming dark 
purple or black, with obscure longitudinal ridges. 

Rarely collected small trees of evergreen forest formations from (0) 400 to 2,000 
m elevation; flowering from February to May in Costa Rica. The species has only 
been collected along the Pacific watershed in Costa Rica from the Nicoya pen- 
insula and easternmost Guanacaste province to the General Valley and along the 
Pacific slopes of the Talamanca mountains. The species ranges from central 
Costa Rica into Panama and probably into northern South America. 

Guapira costaricana is recognized by the often unequal opposing leaves (occa- 
sionally in whorls of 4), the reddish puberulent terminal inflorescences with 
very small tubular female flowers and exserted fimbriate stigmas or slightly 
larger campanulate male flowers with exserted stamens, and the fruit becoming 
dark purple or black on a red inflorescence. These plants are restricted to central 
and southern Costa Rica along the Pacific slope and have not been collected in 
the same areas as our representatives of Neea, as if they were excluding each 
other from the same habitat. The reason for making such a remark is that Neea 
has a rather unusual distribution in Costa Rica and, in addition, our species of 
Guapira and Neea should probably be united in the same genus. With very dark 
fruit on bright red inflorescences, one would expect these plants to be collected 
more often; they appear to be restricted to tropical moist premontane wet forest 
formations and to flower only in the dry season. 

MIRABILIS Linnaeus 

Herbs or small subshrubs, perennial but often capable of flowering after only a few 
months growth (annual), sometimes woody near the base, usually much branched, the 
nodes often thickened, rootstocks often tuberous; stipules absent. Leaves opposite and 
simple, petiolate (in ours) or sessile, entire or undulate, pinnately veined. Inflorescences 
mostly small cymes or clusters of bracteate flowers in leaf axils or terminal, with 1 or 
several flowers subtended by leaflike bracts that are united near the base and form a 
5-parted calyx-like involucre (the product of a reduced cyme); flowers bisexual and radially 
symmetrical, perianth united and forming a campanulate to funnelform or salverform 
tube, the tube short or long, 5-lobed at the apex and induplicate-valvate in bud, the upper 
portion deciduous, stamens 3-5, equaling or exceeding the perianth tube, filaments slen- 
der and unequal, short-connate at the base, ovary ovoid to globose, style slender with 1 
long papillate or capitate stigma. Fruit included within the persisting and slightly enlarged 
bracteate (but calyx-like) involucre, achene-like but said to be an anthocarp formed by 
adnation with the base of the perianth tube, cylindrical to obovoid, terete, with 5 longi- 
tudinal ridges or sulci, often rugose or tuberculate, glabrous or puberulent, constricted just 
above the base, mucilaginous when wet; embryo sharply curved. 

A genus of perhaps 60 species, nearly all American. One species (M. jalapd) is 
now widely naturalized and planted for ornament. The opposite leaves that are 
often slightly viscid and triangular in outline, the bracteate calyx-like involucre 
subtending one or a few flowers, the showy corolla-like perianth tube usually 
bright reddish purple in color, and the unusual fruit distinguish this genus 
which can be mistaken for members of the "Tubiflorae" (Gentianaceae, 
Solanaceae, etc.). The genus Oxybaphus is no longer considered distinct from 
Mirabilis. 



192 FIELDIANA: BOTANY 

KEY TO THE SPECIES OF Mirabilis 

la Perianth tube 3.5 cm long; fruit 7-9 mm long; common plants of weedy and cultivated 
sites in evergreen and partly deciduous areas M. jalapa 

Ib Perianth tube 0.5-1 cm long; fruit 3-4 mm long; plants restricted to the seasonally dry 
Pacific lowlands of central and northern Costa Rica M. violacea 

Mirabilis jalapa L., Sp. PI. 177. 1753. 

Herbs or subshrubs to 1.3 m tall, annual or perennial, bisexual, much branched, leafy 
internodes 1-10 (15) cm long, 1-5 mm thick (dry), usually minutely (0.1-0.5 mm) puber- 
ulent with crooked brownish multicellular trichomes, the hairs often dense in longitudinal 
grooves and at the thickened nodes, occasionally glabrous. Leaves opposite and usually 
equal at a node, petioles 0.8-6 cm long, 0.5-1.5 mm broad (dry), with an adaxial sulcus 
or groove, usually sparsely puberulent; laminae 2-10 (14) cm long, 1-6 (8) cm broad, 
triangular to ovate-deltoid or ovate, tapering gradually to the acute or acuminate apex, 
rounded or abruptly truncate (subcordate) at the base, short-decurrent on the petiole, 
margins entire and often ciliolate, the laminae drying membranaceous to thin- 
chartaceous, usually sparsely puberulent with scattered hairs 0.3-1 mm long between the 
veins and shorter dense hairs on the veins above, usually glabrous beneath, with 3-5 pairs 
of major secondary veins. Inflorescence cymose or glomerate in leaf axils or terminal, 
occasionally solitary and axillary, peduncles less than 5 mm long; flowers to 7 cm long, 
subtended by a sepaloid whorl of 3-5 partly united leaflike bracts 7-15 mm long, green 
and sparsely puberulent, the perianth with a long narrow tube and funnelform, to 6 cm 
long and 2.5-4 cm broad at the apex, usually deep fuchsia magenta, or purple- red, occa- 
sionally yellow, orange, pink, or white; stamens equaling or slightly exceeding the peri- 
anth. Fruit 7-9 mm long, ca. 5 mm thick, ellipsoid or ovoid, with 5 thin dark longitudinal 
ridges, dark brown and verrucose, with a slight constriction just above the base. 

Cultivated plants in gardens and weeds of open early secondary vegetation, 
ranging from sea level to about 2,000 m in both evergreen and partly deciduous 
formations in Costa Rica; probably flowering throughout the year, but with 
collections made primarily from June to January. This species is now widespread 
throughout the tropics and subtropics both as an ornamental and a weed; its 
origin appears to have been in Mexico. 

Mirabilis jalapa is recognized by its tubular, orange, white, or purplish flowers 
subtended by a calyx-like involucre of united bracts, opposite leaves with the 
larger laminae almost triangular in outline, and the usual association with culti- 
vated or disturbed areas. Flowers of different colors are occasionally produced by 
the same plant, and a perianth with longitudinally striped colors is sometimes 
seen. The species is called Maravilla throughout Central America and "four- 
o'clock" in English-speaking countries. 

Mirabilis violacea (L.) Heimerl, Beitr. Syst. Nyctag. 23. 1897. Allionia violacea 
L., Syst. ed. 10. 890. 1759. Oxybaphus violaceus Choisy, in DC., Prodr. 13, pt. 
2:432. 1849. 

Herbs, erect, procumbent, or clambering to 1 m tall, annual or with a perennial root- 
stock, bisexual, leafy internodes (0.8) 1.5-9 cm long, 0.3-2 mm thick (dry), sparsely to 
densely puberulent with thin brownish multicellular or gland-tipped hairs, the trichomes 
often restricted to longitudinal grooves. Leaves opposite and equal at a node, petioles 
0.5-3 (6) cm long, ca. 0.5 mm broad (dry), glandular puberulent, with 2 abaxial ridges 
forming a groove or sulcus above; laminae 1.5-5 (7) cm long, 1-3 (5) cm broad, ovate- 
triangular, to broadly ovate or narrowly triangular, tapering gradually to the acuminate 
(rarely obtuse) apex, rounded at the cordate to truncate base, margin entire, the laminae 
drying membranaceous to thin-chartaceous (sometimes slightly succulent in life), sparsely 
puberulent or minutely puberulent only on the veins above, usually glabrous beneath but 
with cystoliths conspicuous on the dried undersurface, with 2 or 3 pairs of major second- 



BURGER: FLORA COSTARICENSIS 193 

ary veins. Inflorescences small terminal or axillary cymes (flowers sometimes solitary and 
axillary), usually congested but sometimes to 5 cm long and with peduncles or pedicels 
becoming 2 cm long, pedicels thin and densely covered with thin brownish or glandular 
hairs; flowers 10-15 mm long and subtended by a calyx-like involucre of broad green 
leaflike puberulent bracts 3-4 mm long and enlarging in fruit to 6 mm long, united near 
the base and with viscid hairs, perianth tube 5-10 mm long, 5-lobed, purplish or rarely 
white, stamens usually 3. Fruit narrowly obovoid or cylindrical, 3-4 mm long, 2-2.5 mm 
thick, dark brown, narrowed at the apex and constricted above the base, usually with 
paler-colored longitudinal ribs, puberulent. 

Small plants of both open early secondary and weedy sites and in shaded 
woodland in the seasonally dry deciduous vegetation of the Pacific lowlands in 
Guanacaste and northern Puntarenas provinces; flowering collections have been 
made from mid- April to August in our area and from March to November in 
Nicaragua and Honduras where the plants are found as high as 900 m above sea 
level. The species ranges from southern Mexico along the Pacific side of Central 
America to the northern half of Costa Rica, Colombia, and Venezuela. 

Mirabilis violacea is recognized by its small stature, opposite cordate to truncate 
leaves, bracteate involucre united at the base, pink-purplish perianth tube, usual 
presence of viscid hairs, and restriction (in our area) to the drier Pacific lowlands. 

NEEA Ruiz & Pavon 

Small subshrubs to small- or medium-sized trees (rarely more than 8 m tall), unisexual, 
usually reddish brown puberulent in early stages, often becoming glabrescent. Leaves 
opposite or in whorls of 4 at flowering or branching nodes, occasionally subopposite or 
alternate on the same plant, leaves of the same node often differing in size, petiolate, 
laminae entire and pinnately veined, often slightly succulent in life. Inflorescences termi- 
nal (appearing axillary only with further growth of a subtending axillary twig), usually 
solitary at a node (rarely 2 or 3), paniculate or thyrsiform with a single slender peduncle 
and usually a single primary rachis with opposite to alternate primary branches, the 
flowers often in cymelike distal groups of 3, sessile or pedicellate and with 1-3 minute 
bracteoles at the base of the perianth tube, the inflorescence and its branches often bright 
red or purple. Male flowers with an ellipsoid to ovoid perianth tube with 5 small perianth 
lobes at the narrow apex of the tube, often semisucculent in life, stamens usually 8 (5-10), 
included within the perianth tube, filaments unequal in length and fused at the base, a 
pistillode present and often of normal size. Female flowers urceolate to tubular, the tube 
often constricted beneath the 5 small lobes, usually much smaller than the male flowers, 
staminodes present and with normal but nonfunctional anthers, pistil sessile or narrowed 
at the base, unilocular with 1 style and a single fimbriate stigma. Fruit a fleshy anthocarp 
formed by the succulent perianth tube tightly enclosing the ovary, bright yellow, pink, 
deep red or purple, free distal portion of the perianth tube usually deciduous, surface 
smooth but the longitudinal ribs often apparent when dry; seed with straight embryo and 
contorted cotyledon, little endosperm. 

Neea ranges from southern Florida and central Mexico through Central Amer- 
ica and the West Indies as far as Bolivia. These plants, with their shrubby or 
small tree habit, opposite leaves, and narrow tubular flowers resemble members 
of the Rubiaceae family, but that family has stipules, an inferior ovary, and a 
calyx and corolla. The terminal inflorescences of Neea often produce dichoto- 
mous branching as growth proceeds beyond the flowering node. The genus Neea 
may not be sufficiently distinct from Guapira to merit generic rank, in which case 
the species listed here would have to be transferred to Guapira (q.v.). I have seen 
no reference to the economic use of these plants, though it is said that the fruit 
have been used for coloring. 

There seem to be no clearly defined species of Neea in Costa Rica. Even the 
most unusual plants can be related to more common forms by intermediate 



194 FIELDIANA: BOTANY 

collections. There may be more species than the two generalized concepts 
presented here, but variation is so great among the common forms that there is 
no way of clearly delimiting the rarer forms. This troublesome variability ap- 
pears to affect all aspects of the plants: habit, leaves, pubescence, inflorescences, 
flowers, and fruit. Add to this the problem of relating specimens with male 
flowers to those with female flowers or fruit, and one can understand why 
identifying species (if such exist in Need) is so difficult. I have illustrated and 
written a key to two "species groups"; these can then be further divided by using 
the brief subsidiary keys and the illustrations. However, the two "species 
groups," treated as two species in a wide sense in the descriptions, have the 
same flowering periodicity, the same altitudinal range, and similarly peculiar 
distribution patterns within Costa Rica. This seems to indicate that, however 
different some of these plants may look from each other, there may be no 
barriers to gene flow within the genus in southern Central America and, in 
effect, no real species. 

KEY TO THE SPECIES GROUPS OF Neea IN COSTA RICA 

la Fruit of the lateral inflorescence branches sessile, subsessile or borne on relatively 
short thick pedicels shorter than the fruit; leaves becoming quite large (20-35 cm) and 
broadly obovate to broadly oblong or broadly elliptic (leaves shorter above 1,200 m 
elevation), glabrous or puberulent; small subshrubs, few-stemmed shrubs or small 
trees, 1-3 (8) m tall, often found in the deep shade of the forest understory 

N. amplifolia s.l. 

Ib Fruit of the lateral inflorescence branches borne on slender pedicels, the pedicels often 
becoming as long or longer than the fruit (terminal flowers and fruit often sessile); 
leaves rarely exceeding 18 cm in length, generally elliptic to elliptic-oblong (sometimes 
obovate in smaller leaved individuals), gradually tapering to both apex and base, 
usually glabrous; shrubs, small trees or rarely large (20 m) trees, often found in open 
secondary growth N. psychotrioides s.l. 

Neea amplifolia Donnell Smith, Bot. Gaz. 61:386. 1916. N. orosiana Standl., J. 
Wash. Acad. Sci. 15:473. 1925. N. urophylla Standl., Publ. Field Columbian Mus., 
Bot. Ser. 4:203. 1929. N. elegans P. H. Allen, Rain Forests of Golfo Dulce 273 & 
409. 1956. Figure 35. 

Few-branched subshrubs or small trees, 0.4-2 m tall, unisexual, leafy inter nodes 0-10 
cm long, 1-4 mm thick, soon becoming glabrous, smooth and pale colored in later stages. 
Leaves usually opposite, petioles 3-30 (65) mm long, with lateral ridges; laminae 8-26 (35) 
cm long (2) 5-12 (17) cm broad, obovate to broadly elliptic-oblong, less often broadly 
elliptic, oblong or ovate, usually abruptly narrowed to the apex, usually tapering gradually 
to the base, margin entire, surfaces smooth, glabrous or minutely puberulent beneath, 
with 6-13 pairs of major secondary veins. Inflorescences terminal, rarely more than 6 cm 
long in flower (to 10 cm in fruit, peduncle becoming 7 cm long in fruit). Male flowers 5-9 
mm long; female flowers 2-4 mm long at anthesis, usually densely puberulent. Fruit 
rounded to oblong or ellipsoid, to 1 cm long when dry, usually borne on a pedicel shorter 
than the body of the fruit. 

Small few-stemmed shrubs of forest shade in moist evergreen formations from 
sea level to 1,600 m elevation; flowering from April to November, but fruit have 
been collected from January to November. Distribution in Costa Rica is very 
similar to that of N. psychotrioides; throughout the Caribbean lowlands, along the 
northwestern volcanic chain to San Ramon and Zarcero, uncommon on the wet 
Caribbean slope near La Palma and Bajo La Hondura, Muneco, Orosi, and 
Turrialba, and it has not been collected in the General Valley or on the Pacific 
slopes of southern Costa Rica. The species ranges from Nicaragua to Panama. 



BURGER: FLORA COSTARICENSIS 195 

Neea amplifolia is recognized by its larger, obovate to very broadly elliptic- 
oblong leaves, short stature, small inflorescences, fruit borne on relatively short 
pedicels, and shaded forest habitat. There appears to be no way in which this 
taxon can be sharply distinguished from N. psychotr hides, and intermediate 
plants are found with some frequency. It may be that the plants placed here are 
no more than an ecotype found in deeply shaded sites. The two species, N. 
amplifolia and N. psychotrioides, share the same peculiar distribution pattern in 
Costa Rica, except that N. amplifolia is more common in the drainage area of the 
Rio Reventazon and appears to be absent from the Golfo Dulce area. Flowering 
periodicity is also nearly identical in the two entities. I believe that the extreme 
forms differ so greatly and with sufficient frequency that it may be useful to 
retain N. amplifolia at the level of species rank until we have a better idea of what 
is actually going on within and between these populations. Neea acuminatissima 
Standley with long (ca. 30 cm) leaves that taper very gradually to the acuminate 
apex may be a similar species of deeply shaded sites in the Caribbean lowlands 
of northern Central America. 

Neea pittien 'Standley (Conrr. U.S. Natl. Herb. 13:383, 1911) appears to belong 
in this group and is the earliest name available. However, the type is rather 
atypical of the assemblage, and its restriction to higher elevations makes its 
placement provisional, hence, use of the name amplifolia. 

POSSIBLE SEGREGATES OF Neea amplifolia (IN A WIDE SENSE) 

la Montane plants above 500 m elevation; leaves often very broad, occasionally obovate; 

shrubs 1-3 m tall N. pittien Standley 

Ib Lowland plants 2a 

2a Small plants (1-2 m tall) of the dark forest understory, leaves often obovate (to 

elliptic-oblong), often attacked by leaf miners N. amplifolia sensu stricto 

2b Larger plants usually becoming small trees; leaves rarely obovate; uncommon 

plants 3a 

3a Leaves very broadly oblong or elliptic-oblong, becoming glabrous in age 

N. urophylla Standley 
3b Leaves elliptic to elliptic-oblong, remaining brownish puberulent in age 

N. elegans P. H. Allen 

Neea psychotrioides Donnell Smith, Bot. Gaz. 16:199. 1891. N. laetevirens 
Standl., Publ. Field Columbian Mus., Bot. Ser. 4:204. 1929. N. belizensisLundell, 
Conrr. Univ. Michigan Herb. 7:9. 1942. N. pycnantha Standl., Ann. Missouri Bot. 
Card. 30:85. 1943. N. xanthina Standl., loc. tit. 30:86. 1943. N. popenoei P. H. 
Allen, Rain Forests of Golfo Dulce 274 & 410. 1956. Figure 34. 

Shrubs, small trees or occasionally subshrubs, 1-5 (8) m tall, unisexual, leafy internodes 
0-6 (10) cm long, 1-4 mm thick, minute reddish brown tomentulose in early stages but 
quickly becoming glabrescent, smooth and terete, the older stems often pale grayish in 
color in contrast to the newer stems which often dry very dark. Leaves usually opposite, 
often in a whorl of 4 at branching or flowering nodes, occasionally alternate or subopposite 
on the same branch, opposing leaves of a node often slightly unequal, petioles 4-30 mm 
long, 0.4-1.6 mm thick, with 2 lateral ridges continuous with the lamina margins; laminae 
(2) 3-15 (23) cm long, 1.8-8 cm broad, generally elliptic to elliptic-oblong (obovate to ovate 
usually only in small-leaved plants of higher altitudes or seasonally very dry areas), 
tapering gradually or abruptly to an acute or short acuminate apex, tapering gradually or 
abruptly to an acute to obtuse base, often somewhat unequal at the base, margin entire, 
surface smooth and glabrous in age (occasionally remaining brownish puberulent be- 
neath), with 5-11 pairs of major secondary veins, the midvein often pinkish or reddish in 
life. Inflorescences (3) 8-35 cm long, terminal (apparently axillary by continued growth of 



196 FIELDIANA: BOTANY 

a subtending stem), usually pendulous or becoming so in fruit, often a panicle with a long 
primary peduncle and openly dichotomous cymelike distal branches, the primary pedun- 
cle to 20 cm long and often exceeding the length of the flowering portion of the in- 
florescence, branches of the inflorescence usually minutely (0.1 mm) reddish brown puber- 
ulent, floral bracts 0.5-1 mm long, pedicels 0-5 mm long, often equaling or exceeding the 
flowers in length. Flowers deep red in bud but becoming yellowish white or greenish 
white, male flowers with a floral tube 4-7 (9) mm long, female flowers with a floral tube 
2-3 mm long at anthesis. Fruit becoming 6-10 mm long (dry), ellipsoid to subglobose, 
ribbed when dry, pink to deep red. 

Shrubs and small trees often found in secondary growth and openings in the 
forest interior; ranging from sea level to about 1,500 m elevation. The species 
appears to flower for much of the year, but we have very few flowering col- 
lections from November to January in Costa Rica. The species ranges from 
southern Mexico to Panama and probably extends into South America under a 
variety of other names. The geographic distribution of this species in Costa Rica 
is unusual. It is not uncommon in the northwestern highlands, as far east as San 
Ramon and Zarcero, but it has not been collected from the central volcanoes nor 
from the Talamanca range. Likewise, though common in the Caribbean low- 
lands, it is not known from the General Valley and appears to be quite uncom- 
mon in the evergreen forests along the Pacific in southern Costa Rica. 

POSSIBLE SEGREGATES OF Neea psychotrioides (IN A WIDE SENSE) 

la Leaves usually less than 13 cm long; infructescences usually less than 10 cm long; 
Pacific slope of Central America southward to Guanacaste and the Sierra de Tilaran to 
the western edge of the Meseta Central, occasional in the Caribbean lowlands in open 
sites N. psychotrioides sensu stricto 

Ib Leaves or the fruiting inflorescences larger than above; not known from northwestern 
Costa Rica or the Pacific slope of northern Central America 2a 

2a Peduncles and pedicels long and thin, pendulous from early stages, pedicels often 
greatly exceeding the fruit in length, fruit less than 10 mm long; leaves often quite 
narrow, rarely collected N. delicatula auct. in herb. 

2b Peduncles and pedicels not so thin, becoming pendulous in later stages(?) 3a 

3a Trees to 20 m tall, leaves often abruptly acuminate; male flowers to 7 x 4 mm on long 
inflorescences, fruit(?) to 2 cm long; rare N. popenoei P. H. Allen 

3b Shrubs or small trees, leaves usually tapering gradually or abruptly to the apex; 
male flowers smaller; fruit not so long; very common and intergrading with 
N. amplifolia N. laetevirens Standley 

PISONIA Linnaeus 

Shrubs, small trees, or lianas, unisexual, glabrous or puberulent, axillary short straight 
or curved spines usually present, younger leaves often developing from the sides of the 
spines. Leaves opposite, subopposite, or occasionally in alternate nearby pairs, laminae 
decurrent on the petiole, simple and entire, venation pinnate. Inflorescences solitary or 
fasciculate, axillary or terminal on highly modified axillary short shoots, the flowers often 
borne in cymes but the cymes clustered in umbelliform, capitate, corymbiform, or other 
arrangements. Flowers small and radially symmetrical, greenish, unisexual, subtended by 
bracteolate pedicels; male flowers with a campanulate perianth tube, the tube with 5 
obscure distal lobes or teeth, stamens 6-8 (10), exerted at anthesis, filaments slender, 
united near the base to form a small tube and adnate to the base of the pistillode; female 
flowers with a narrow perianth tube, staminodes often in the form of a dentate disk adnate 
to the narrowed base (stipe) of the pistil, ovary 1-Iocular and with 1 ovule, style narrow 
and with a fimbriate stigma. Fruit an anthocarp formed by the union of perianth tube and 
pistil, narrowly elongate, terete or 5-angIed in cross section, with longitudinal rows of 
stalked glands in 1 or several ranks, the fruit at maturity usually borne on greatly elongated 
peduncle and pedicels. 



BURGER: FLORA COSTARICENSIS 197 

A pantropical genus with species estimated to number between 15 and 50. The 
slender coriaceous fruit borne on elongated pedicels and with longitudinal rows 
of stalked glands are quite distinctive. These fruits are said to adhere to the 
feathers of birds with their viscid glands. 

Pisonia fasciculata, described by Standley (Contr. U.S. Natl. Herb. 13:388, 
1911), bears fascicles of little subcapitate inflorescences borne on short shoots 
and straight spines. The type was collected by C. Wright on the Pacific side of 
Nicaragua between 1853 and 1856. This species appears to be a rare endemic of 
Central America's seasonally very dry Pacific lowlands, and it might possibly 
occur in northwestern Guanacaste. 

la Spines usually curved, stems and leaves glabrous or puberulent, laminae often ob- 
ovate; fruit 15-20 mm long; shrubs, trees, or lianas in both deciduous and evergreen 
formations, 0-1,000 (rarely to 1,800) m elevation P. aculeata 

Ib Spines straight, stems and leaves glabrous, laminae usually narrowly elliptic; fruit 
8-10 mm long; shrubs or small trees of evergeen montane forests, 1,000-2,200 m 

P. silvatica 

Pisonia aculeata L., Sp. PL 1026. 1753. P. aculeata var. macranthocarpa Donn. 
Smith, Bot. Gaz. 16:198. 1891. P. macranthocarpa Donn. Smith, Hot. Gaz. 20:293. 
1895. P. grandifoliaStandl., Contr. U.S. Natl. Herb. 13:391. 1911, not P. grandifolia 
Warb., 1891. Figure 33. 

Shrubs or small trees to 10 m tall, often with clambering branches, becoming large lianas 
in evergreen formations, unisexual, leafy internodes 0.1-6 (12) cm long, 0.7-6 mm thick, 
glabrous and reddish brown to densely puberulent or villous and yellowish brown or 
grayish, becoming lenticellate, the nodes slightly thickened and often bearing 1 thick 
recurved (less often straight) spine from each axil, newer leaves often borne from the side 
of the spine. Leaves opposite, subopposite, or occasionally alternate (on the same stem), 
the leaves often borne on short shoots in the axils of fallen leaves, petioles 2-40 mm long, 
often very variable on the same stem, with 2 adaxial ridges continuous with the lamina 
margins; laminae 2-15 cm long, 1.5-6 (9) cm broad, elliptic to obovate or obovate- 
orbicular, usually abruptly narrowed to an obtuse, acute or short-acuminate apex, gradu- 
ally narrowed to the acute (less often obtuse) base and decurrent on the petiole, margins 
entire, the laminae drying thin- to stiff-chartaceous, smooth, glabrous to densely puber- 
ulent on both surfaces or often puberulent only along the midvein beneath, with 5-8 pairs 
of major secondary veins. Inflorescences solitary and axillary, 2-6 cm long, made up of 
little cymes in complex umbel-like or panicle-like arrangements, unisexual, very minutely 
puberulent to hirsutulous with trichomes 0.05-0.5 mm long, often viscid, primary pedun- 
cles 1-4 cm long, pedicels subtended by small (1 mm) deciduous bracts, both peduncles 
and pedicels greatly elongating in fruit; male flowers with a campanulate perianth tube 2-4 
mm long and ca. 3 mm broad, stamens 6 and exerted 2-3 mm beyond the perianth, anthers 
ca. 0.5 mm long; female flowers with a tubular or narrowly urceolate perianth tube 2-3 mm 
long. Fruit borne on open few-branched expanded infructescences with pedicels 1-3 cm 
long, the anthocarp 1.5-2 cm long (in ours), 5-8 mm thick, ellipsoid to narrowly obovoid- 
clavate, 5-angled (in cross section), with 5 longitudinal ridges, each ridge or angle with 
1-3 ranks of stalked viscid glands, surfaces between the ridges densely and very minutely 
(0.05 mm) pale grayish or yellowish velutinous. 

Shrubs, small trees, or rarely vines in seasonally very dry deciduous for- 
mations or becoming large woody lianas in moist or wet evergreen formations, 
to about 1,000 (very rarely 1,800) m elevation in our area; flowering and fruiting 
from July to March, but with most of our collections made between November 
and February. The species ranges from the southern tip of Florida and Mexico, 
through Central America and the West Indies, to Ecuador and northern Argen- 
tina; the species is also found in central Africa, southern Asia, and the Philip- 
pines. 



198 FIELDIANA: BOTANY 

Pisonia aculeata is recognized by the opposite or subopposite leaves with vari- 
able petioles and decurrent lamina bases, the short thick usually curved spines, 
the unisexual flowers with small perianth tubes in dense little inflorescences, 
and the very unusual fruit on open few-branched infructescences. The species 
appears to present a very unusual correlation between life-form and habitat. In 
wet evergreen forests, the plants are described as woody lianas reaching the tops 
of tall trees, while in deciduous vegetation, the plants are nearly always shrubs 
or small trees. Also, the wet forest material is often densely puberulent and has 
larger broader leaves (as in Skutch 4848 from the General Valley). We have very 
little material representing these wet forest lianas, and it may be that they differ 
in other ways and are worthy of taxonomic recognition as a subspecies or 
variety. This species is known as Una de Tigre in Central America. 

Pisonia sylvaticaStandley, Publ. Field Mus. Nat. Hist., Bot. Ser. 18:425. 1937. 

Slender shrubs or small treelets, 1.5-4 m tall, unisexual, often much branched, leafy 
internodes 1-6 cm long, ca. 1-2 (4) mm thick, glabrous, pale in color and relatively smooth 
with very few lenticels developing, nodes slightly thickened; spines axillary, 0.5-1.5 cm 
long, ca. 1.5 mm thick at the base, straight, smooth and sharp-tipped. Leaves opposite, 
subopposite or in alternate nearby pairs, petioles 3-10 mm long, ca. 1.3 mm thick, sulcate 
above with 2 adaxial ridges continuous with the lamina margins; laminae 4-10 (13) cm 
long, 2-4 (5) cm broad, elliptic, narrowly ovate-elliptic, or narrowly oblong-elliptic, taper- 
ing gradually to the acuminate or less often acute apex, tip usually blunt, tapering to the 
acute base, margin entire and decurrent on the petiole, the laminae drying stiffly char- 
taceous, smooth and glabrous on both surfaces, the midvein raised above, the 4-7 pairs 
of major secondary veins obscure on both surfaces. Inflorescences axillary and solitary, a 
cluster of small cymes on a long peduncle resulting in a capitate appearance in early stages, 
peduncles 1-4 cm long, glabrous but the pedicels papillate-puberulent; male flowers ca. 4 
mm long and borne on pedicels to 3 mm long, the perianth tube campanulate with the 
usually 10 stamens extended 2-4 mm beyond the tube, anthers ca. 0.5 mm long; female 
flowers 2-3 mm long (dry), perianth tube minutely papillate puberulent, style and fim- 
briate stigma exerted. Fruit borne on pedicels elongating to 3 cm and becoming reddish, 
body of the fruit (anthocarp) 8-10 mm long, 3-4 mm thick (dry), narrowly ellipsoid to 
ellipsoid-cylindrical, style and stigma persisting and exerted, with 10 longitudinal rows of 
single-ranked stalked gland- tipped projections ca. 0.5 mm long. 

Shrubs and small trees of evergreen premontane and lower montane moist 
forest formations between 1,000 and 2,200 m elevation; flowering and fruiting 
collections have been made from October to December and February and March. 
This species is known only from the areas near Monteverde in the Sierra de 
Tilaran and from near San Ramon and Zarcero on the western edge of the Meseta 
Central in Costa Rica. 

Pisonia silvatica is recognized by the glabrous parts (except for the flowering 
parts of inflorescences), opposite to subopposite leaves with straight axillary 
spines, closely clustered flowers on a distinctive peduncle, and the fruit borne 
on greatly elongated pedicels and with 10 longitudinal rows of stalked glands. 
It is interesting that this endemic has never been found in areas east of Zarcero 
where collecting has been extensive; it may occur in the Sierra de Guanacaste 
which has been little collected. 

SALPIANTHUS Humboldt and Bonpland 

Herbs or small shrubs, usually much branched, bisexual, usually glandular puberulent, 
at least near the inflorescences; stipules absent. Leaves alternate and simple, laminae 
usually decurrent on the petiole, entire. Inflorescences small racemes, cymes or congested 
clusters, often in distal paniculate arrangements, terminal or axillary, bracts subtending 



BURGER: FLORA COSTARICENSIS 199 

the flowers very small and inconspicuous; flowers bisexual and radially symmetrical, 
sessile or pedicellate, perianth tube cylindrical to urceolate, subcoriaceous, with 4 or 5 
short lobes, covered with gland-tipped hairs (uncinate hairs present in ours), with 4 or 5 
longitudinal ribs, not enlarging in fruit, stamens 3 and borne from 1 side of the perianth 
tube, filaments often unequal, anthers rounded, ovary sessile and with a slender style, 
stigma simple and acute, ovule solitary and basal. Fruit an achene-like utricle, the persist- 
ing glandular-pubescent perianth tube tightly enclosing fruit and seed; seeds very smooth 
and lustrous. 

A genus of a few, principally Mexican, species. Salpianthusis closely related to 
Mirabilis among our representatives of the family, but lacks the corolla-like tube 
and subtending bracteate involucre. The broad basal triangular leaves, gland- 
tipped hairs on distal parts, stiff calyx tube (perianth tube) with hooked hairs, 
3 stamens with thin filaments and rounded anthers exceeding the tube, and 
shiny black seed tightly enclosed in the persisting perianth tube help to dis- 
tinguish our species of this genus. 

Salpianthus purpurascens(Cav.) Hook. & Arn., Bot. Beechey Voy. 308. 1837. 
Boldoa purpurascens Cav . ex Lagasca, Gen. & Sp. Nov. 10. 1816. B. ovatifoliaLag., 
loc. cit. Figure 32. 

Herbs or subshrubs to 1.5 (2) m tall, much branched, leafy internodes 1-10 cm long 1-7 
mm thick, glabrous or very minutely puberulent, angulate, the distal inflorescence bearing 
stems densely viscid puberulent. Leaves alternate, very variable in size on the same plant 
with smaller leaves on the distal flowering stems, petioles 0.3-10 cm long, with lateral 
ridges becoming winglike distally and continuous with the lamina margins; laminae 2-20 
cm long, 1.5-18 cm broad, ovate to ovate- triangular or rhombic-ovate, tapering gradually 
to the bluntly acute or obtuse apex, rounded and truncate to subtruncate above the 
cuneate and long decurrent base, margins entire, the laminae drying thin- chartaceous, 
very minutely (0.1-0.2 mm) puberulent above, very minutely puberulent or glabrous 
beneath, short linear cystolith-like projections on the dried surface beneath, with 3-6 
pairs of major secondary veins, the basal secondaries often very prominent and the ve- 
nation subpalmate. Inflorescences small (1-5 cm) terminal and axillary panicles of short 
racemes or glomerules, peduncles and pedicels covered with small (0.2-0.3 mm) gland- 
tipped hairs; flowers sessile or subsessile, perianth tube 3-4 mm long, ca. 1.5 mm in 
diameter, narrowly urceolate to tubular, perianth lobes obtuse, perianth covered with both 
gland-tipped and sharply hooked (uncinate) trichomes. Fruit tightly enclosed within the 
persisting (but not enlarged) perianth ca. 3 mm long; seed ca. 1.5 mm long, suborbicular 
in outline, thick lenticular, lustrous black. 

Plants of open fields and partly shaded woodlands from sea level to about 300 
m elevation in Costa Rica; flowering from June to January in southern Central 
America. The species ranges from Mexico along the Pacific side of Central Amer- 
ica to Guanacaste Province in Costa Rica, and it also occurs in Cuba and 
Venezuela. 

Salpianthus purpurascens is recognized by its very broad ovate triangular leaves 
usually found at the base of the plant, the small flower clusters on distal stems 
with small leaves, the short narrow perianth tube with both gland-tipped and 
sharply hooked hairs on its surface, and the shiny black seed tightly enclosed 
within the persisting perianth tube. This species was earlier placed in the genus 
Boldoa. 

PHYTOLACCACEAE 

REFERENCES: Katherine Raeder, Phytolaccaceae in Flora of Panama. Ann. Mis- 
souri Bot. Card. 48:408-421. 1961. Joan W. Nowicke, Palynotaxonomic study of 
the Phytolaccaceae. loc. cit. 55:294-364. 1969. 



TRICHOSTIGMA 
polyandrum 



T. octandrum 




RIVINA humilis 

10 cm MICROTEA debilis 

FIG. 36. Phytolaccaceae: Costa Rican representative of Microtea, Rivina, and Trichostigma. 



200 



PHYTOLACCA 
rugosa 





P. rivinoides 



1 * * * * * * * * * * * ^ 
10 cm 



Fie. 37. Phytolaccaceae: three species of Phytolacca. 



201 




1 mm 



FIG. 38. Phytolaccaceae and Chenopodiaceae: a species of Chenopodium and species of 
Petiveria and Stegnosperma of the Phytolaccaceae. 



202 



BURGER: FLORA COSTARICENSIS 203 

Herbs or succulent subshrubs, erect or clambering, rarely larger woody shrubs or trees, 
bisexual (in ours) or less often unisexual, glabrous or sparsely and minutely puberulent; 
stipules absent or small and usually inconspicuous. Leaves alternate, simple and entire, 
pinnately veined, often with short linear crystals within. Inflorescences terminal, axillary 
or leaf-opposed usually solitary, racemose, spicate or compound paniculate with spicate 
or racemose branches, bracts and minute bracteoles present or absent; flowers small and 
bisexual in ours (unisexual by abortion), radially symmetrical or rarely somewhat bilater- 
ally symmetrical, perianth usually of 1 whorl of 4 or 5 (rarely more) perianth parts (sepals 
or tepals), free or united near the base, imbricate in bud, usually persisting in fruit, 
greenish white to pink or purple, stamens often as many as the perianth parts and 
alternate with them or 3 to many and variously arranged, filaments free or united only at 
the base, often borne on a hypogynous disk, slender, anthers 2-thecous, dorsifixed or 
basifixed, dehiscing laterally; pistil simple or compound, 1-carpellate (unilocular) or of 2 
to many carpels free or variously united, each locule with a single basal ovule, stigmas 
linear to capitate, sessile or borne on a short style. Fruit various, made up of 1 or more free 
or united carpels, fleshy or dry (rarely winged), subtended by the persisting perianth; seed 
subglobose to lenticular or reniform, erect, embryo annular or curved, endosperm present. 

A family of about 17 genera and 70 to 80 species, with the majority of genera 
and species confined to the South American tropics. The flowers are character- 
ized by a single perianth whorl that persists in fruit, and stamens alternating 
with the perianth parts when of the same number. However, the number of 
stamens and carpels varies greatly, occasionally on the same plant. The locules 
of the ovary always have a single basal ovule that produces a curved or annular 
embryo. The vegetative parts are often semisucculent and glabrous or only very 
sparsely puberulent. 

The genus Hilleria is not known to occur in Central America or Panama. 
Hilleria subcordata Standl. & L. O. Wms., described in Ceiba 3:199 (1953), was 
based on a collection from Turrialba (/. Leon 3488), and this is undoubtedly a 
specimen of Scutellaria of the Labiatae family with immature flowers. Species of 
the genus Hilleria differ from all our representatives of the family in having a 
bilaterally symmetrical perianth with 3 united perianth parts and 1 free perianth 
part. The plants are similar to Rivina, but with more densely flowered racemes 
and a dry somewhat flattened fruit. 

Agdestis clematoides Mocino & Sesse ex DC. from Mexico and northern Central 
America is similar to our species of Trichostigma, but the pistil is partly inferior 
and has three or four stigmas that become recurved; the leaves are usually 
subcordate and the inflorescences become white. This species is sometimes 
planted as an ornamental climber, but it has not been recorded from southern 
Central America. Its common names are Bejuco de ajo and Vomita because of the 
plant's unpleasant odor when crushed. 

KEY TO THE GENERA OF PHYTOLACCACEAE 

la Flowers subsessile on long open spikes; fruit a narrow achene with 4 sharply retrorse 
spines at the top, partly enclosed by the dry persisting appressed perianth; usually 

found below 500 m elevation Petiveria 

Ib Flowers borne on easily seen pedicels in open racemes or panicles; fruit without 

spines, usually globose, persisting perianth not ascending appressed 2a 

2a Perianth of 5 or 10 parts; ovary with 2-15 stigmas 3a 

2b Perianth of 4 parts; ovary with a single stigma 5a 

3a Fruit a capsule splitting open with valves, usually with 1 seed; stamens 10; woody 
plants of the very dry deciduous lowlands of northern Guanacaste 

Stegnosperma 

3b Fruit a berry or drupe, not splitting by valves; herbs and subshrubs not known 
to occur in drier northern Guanacaste . . . . 4a 



204 FIELDIANA: BOTANY 

4a Succulent subshrubs 0.3-4 m tall; ovary with 5-15 locules and 5-15 stigmas, fruit 
a fleshy berry with 5-15 seeds; stamens 6-30; common plants from 0-3,300 m 

elevation Phytolacca 

4b Small semisucculent herbs to 0.8 m tall; ovary with 1 locule and 2 stigmas, fruit 
small and globose with spiny ridges forming a reticulum on the surface; stamens 

usually 5 (3-9); uncommon plants, below 500 m elevation Microtea 

5a Herbs or subshrubs with erect stems; stamens 4; fruit becoming bright red . . Rivina 

5b Woody climbers or shrubs with clambering stems; stamens 8 or more; fruit usually 

becoming black Trichostigma 



MICROTEA Swartz 

Small annual herbs, erect or decumbent, stems usually somewhat succulent and gla- 
brous; stipules absent or represented by minute tubercles. Leaves alternate and usually 
small, petiolate or subsessile, laminae simple and entire, glabrous. Inflorescences terminal 
and axillary, 1 to several at a node, racemose, spicate or paniculate, with floral bracts and 
with or without bracteoles; flowers very small, bisexual, sepals 5 (4), free above a thickened 
receptacle, persisting in fruit, stamens 5 (3-9), usually alternating with the perianth parts, 
free or united near the base, anthers dorsifixed, thecae globose and dehiscing laterally, 
ovary with 1 locule and 1 ovule, style short, stigmas 2 or 3. Fruit fleshy or hard, smooth 
to tuberculate or echinate, the pericarp adhering to the seed; seed erect, embryo curved, 
endosperm fleshy. 

A neotropical genus of nine species, with only one species reaching con- 
tinental North America. The plants resemble some small Caryophyllaceae and 
slender stemmed Chenopodiaceae. 

Microtea debilis Swartz, Prodr. Veg. Ind. Occ. 53. 1788. Figure 36. 

Annual herbs, 15-80 cm tall, usually much branched with prostrate or ascending stems, 
leafy internodes 0.5-3 (5) cm long, 0.5-2 mm thick and pale greenish gray when dry, 
longitudinally ribbed and glabrous, somewhat succulent in life. Leaves alternate and often 
distichous, slightly succulent, petioles 2-20 mm long, poorly differentiated from the blade 
with lateral margins continuous with the lamina margins; laminae 0.64 (8) cm long, 0.5-2 
(3.5) cm broad, elliptic to obovate or ovate, bluntly obtuse to acute at the apex, attenuate 
at the base, margin entire, the laminae drying thin chartaceous to membranaceous, 
smooth and glabrous on both surfaces, the 4-7 pairs of major secondary veins arising at 
angles of ca. 40-60. Inflorescences terminal or axillary, often 2 (1) at a node, 1.5-6 cm 
long, open racemes or occasionally paniculate with 2 racemose axes, rachis 0.1-0.4 mm 
thick (dry), glabrous, flowers on short (0.3-2 mm) thin pedicels, subtended by mem- 
branous linear bracts ca. 1 mm long; flowers ca. 1 mm long, tepals 5, narrow, borne on the 
edge of a short receptacle, white, 0.5-0.7 mm long, stamens ca. 0.4 mm long, ovary ca. 0.5 
mm long, glabrous. Fruit globose, greenish, ca. 1.5 mm long, with a reticulum on the 
surface formed by interconnected ridges of tubercles, subtended by the persisting perianth 
parts; seed black. 

Uncommon weedy little plants of the wet evergreen lowland forest formations 
between sea level and 100 (300) m elevation on both the Caribbean and Pacific 
coastal plains of Costa Rica; probably flowering throughout the year, but col- 
lections from our area have only been made from December to May and in 
August. The species ranges from Guatemala and the West Indies to Peru and 
Brazil. 

Microtea debilis is recognized by its small habit, glabrous slightly succulent 
parts becoming very thin when dried, alternate leaves with winged petioles, 
minute flowers on open racemes, and unusual little fruit with reticulate surface. 
This species has only been collected a few times in Costa Rica: from the Carib- 
bean lowlands and the Golfo Dulce region. The plants appear to prefer sandy 
soils and are often found along stream and river banks. 



BURGER: FLORA COSTARICENSIS 205 

PETIVERIA Linnaeus 

Erect herbs or subshrubs, woody at the base, minutely puberulent or glabrescent, stems 
with longitudinal ridges, tissues often with the odor of garlic (Allium sativum); stipules 
paired and lateral. Leaves alternate in a spiral or distichous, petioles canaliculate adaxially, 
the laminae simple and entire, acute to acuminate. Inflorescences slender elongate spike- 
like racemes of distant flowers subtended by short bracts, terminal or axillary and solitary 
or several from a node, the flowers very short pedicellate or subsessile; flowers bisexual 
and radially symmetrical, small, perianth of 4 free parts, equal and acute, narrow, spread- 
ing at anthesis, persisting and erect in fruit, stiff and dry, stamens 4-9, alternate with the 
perianth parts or irregularly placed, shorter than the perianth, filaments filiform, anthers 
dorsifixed and linear, 2-cleft at apex and base, ovary unilocular with 4 or 6 reflexed spines 
near the apex, stigma solitary, sessile and penicillate, ovule erect. Fruit a long narrow 
cuneate achene, laterally compressed with 2 slightly flattened carinate sides, apically 
2-lobed with 4 or 6 retrorse or recurved spines, pericarp adhering to the seed; seeds erect 
and linear. 

A New World genus of one species with two varieties: one widely ranging 
throughout the warm areas of the hemisphere and the other in Brazil. The plants 
resemble certain Amaranthaceae. Petiveriais distinguished from the Amarantha- 
ceae because it lacks stamens that are equal in number and opposite to the 
perianth parts and because the stamens are not basally united. 



Petiveria alliacea L., Sp. PI. 342. 1753. Figure 38. 

Herbs or small subshrubs, 0.5-1.5 (2) m tall, base and lower stems woody, leafy inter- 
nodes 1-6 cm long, 1.5-4 cm thick, minutely (0.1-0.3 mm) puberulent with slender 
ascending pale-colored hairs, longitudinally ridged; stipules ca. 2 mm long and 0.4 mm 
broad, persisting, brownish. Leaves alternate in a spiral or distichous, petioles 4-18 mm 
long, ca. 1 mm thick, minutely puberulent, with an adaxial sulcus; laminae 5-16 (20) cm 
long, 2-6 cm broad, elliptic to elliptic-oblong, short acuminate at the apex (occasionally 
acute), acute at the base, the margins entire, the laminae drying thin to stiffly chartaceous, 
smooth above and below, sparsely and very minutely puberulent along the veins but often 
becoming glabrous, the 5-8 pairs of major secondary veins arising at angles of 40-70. 
Inflorescences 1-5 in terminal groups or axillary, slender spikes 10-40 cm long, the flowers 
5-15 mm distant on the slender (0.5-1 mm) sparsely puberulent rachis, flowers subtended 
by scarious triangular bracts 1-2 mm long; flowers ca. 3-4 mm long, subsessile or on very 
short (less than 3 mm) pedicels, puberulent on the lower parts, perianth parts 4, white or 
greenish, stiff and scarious, 0.5-1 mm broad, stamens 8 (4, 6), free, to 3 mm long, ovary 
with 4 retrorse spines near the apex, stigmas 2. Fruit 6-8 mm long, somewhat flattened 
and oblanceolate with a deep apical notch separating 2 lateral projections, each of which 
bears 2 (3) retrorse spines 1.5-3 mm long, greenish and longitudinally striate, minutely 
and sparsely puberulent, subtended by the persisting appressed bracts and perianth, the 
fruit and bracts and perianth appressed against the axis of the inflorescence, ascending. 

Plants of weedy habitats in partly open as well as shaded sites in both season- 
ally dry and deciduous habitats and in wet evergreen formations from sea level 
to 300 (rarely to 1,500) m elevation in Costa Rica; probably flowering throughout 
the year, but collected with flowers and fruit in our area from August to February 
and in April and June. The species ranges from the southern United States 
through the West Indies and Central America to Argentina and Peru. 

Petiveria alliacea is recognized by its small weedy habit with woody base, 
glabrescent alternate leaves, and long spikes with separate scarious flowers that 
resemble grass spikelets. The unusual fruit with four sharp recurved spines at 
the apex and vegetative parts that often smell like garlic (Allium sativum) further 
distinguish this species. Our material belongs to variety alliaceae as defined by 
Nowicke. These plants are easily mistaken for members of the Amaranthaceae 



206 FIELDIANA: BOTANY 

family, while the inflorescences resemble those of some Acanthaceae and Gram- 
ineae. Pseudelephantopus of the Compositae also resembles this species. 

PHYTOLACCA Linnaeus 

Herbs or subshrubs, rarely trees, bisexual in ours, stems erect or clambering, often 
somewhat succulent, glabrous or sparsely puberulent; stipules absent. Leaves alternate in 
a spiral, simple, sessile or petiolate, margin usually entire, usually glabrous, pinnately 
veined. Inflorescences at first terminal but soon becoming leaf-opposed or extra-axillary, 
spikes, racemes or raceme-like panicles, pedicels subtended by narrow bracts and often 
with 1 or 2 small bracteoles along the length of the pedicel; flowers small and radially 
symmetrical, bisexual (in ours) or unisexual, the perianth of 1 whorl of 5 usually free 
tepals, the tepals greenish or white to pink and purple, androecium of 5-30 stamens in 1 
or 2 whorls, sometimes differing in number in flowers of the same inflorescence, filaments 
free or united at the base and borne on a disk, anthers dorsifixed; ovary usually broader 
than long, made up of a whorl of 5-16 partly or completely united carpels, the 5-16 locules 
with 1 erect ovule each. Fruit usually a fleshy and juicy berry, broader than long with a 
centrally depressed apex, 5- to 16-ribbed or parted; seed compressed, embryo curved. 

A genus of worldwide distribution, but with most of the 30-odd species in the 
American tropics and a few species reaching the temperate zone. The broad 
gynoecium with incompletely fused carpels, variable number of stamens, single 
perianth whorl, and solitary erect ovule are distinctive features. The semi- 
succulent stems and leaves and frequent presence of bright rose red to purplish 
pigments in vegetative parts and fruit are also characteristic. Hybridization has 
been suspected between many of the species. Plants of this genus resemble, 
superficially, Sphenodea zeylanica Gaertn. (Campanulaceae or Sphenocleaceae) 
and some species of Monnina (Polygalaceae). 

As can be seen in our illustration, P. icosandra is intermediate between P. 
rivinoides and P. rugosa in some respects. Jerold I. Davis, who has studied 
Phytolacca material from throughout Central America, believes that the earlier 
proposed species concepts can be placed in a linear arrangement, reflecting 
morphological transitions and hybridization, as follows: P. rivinoides, P. ico- 
sandra sensu stricto, P. purpurascens, P. meziana, P. octandra, P. rugosa, P. cos- 
taricensis. This sequence also reflects an altitudinal shift from lowland P. riv- 
inoides to P. costaricensis above 3,000 m elevation, with P. rivinoides being most 
easily separated from among the group (Davis, personal communication, 1980). 
While hybridization and intergradation do exist, it is my impression that the 
keys and species descriptions provided here will effectively categorize a large 
majority of our Costa Rican collections and that hybrid populations or inter- 
mediate individuals are relatively rare in Costa Rica. 

The fruit contain saponins and have been used as a substitute for soap in many 
areas. The common name Jaboncillo, widely used in Central America, reflects this 
usage. Other names used in our area are Calalu and Tinta, the latter referring to 
the pigments sometimes used as ink (mostly from the fruit). See the discussion 
of uses in the Flora of Guatemala (Fieldiana, Bot. 24, part 4:198, 1946). 

la Inflorescence axis glabrous, 15-80 cm long; ovary with more than 10 styles, fruit with 
more than 10 ribs, fruiting pedicels 5-18 mm long, styles closely connivent; 0-1,300 
(1,800) m elevation P. rivinoides 

Ib Inflorescence axis with small scurfy or scalelike hairs; ovary with usually 8 styles, fruit 
with usually 8 ribs or seeds, fruiting pedicels less than 6 mm long 2a 

2a Inflorescence axis 5-15 (20) cm long, pedicels 3-6 mm long; fruit with the styles 1-2 
mm distant from the central apex; (1,500) 2,000-3,300 m elevation P. rugosa 

2b Inflorescence axis 10-36 cm long, pedicels 0.3.-3 mm long; fruit with the styles close 



BURGER: FLORA COSTARICENSIS 207 

together at the apex in the depressed center of the fruit; (500) 1,000-1,500 (1,800) m 
elevation P. icosandra 

Phytolacca icosandra I ., Syst. Nat. ed. 10. 1040. 1759. Figure 37. 

Herbs or stout subshrubs to 1.5 (2) m tall, leafy internodes 3-40 mm long, (1) 2-8 mm 
thick, longitudinally ribbed when dry, glabrous. Leaves with petioles 5-30 mm long, ca. 
1 mm thick (dry) and with lateral margins continuous with the lamina margins, decurrent 
on the stem; laminae (3.5) 5-15 (35) cm long, (1) 2-10 (18) cm broad, elliptic or occasionally 
ovate-elliptic, tapering to the sharply acute apex, the tip of thickened tissue drying 
yellowish and sharp-pointed, attenuate at the base and decurrent on the petiole, margin 
entire, the laminae drying thin chartaceous, smooth and glabrous on both surfaces, the 
7-9 pairs of secondary veins arising at angles of ca. 45-60. Inflorescences usually be- 
coming leaf-opposed (9) 12-25 (36) cm long, the raceme only 5-15 mm broad, elongating 
in fruit, peduncle 3-6 cm long, the rachis minutely scurfy-puberulent, drying yellowish 
but pink to purplish in life, pedicels 0.3-3 mm long, subtended by linear bracts 3-6 mm 
long and ca. 0.5 mm broad; flowers ca. 6 mm broad, perianth parts 2.5-3.5 mm long, white 
to pale purple, stamens (8) 16-18 (20), 3 mm long, styles usually 8 (6-10). Fruit becoming 
dark blue or black, ca. 8 mm broad and 4 mm long, the styles borne close together within 
the apical depression at the top of the fruit; seed lustrous black, lenticular, ca. 3 mm long 
and 2.5 mm broad. 

Plants of recently disturbed secondary formations in and around the Meseta 
Central in Costa Rica; probably flowering throughout the year, but with no 
collections having been made in September. The Costa Rican collections come 
primarily from between 1,000 and 1,500 m elevation with only a few as low as 
500 or as high as 1,800 m. The species ranges from Mexico and the West Indies 
to northern South America and Ecuador. 

Phytolacca icosandra is recognized by the long narrow racemes with subsessile 
flowers, styles remaining close together as the fruit expands, and scurfy in- 
florescence axis. This species is quite similar to P. rugosa, but the two seem to be 
readily separable in our area. Recent collections made by Robert Wilbur and his 
associates from the area of the eastern Meseta Central and western Talamanca 
mountains indicate that there may be considerable intergradation between P. 
icosandra and P. rugosa between 1,500 and 2,500 m elevation. 

Phytolacca rivinoides Kunth & Bouche, Ind. Sem. Hort. Berol. 15. 1848, and 
Ann. Sci. Nat. Bot. ser 3, 11:231. 1849. Figure 37. 

Herbs or weak stemmed subshrubs 1-2 (5) m tall, leafy internodes (1) 2-7 (11) cm long, 
1.5-12 mm thick, glabrous and smooth, often reddish or pinkish in life, developing very 
small lenticels. Leaves with petioles (1) 2-7 cm long, slightly sulcate above and with lateral 
ridges continuous with the lamina margins and decurrent on the stem, often reddish in 
color; laminae 5-17 (21) cm long, 2-7 (9) cm broad, elliptic to ovate in outline, tapering 
gradually to the sharp-acuminate apex, acute to obtuse or somewhat rounded and sub- 
truncate at the base, margin entire and decurrent on the petiole, the laminae drying 
thin-chartaceous, smooth and glabrous on both surfaces, often with small punctations 
above, the 6-11 pairs of major secondary veins arising at angles of about 60. Inflorescence 
terminal and often becoming positioned just below an opposing leaf, 15-50 (80) cm long, 
the rachis essentially glabrous, peduncle 3-8 cm long, 1.2-2 .4 mm thick, glabrous and 
smooth, pedicles 3-6 (13) mm long and subtended by thin lanceolate bracts ca. 3 mm long 
and with 1 or 2 minute bracteoles along the length of the pedicel, the rachis and pedicels 
smooth and glabrous, often pink to purplish; flowers ca. 5 mm broad (dry), perianth parts 
2.5 mm long, white to rose or magenta, stamens 9-17; ovary usually green with 10-16 
styles. Fruit borne on pedicles 5-18 mm long, ca. 0.5 mm thick (dry), fruit becoming 6-8 
mm broad with 10-16 distinct longitudinal ribs, becoming blue or black when ripe, styles 
closely borne together in the depressed central apex; seeds lenticular, ca. 2 mm long, dull 
black, difficult to separate from the dry fruit. 



208 FIELDIANA: BOTANY 

Plants of open disturbed and early successional vegetation in wet and moist 
evergreen formations from sea level to 1,300 (1,800) m elevation in Costa Rica; 
flowering throughout the year. The species has not been collected below 500 m 
elevation in Guanacaste or northern Puntarenas. The species ranges from Mex- 
ico and the West Indies southward to Bolivia. 

Phytolacca rivinoides is recognized by the smooth glabrous inflorescences that 
become unusually long, the fruit with 12 to 16 ribs, and a preference for moist 
habitats below 1,300 m elevation. Despite the distinct differences between this 
species and the other Costa Rican species, hybridization has been reported with 
P. rugosa at about 1,600 m near Cervantes. 

Phytolacca rugosa Br. & Bouche, Ind. Sem. Hort. Berol. 13. 1851, and Linnaea 
25:296. 1852. P. costaricensis Suessenguth, Bot. Jahrb. Syst. 72:273. 1942. Fig- 
ure 37. 

Herbs or subshrubs 0.3-2 (4) m tall, the basal stems somewhat woody, leafy internodes 
0.5-4 (10) cm long, 2-8 mm thick, glabrous or with scurfy hairs, longitudinally ridged 
when dry and the ridges continuous with the decurrent leaf bases. Leaves often closely 
approximate at the ends of stems in exposed and windy environments, petioles 0.2-3 (5) 
cm long, with thin lateral margins continuous with the lamina margins and decurrent on 
the stem; laminae (4.5) 6-12 (19) cm long, (1) 2-4 (6.5) cm broad, narrowly elliptic to 
elliptic-oblong, gradually tapering to the acute or sharply acuminate apex, acute at the 
base, margin entire and decurrent on the petiole, the laminae drying thin to stiffly char- 
taceous, smooth and glabrous or with scattered minute (0.1-0.2 mm) scurfy hairs on the 
veins beneath, the 6-8 pairs of secondary veins arising at angles of ca. 45. Inflorescence 
terminal and becoming more or less leaf-opposed, 5-15 (20) cm long, at first with the 
flowers clustered in a compact conic raceme but soon elongating, peduncle 2-6 cm long 
and at first exceeding the flowering rachis in length, rachis and pedicels usually scurfy- 
rugose and drying yellowish but often bright pink or reddish purple in life, pedicels 3-6 
mm long, subtended by linear bracts ca. 5 mm long, with 1 or 2 bracteoles along the length 
of the pedicel; flowers 4-5 mm broad (dry), perianth parts ca. 3 mm long, pink to reddish, 
stamens 6-12 in 1 cycle, 1.3-2 mm long, ovary with usually 8 styles. Fruit 6-10 mm broad 
and 2-4 mm high, green becoming dark purple, styles becoming 1-2 mm distant from the 
central depressed apex of the mature fruit; seeds lenticular, lustrous black, ca. 3.5 mm long 
and 2.5 mm broad. 

Plants of recently disturbed and open early successional stages in evergreen 
highland forest formations between 1,500 and 3,300 m elevation; flowering and 
fruiting throughout the year. The species ranges from Mexico to Colombia. 

Phytolacca rugosa is recognized by its relatively broad racemes with scurfy 
rachis and distinctly pedicellate flowers and the fruit with clearly separate styles 
borne some distance from the central apex. This is the only species of Phytolacca 
to be found commonly above 2,000 m elevation in Costa Rica. There may be 
hybridization between this species and P. icosandra. 

An unusual collection by W. Hatheway (2358) from near the summit of Volcan 
Poas has the flowers borne on a superficially racemose inflorescence that is 
actually paniculate. The main axis bears short lateral flowering branches with 
several flowers, but this collection seems to differ in no other way from typical 
P. rugosa. 

RIVINA Linnaeus 

Perennial herbs or subshrubs, usually woody near the base, glabrous or minutely puber- 
ulent; stipules absent. Leaves alternate in a spiral, on slender petioles, simple and entire, 



BURGER: FLORA COSTARICENSIS 209 

thin in texture, pinnately veined. Inflorescences erect solitary open racemes, terminal or 
becoming axillary, pedicels subtended by narrow little deciduous bracts, 1 or 2 minute 
bracteoles often present at the apex of the pedicel beneath the perianth, the inflorescence 
usually minutely puberulent; flowers bisexual and small, radially symmetrical, perianth of 
4 subequal parts in 2 decussate whorls, slightly imbricate in bud, oblong spatulate and 
usually rounded at the apex, corolla-like and becoming white, persisting and enlarging 
only slightly in fruit, stamens 4, free, alternating with the perianth parts and inserted on 
the slightly elevated receptacle (hypogynous disk), slightly shorter than the perianth, 
anthers elongate and dorsifixed, extrorse-lateral, pistil simple, ovary with 1 locule and 1 
basal ovule, style terminal or subterminal, often curved. Fruit a globose red drupe with 
pericarp adherent to the seed, subtended by the persisting perianth; seed lenticular, often 
with a covering of short hairs, embryo annular. 

A genus of apparently only one somewhat variable species, probably of New 
World origin but now naturalized throughout the tropics. The genus is very 
closely related to Trichostigma, and some authors have treated the included 
plants as congeneric. 



Rivina humilisL., Sp. PI. 122. 1753. Figure 36. 

Perennial (occasionally annual?) herbs and subshrubs 0.3-1 (rarely 2) m tall, usually 
woody at the base and sometimes with the lower stems woody, leafy internodes 1-8 cm 
long, 1-3 mm thick, glabrous or more often puberulent with thin whitish haris 0.1-0.5 mm 
long, longitudinally ridged when dry and greenish; stipules absent. Leaves alternate in a 
spiral, petioles 0.4-4 (8) cm long, ca. 1 mm thick when dry, usually puberulent, with a 
slight adaxial groove above; laminae (2) 4-12 (17) cm long, (1) 2-6 (8) cm broad, ovate to 
elliptic-ovate or lanceolate, tapering gradually to the acuminate apex, rounded and trun- 
cate to rounded and obtuse at the base, margin entire, the laminae drying thin-chartaceous 
and usually greenish, smooth above and below, usually glabrous above (except on the 
midvein) and sparsely puberulent on the veins beneath, the thin pale-colored hairs ca. 0.2 
mm long, linear crystals usually visible as minute (0.3 mm) prominent lines between the 
veinlets of dried leaves, the 5-7 pairs of major secondary veins arising from the midvein 
at angles of ca. 45. Inflorescences terminal or axillary, racemes 4-12 (16) cm long (be- 
coming longer after anthesis), rachis and pedicels usually with very short (0.2 mm) thin 
whitish hairs, bracts 1-2 mm long and deciduous, pedicels 2-4 mm long at anthesis and 
up to 8 mm long in fruit, slender and only ca. 0.2 mm thick when dry; flower buds ca. 
2 mm long, perianth parts ca. 2 mm long, green becoming white or pinkish white, 
filaments 1-1.8 mm long, anthers ca. 0.7 mm long, ovary ca. 1 mm long with a style 0.5 
mm long. Fruit becoming a bright red or orange globose fleshy drupe, 4-6 mm in diameter, 
subtended by the persistent and usually reflexed or spreading perianth parts (in late 
stages), the perianth parts to 4 mm long and 1-1.5 mm broad; the seed often with a 
reticulate surface formed by the adherent pericarp, seeds 2-2.5 mm broad, dark brown and 
with minute brownish hairs on the surface. 

Plants of wet or seasonally dry evergreen formations or in moist situations 
(such as riparian understory) in deciduous areas between sea level and 1,200 
(1,600) m elevation in Costa Rica; flowering throughout the year, but collected 
most often from December to January and June to September. The species ranges 
from the southern United States (Texas and Oklahoma to Florida) through 
Mexico and the West Indies to South America as far as Argentina; the species 
is widely naturalized in the Old World. 

Rivina humilis is recognized by its short stature from a woody base, thin ovate 
leaves on slender petioles, open racemes, flowers with only four perianth parts 
and four alternating stamens, and simple pistil that forms a bright red drupe. 
The fruits are said to have been used as a source for red pigment. The plants 
resemble some small species of Solanaceae. 



210 FIELDIANA: BOTANY 

STEGNOSPERMA Bentham 

REFERENCES: H. G. Bedell, A taxonomic and morphological re-evaluation of 
Stegnospermaceae. Syst. Bot. 5:419-431, 1980. D. J. Rogers, Stegnosperma: A new 
species and a generic commentary. Ann. Missouri Bot. Gard. 36:475-477, 1949. 

Shrubs or small trees, the branches often drooping, vining or clambering, bisexual, 
glabrous; stipules absent. Leaves alternate and simple, petiolate and entire, glabrous, often 
slightly succulent and drying stiff. Inflorescence racemose, terminal or axillary, solitary, 
the pedicels subtended by a bract and 2 bracteoles; flowers bisexual and radially sym- 
metrical, borne on slender pedicels, perianth of 2 whorls, the 5 sepals free and imbricate, 
thin, persisting and enlarging slightly in fruit, petals or staminodia 5, free, shorter than the 
sepals, whitish, stamens 10, filaments slender but expanded near the base and connate to 
form a very short ring (perigynous annulus), anthers basifixed and sagittate; ovary supe- 
rior and ovoid or ellipsoid, 3- to 5-Iocular but becoming unilocular with a central column, 
ovules basal, as many as the locules or style branches (stigmas). Fruit a globose or ovoid 
capsule, opening by 3-5 coriaceous valves, styles persisting; seeds 1-5, cochleate- 
ellipsoid, with a smooth dark reddish or black lustrous surface and a white or yellow- 
ish aril. 

A genus of three species; two species are found only in Baja California and 
adjacent Mexico, while the third species ranges from Mexico to Costa Rica and 
the Greater Antilles. The capsular fruit, two perianth whorls, and woody habit 
distinguish this genus among our representatives of the family. The genus has 
only recently been found in Costa Rica. This genus has been elevated to family, 
but its position in the Caryophyllales remains the same, close to the putatively 
primitive Phytolaccaceae (see Bedell, 1980). 

Stegnosperma cubense A. Rich., in Sagra, Hist. Nat. Cuba 10:309; 12; tab. 44. 
1845. Trichilia scandens A. Robinson ex Lunan, Hort. Jam. 2:319-320. 1814, an 
invalid polynomial (fide Rogers). S. scandens (Lunan) Standley, Publ. Field Mus. 
Nat. Hist., Bot. Ser. 23:6. 1943. Figure 38. 

Small trees or shrubs with scandent or clambering stems, to 3 m tall or 4 m long, leafy 
internodes 2-20 mm long, 1-4 mm thick, smooth and glabrous, pale in color but soon 
becoming dark. Leaves alternate in a spiral, petioles 5-12 mm long, deeply sulcate above 
with 2 longitudinal adaxial ridges continuous with the laminae margins; laminae 2-8 (11) 
cm long, 1-5 (7) cm broad, obovate to orbicular or elliptic, obtuse to rounded at the apex, 
obtuse to acute at the base and decurrent on the petiole, margins entire, laminae drying 
stiffly chartaceous, smooth and glabrous, with 3-5 pairs of major secondary veins (often 
obscure). Inflorescences 3-13 cm long, the flowers closely crowded or separated by as 
much as 5 mm on the slender rachis, bract and bracteoles 1-1.5 mm long, pedicels 2-12 
mm long; flowers 4-6 mm long (dry), sepals 3-4 mm long, broadly imbricate, petals 
included within the sepals, filaments 3-4 mm long, slender and united near the base, 
anthers 1.5 mm long, styles and stigmas usually 4 (3-5), ca. 1 mm long. Fruit an ovoid to 
subglobose capsule 6-7 mm long, subtended by the persisting perianth and with persist- 
ing styles, often with only 1 seed per fruit; seed ca. 5x3 mm, cochleate-ellipsoid in 
outline, lustrous black, the surface smooth or slightly irregular. 

Small trees or clambering shrubs in seasonally very dry deciduous formations 
of the northwestern Pacific lowlands in Costa Rica. This species ranges from 
northern Mexico to Guatemala and along the Pacific lowlands to Costa Rica and 
from Cuba to Puerto Rico in the West Indies. 

Stegnospermum cubense is distinguished by its small rounded leaves, lack of 
pubescence, terminal racemes, conspicuous pedicels, small petals hidden by the 
sepals, and capsular fruit with shiny black seed. This species and genus were not 
known to exist in Costa Rica until the recent intensive surveys of Santa Rosa 
National Park in Guanacaste Province. These little trees with drooping branches 



BURGER: FLORA COSTARICENSIS 211 

or shrubs with clambering branches often form thickets behind sand dunes and 
on rocky outcrops in northern Central America. Our specimen (Liesner 2284) has 
much larger leaves than most Central American material, and the staminal cup 
appears to be less well developed. More collections from Guanacaste are needed 
to determine whether the Costa Rican populations merit separate specific or 
subspecific status. 



TRICHOSTIGMA A. Richard 

Shrubs or woody climbers, usually glabrous; stipules minute and caducous or not 
apparent. Leaves alternate in a spiral, petiolate, the laminae simple and entire, pinnately 
veined, chartaceous when dry. Inflorescences terminal or axillary, solitary, elongate open 
racemes, the flowers clearly pedicellate, bracts subtending the pedicels present and cadu- 
cous or absent, the pedicels often with small bracts and 2 minute bracteoles; flowers 
bisexual and radially symmetrical, perianth of 4 subequal parts in 2 whorls, broadly 
imbricate in bud persisting and usually reflexed in fruit, becoming reddish, stamens 8-25, 
free, borne on the elevated receptacle (hypogynous disk), filaments slender, anthers dor- 
sifixed, longer than wide, pistil simple with sessile or subsessile penicillate stigma, ovary 
1-locular and with 1 ovule. Fruit a globose fleshy drupe, pericarp attached to the seed; 
seed solitary with annular embryo and curved cotyledons, erect. 

A New World genus of three species closely related to and perhaps congeneric 
with Rivina (q.v.). The plants are recognized by their climbing or trailing stems 
with glabrous leaves, open inflorescences that become reddish or purple in fruit, 
flowers with only four perianth parts and eight to 25 stamens, and simple pistil 
forming a fleshy black fruit. Like Phytolacca the open inflorescence and its pedi- 
cels often become wine red or purplish in color. While differing primarily in 
floral characters, the two species found in Costa Rica are apparently most com- 
mon in the same restricted area: the Sierra de Tilaran and its Caribbean drain- 
age area. 

la Flowers with ca. 20 stamens, the filaments less than 0.5 mm long and never persisting 
in fruit, perianth becoming 5-10 mm long in fruit; the racemes becoming 10-25 cm 
long T. polyandrum 

Ib Flowers with usually 10 stamens, the filaments to 3 mm long and often persisting 
beneath the fruit, perianth not exceeding 5 mm in length; racemes up to 15 cm long 

T. octandrum 



Trichostigma octandrum (L.) H. Walter, in Engler, Pflanzenr. IV, 83:109. 
1909. Rivina octandra L., Cent. PI. 2:9. 1756. Figure 36. 

Scandent shrubs or lianas, growing to a height of ca. 10 m, leafy internodes 5-50 mm 
long, 1-5.5 mm thick, glabrous, often with prominent lenticels, grayish when dry. Leaves 
alternate in a spiral, petioles 1-5 cm long, 0.5-1 mm thick, deeply sulcate above (adaxially); 
laminae 6-15 cm long, 2-7 cm broad, elliptic to narrowly elliptic-oblong or narrowly ovate, 
acute to short-acuminate at the apex, acute at the base with the margins shortly decurrent 
on the petiole, margins entire, laminae drying chartaceous, smooth and glabrous on both 
surfaces, the 6-9 (12) pairs of major secondary veins arising at angles of 45- 70, often 
loop-connected near the margins but difficult to see. Inflorescences solitary and axillary 
racemes, 5-11 cm long, peduncle and rachis glabrous, ca. 0.5 mm thick and longitudinally 
striate when dry, peduncle (distance to the first flower) usually 2-3 cm long, pedicels 3-6 
mm long and 1-6 mm distant on the rachis, with a linear bracteole ca. 2 mm long halfway 
up the pedicel; flowers ca. 4 mm long, perianth parts ca. 4 mm long, white, stamens 
usually 12 with anthers ca. 2 mm long borne on persisting filaments 2-3 mm long; pistil 
1.5 mm long, the penicillate stigma ca. 0.5 mm long. Fruit becoming 8 mm long, globose, 
black, succulent, surface venation not readily visible when dry. 



212 FIELDIANA: BOTANY 

Plants of wet evergreen forest formations on both the Caribbean and Pacific 
sides of Costa Rica between 10 and 800 (1,000) m elevation; fruiting collections 
have been made from January through April. This is a wide-ranging species 
found from Mexico and southern Florida (U.S.A.) through Central America and 
the West Indies to Argentina. 

Trichostigma octandrum is recognized by the climbing stems, glabrous parts, 
racemose inflorescences with slender rachis and pedicels, numerous stamens 
persisting as filaments with the fruit, and black succulent drupes. While rela- 
tively few collections of this species have been made in Costa Rica, it is inter- 
esting to note that many of these come from the same areas where collections of 
the congener, T. polyandrum, have been made: Tilaran and the areas bordering 
the San Carlos plain. However, this species has been collected in the Golfo Dulce 
area, and T. polyandrum has not. The relationship between these two species 
growing in the same areas and the differences in their flowers might make an 
interesting study. 



Trichostigma polyandrum (Loes.) H. Walter, in Engler, Pflanzenr. IV, 83:112. 
1909. Rivina polyandra Loesner, Bot. Jahrb. Syst. 23:123. 1896. Figure 36. 

Scandent or erect shrubs 1-3 (5) m tall, the stems usually clambering, leafy internodes, 
0.5-16 cm long, 0.8-3 mm thick, glabrous or less often very minutely (0.1 mm) puberulent 
with straight erect hairs, becoming longitudinally ridged when dry. Leaves alternate in a 
spiral, closely spaced on lateral stems as well as widely spaced on long climbing stems, 
petioles (0.6) 1-3 cm long, 1-2.5 mm thick, broadly to narrowly canaliculate above; lami- 
nae 7-16 (18) cm long, 2-7 (9) cm broad, narrowly ovate to elliptic-ovate, acuminate at the 
apex, obtuse to acute or occasionally rounded at the base, margin entire, the laminae 
drying thin-chartaceous, smooth and glabrous above and below or with very minute erect 
hairs on the veins beneath, the 5-8 pairs of major secondary veins arising at angles of 
60-80, arcuate ascending distally and often loop-connected near the margin. In- 
florescences terminal or axillary, open racemes of distant flowers 7-15 cm long and be- 
coming up to 25 cm long in fruit, peduncle and rachis glabrous or occasionally very 
minutely (0.1 mm) puberulent, 0.3-1 mm thick (dry) and reddish or purple after anthesis, 
pedicels (3) 6-12 (20) mm long with a small (1 mm) linear bracteole on the basal half, larger 
(2 mm) bracts subtending the pedicel sometimes present in early stages and caducous, 2 
minute (0.5 mm) bracteoles sometimes present on the distal half of the pedicel; flower buds 
2-4 mm long, green to pale greenish white, perianth becoming 6-10 mm long in fruit and 
rose to red or purple in color, stamens 20-25 with very short (0.5 mm) filaments and 
anthers ca. 1.5 mm long, quickly caducous after the flower opens, pistil 3 mm long and 1 
mm thick. Fruit 5-8 mm long and equally broad, broadly ellipsoid or ovoid, becoming 
black, succulent but with the veins prominent on the outer surface when dry, subtended 
by the 4 persisting and brightly colored perianth parts. 

Plants of evergreen wet forest formations of the Caribbean slope and lowlands, 
from sea level to 1,000 (rarely 1,500) m elevation; flowering and fruiting col- 
lections have been made from January to October in Costa Rica. This species is 
especially common in the wetter parts of the Sierra de Tilaran and the Caribbean 
lowlands of Alajuela Province; the species ranges from southern Nicaragua to 
western Panama. 

Trichostigma polyandrum is recognized by its climbing stems, long fruiting 
inflorescences with distant and long-pedicellate fruit usually subtended by four 
red or purplish perianth parts. This species is more commonly collected than T. 
octandrum in our area, perhaps, because it has a longer flowering and fruiting 
season. 



BURGER: FLORA COSTARICENSIS 213 

AIZOACEAE 

Herbs or subshrubs (rarely shrubs), annuals or perennials, prostrate or erect, stems and 
leaves often succulent, glabrous or puberulent; stipules small and thin or absent. Leaves 
alternate, opposite or whorled, simple and entire, equal or unequal at a node, sessile or 
petiolate, petioles often with a thin sheathing margin at the base; laminae often fleshy, 
sometimes reduced to scales. Inflorescences cymose or the flowers solitary, in the axils of 
leaves or terminal, flowers sessile or pedicellate, bisexual (rarely unisexual), small (in 
ours), radially symmetrical, perianth usually of 1 whorl of 5 (less often 3 or 4) free or united 
sepals (tepals), often with an extension or appendage on the back of the midvein distally, 
petals (actually staminodes) present and numerous in some cultivated and introduced 
genera but not in our native and naturalized species; stamens 3, 4, 5, 10 to many, alternate 
with the sepals when of the same number, filaments free or united into fascicles, rarely 
united to the perianth, anthers dehiscing longitudinally; pistil 1, ovary superior (in ours) 
or inferior, 1- to 5-locular (rarely 6- to 20-locular), placentation axile, basal, apical, or 
parietal but not free central, ovules 1 to many in each locule, styles as many as the locules, 
stigmas usually narrow, slender. Fruit a loculicidal or circumscissile capsule or indehiscent 
and nutlike or baccate; seeds cochleate to reniform, with mealy endosperm, rarely stro- 
phiolate, embryo usually curved. 

The family, though a member of the very natural order Centrospermae (Caryo- 
phyllales), is not easily defined. Some of its genera appear to form links with the 
Caryophyllaceae, Portulacaceae, and Chenopodiaceae. The family is very di- 
verse in southern Africa, with Australia a secondary center of diversity. Mem- 
bers of the family are rarely met with in the wild in Costa Rica. The unusual 
succulent forms from South Africa, with larger many-parted flowers, such as 
Mesembryanthemum (sensu lato) and the "flowering stones" are popular with 
gardeners and collectors of exotic plants. Tetragonia expansa Murr. (Espinaca or 
"New Zealand Spinach") is grown in Central America as a vegetable; the alter- 
nate slightly fleshy deltoid leaves are abruptly narrowed to the petiole and 
become as much as 12 cm long. 

la Leaves whorled or opposite, not very fleshy and not sheathing or clasping the stem; 
perianth parts free to the base; fruit a loculicidal capsule splitting longitudinally into 
3-5 valves 2a 

Ib Leaves opposite and fleshy, sheathing or clasping the stem at their base; perianth 
parts united to form a short tube, perianth lobes with small distal appendages; fruit 
opening by a transverse slit (circumscissile) with the distal lid or cap coming off, 1- 

to 5-locular 3a 

2a Plants usually puberulent with slender stellate hairs; leaves oblanceolate to ob- 
ovate; flowers sessile or subsessile, perianth with slender distal appendages; 
seeds ca. 0.3 mm broad, strophiolate (with an aril-like development at the base) 

Glinus 

2b Plants glabrous, leaves generally very narrow; flowers on slender pedicels; peri- 
anth without appendages; seeds ca. 0.5 mm broad, estrophiolate Mollugo 

3a Leaves linear to narrowly obovate, basal sheath sometimes united across the stem but 
without appendages, laminae equal or subequal at a node, young stems glabrous; 
ovary 3- to 5-locular, styles 3-5, seeds numerous, 0.5-1.5 mm broad Sesuvium 

3b Leaves obovate to rounded-spatulate, sheathing at the base and with an appendage 
on the united interpetiolar sheath, laminae often very unequal at a node, young stems 
often with a longitudinal ridge bearing crooked hairs; ovary 1- or 2-locular, styles 1 
or 2; seeds less than 15, 1-2 mm broad Trianthema 



GLINUS Linnaeus 

Herbs, annual, procumbent or ascending, stems slightly succulent, often much 
branched, with simple or stellate hairs; stipules absent. Leaves opposite or whorled by 



214 FIELDIANA: BOTANY 

condensation, often unequal at a node, petiolate; laminae linear to orbicular, entire. In- 
florescences of fasciculate or solitary flowers in the axils of leaves, sessile or pedicellate, 
often forming congested verticels; flowers bisexual, radially symmetrical, small and incon- 
spicuous, perianth of 1 whorl but sometimes with petaloid staminodes, sepals (tepals) 5, 
thin and stiff, free, staminodes 0-20, often divided apically; stamens 3-30, free, filaments 
slender and borne from the base of perianth; ovary superior, 3- to 5-locular, with numer- 
ous ovules on axile placentae, styles short 3-5. Fruit a loculicidal capsule breaking into 3-5 
thin-walled valves; seeds numerous and reniform, smooth or granulate, borne on slender 
funicles, strophiolate. 

A genus of six to 10 species, four native to Africa and only one in our area. 
These small diffuse herbs are easily mistaken for members of the Caryo- 
phyllaceae. 

Glinus radiatus(R. & P.) Rohrb., in Mart., Fl. Bras. 14, pt. 2:238, pi. 55, f. 1. 
1872. Mollugo radiata Ruiz & Pavon, FI. Peruv. 1:48. 1798. Figure 42. 

Herbs, prostrate or ascending, to 50 (80) cm tall, bisexual, leafy internodes 0.5 cm long, 
0.3-2 (3.5) mm thick (dry), densely to sparsely puberulent with thin whitish stellate hairs. 
Leaves opposite or whorled, often unequal, petioles 1-5 (12) mm long, with lateral ridges 
continuous with the lamina margins; laminae 2-15 (30) mm long, 2-15 mm broad, elliptic 
to obovate or spatulate, usually broadest above the middle, obtuse or rounded at the apex, 
obtuse to cuneate at the base, margins entire and decurrent on the petiole, sparsely to 
densely puberulent with stellate whitish or grayish white hairs to 1 mm broad, venation 
pinnate with 1-3 pairs of major secondary veins. Flowers clustered in the leaf axils, sessile, 
or subsessile, densely or sparsely puberulent, perianth parts 4-4.5 mm long, greenish, 
with a short slender distal extension ca. 0.7 mm long. Fruit ca. 4 mm long and 2 mm thick, 
subtended and enclosed loosely by the persisting perianth; seeds many, 0.3-0.4 mm 
broad, reniform, smooth and bright reddish brown, lustrous. 

A small weedy plant of open sites and often found on muddy river banks, road 
sides, cultivated fields and thickets in the Pacific lowlands (0-600 m) of Central 
America. Though the species is said to be common in the wet season, we have 
very few collections from Central America, and those were mostly made in the 
dry season; flowering material has been collected in April and June. The species 
ranges from Mexico to central Costa Rica and from the West Indies to South 
America. 

Glinus radiatus is recognized by its small habit, opposite or whorled leaves, 
thin-branched stellate hairs, inconspicuous flowers tightly clustered in the leaf 
axils, and minute shiny reddish brown seeds. I have seen only a single collection 
from Costa Rica: Brenes 3872 from "Los Liros." These plants are very similar to 
some species of Caryophyllaceae. 



MOLLUGO Linnaeus 

Herbs, annuals or short-lived perennials, stems usually slender and much branched, 
often prostrate, not conspicuously succulent, glabrous; stipules minute or absent, decid- 
uous. Leaves usually in whorls, rarely opposite, often beginning with a basal rosette; 
laminae simple and entire, usually broadest above the middle (often very narrow), gla- 
brous. Inflorescences cymose or of solitary axillary flowers forming verticels at each node, 
pedicellate; flowers small, radially symmetrical, bisexual, perianth of 1 whorl of 5 equal or 
subequal tepals (sepals), imbricate in bud, free to the base; stamens 3-5 (rarely 6-10); ovary 
3- to 5-locular, superior, ovules usually numerous on axile placentae, styles 3-5, short and 
slender. Fruit a thin-walled loculicidal capsule, breaking into 3-5 valves; seeds few to 
many, reniform to cochleate, embryo curved. 

A genus of about 20 species, mostly in Africa and Asia, ranging from the 
tropics and subtropics into the temperate zone. These plants are very similar in 



BURGER: FLORA COSTARICENSIS 215 

appearance to some of our species of Caryophyllaceae. Only one species is found 
in Central America. 

Mollugo verticellata L., Sp. PI. 89. 1753. Figure 41. 

Herbs, annuals to ca. 0.5 m tall, prostrate or erect, with much-branched slender stems, 
leafy internodes 1-9 on long, 0.2-1 mm thick (dry), glabrous; stipules absent. Leaves 4-6 
at a node in whorls or pseudowhorls (by condensation), variable in length and shape 
(often on the same plant), petioles 14 mm long and little differentiated from the lamina, 
slightly expanded at the base; laminae 5-30 (50) mm long, 0.5-4 (10) mm broad, linear to 
narrowly oblanceolate, broadest above the middle in larger leaves, acute at the apex, 
tapering gradually into the petiole, margins entire and continuous with the lateral margins 
of the petiole, glabrous and smooth, venation pinnate but usually obscure. Inflorescences 
verticel-like with 3-6 flowers in the axils of leaves (at a node), pedicels (3) 5-15 mm long, 
very slender (0.1-0.3 mm) and glabrous; flowers 2-3 mm long, white, perianth parts 2-2.5 
mm long, 0.5-0.8 mm broad; stamens 3, to 2 mm long; ovary 3-locular, 1-1.5 mm long, 
styles 3. Fruit a loculicidal capsule subtended by the persisting perianth parts, 2.5-3 mm 
long, ovoid, thin- walled; seeds 20-30 per capsule, ca. 0.5 mm broad, cochleate to reniform, 
ridged along the curved back, dark reddish brown, lustrous. 

Plants of open early secondary growth; often found on sandy sites along 
streams and in cultivated fields. Mollugo verticellata ranges from sea level to 500 
(rarely 1,000) m elevation on both the Pacific and Caribbean slopes in Central 
America; flowering throughout the year, but with very few collections made in 
August and September. This species has a pantropical distribution, but appears 
to be uncommon in southern Central America. 

Mollugo verticellata is recognized by its diffuse herbaceous habit, slender stems, 
verticels of narrow leaves, and small flowers on slender petioles. This species has 
been called Clavellina monies in El Salvador, according to Standley. It is easy to 
mistake this species for members of the Caryophyllaceae, such as Arenaria lanu- 
ginosa and Spergula arvensis, but these plants are restricted to higher elevations in 
Central America. 

SESUVIUM Linnaeus 

Herbs or subshrubs, prostrate to decumbent or erect, often rooting at the nodes, bisex- 
ual, glabrous, stems succulent; stipules absent. Leaves opposite, subopposite or alternate, 
simple and succulent, sessile or petiolate, clasping or sheathing at the base with the leaf 
bases of opposing leaves united across the node; laminae entire, linear to ovate. In- 
florescences of solitary axillary flowers, sessile or pedicellate, subtended by 2 minute 
bracteoles; flowers bisexual, radially symmetrical, perianth of 1 whorl (sepals or tepals) 
united at the base to the floral cup (calyx cup), 5-parted, triangular, imbricate in bud, with 
a dorsal (abaxial) distal appendage; stamens 5-15 or many, filaments free or united at the 
base, borne on the floral cup; ovary superior and with 2-5 locules, ovules usually many 
on axile placentae, styles 2-5, slender. Fruit a circumscissile capsule, the apical lid coming 
off as a single unit; seeds several to many, black, cochleate to annular or reniform. 

A genus of about six species: one a pantropical plant of the seashore, one 
endemic to the Galapagos Islands, and several restricted to eastern Africa. 

Sesuvium portulacastrum (L.) L., Syst. Nat. ed. 10:1058. 1759. Portulaca por- 
tulacastrum L., Sp. PI. 446. 1753. Figure 39. 

Herbs, perennial, prostrate or suberect, often creeping and rooting at the nodes and 
much branched, occasionally forming mats, stems thick and succulent, leafy internodes 
(0.5) 3-50 (80) mm long, 1-5 mm thick (dry), glabrous; stipules absent but the opposing 
leaf bases sheathing the stem and united. Leaves opposite, simple, petioles 2-6 mm long 
but not clearly differentiated from the lamina, with broad thin sheathing base; laminae 1-7 



216 FIELDIANA: BOTANY 

cm long, 1.5-8 (14) mm broad, linear to oblanceolate, obtuse or rounded at the apex, 
margin entire and gradually decurrent on the petiole, smooth and glabrous, succulent and 
bright green or reddish in life but drying dark and coriaceous, venation usually obscure. 
Flowers solitary in leaf axils, glabrous, pedicels 3-10 (15) mm long, ca. 1 mm thick, flowers 
7-12 mm long, perianth lobes ca. 5 mm long and unequal, with a thickened central area 
and thin lateral margins, greenish on the outside and pink to reddish on the inside, with 
a short (1-1.5 mm) stiff appendage on the back (abaxial) distally, floral cup ca. Va the 
length of the perianth lobes; stamens numerous and free, filaments 1.5-3.5 mm long, 
anthers 0.5-0.8 mm long; ovary 3-4 mm long, 3-locular (rarely 2 or 4), styles 3 or 4. Fruit 
5-11 mm long and 5-6 mm thick, opening by a circumscissile slit, the perianth lobes 
persistent; seeds 8-30, black and smooth, 0.5-1.5 mm broad, reniform-cochleate. 

Sprawling succulent plants usually found on or near sea beaches, occasionally 
found in salt flats and on open sandy or rocky sites from sea level to about 50 
m elevation. Probably flowering throughout the year in Central America, but 
collected primarily from December through March and June through August. 
This species is pantropical, but appears to be uncommon in southern Central 
America. 

Sesuvium portulacastrum is recognized by its succulent parts, narrow opposite 
leaves sheathing the stem at their base and united across the stem, solitary 
bright pink flowers with many stamens, and capsules opening by a circular slit. 
These plants are rarely found far from the seashore. The species has served as a 
vegetable, either eaten raw or cooked as greens. Superficially, this species re- 
sembles Philoxerus vermicularis of the Amaranthaceae, with small flowers in 
whitish spikes. 



TRIANTHEMA Linnaeus 

Herbs or subshrubs, annual or short-lived, prostrate to erect, stems succulent, bisexual, 
glabrous or puberulent; stipule-like developments sometimes present on the united inter- 
petiolar sheathing leaf bases. Leaves opposite or subopposite, simple, the opposing leaves 
at a node often unequal, petioles expanded at the base and clasping or sheathing the stem; 
laminae linear to orbicular, entire, succulent or semisucculent. Flowers solitary or fascicu- 
late in leaf axils, sessile or pedicellate, sometimes united to the leaf base, radially sym- 
metrical, bisexual, perianth united at the base to form a perianth tube (floral cup or calyx 
tube), 5-lobed, lobes often with a distal abaxial (dorsal) appendage; stamens 5 or 10 to 
many, borne on the edge of the perianth tube, alternate with the perianth lobes when of 
the same number, filaments free; ovary superior, 1-locular, ovules 2 to many on a parietal 
placenta, apex of the ovary truncate or depressed around the style, style 1, linear. Fruit a 
circumscissile capsule, seeds cochleate-reniform, with a rough or ridged surface. 

A genus of nine species: one pantropical, one in Argentina, and the others in 
Africa, Asia, and Australia. 



Trianthema portulacastrum L., Sp. PI. 223. 1753. Figure 39. 

Herbs, annual, prostrate to decumbent or erect, to 50 cm tall or 1 m long, bisexual, 
succulent, often reddish in color, often with alternate branching from the axil of the 
smaller leaf of a node, leafy internodes 0.5-10 cm long, 0.5-3.5 mm thick (dry), glabrous 
or with a single longitudinal ridge bearing slender crooked hairs on younger parts; sheath- 
ing leaf bases of opposing leaves united across the node and with a triangular stipule-like 
appendage to 3 mm long borne on the interpetiolar portion of the sheath. Leaves opposite 
or subopposite, the leaves of each node usually very different in size (the smaller often half 
the size of the larger), petioles 2-20 (30) mm long, conspicuously expanded at the base to 
form a thin sheathing base united with that of the opposing leaf and encircling the stem; 
laminae 1-4 (7) cm long, 0.5-2 (6) cm broad, broadly elliptic to spatulate in smaller leaves, 
to broadly obovate or suborbicular, larger leaves abruptly rounded at the apex and often 



BURGER: FLORA COSTARICENSIS 217 

apiculate or emarginate, cuneate to obtuse at the base, margin entire, drying stiffly char- 
taceous to subcoriaceous, smooth and glabrous, with 2-4 pairs of major secondary veins. 
Flowers solitary and sessile in the leaf axils, bisexual, ca. 5-8 mm long, perianth tube 
campanulate, perianth lobes ca. 1.5 mm long and 1 mm broad; stamens 10, arising from 
the apex of the perianth tube (floral cup), filaments 1.5 mm long, anthers 0.5 mm long; 
ovary 1 mm long, irregularly lobed at the apex, style 1. Fruit a capsule surrounded by the 
persistent perianth tube and hidden within the sheathing leaf bases, ca. 5 mm long, 4 mm 
thick, crested at the apex, with circumscissile dehiscence at the middle; seeds 2-12, 1.5-2 
mm broad, reniform-cochleate, reddish brown to black, with a rough surface. 

Plants of open disturbed sites, from sandy sea beaches to cultivated ground 
and roadsides; ranging in altitude from sea level to 1,200 m, but rarely encoun- 
tered above 500 m elevation in our area. Flowering primarily in the wet season, 
from June to December, but flowering collections have been made throughout 
the year in Central America. The species is pantropical, but has not been col- 
lected along the Caribbean coast in southern Central America. 

Trianthema portulacastrum is recognized by the succulent stems, unequal op- 
posite leaves with united sheathing leaf bases, and small pink flowers barely 
exserted beyond the sheathing leaf bases. This species has been called Verdolaga 
in Guatemala, according to Standley. The flowers are often difficult to see in 
pressed collections, since they are hidden by the sheathing leaf bases and are 
adnate, in part, to the petioles. 



PORTULACACEAE 

Herbs or subshrubs (rarely shrubs), bisexual, usually with succulent stems, glabrous or 
puberulent at the nodes; stipules present or absent, often represented by scarious, fim- 
briate or tufted developments at the node. Leaves alternate, opposite, or condensed and 
basal or pseudoverticellate, simple, sessile or petiolate, the laminae usually thick- 
succulent, glabrous and entire, often small. Inflorescence terminal or axillary, paniculate, 
racemose, cymose or the flowers solitary; flowers bisexual (rarely unisexual), radially 
symmetrical, often small but brightly colored, perianth generally interpreted to be of 2 
dissimilar whorls, sepals 2 (rarely 4-8), imbricate, free or united at the base, scarious or 
herbaceous, persistent or caducous, usually greenish (sepals sometimes interpreted to be 
floral bracts), petals 4 or 5 (6-18), free or united at the base, quickly wilting or rarely 
persisting, white to yellow or red; stamens 4 or 5 to many, often as many as the petals and 
opposite them, usually borne on a short floral cup, filaments free or united into fascicles, 
anthers 2-thecous, dehiscing longitudinally; pistil 1, ovary superior (half-inferior to infe- 
rior in Portulaca), at first with locules and axile placentation but becoming unilocular at 
maturity and with basal placentation, ovules (1) 2 to many, campylotropous, styles 1-9, 
united near the base or free. Fruit usually a capsule, opening by loculicidal or circum- 
scissile dehiscence (rarely a nut); seeds (1) 2 to many, slightly flattened, reniform to 
cochleate, embryo curved or folded. 

A family of about 20 genera and 500 species, best represented in open sunny 
habitats in the seasonally dry tropics and subtropics. The family is closely related 
to Aizoaceae (especially Sesuvium) and exhibits similarities of ovary structure to 
that of the Caryophyllaceae. Our species are characterized by their generally 
small stature, fleshy stems and leaves, flowers subtended by two greenish 
sepals, four or more colorful petals, fruit that begin to open by a circumscissile 
slit, and the dark cochleate seeds borne on a basal placenta. 

la Plants with the leaves all condensed at the apex of a single thick rootstock, leafy 
internodes not visible, leaves linear (1.5-3 mm broad and up to 7 cm long); plants 
found only on the highest paramo, above 3,200 m elevation Lewisia 

Ib Plants with conspicuous aerial stems and internodes, leaves rarely linear; not known 
to grow wild above 2,000 m elevation 2a 



218 FIELDIANA: BOTANY 

2a Ovary partly or wholly inferior, fruit opening by a circumscissile slit at the middle or 
near the top; flowers sessile or subsessile and subtended by a cluster (involucre) of 
leaves; stems usually with tufts of hairs or cilia at the nodes (stipules) .... Portulaca 

2b Ovary superior, fruit opening irregularly; flowers borne on slender pedicels in an 
open panicle, not subtended by leaves; stems and leaves lacking stipules, glabrous 

Talinum 



LEWISIA Pursh 

Herbs, perennial, aerial stem very short from a thick fleshy rootstock, rootstock simple 
or branched. Leaves mostly in a condensed basal cluster at the apex of the rootstock, 
simple and entire, somewhat succulent. Inflorescences racemose, paniculate or solitary 
and axillary, often subtended by leaflike bracts; flowers bisexual, radially symmetrical, 
sepals 2-8, persistent in fruit, petals 4-18, white to pink or red; stamens 5 to many; pistil 
1, ovary superior, placenta basal and central, styles 3-8 and fused near the base. Fruit a 
thin-walled capsule, dehiscence circumscissile near the base and then splitting upward; 
seeds 6 to many, ovate to cochleate, smooth and lustrous. 

A genus of 20 species of the southwestern mountains of the United States; one 
species extends southward on the tops of the highest mountains through Mexico 
to Guatemala and has recently been reported from the Chirripo paramo in Costa 
Rica. Species of this genus are often planted as ornamentals in rock gardens. 

Lewisia megarhiza (Hemsl.) MacBryde, J. Scott. Rock Card. Club 13:295. 1973. 
Calandrinia megarhiza Hemsley, Diagn. PL Nov. 23. 1879. Oreobroma mexicanum 
Rydberg, N. Amer. Fl. 21:326. 1932. O. megarhiza (Hemsl.) Standl. & Steyerm., 
Publ. Field Mus. Nat. Hist., Bot. Ser. 23:49. 1944. 

Herbs, perennial, the short aerial stem and congested leafy internodes from the top of 
a single thick fleshy taproot to 10 cm long and 5-18 mm thick. Leaves all basal and 
congested at the apex of the taproot, simple and sessile; laminae 2-7 cm long, 1.2-3 mm 
broad, linear and entire, expanded near the base with thin sheathing margins, fleshy, 
glabrous. Flowers solitary on axillary pedicels 5-20 mm long, sepals 2, 6-7 mm long, petals 
4-6, ca. 1 cm long, white. Fruit an ellipsoid capsule ca. 7 mm long and 4 mm thick, with 
very thin translucent walls; seeds numerous, 1.5 mm broad, cochleate, black, smooth and 
lustrous. 

This species has been collected by Arthur Weston on Costa Rica's highest 
mountain, Chirripo Grande. All the specimens seen from Mexico and Gua- 
temala were collected above 3,500 m elevation. The large taproot for so small a 
plant, the succulent linear leaves, the presence of only two sepals, and the 
distinctive fruit and seeds easily distinguish this species. 

PORTULACA Linnaeus 
By Donna Ford and William Burger 

REFERENCE: C. Diego Legrand, Desmembracion del genero Portulaca, I and II, 
Comun. Bot. Mus. Hist. Nat. Montevideo vol. 3, no. 31:1-15, 1953 and no. 
34:1-17, 1958. 

Herbs, annual or perennial, often prostrate, stems succulent glabrous or puberulent; 
stipules often reduced to a ridge with conspicuous hairs. Leaves alternate, subopposite or 
crowded and pseudoverticellate, simple and entire, sessile or petiolate, usually succulent 
and glabrous. Inflorescence of 1 to several flowers terminal on main and lateral stems, often 
subtended by closely crowded leaves forming an involucre; flowers bisexual and radially 
symmetrical, sessile or subsessile, perianth of 2 whorls, sepals 2, unequal and united near 
the base, petals 4-6, white, yellow or reddish, united only near the base, quickly with- 



BURGER: FLORA COSTARICENSIS 219 

ering; stamens (4-6) 7 to many, borne on the base of the united corolla, filaments free; pistil 
solitary, ovary half-inferior to inferior, unilocular, ovules numerous on a basal placenta, 
styles 3-9 and united at the base. Fruit a circumscissile capsule, the top coming off as a 
single unit (calyptra), thin-walled; seeds usually numerous, cochleate to reniform, smooth 
to minutely tuberculate. 

A genus of 150-200 species, distributed widely in tropical and subtropical 
regions. The small stature, succulent stems, brightly colored flowers subtended 
by an "involucre" of congested leaves, and calyptrate thin-walled fruit with 
cochleate seeds are distinctive. The genus is well represented in Mexico, and a 
number of species range sourthward to Guatemala and Honduras. 

la Leaves usually more than 4 mm wide, laminae flat; axillary hairs absent or inconspic- 
uous (to 1 mm long) 2a 

Ib Leaves usually less than 4 mm wide, laminae often terete; axillary hairs present and 

conspicuous, 1-18 mm long 3a 

2a Ovary superior to half-inferior; capsule not winged, circumscissile at the middle 
or below, operculum hemispherical; seeds black, brown or blue-waxy; flowers 

yellow P. oleracea 

2b Ovary half-inferior to inferior; capsule with a circular wing, circumscissile at the 
middle or above, operculum flat or slightly rounded; seeds gray at maturity; 

flowers yellow to red P. umbraticola 

3a Petals less than 1 cm long, pink to purple; stamens fewer than 40; small plants of open 

weedy sites P. pilosa 

3b Petals more than 1 cm long and the flowers more than 2 cm broad, variously colored; 
stamens more than 40; cultivated ornamentals and not naturalized in Costa Rica; 
P. grandiflora Hooker. 

Portulaca oleraceaL., Sp. PL 445. 1753. P. marginataH.B.K., Nov. Gen. & Sp. 
6:58. 1823. Figure 39. 

Herbs, prostrate or ascending, often with many branches radiating from a single base, 
stems succulent and often becoming reddish, leafy internodes 0-5 cm long, 0.5-3 mm 
thick (dry), glabrous except at the nodes; stipules present in the form of a minute ridge 
with slender whitish hairs to 1 mm long (just below the leaf base). Leaves alternate to 
subopposite and opposite, often crowded together at the ends of branches; petioles 0.5-4 
(8) mm long, expanded at the base with thin lateral margin; laminae 0.4-4 cm long, 0.3-2 
cm broad, spatulate to obovate or obtriangular, bluntly rounded at the apex, tapering 
gradually to the cuneate base, margins entire and decurrent on the petiole, smooth and 
glabrous, succulent but drying dark and stiffly chartaceous, venation obscure. Flowers 
sessile at the ends of branches, solitary or clustered together, subtended by a cluster of 
leaves, hairs at the base of the flower inconspicuous, with a short floral cup (perianth 
tube), sepals 2, broadly ovate, 3-4.5 mm long, petals 4-6, 34.5 mm long, bright yellow; 
stamens 6-15, filaments ca. 1.6 mm long; style with 4-6 branches. Fruit ovoid, 4-8 mm 
long, 3-4 mm thick, circumscissile below the middle, distal cap 2-4 mm long; seeds 0.6-1 
mm broad, cochleate, black, with granular or minutely tuberculate surface. 

Plants of open sunny sites, often found along roadsides, on sand and gravel 
bars along streams, and in open weedy fields from sea level to 1,500 (2,000) m 
elevation on both the Caribbean and Pacific sides of Central America. The 
species appears to flower throughout the year, but is most commonly encoun- 
tered from October to March. This species has become established all over the 
world, in both tropics and subtropics. 

Portulaca oleracea is recognized by its small stature, numerous glabrous stems, 
succulent little leaves often crowded at the ends of stems and forming an in- 
volucre beneath the sessile yellow flowers, and the circumscissile fruit with basal 
placentation. The distal flowers on main stems and lateral stems with terminal 
flower clusters often form cymelike arrangements. These plants are called 



220 FIELDIANA: BOTANY 

Verdolaga in Central America ("Purselane" in English) and are often cooked as a 
vegetable. 

Portulaca pilosa L., Sp. PI. 445. 1753. Figure 41. 

Herbs, prostrate or erect, stems succulent, rarely exceeding 20 cm in length, leafy 
internodes 0-2 cm long; intrapetiolar stipule present, with tufts of whitish haris 3-10 mm 
long from a band of tissue ca. 1.5 mm broad just above the leaf base. Leaves alternate or 
crowded together, sessile or with a short (1 mm) petiole; laminae 0.5-2 cm long, linear to 
narrowly lanceolate, acute at the apex, gradually narrowed at the base and decurrent on 
the petiole, margins entire, the laminae succulent (often terete) in life and glabrous, drying 
dark, venation obscure. Flowers sessile and crowded at the ends of stems, 2.5-3 mm long, 
subtended by a cluster of leaves forming an involucre, sepals 2-3 mm long, petals 3-5.5 
mm long, reddish or purple; stamens 15 to many, filaments red. Fruit a circumscissile 
capsule, 3-4 mm in diameter; seeds 0.5-0.7 mm broad, slightly flattened, cochleate in 
outline, minutely tuberculate, black. 

Plants of open sunny sites and often found on rocky sites or sand along 
streams from near sea level to 1,200 m elevation along the Pacific slope of Central 
America and in the Caribbean lowlands; flowering primarily from June to 
February. The species ranges from the southeastern United States, the West 
Indies, and Mexico through Central America to South America. 

Portulaca pilosa is characterized by its small succulent stems with unusual 
h'mbriate intrapetiolar stipules that give a tufted white-hairy appearance to the 
stems. The distal rose red flowers subtended by similar tufted hairs and by a 
cluster of leaves are also distinctive. The species has only been collected in the 
seasonally very dry areas of the northern Pacific slope in Costa Rica, during the 
wet season. 



Portulaca umbraticola H.B.K., Nov. Gen. & Sp. 6:72. 1823. P. lanceolata En- 
gelm., Boston J. Nat. Hist. 6:154. 1850, non Haw. 1803. P. coronata Small, Bull. 
Torrey Bot. Club 23:126. 1896. P. plano-operculata Kuntze, Rev. Gen. 3:16. 1898. 
P. denudataPoellin., Repert. Spec. Nov. Regni Veg. 33:159. 1933. 

Herbs, 10-50 cm tall, annual, stems prostrate to erect and simple or with open branch- 
ing, stems glabrous and green to magenta, roots fibrous; stipules absent or represented by 
short (1 mm) whitish hairs at the axils. Leaves alternate along the stems and in whorls of 
3-8 beneath the flowers, subsessile or with short (1-2 mm) petioles; laminae 1-3 (5) cm 
long, 0.4-1.1 (1.6) cm broad, lower laminae spatulate to obovate, the upper oblanceolate 
to oblong, usually rounded at the apex, tapering gradually to the base, glabrous, succulent, 
venation obscure. Flowers in terminal clusters, bracteoles 1.5-2 mm long, lanceolate to 
deltoid; sepals 2, 3-5 (8) mm long, ovate, petals to 1 cm long, yellow to orange or red, 
spatulate or obovate; stamens 7-27, anthers narrow; ovary with an adnate corona, style 
5-8 mm long, stigmatic branches 3-8. Fruit a capsule subtended by the persisting leaves 
and calyx, 3-5 mm long, usually turbinate, sessile or borne on a pedicel to 4 mm long, 
circumscissile at the middle or above, the operculum rounded, 3-4 mm broad and 1-2 mm 
high, the coronal wing 0.5-1 mm wide, arising just below the line of dehiscence; seeds 
0.7-1 mm broad, gray, cochleate and tuberculate. 

Plants of open sunny sites in seasonally dry areas, ranging from near sea level 
to 1,200 m in our area, but rarely collected below 600 m in central Central 
America. Flowering material has been collected from June to September in Cen- 
tral America, along the Pacific slope, and in the Central Highlands. The species 
ranges from the southern United States (Arizona to Georgia), Mexico, and the 
West Indies through Central America to South America. 

Portulaca umbraticola is recognized by its succulent and glabrous stems and 



BURGER: FLORA COSTARICENSIS 221 

leaves (hairs only at the leaf axils), the terminal flowers subtended by a whorl of 
leaves, fruit opening by the circumscissile dehiscence of a slightly domed 
(curved) lid or operculum, and the restriction to seasonally very dry vegetation. 
This species has only recently been collected in Costa Rica at the Santa Rosa 
National Park in Guanacaste province (Liesner & Lockwood 2687). While common 
in Honduras between 600 and 1,100 m elevation, we have not seen specimens 
from Guatemala. In Honduras the species is called Verdolaga. 

TALINUM Adanson 

Herbs or subshrubs, annual or perennial, bisexual, stems often succulent, usually gla- 
brous; stipules absent. Leaves alternate or subopposite, simple and entire, usually quite 
succulent. Inflorescences often cymose, the cymes arranged in compound panicles or 
simple and few flowered, flowers rarely solitary and axillary, usually pedicellate; flowers 
bisexual, radially symmetrical, sepals 2, opposite and free, usually early deciduous, petals 
5 or more, free or connate at the base, deciduous; stamens 5 to many, sometimes united 
into antipetalous fascicles, filaments slender; pistil 1, ovary superior, 1- or 3-locular near 
the base, placentation basal or free central, styles 3, united near the base. Fruit a capsule, 
1- or 3-locular near the base, opening from the top into 3 valves or irregularly; seeds 
somewhat flattened, cochleate to reniform in outline. 

A genus of probably fewer than 50 species, two of which are found in Cen- 
tral America. The genus ranges from temperate and tropical America to Africa 
and Asia. 

la Plants with succulent stems that do not persist through the dry season; larger leaves 
3-6 cm broad; inflorescence a much-branched panicle with many distant flowers; 
sepals 3-4 mm long; uncommon plants of the seasonally dry Pacific slope from Mexico 
to Costa Rica T. paniculatum 

Ib Plants with woody stems that persist through the dry season and are perennial; larger 
leaves rarely exceeding 2.5 cm in breadth; inflorescence a few-branched cyme or 
raceme; sepals 5-6 mm long; ranging from Mexico to central Nicaragua and not 
included in the descriptions: T. triangulare (J acc l-) Willd. (See note below.) 

Talinum paniculatum Qacq.) Gaertner, Fruct. & Sem. 2:219, pi. 128, f. 13. 
1791. Portulaca paniculata Jacquin, Enum. PI. Carib. 22. 1760. P. patensL., Mant. 
PI. 242. 1771. T. patens (L.) Willd., Sp. PL 2:863. 1800. Claytonia paniculata (Jacq.) 
O. Ktze., Rev. Gen. 1:57. 1891. Figure 40. 

Herbs, erect to 1 m tall, stems succulent and simple or with a few lateral branches, from 
a tuberous base, glabrous, leafy internodes 0.5-10 cm long, 1-6 mm thick; stipules absent. 
Leaves alternate, glabrous, petioles 1-15 mm long and not clearly differentiated from the 
lamina, with lateral wings continuous with the lamina margins; laminae 2-13 cm long, 1-6 
cm broad, elliptic to obovate, abruptly obtuse or rounded at the apex, tapering gradually 
to the cuneate base and decurrent on the petiole, margins entire, succulent in life but 
drying brittle (chartaceous to subcoriaceous) and dark, the 2-4 pairs of major secondary 
veins often obscure. Inflorescences 10-60 cm long, 6-20 cm broad, terminal, paniculate 
with a central stem and slender alternate branches, flowers in open cymes on very slender 
(0.2 mm, dry) pedicels 1-2 cm long; flowers 3-4 mm long, perianth of 2 whorls and not 
persisting in fruit, sepals ca. 2 mm long, petals ca. 3 mm long, yellow or pink; stamens 15 
or more, filaments 1.2-2 mm long, anthers 0.3-0.5 mm long; ovary globose, 1 mm long. 
Fruit a lustrous yellowish globose capsule 3.5-5 mm in diameter, breaking open irregu- 
larly; seeds slightly flattened, cochleate in outline, 1-1.5 mm broad, surface black and 
lustrous, minutely reticulate, strophiolate. 

Plants of open weedy sites, riverbanks, and thickets from (0) 100 to 1,200 m 
elevation along the seasonally very dry Pacific slope of Central America; grow- 
ing and flowering in the wet season, from June to December. The species ranges 



222 FIELDIANA: BOTANY 

from the southern United States, Mexico, and the West Indies through Central 
America and Panama to South America. 

Talinum paniculatum is recognized by its succulent alternate leaves on few- 
branched stems, open paniculate inflorescences with slender stems, small flow- 
ers with only two sepals, and capsules opening irregularly to disperse small 
black snail-shaped seeds. These plants are rarely collected in Costa Rica and are 
probably confined to the northern half of the Pacific slope. 

Note added in proof: Talinum triangulate Qacq.) Willd. has recently been collected 
by Robert Wilbur near the railroad yards at Puerto Limon, where it appears to 
be a recent arrival. 



BASELLACEAE 

Twining herbs or climbing subshrubs or vines, annual or perennial, bisexual, glabrous; 
without stipules. Leaves alternate and simple, petiolate, often cordate, usually slightly 
succulent, entire and glabrous. Inflorescences axillary or terminal, spikes, racemes or 
panicles, glabrous, small slender bracts present at the base of the pedicels and with 2-4 
sepaloid bracteoles; flowers small, bisexual or unisexual, perianth of a single whorl but 
often appearing to have 2 whorls because of the sepaloid bracteoles adnate to the base of 
the flowers, perianth petaloid and 5-parted, forming a tube or almost free to the base; 
stamens 5, opposite the perianth parts and borne at their base, filaments free, anthers 
versatile, dehiscing variously; pistil 1 with superior ovary, 1-locular with basal placen- 
tation, ovule solitary, short-stalked and campylotropous, style 1-3, stigmas separate or 
3-lobed. Fruit an indehiscent utricle, enclosed by the often fleshy perianth or winged 
bracteoles (winged sepals of some authors); seeds solitary, small, spherical or flattened. 

A small tropical family of five genera. Anredera vesicaria (Lam.) Gaertn., with 
fruit bearing wings 4 to 5 mm long, is found in northern Central America. 
Ullucus tuberosa Lozano, with potato-like tubers, is an important food plant in the 
Andean region of South America. Basella alba L. of the Old World tropics is 
cultivated for its fleshy leaves which serve as an excellent spinach-like vegetable. 
None of the aforementioned species has been reported in Costa Rica, but Basella 
albais cultivated in central and eastern Panama (see treatment of the family in the 
Flora of Panama, Ann. Missouri Bot. Card. 66:109-115, 1979). The family is 
closely related to the Portulacaceae. 

BOUSSINGAULTIA Humboldt, Bonpland, and Kunth 

Vines or herbaceous twiners with slender distal stems, bisexual, glabrous, often succu- 
lent; stipules absent. Leaves alternate and simple, petiolate, slightly succulent, often 
becoming cordate in larger leaves. Inflorescences axillary or terminal, racemes or panicles, 
flowers subtended by slender bracts and with 2 sepal-like bracteoles at the apex of the 
pedicel; flowers bisexual and radially symmetrical, perianth of 5 petaloid parts whitish but 
often turning dark when dry, the sepaloid bracteoles united to the base of the corolla-like 
perianth tube; stamens borne on the base of the corolla tube, inflexed in bud, filaments 
slender, anthers versatile; ovary ovoid, style 1 with 3 stigmas or the style with 3-lobed 
stigma. Fruit a utricle enclosed within the persisting perianth; seed solitary erect. 

A genus of about 10 species in tropical America. Three species are found in 
northern Central America, but only one of these species has been recorded from 
Costa Rica. 

Boussingaultia ramosa (Moq.) Hemsley, Biol. Centr. Amer. Bot. 3:27. 1882. 
Tandonia ramosa Moq., in DC., Prodr. 13, pt. 2:227. 1849. Dioscorea calyculata 
Donnell Smith, Bot. Gaz. 20:295. 1895. Figure 40. 



PHILOXERUS 
vermicularis 



TRIANTHEMA 
portulacastrum 




SESUVIUM 
portulacastrum 



FIG. 39. Cnryophyllales: succulent species with opposite leaves usually clasping the stem 
at their base. Aizoaceae: species of Sesuvium and Trianthema. Amaranthaceae: Philoxerus 
vermicularis. Portulacaceae: Portulaca oleracea. 



223 



BOUSSINGAULTIA 
ramosa 



TALINUM 
paniculatum 




FIG. 40. Caryophyllales: a climber and an erect herb, both with semisucculent leaves. 
Basellaceae: a species of Boussingaultia. Portulacaceae: a species of Talinum. 



224 




ARENARIA 



lanuginosa 
ssp. lanuginosa 




SAGINA 
procumbens 



SCLERANTHUS 
annuus 



MOLLUGO 

verticellata 




FIG. 41. Caryophyllales: herbs with narrow opposite leaves. Aizoaceae: Mollugo verti- 
cellata. Portulacaceae: Portulacapilosa. Caryophyllaceae: species of Arenaria, Sagina, Scleran- 
thus, and Spergula. 



225 



ARENARIA 

lanuginosa 

ssp. guatemalensis , 



STELLARIA 
ovata 




CERASTIUM 
guatemalensis 



5 mm 



GLINUS 
radiata 



FIG. 42. Caryophyllales: species with broader opposite or whorled leaves. Aizoaceae: 
Glinus radiatus. Caryophyllaceae: species of Arenaria, Cerastium, Drymaria, and Stellaria. 



226 



BURGER: FLORA COSTARICENSIS 227 

Herbaceous or woody climbers, annual or perennial, distal stems often pendulous, 
glabrous, leafy internodes 2-6 cm long, 1-4 mm thick; stipules absent. Leaves alternate in 
a spiral, distant, glabrous, petioles 6-25 mm long, sulcate above with 2 adaxial ridges 
continuous with the lamina margins; laminae 2-6 cm broad, broadly ovate, acute to obtuse 
at the apex and with a mucronate tip ca. 3 mm long, obtuse to truncate or cordate (in larger 
leaves) at the base, margins entire and decurrent on the petiole, somewhat succulent in life 
but drying thin-chartaceous or membranaceous, venation pinnate or subpalmate with 2 or 
3 pairs of major secondary veins, smooth and glabrous. Inflorescences slender open ra- 
cemes borne on leafless paniculiform axillary or terminal branches, 6-35 cm long, rachis 
0.2-0.6 mm thick (dry) and glabrous, with slender linear-lanceolate bracts subtending the 
pedicels ca. 2 mm long, pedicels ca. 1.5 mm long; flowers ca. 2 mm long, subtended by a 
pair of sepaloid bracteoles ca. 0.6 mm long, perianth petaloid, 2 mm long, broadly imbri- 
cate, whitish but becoming dark when dried, united and narrowed above the calyx- 
like bracteoles, ovary ca. 1 mm long, ovoid. Fruit apparently quickly caducous, usually 
enclosed by the dark perianth and pale-colored subtending bracteoles, with 2 lateral 
winglike developments at the base of the perianth ca. 1 mm long, fruit lustrous subglobose 
and with a small disk at the apex, ca. 0.7 mm long; seed difficult to extricate from the 
tightly enclosing fruit wall. 

Plants of open thickets and climbing over others, from 700 to 2,000 m elevation 
along the Pacific slope of Central America; collections with flowers and fruit 
have been made from October to February. The species ranges from Mexico to 
Costa Rica. 

Boussingaultia ramosa is characterized by its glabrous slender distal climbing 
stems with alternate slightly succulent leaves, the long pendulous racemes with 
little white flowers, the two sepaloid bracteoles at the apex of the pedicel, and 
the minute fruit with single seed. This species resembles some species of Di- 
oscorea and Polygonaceae, but the five-parted perianth and estipulate leaves 
serve to place these slender climbers in their appropriate family. 

CARYOPHYLLACEAE 

By Richard A. Baker and William C. Burger, 
with Cerastium by David Good 

Herbs (rarely subshrubs or shrubs), annuals or perennials, plants bisexual (rarely uni- 
sexual), glabrous to densely puberulent, nodes often slightly thickened; stipules present 
or absent and then the leaf often with a clasping or sheathing base, interpetiolar ridges or 
sheaths sometimes present. Leaves simple and undivided, opposite or pseudoverricellate 
(rarely alternate), laminae usually entire. Inflorescences often cymose, loosely dichasial to 
compact and capitate, many to few flowered or the flowers solitary on distal stems, floral 
bracts or reduced leaves often subtending the pedicels, rarely with 1-3 pairs of bracts 
immediately subtending the calyx (called an epicalyx) as in Dianthus. Flowers bisexual 
(rarely unisexual), radially symmetrical, calyx of 5 or 4 free sepals or united to form a calyx 
tube with 5 (4) lobes or teeth, hypogynous or borne on a cupulate hypanthium, persisting 
in fruit and becoming dry and stiff; petals 5 or 4 (0), free, entire to deeply bilobed or serrate 
at the apex, white to pink or purple and red (the petals usually divided into a narrow 
petiole-like claw at the base and a distal expanded blade in genera with united sepals, the 
clawed petals often with small ligule-like appendages above the junction of claw and 
blade); stamens usually 10 in 2 whorls of 5, often fewer by reduction, often united at the 
base but the filaments free for most of their length, anthers 2-celled, dehiscing longi- 
tudinally; pistil solitary, often narrowed at the base or borne on a short stalk, ovary 1- to 
5-Iocular, often with septa at the base and a single locule in the upper half, placentation 
axile, central, free-central or basal, ovules few to many (rarely solitary), styles 2-5, free or 
united at the base. Fruit usually a thin-walled capsule (1-seeded indehiscent utricles or 
berry-like in a few genera), often borne on a short stalk, usually breaking into as many 
septa as there are styles, capsules of flowers with united tubular calyx usually opening only 
at the top with small teeth; seeds usually reniform to cochleate or circular, often slightly 
flattened on 2 sides, smooth to tuberculate, with or without a small aril-like appendage 



228 FIELDIANA: BOTANY 

(strophiolate or estrophiolate); seeds usually with a curved embryo enclosing perisperm 
and little or no endosperm. 

A family of about 75 genera which is most numerous in the cooler regions of 
the world and very poorly represented in the lowland tropics. A number of 
taxonomically difficult genera include species that have become cosmopolitan 
weeds; the names and status of these species will probably continue to give us 
difficulty for years to come. The family includes a number of ornamentals that 
are important both in gardens and in the cut-flower trade. These herbaceous 
plants can usually be recognized by their opposite simple and entire leaves, the 
separate petals often cleft or fimbriate at the apex, the thin- walled capsules, and 
the seeds usually reniform (kidney-shaped) to cochlea te (snail-shaped). 

la Flowers with the sepals free or united only at the base (calyx-tube, calyx-cup or 
urceolate hypanthium absent); native and naturalized weedy plants, not grown for 

ornamental use 2a 

Ib Flowers with the calyx united to form a cup or a tube, or the sepals borne on the apex 
of an urceolate hypanthium; introduced weeds or garden plants grown for their 

ornamental flowers and inflorescences 8a 

2a Stipules present at the leaf base (sometimes falling off early), leaf bases not 

clasping or sheathing the stem, interpetiolar lines often present 3a 

2b Stipules absent, leaf bases often clasping or sheathing the stem, an interpetiolar 

line or sheath often present 5a 

3a Leaves opposite and broad; styles united near the base; seeds cochleate and 

tuberculate; commonly encountered native plants Drymaria 

3b Leaves opposite or whorled or appearing to be whorled by condensation of 
short axillary shoots, leaves linear to narrowly obovate; rarely collected 

introduced weeds of higher elevations 4a 

4a Leaves linear and appearing to be whorled; styles free to the apex of the 
ovary; seeds subglobose and with a whitish circumferential margin or wing 

Spergula 

4b Leaves narrowly obovate or oblong-obovate, opposite or whorled; styles 
united for most of their length; seeds semicircular to sublunate and without 

a margin or wing Polycarpon 

5a Capsule cylindrical and usually somewhat curved, opening by 10 short teeth; 

plants often conspicuously puberulent Cerastium 

5b Capsule ovoid and straight, opening by 2-8 teeth 6a 

6a Seeds reniform-globose, seed coat lustrous and smooth, maroon to black in 
color; petals entire; laminae often with a delicate submarginal vein along distal 

margins Arenaria 

6b Seeds usually cochleate with muricate to tuberculate surfaces, brownish and 

dull; petals entire to deeply 2-lobed 7a 

7a Petals entire; styles 4 or 5; leaves linear and less than 8 mm long, a submarginal 

vein absent Sagina 

7b Petals 2-lobed; styles usually 3; leaves usually ovate to cordate and the larger 
more than 8 mm long (S. nubigena has small lanceolate leaves but is very rare), 

a submarginal vein present or absent Stellaria 

8a Sepals narrow and borne at the distal rim of a small (1.5 mm) urceolate hypanthium, 
petals absent; leaves linear and rarely more than 12 mm long, with an interpetiolar 

sheath at the base; fruit with 1 seed; weeds (rare in Costa Rica) Scleranthus 

8b Sepals united for much of their length to form a tube or united halfway to form an 
open cup; petals present; fruit with numerous seeds; planted for ornament or an 

escaped weed with viscid glandular hairs in Silene gallica 9a 

9a Flowers less than 1 cm long, calyx united for half its length; styles 2 or 3; capsules 
4-valved, 4-5 mm long; inflorescences open and diffuse, with many flowers on long 

slender pedicels; grown for ornament Gypsophila 

9b Flowers usually over 15 mm long, calyx united to form a tube with small apical teeth, 
calyx tube usually enclosing most of the fruit; capsules opening by small apical teeth, 
more than 5 mm long; inflorescences usually few-flowered lOa 



BURGER: FLORA COSTARICENSIS 229 

lOa Styles 5 or 4; calyx 15-20 mm long; garden plants covered with grayish white 
tomentum Lychnis 

lOb Styles 2 or 3; plants never covered with dense grayish white puberulence lla 

lla Styles 3; calyx 6-16 mm long, with 10 or more thick distinct veins; capsule with 6 
short apical teeth; glabrous and with showy flowers or a weed with glandular pubes- 
cence distally Silene 

lib Styles 2; calyx 15-24 mm long, with many veins, the veins not thickened; capsule 
usually with 4 apical teeth; glabrous garden plants Saponaria 



ARENARIA Linnaeus 

REFERENCE: J. McNeill, The delimitation of Arenaria and related genera 
in North America, with 11 new combinations in Minuartia. Rhodora 82:495- 
502. 1980. 

Annual, biennial or perennial herbs, sometimes with a woody rootstock, stems diffusely 
branched, procumbent, repent or ascending and clambering, occasionally forming dense 
cushion-like mats, glabrous or puberulent; estipulate. Leaves opposite, sessile or very 
short petiolate, linear to narrowly elliptic or ovate, entire, usually clasping the stem at their 
base. Inflorescences dichasial, axillary or terminal, or the flowers solitary at the nodes (as 
in ours); flowers bisexual, radially symmetrical, small, sepals 5, free or only slightly united 
at the base, petals 5 (absent in A. quirosiiand some northern subspecies of A. lanuginosa), 
white (in ours), free, apically entire to slightly emarginate or dentate; stamens 10, rarely 
5, usually borne on a slightly elevated perigynous disk, anthers versatile, dehiscing 
longitudinally, 2-thecous; ovary superior, unilocular, placentation basal with many 
ovules, styles usually 3 or 5 (occasionally 2 or 4), free. Fruit a capsule dehiscing by as many 
valves as there are styles, valves 1-lobed or bilobed at the apex, thin-walled, unopened 
fruit ovoid to globose or oblong; seeds often numerous, subglobose or slightly compressed, 
reniform to subcircular in outline, the surface smooth and lustrous (in ours) or rough and 
tuberculate, estrophiolate. 

A genus of perhaps 200 species, primarily of seasonally cold habitats in the 
Northern Hemisphere. Two species occur in Costa Rica, one apparently en- 
demic. The Costa Rican species of Arenaria can be distinguished from our other 
Caryophyllaceae by the combination of their dark maroon or black, smooth and 
shiny, reniform-globose seeds, the lack of stipules, the usually narrow leaves, 
the solitary axillary flowers borne on conspicuous slender pedicels, and the 
entire petals (when petals are present). The members of this genus have only 
rarely been collected below 1,000 m elevation in Costa Rica. One of our species 
is polymorphic and is here treated as a single species; see the discussion under 
A. lanuginosa. 

la Laminae less than 5 mm long, broadly ovate to obovate; flowers lacking petals; prob- 
ably restricted to areas above 3,000 m elevation, rarely collected A. quirosii 

Ib Laminae usually over 10 mm long (linear to lanceolate or narrowly elliptic-ovate when 
less than 10 mm long); flowers with petals but the petals deciduous; a polymorphic 
array of plants ranging from 700 to 3,400 m elevation A. lanuginosa 

Arenaria lanuginosa (Mich.) Rohrbach, in Mart., Fl. Brasil. 14, pt. 2:274. 1872, 
sensu la to. Spergulastrum lanuginosum Michaux, Fl. Bor. Amer. 1:275. 1803. A. 
alsinoides Willd. ex Schlecht, Mag. Ges. Naturf. Freund. Berlin 7:201. 1816. A. 
nemorosa H.B.K., Nov. Gen. & Sp. 6:35. 1823. A. saxosa A. Gray, PI. Wright. 
11:18. 1853. A. guatemalensis Standl. & Steyerm., Publ. Field Mus. Nat. Hist., 
Bot. Ser. 23:50. 1944. A. lanuginosum ssp. saxosa (A. Gray) Maguire, Amer. Midi. 
Naturalist 49:498. 1951. A. lanuginosa ssp. guatemalensis (Standl. & Steyerm.) J. 
Duke, Ann. Missouri Bot. Card. 48:93. 1961. Figures 41 and 42. 



230 FIELDIANA: BOTANY 

Herbs, prostrate, decumbent or clambering over other plants, to 1 m tall, perennial from 
a taproot, usually much branched from the base, bisexual, leafy internodes 0.2-5 (15) cm 
long, 0.3-2 mm thick, usually puberulent with slender whitish hairs 0.1-0.3 mm long, 
hairs often confined to longitudinal ridges. Leaves opposite, equal or subequal at each 
node, differing greatly in different plants but usually quite similar on the same plant, 
sessile or subsessile, petioles to 3 mm long; laminae 4-30 (40) mm long, 1-16 mm broad, 
linear to narrowly elliptic or elliptic-ovate, obtuse or acute at the apex, slightly (0.5 mm) 
mucronate at the tip, gradually narrowed at the base and clasping the stem, margins entire 
and often minutely ciliate; laminae drying thin-chartaceous, smooth and usually puber- 
ulent (especially on the midvein) with thin whitish hairs ca. 0.2 mm long, with a single 
prominent midvein, secondaries obscure. Flowers solitary and borne from the axils of 
distal leaves, pedicels slender, 0.5-4 cm long, usually puberulent, the flowers small, 3-6 
mm long, sepals 2-5 mm long, usually with green center and translucent margins, acute 
at the apex, persisting in fruit; petals shorter or longer than the sepals, to 8 mm long, thin 
and whitish, usually deciduous; stamens shorter than or as long as the sepals, filaments 
1-4 mm long; ovary ovoid. Fruit 2.5-6 mm long, ovoid-ellipsoid, valves 2-5, thin-walled 
and yellowish, splitting to the base or only halfway, thin-walled and yellowish; seeds 
0.6-1 mm broad, slightly flattened, suborbicular to slightly cochleate in outline, reddish 
brown (in early stages) to lustrous black, surface usually smooth. 

Horizontally spreading or clambering herbs in open sites and in moist forest 
understory of montane forest and highlands. The species is rarely found below 
1,500 m elevation in Costa Rica, but ranges as low as 500 m in Guatemala; it can 
be found on our highest mountains, and flowering collections have been made 
throughout the year. The species ranges from the southern United States 
through Mexico and Central America to Peru and Brazil. 

Arenaria lanuginosa (in a wide sense) is characterized by its opposite subsessile, 
narrow, little leaves, sprawling or clambering stems, solitary little flowers on 
thin pedicels arising from the axils of distal leaves, the biseriate perianth with 
undivided petals (in our area), and the thin-walled capsule with basal placenta. 

The broad circumscription of this species avoids the problems of erecting new 
species, but such a treatment obscures what may be real differences between 
population groups in Central America. The following key was developed by 
Richard Baker and recognizes four species-like taxa in Costa Rica. Three are 
designated subspecies and are consistent with the treatment by James Duke in 
the Flora of Panama; the fourth is unnamed. This key seems to work effectively 
for a majority of the specimens encountered in Central America, but it may be 
ineffective elsewhere in the range of the species. There are occasional collections 
that seem to have intermediate characteristics, and this is consistent with the 
experience that others have had with other species of Arenaria. We do not know 
if the four entities separated by the key deserve specific rank as they were given 
in the Flora of Guatemala; we present this key in the hope that it will suggest 
further study. 

la Valves of the mature capsule not exceeding or only slightly exceeding the sepals; 
sepals glabrous, 34.5 mm long, petals as long as or longer than the sepals; laminae 
usually less than 2 cm long and 5 mm broad, ciliate along the margin only on the 
proximal half of the lamina; styles 2 or 3; plants found above 3,000 m elevation on 
Volcan Baru, Chiriqui, Panama ssp. saxosa 

Ib Valves of the mature capsule usually exceeding the sepals; sepals usually puberu- 
lent 2a 

2a Petals longer than the sepals; styles usually 3, capsule valves more than 4.5 mm long; 
pedicels (1.5) 2-5 cm long; laminae to 4 cm long and often more than 5 mm broad; 
plants usually found only above 1,800 m elevation ssp. guatemalensis 

2b Petals equaling or shorter than the sepals; capsule valves shorter than 4.5 mm or, if 
longer, the pedicels 1.5 cm long or less; laminae rarely more than 2.5 cm long or 5 mm 
broad . . . . 3a 



BURGER: FLORA COSTARICENSIS 231 

3a Styles 2-4; capsule valves 2-4, usually bilobed and revolute, 3-4 mm long (rarely 
longer); sepals usually 2-3 mm long; 500-1,800 (2,400) m elevation . .ssp. lanuginosa 

3b Styles 5; capsule valves 5, sometimes bilobed, usually entire and straight, 5-7 mm 
long; sepals 2.7-4 mm long; (1,800) 2,000-2,800 (3,300) m elevation, (undesignated) 

Arenaria quirosii Standley, Publ. Field Mus. Nat. Hist., Bot. Ser. 22:19. 1940. 

Small herbs, the stems to 6 cm tall, erect; internodes 1.5-5 mm long, densely pubescent 
with multicellular trichomes to 0.3 mm long. Leaves opposite, sessile, the laminae 2.5-5 
mm long, 1-2.5 mm broad, ovate to obovate, apically acute to obtuse and short-acuminate 
with the tip often thickened and brownish (dry), the base broadly attenuate, the margin 
entire, the lamina drying thick-chartaceous and yellowish to brownish, sparsely puber- 
ulent above and below, sparsely to densely ciliate along the midrib below and along the 
proximal % of the margin, only the midvein conspicuous. Flowers solitary and axillary, the 
pedicels 2-4 mm long, densely pubescent with short multicellular hairs; sepals 5, 2.2-3 
mm long (anthesis to fruiting), lanceolate to oblong-ovate, the apex short-acuminate, the 
tip often thickened and brownish, margins rather broad and scarious, ciliate along the 
midvein; petals absent; stamens 10, the filaments 0.5-0.8 mm long, anthers 0.2 mm long 
(anthesis); ovary ovoid, ca. 0.6 mm long (anthesis); styles 3, ca. 0.4 mm long (anthesis) to 
1.2 mm long (fruit). Fruit a capsule, ellipsoid, the valves after dehiscence approximately 
equaling the sepals (ca. 3 mm); seeds numerous, 0.7 mm broad, reniform-globose, seed 
coat smooth and shiny, dark maroon to black. 

Arenaria quirosii can be recognized by its very small habit, its small broad 
leaves, its short pedicels, and its lack of petals. This species was known only 
from the type collection (M. Quiros C. 812 collected on Volcan Irazu in September 
1938), but has recently been found on Costa Rica's highest mountain, Chirripo, 
by Arthur Weston. 

CERASTIUM Linnaeus 
By David Good 

Herbs, annual or perennial, low and caespitose to tall and erect, often ascending, stems 
almost always puberulent, with or without glandular hairs; stipules absent. Leaves op- 
posite and sessile or subsessile, a basal rosette present or absent, cauline leaves few to 
many, usually shorter than the basal leaves when the latter are present; laminae linear to 
elliptic, ovate or spatulate, acute or obtuse at the apex, often clasping the stem at their base 
and the opposing leaf bases sometimes united, entire, usually puberulent. Inflorescence 
invariably a cyme, either compact or loose, borne on distal stems, usually puberulent. 
Flowers very small (2-3 mm) to medium sized (ca. 1 cm), bisexual, radially symmetrical, 
sepals 5 (4), free, lanceolate to elliptic, acute, scarious margined, usually pubescent, petals 
5 (4, 0), free, usually white, variously bifid; stamens 10 (5, 4), free, shorter than the petals; 
ovary superior, carpels and styles 5 (rarely 4 or 3), opposite the sepals. Fruit a capsule, 
usually well exserted beyond the persisting sepals at maturity and opening apically by 
twice as many teeth as there were styles; 1-locular, thin walled, often curved at maturity; 
seeds many, small (0.3-1.2 mm), cochleate to U-shaped or subcircular in outline, some- 
what compressed, the surface variously tuberculate. 

A virtually cosmopolitan genus of 50 to 100 species of small more or less scruffy 
herbs. These plants are confined to cooler habitats and are not found below 1,200 
m elevation in Central America. The genus can be confused with any of several 
other genera in the Caryophyllaceae, particularly with Stellariaand Arenaria, but 
the presence of five styles, considerable pubescence, and the exserted curved 
capsules usually set it apart. Flowers of Costa Rican species are all five-parted, 
with five sepals, five petals, 10 stamens, and five styles. 

la Cauline leaves elliptic to ovate or obovate, usually obtuse to rounded at the apex; 
pedicels 1-5 mm long, sepals 2.5-5 mm long; capsules 5-8 mm long, seeds 0.3-0.4 
mm in diameter C. glomeratum 



232 FIELDIANA: BOTANY 

Ib Cauline leaves linear to lanceolate or narrowly elliptic, acute to acuminate at the apex; 

sepals 4.3-6.5 mm long; capsules 7-12 mm long 2a 

2a Pedicels up to 14-35 mm long; petals divided for % of their length; seeds 0.8-1 mm 

in diameter C. guatemalensis 

2b Pedicels 2-9 mm long; petals divided for Va of their length; seeds 0.5-0.7 mm in 

diameter C. triviale 

Cerastium glomeratum Thuillier, Fl. Paris, ed. 2, 226. 1799. C. viscosum L. 
(nom. ambig.), Sp. PI. 437. 1753. 

Annual plants with stems ascending or erect, sometimes caespitose, 2.5-30 cm tall, very 
much branched at the base, little otherwise, branches pilose, leafy internodes usually 
longer distally than basally, longer or shorter than the leaves. Leaves similar through- 
out, perhaps slightly smaller above, basal rosette lacking; laminae broadly elliptic to 
orbicular or spatulate, 5-20 mm long, 3-12 mm wide, obtuse, pilose. Basal rosette lacking. 
Cymes many flowered, flowers very crowded terminally, pedicels very short, 1-5 mm 
long, pilose, sometimes slightly glandular. Sepals lanceolate, 2.8-5.1 mm long, 0.5-1.6 
mm wide, acute, scarious margined, pilose, sometimes glandular; petals shorter than or 
equal to the sepals, bifid ca. V4 of their length, white; filaments 1.8-2.3 mm long, anthers 
0.1 mm long; styles 0.8-1.1 mm long. Capsules 5.0-8.8 mm long, 1.3-1.8 mm wide, 
curved; seeds 0.3-0.4 mm in diameter, finely tuberculate. 

An introduced species of varied habitats including roadsides, fields, wood- 
lands, volcanic rocks, cornfields, gardens, and other areas. In Costa Rica it has 
been collected at altitudes of between 1,460 and 2,600 m in the provinces of 
Alajuela, Cartage, and San Jose. Native to Europe, Cerastium glomeratum is found 
in North America throughout much of the southern and central United States, 
in central Mexico, and from southern Mexico (Chiapas) south to Chiriqui Prov- 
ince, Panama. Flowering specimens can be found virtually throughout the year. 

Cerastium glomeratum is recognized by its usually broadly elliptic-ovate leaves, 
its bracts lacking scarious margins, and its inflorescences of very small, very 
crowded flowers. 

Cerastium guatemalense Standley, Field Mus. Nat. Hist., Bot. Ser. 17:244. 
1937. Figure 42. 

Perennial plants with stems to 45 cm tall, often much branched basally and above, 
branches erect or ascending, densely glandular-pilose, internodes usually more or less 
equal except at the base, where shorter. Leaves usually similar throughout or the lower 
ones somewhat shorter, basal rosette lacking; laminae linear to lanceolate, widest at the 
base, narrowing to an attenuate tip, 15-48 mm long, 2-5 mm wide, glandular-pilose, 
particularly on the lower surface. Cymes 3-40 flowered, usually 3-15, bracts not scarious 
margined, lowermost (longest) pedicels 14-35 mm long, upper ones shorter, all hooked 
in fruit, glandular-pilose. Sepals lanceolate, 4.4-6 mm long, 1-1.7 mm wide, acute, scar- 
ious margined except at the apex, glandular, petals 6-7.1 mm long, bifid ca. Vs of their 
length, white; filaments 3.2-3.5 mm long, anthers 0.3 mm long; styles 1.9-2.1 mm long. 
Capsules 7.8-11.8 mm long, 2-2.8 mm wide, curved; seeds tuberculate, 0.8-1 mm in 
diameter. 

Species of the high (2,100 to 4,400 m) pine and juniper forests on many of the 
volcanoes of Guatemala and adjacent Mexico. It is also sometimes found in open 
upland meadows. In Costa Rica, only a single collection has been made (Burger 
and Gomez P. 8216), and it probably represents a disjunct population. This col- 
lection was made at 3,250 to 3,450 m altitude on Cerro Chirripo along the upper 
Rio Talari, Prov. San Jose. In the main part of its range, this species has been 
collected in flowering condition in January, February, and July through October. 
It probably flowers to some degree throughout the year. 



BURGER: FLORA COSTARICENSIS 233 

Cerastium guatemalense is distinguished by its more or less erect habit and its 
open inflorescences of relatively (compared to C. triviale and particularly to C. 
glomeratum) large flowers. It is the only native species of Cerastium ever collected 
in Costa Rica. 

Cerastium triviale Link, Enum. Hort. Berol. 1:433. 1821. C. vulgatumL. (nom. 
ambig.), Sp. PI., ed. 2, 627. 1762. C. caespitosum Gilibert (nom. ambig.), Fl. 
Lithuan. 2:159. 1781. C. holosteoides Fries (nom. ambig.), Novit., ed. 2, 126. 1823. 
C. fontanum subsp. triviale (Link) Jalas, Arch. Soc. Zool. Bot. Fenn. "Vanamo" 
18:63. 1963. 

Weakly perennial plants, much branched, mostly basally, often caespitose, branches 
10-25 cm long, decumbent, often long-pilose, internodes longest just below the in- 
florescence, shorter below. Leaves usually similar throughout, basal rosette lacking; lami- 
nae ovate to spatulate, 7-30 mm long, 3-10 mm wide, acute, sometimes obtuse, pilose. 
Cymes usually quite dense, few to many flowered, bracts with scarious margins, pedicels 
short, 2.2-8.4 mm long, long-pilose. Sepals lanceolate, 4.3-6.2 mm long, 1-1.6 mm wide, 
scarious margined, acute, pilose, petals slightly shorter to slightly longer than the sepals, 
bifid ca. Va of their length, white; filaments 3.7-4 mm long, anthers 0.3 mm long; styles 
1.8-2.2 mm long. Capsules 7-11.6 mm long, 2.1-3 mm wide, curved; seeds 0.5-0.7 mm 
in diameter, red-brown, tuberculate. 

An introduced upland species (in our area 1,400 to 2,400 m) of varied habitats 
including fields, roadsides, brushy thickets, woody areas, and even cloud forest. 
Native to Europe, this species is found in North America throughout most of the 
United States and southern Canada, in central Mexico and in Central America 
from southern Mexico (Chiapas) south to Chiriqui Province, Panama. In Costa 
Rica it has been collected virtually throughout the year from the provinces of 
Alajuela, Cartago, and San Jose. 

Cerastium triviale is recognized by its prostrate habit, its fairly broad leaves, its 
scarious margined bracts, and its inflorescences of crowded, fairly small (though 
larger than in C. glomeratum) flowers. The choice to use the name C. triviale in 
this work instead of C. fontanum subsp. triviale is arbitrary. Sound judgment on 
the best taxonomic level for this taxon would require study of European material. 

DIANTHUS Linnaeus 

Herbs, biennial or perennial, stems often stiff and erect, nodes usually thickened, 
glabrous or glaucous (rarely puberulent); stipules absent. Leaves opposite and narrow, 
sessile, leaf bases of opposing leaves connate and forming a short scarious sheath, laminae 
entire or serrulate. Inflorescences terminal and often showy, capitate, cymose or pan- 
iculate or the flowers solitary, flowers subtended by 1-3 opposing pairs of bracts. Flowers 
radially symmetrical, bisexual, sepals united to form a calyx tube, 5-toothed at the apex of 
the tube, with multiple parallel veins; petals 5 or more, usually narrowed at the base to 
form a petiole-like structure (clawed), the distal blade of the petal entire to dentate or 
fringed, lacking appendages at the base, white to rose, red or purple; stamens 10, free; 
ovary superior and unilocular, narrowed at the base or stipitate, styles 2, free. Fruit a 
capsule, cylindric to oblong or ovoid, dehiscent by 4 (5) valves or teeth; seeds numerous, 
usually flattened and with an oval outline, attached on 1 of the flat faces, smooth to 
rugose. 

A genus of between 200 and 300 species native to the Old World. The four 
species mentioned here are the most showy and popular of the species that may 
be found in cultivation in the tropics. Each of these four species represents one 
of a total of nine horticultural classes listed in Bailey's Manual of Cultivated 
Plants. Bailey's manual lists more than 30 species and varieties grown in gardens 



234 FIELDIANA: BOTANY 

throughout the world; they generally grow best only at higher elevations in the 
tropics. This genus is distinguished from our other ornamental genera by the 
presence of one to three pairs of appressed bracts at the base of the calyx tube. 

la Flowers crowded into dense round-topped or flat-topped heads, bracts linear and 
usually as long as the calyx (sepal tube) D. barbatus 

Ib Flowers in loose cymes with 2 to many flowers (note that individual flowers with 
multiple petals in D. caryophyllus may appear similar to heads, but each one is enclosed 
in a single calyx tube), bracts shorter than the calyx tube 2a 

2a Bracts Vi-% the length of the calyx, caudate at the apex; leaves narrow-elliptic to 
oblanceolate D. chinensis 

2b Bracts Vt- l /3 the length of the calyx, acuminate at the apex; leaves linear 3a 

3a Leaf margins and bract margins minutely serrulate to subentire or ciliate, leaves 
mostly in a basal tuft and with few stem leaves; flowers not double (with 5 
petals) D. plumarius 

3b Leaf margins and bract margins entire and glabrous, with prominent stem leaves; 
flowers usually double (10 or more petals); an important species in cut-flower 
commerce D. caryophyllus 

Dianthus barbatus L., Sp. PI. 409. 1753. 

Perennial herbs, glabrous, stems erect, 20-60 cm tall. Leaves with lanceolate to elliptic 
laminae, 3.5-8 cm long, 0.5-1.5 cm wide, apically acute, the margins usually minutely 
(0.1-0.5 mm) serrulate (appearing almost ciliate). Inflorescence a dense terminal cyme that 
often appears capitate, floral bracts linear to filiform, usually equalling the calyx in length; 
flowers numerous within the cyme and sessile, calyx deeply toothed, the teeth long- 
acuminate, distal lamina of the petals dentate or crenate, red, purple, pink, white or 
variegated, corolla not usually more than 3 cm broad, rarely double. 

Dianthus barbatus is a native of southern. Europe and is representative of the 
horticultural group called "Sweet Williams" and Clavel Imperial. They are charac- 
terized by having small flowers in bracteate heads. As with the other species 
mentioned here, many variants and hybrids with other species are found in 
cultivation. 

Dianthus caryophyllus L., Sp. PI. 410. 1753. 

Glabrous and glaucous herbs, the stems erect and stiff, few branched, with conspicuous 
nodes, to 1 m tall. Basal leaves 5-15 cm long, linear and stiff, the margins entire or 
minutely serrulate near the base, leaves of the stem becoming smaller distally. In- 
florescence cymose, few flowered, floral bracts ca. V* as long as the calyx, abruptly acute, 
pedicels subtending the flowers and their involucre of bracts to 3 cm long; calyx 2-3 cm 
long, calyx teeth acute, petals usually double (10), rose, purple, or white, corolla 2-9 cm 
broad and showy, very fragrant. 

Dianthus caryophyllus is native to southern Europe. The "Carnation" (Clavel) is 
perhaps the most popular of all the species of Dianthus, cultivated for its showy 
and fragrant flowers. The distinctive odor is similar to cloves (Clavero; Syzygium 
aromaticum) and cinnamon (Canela; Cinnamomum zeylanicum). In Costa Rica it is 
cultivated at the middle and higher altitudes, and it is a very important element 
in the ornamental cut-flower trade (see discussion in the Flora of Guatemala, 
Fieldiana, Bot. 24, pt. 4:226-227, 1946). 

Dianthus chinensis L., Sp. PI. 411. 1753. 

Herbs, short-lived perennials, glabrous or nearly so, the stems erect. Basal leaves cadu- 
cous, stem leaves 2-8 cm long, 0.5-1 cm wide, narrowly elliptic to oblanceolate, acute at 



BURGER: FLORA COSTARICENSIS 235 

the apex, usually minutely serrulate along the margins. Inflorescence cymose, few to many 
flowered, pedicels to 2 cm long, floral bracts ca. Vi as long as the calyx or slightly longer, 
cuspidate to caudate at the apex, often divergent; calyx 1.5-2.5 cm long, calyx teeth acute 
to acuminate, petals rarely double, variously colored, the corolla often with concentric or 
circular patterns, to 3 cm broad, odorless. 

Dianthus chinensis is a native of eastern Asia. The circular patterns of the 
broadly rotate corolla have resulted in the common name "Rainbow Pinks" for 
these plants. Because of the smaller flowers they have been called Clavellina in 
Spanish. 

Dianthus plumariusL., Sp. PI. 411. 1753. 

Glabrous or glaucous herbs, the stems caespitose, to 30 cm long. Basal leaves 2-10 cm 
long, linear, the margins minutely serrulate, stem leaves becoming smaller distally. In- 
florescence cymose and few flowered, the pedicels to 4 cm long, floral bracts V4-V3 the 
length of the calyx, relatively broad, acute to acuminate at the apex; calyx ca. 2 cm long, 
the teeth acute, petals dentate or more commonly deeply fringed, red, pink or white, the 
corolla 3-4 cm broad, fragrant. 

Dianthus plumarius is native to eastern Europe and Russia. It is representative 
of a group called the "Cottage Pinks," characterized by their fragrant flowers and 
tufted habit. 

DRYMARIA Willdenow 

REFERENCE: James A. Duke, Preliminary Revision of the Genus Drymaria, Ann. 
Missouri Bot. Card. 48:173-268, 1961. 

Herbs, annual or perennial, stems procumbent to erect, occasionally slightly woody at 
the base, glabrous or puberulent; stipules present, entire to multilacerate, caducous or 
persistent. Leaves opposite (in ours) or appearing verticellate, sessile or petiolate; laminae 
broad and flat (in ours) to linear, margin entire or rarely dentate, venation palmate to 
parallel. Inflorescences dichasial (in ours), terminal or axillary or with flowers clustered or 
solitary at the nodes; flowers bisexual, radially symmetrical, small, sepals 5, free, green 
with scarious or membranous margins, lanceolate to ovate, petals 3, 4 or 5 (rarely 0), 
normally 2-cleft (bifid) at the apex or distal half and often with small auricles at the base; 
stamens 2-5, filaments slightly connate at the base (rarely alternating with staminodes), 
the anthers versatile, 2-thecous; ovary superior and narrowed at the base, unilocular, 
placentation free central with few to many ovules, styles usually 3 (2) and united for ca. 
Vz their length. Fruit a capsule, ovoid to globose, dehiscing by as many valves as there are 
styles (usually 3-valved), thin-walled; seeds 1 to many, cochleate (in ours) to reniform- 
globose, usually with the surfaces and edges tuberculate, embryo curved. 

A genus of 48 species, according to Duke, ranging from the southern United 
States to subtropical South America and with two of these species now natural- 
ized in Asia and Africa, Australia, and the Pacific. Three species occur in Costa 
Rica in areas characterized by evergreen (or largely evergreen) vegetation and the 
genus can be found at all elevations. 

Vegetatively, the Costa Rican species of Drymaria resemble those of Stellaria, 
and the two are occasionally confused. Drymaria differs from Stellaria by having 
three-valved capsules, partly united styles, and by the presence of stipules. 
However, the stipules are often caducous or difficult to distinguish from the 
surrounding trichomes and this feature may not be helpful. Species of Stellaria 
with broad leaves are pinnately veined with a more or less distinct submarginal 
collective vein. In contrast, Drymaria has one to five parallel or palmate primary 
veins and lacks a submarginal collective vein. 



236 FIELDIANA: BOTANY 

la Flower pedicels covered in part with a minute dense gland-tipped tomentum that is 
whitish, petals often smaller than the sepals; stipules multilacerate and usually per- 
sistent; common plants from 0-1,600 m elevation D. cordata 

Ib Flower pedicels glabrous to sparsely hirsute or villous or glandular, never with a 
minute dense whitish or farinose tomentum; petals usually as large or larger than the 
sepals; uncommon or rare plants 2a 

2a Plants hirsute to glabrate; laminae rarely more than 10 mm broad, drying opaque and 
the venation obscure; stipules lacerate with filiform hairlike lobes but caducous; sepals 
2-3.5 mm long, elliptic to ovate; plants usually found from 1,000-2,000 m elevation 

D. villosa 

2b Plants glabrous to sparsely glandular hairy; laminae usually more than 10 mm broad, 
drying membranaceous and the venation easily seen; stipules with lanceolate lobes 
and persistent; sepals 3-6 mm long, 1,600-3,000 m elevation D. multiflora 

Drymaria cordata (L.) Willd. ex Roem. & Schult, Syst. Veg. 5:406. 1819. 
Holosteutn cordatum L., Sp. PI. 88. 1753. H. diandrum Sw., Prodr. 27. 1788. D. 
diandra Blume, Fl. Nederl. Ind. 62. 1825. Figure 42. 

Herbs, annual, prostrate to spreading or erect, to 70 cm long, often rooting at the nodes, 
glandular puberulent to glabrate, leafy internodes 0.5-3 cm long, ca. 0.5 mm thick (dry); 
stipules to 2 mm long, lacerate, often persisting. Leaves opposite and usually well spaced 
along the stem, petioles 2-15 mm long; laminae 5-18 (25) mm long, 5-20 (30) mm broad, 
broadly ovate to orbicular or reniform, rounded at the apex and occasionally mucronulate, 
abruptly rounded at the base and truncate to cordate, entire, usually glabrous. In- 
florescences terminal or axillary, few- to many-flowered cymes (rarely solitary axillary 
flowers), bracts 2-3 mm long, narrowly lanceolate, pedicels 2-15 mm long, slender and 
usually with a covering (at least in part) of very minute (0.1 mm) whitish glandular 
puberulence. Flowers small, sepals 5, 2.5-4 (5) mm long, lanceolate to ovate, acute, 
glandular puberulent to glabrous, lateral margins translucent, petals 5, 2-3 mm long, 
deeply bifid with linear 1-veined lobes, lacking auriculae (rarely subdentate) at the base; 
stamens 2 or 3 (4, 5), filaments 2-2.5 mm long and flattened, anthers suborbicular, 0.2-0.3 
mm long; ovary with few to many ovules, style 0.5-1 mm long, 2- or 3-parted. Capsule 
ovoid, 1.5-2.5 mm long, breaking into 3 entire valves; seeds 1 to many, 1-1.5 mm broad, 
cochleate, dark reddish brown, surface with rows of tubercles. 

Plants of open sunny or shaded (early secondary) sites in areas of evergreen 
vegetation in the Central Highlands and Caribbean side of Costa Rica from near 
sea level to 1,400 (1,600) m elevation; collected with flowers throughout the year 
in southern Central America. Our plants belong to subspecies cordata which 
ranges throughout the American tropics, from Mexico and Florida through Cen- 
tral America and the West Indies to Argentina. Subspecies diandra (Blume) Duke 
occurs in tropical Asia, Africa, Australia, and the Pacific. 

Drymaria cordata is recognized by the small opposite, often broadly cordate, 
leaves that are usually evenly spaced along the slender stems, the unusual 
puberulence producing a farinose-like whitish covering on a portion of the 
flower pedicels and the small petals. This species has not been collected from 
below 1,000 m elevation on the Pacific side of Costa Rica. 

Drymaria multiflora Brandegee, Zoe 5:232. 1906. 

Herbs, perennial, erect or ascending, to 50 cm tall, much branched (in vigorous plants), 
glabrous to stipitate-glandular (rarely sparsely villous), leafy internodes 1-10 cm long, 
0.5-1.5 mm thick (dry); stipules 1-2.5 mm long, lanceolate, entire. Leaves opposite and 
often widely spaced, petioles 2-20 mm long; laminae 4-22 mm long, 4-25 mm broad, 
broadly deltoid-ovate to orbicular or reniform, rounded to emarginate at the apex, obtuse 
to truncate at the base, entire, drying membranaceous, the 3-5 primary veins often clearly 
visible. Inflorescences terminal, cymose with 3 to many flowers, peduncles to 10 cm long, 
often stipitate-glandular. Flowers small, whitish, sepals 5, 3-6 mm long, 1.2-2 mm broad, 



BURGER: FLORA COSTARICENSIS 237 

ovate to narrowly triangular, often saccate at the base, petals 5, 2.5-7 mm long, equalling 
or exceeding the sepals, bifid for % of their length, lobes rounded, with ciliate auricles at 
the base; stamens 3-5, 2-3.5 mm long, anthers 0.3-0.5 mm long; ovary globose to ovoid, 
styles 1-2 mm long, 2- or 3-parted. Capsule 2-3.5 mm long, ovate, with 4-26 seeds; seeds 
ca. 1 mm broad, with long dorsal tubercles and substellate facial tubercles. 

Rare plants (in Costa Rica) of shaded sites in montane forest between 1,500 and 
3,000 m elevation. Flowering collections have been made from October to Febru- 
ary in Central America. The species ranges from Mexico to westernmost 
Panama. 

Drymaria villosaCham. & Schlecht., Linnaea 5:232. 1830. D. hirsuta Bartl. in 
Presl, Rel. Haenk. 2:8. 1831. 

Herbs, annual, prostrate or more often ascending, to 45 cm long, sparsely villous to 
hirsute with slender translucent hairs to 2 mm long, leafy internodes 0.5-5 cm long, ca. 
0.5 mm thick; stipules 0.5-1.5 mm long, slender and usually entire, similar to the tri- 
chomes. Leaves opposite and usually evenly spaced along the stems, petioles 1-10 mm 
long; laminae 3-15 mm long, 3-15 mm broad, orbicular to reniform or broadly ovate, 
rounded to acute at the apex, rounded at the truncate to subcordate base, entire, usually 
sparsely hirsute or villous. Inflorescences cymose, terminal or axillary, with 5 to many 
flowers (ultimate parts often racemose), peduncles 1-5 cm long, bracts 0.5-1.5 mm long, 
pedicels 2-20 mm long, slender and sparsely villous. Flowers whitish, sepals 5, 2-3.6 mm 
long, 1-2 mm broad, elliptic to broadly ovate, acute to obtuse at the apex, villous to 
glabrescent, margins translucent, petals 5 (rarely reduced or absent), 2-3.6 mm long, 
divided distally into 2 parts (bifid) for half their length or more, 4-veined, with caducous 
filiform auricles at the base, stamens usually 5, 2-3.5 mm long; ovary ovoid to globose, 
style 1-1. 5 mm long, the distal half 3-parted. Fruit an ovoid to ellipsoid capsule, 2-3. 5 mm 
long, equalling or exceeding the sepals; seeds usually many, 0.5-0.9 mm broad, cochleate, 
tuberculate with the facial tubercles stellate. 

Small weedy plants of open sunny sites in evergreen vegetation formations, 
primarily between 1,000 and 2,000 m elevation, in Costa Rica. Flowering and 
fruiting collections have been made from June through the wet season to March. 
This species is represented in our area by ssp. villosa; this subspecies ranges from 
Mexico through Central America and along the western slopes of South America 
to Peru. 

Drymaria villosa ssp. villosa is characterized by its small stature, its open dif- 
fused branches and inflorescences, pubescence of slender translucent hairs, the 
small broad subcordate opposite leaves well spaced along the stem, and the 
slender peduncles and pedicels bearing small 5-parted flowers. 



GYPSOPHILA Linnaeus 

Herbs or rarely subshrubs, annual or perennial, erect or spreading, usually much 
branched, glabrous or glaucous; stipules absent. Leaves opposite, often narrow and sessile 
or subsessile, entire. Inflorescences cymose in dichasial or paniculate arrangements (rarely 
capitate), with numerous flowers, bracts present at the base of pedicels and not at the apex 
(an epicalyx lacking). Flowers small, bisexual, radially symmetrical, calyx forming a tube 
or united only near the base and campanulate, 5-toothed and 5-veined, scarious (thin) 
between the veins, petals 5, exceeding the sepals, white to rose, usually narrowed at the 
base (with a claw) and the expanded blade entire to emarginate, lacking appendages near 
the juncture of claw and blade; stamens 10; ovary 1-locular and with many ovules, styles 
2 (3), free. Fruit a capsule, ovoid to globose, dehiscing by 4 (6) valves or teeth, sessile; seeds 
with flattened faces, subreniform, black and tuberculate. 

A genus of about 125 species native to Europe and Asia, with outlying species 
in Egypt and Australia. One species is commonly cultivated in Central America, 



238 FIELDIANA: BOTANY 

while a second species (G. paniculata L.), growing to 1 m tall and with a stout 
rhizome, may also be found. Both are called "Baby's Breath/' Gipsofila, or L/o- 
visna. The open panicle of small long-pedicelled flowers give a diffuse misty 
effect, both in gardens and in flower arrangements. The inflorescences are some- 
times sprayed with paint for more colorful effects. 

Gypsophila elegans Bieb., Fl. Taur. Cauc. 1:319. 1801. 

Annual herbs, stems erect, to 60 cm tall, much branched distally, glabrous. Leaves 
sessile, 2-7 cm long, 0.2-1 cm broad, linear-lanceolate to lanceolate, leaf bases clasping the 
stem and the opposing leaf bases slightly connate or free. Inflorescences cymose, open and 
much branched and with many flowers, pedicels 1-3 cm long, slender or filiform. Flowers 
small, calyx 4-5 mm long, calyx tube half the length and campanulate, weakly 5-veined, 
calyx lobes acute and with thin margins, petals 2-4 x the length of the calyx, white to red, 
emarginate; stamens 4-5 mm long; ovary ca. 2 mm long, ovoid, styles ca. 3 mm long, 
filiform. Capsule 3.5-5 mm long, ovoid; seeds 1-1.5 mm broad, tuberculate. 

Gypsophila elegans, a native of the Caucasus mountain region, Turkey and Iran, 
is locally naturalized in Guatemala and commonly grown in gradens. This spe- 
cies is important in the cut-flower trade for its many-branched diffuse in- 
florescences for which the name Llovisna is so appropriate. 

LYCHNIS Linnaeus 

Herbs, annual or perennial, stems erect; lacking stipules. Leaves opposite. In- 
florescences cymose, often lax and few flowered or capitate and many flowered. Flowers 
usually bisexual, radially symmetrical, without an epicalyx, calyx united to form an ovoid 
to obovoid tube, 10-veined, petals 5, with a proximal narrow claw and distal blade, entire 
to bifid, emarginate or lacerate at the apex, usually with adaxial appendages at the junction 
of claw and blade; stamens 10, filaments united only at the base; pistil short-stipitate, 
ovary incompletely 5-locular at the base and 1-locular near the apex, with many ovules, 
styles usually 5, free. Fruit a capsule dehiscing by 5 teeth (less often 10), borne on a short 
stalk; seeds circular to reniform, surface minutely tuberculate. 

A genus of about 35 species of north temperate and arctic areas. One species 
is likely to be found at higher elevations in tropical American gardens. 

Lychnis coronaria (L.) Desr., Lam. Encyc. 3:643. 1792. Agrostema coronariaL., 
Sp. PI. 436. 1753. 

Herbs perennial, erect to 1 m tall, all parts densely white-tomentose (woolly). Basal 
leaves spatulate and petiolate, 5-18 cm long, stem leaves sessile and smaller, narrowly 
ovate to elliptic, acute at the apex, clasping the stem at the base. Inflorescence a compound 
dichasium of only a few flowers, pedicels 4-10 cm long, thick and white-woolly. Flowers 
showy, calyx 15-20 mm long (including the calyx teeth), teeth contorted in bud, ca. 5 mm 
long, linear, petals ca. 3 cm long, the blade usually equalling the claw, appendages 2.5-3 
mm long present at the junction of claw and blade; stamens ca. 14 mm long; styles 5, ca. 
3 mm long, free. Capsule ca. 12 mm long, borne on a stipe ca. 2 mm long, teeth spreading 
at the apex of the capsule; seeds numerous, less than 1 mm broad. 

Lychnis coronaria, the "Rose Campion" or Espanolita, is easily recognized by its 
densely white-woolly stems and leaves and its large deep rose- or purple-colored 
flowers. This species is native to southeastern Europe and generally found only 
in gardens above 1,800 m elevation in Central and South America. 

POLYCARPON Loefling ex Linnaeus 

Herbs, annual or perennial, stems diffuse or dichotomously branching, usually less than 
30 cm long, internodes with minute longitudinal ridges, glabrous or puberulent; stipules 



BURGER: FLORA COSTARICENSIS 239 

present and scarious. Leaves opposite or whorled, laminae obovate to orbicular, entire. 
Inflorescences cymose, with few or many branches, flowers subtended by scarious bracts 
and usually pedicellate. Flowers small, bisexual, radially symmetrical, sepals 5, with 
keeled or prominent midrib and thin margins, free, petals 5, hyaline and smaller than the 
sepals, free; stamens 1-5, filaments united at the base; ovary unilocular, ovules few to 
many on a free central placenta, style short and 3-lobed. Fruit a 3-valved capsule, valves 
splitting almost to the base, becoming spirally twisted; seed ovoid to lenticular or curved, 
embryo incurved or almost straight. 

A cosmopolitan genus of temperate regions and cooler tropical highlands, 
with about 15 species. A number of species are known from southern South 
America, but the genus has not been previously recorded from Central America. 

Polycarpon tetraphyllum (L.) L., Syst. Nat. ed. 10, 2:881. 1759. Mollugo tet- 
raphylla L., Sp. PI. 1:89. 1753. 

Small herbs, annual or rarely perennial (lacking a woody rootstock), stems often much 
branched, to 20 cm long, essentially glabrous, internodes 5-15 mm long, with thin and 
minutely serrulate ridges; stipules conspicuous, 2-3 mm long, triangular, thin and trans- 
lucent, erose to cuspidate with a long slender tip. Leaves opposite or in whorls of 4, 
petioles ca. 3 mm long; laminae 0.3-1 cm long, 2-6 mm broad, narrowly obovate to 
oblong-obovate, bluntly rounded at the apex, tapering gradually to the attenuate base, 
essentially glabrous, secondary venation obscure. Inflorescence with few or many 
branches, cymose, floral bracts whitish translucent, 1-2 mm long and resembling the 
stipules. Flowers small, 2-3 mm long, sepals 1.5-2 mm long, dark green along the midvein 
and somewhat keeled, margins thin and translucent, petals smaller than the sepals, 
emarginate; stamens usually 3-5. Fruit less than 3 mm long; seeds ca. 0.5 mm long, 
semicircular or slightly lunate in outline, pale orange-brown. 

Weedy little plants from Europe often found on sandy or rocky soil. The first 
collection recorded for Central America was made in June 1982 on the slope of 
Volcan Irazu near Tierra Blanca, Cartago, at an elevation of 2,100 m by Jorge 
Gomez-Laurito (8630). The species is naturalized in South America and in 
Mexico. 

Polycarpon tetraphyllum is recognized by its very small stature, the two or four 
small obovate leaves at each node, the conspicuous stipules, the cymose in- 
florescences, and the small flowers with slightly "keeled" sepals. 

SAGINA Linnaeus 

REFERENCE: Garrett E. Crow, A Taxonomic Revision of Sagina (Caryophylla- 
ceae) in North America, Rhodora 80:1-91, 1978. 

Herbs, annual or perennial, stems procumbent, decumbent or ascending, sometimes 
slightly woody at the base, short in stature, stems glabrous or glandular puberulent; 
stipules absent. Leaves opposite along the stem, rosettes or tufts of basal leaves may be 
present in perennial species, without distinct petioles; laminae of the cauline leaves linear 
to subulate, simple and entire, clasping the stem at their base and connate with the 
opposing leaf base. Inflorescences of solitary flowers, terminal or in the axils of distal 
leaves; flowers bisexual, radially symmetrical, small, whitish; ebracteate; sepals 4 or 5, free, 
obtuse and with scarious margins, imbricate, petals 4 or 5 (rarely fewer or none), 
free, entire or slightly emarginate; stamens 4, 5, 8 or 10, equalling or twice as many as the 
styles, in 1 or 2 whorls, nectaries present at the base of the outer whorl, filaments free, 
anthers dehiscing longitudinally and extrorse; ovary superior and unilocular, placentation 
free central with numerous ovules, styles the same number as the sepals and alternate 
with them, united at the base, becoming recurved. Fruit a many-seeded capsule breaking 
into 4 or 5 valves, the valves opposite the sepals and thin- walled; seeds usually 0.3-0.5 mm 
broad, reniform to triangular or subglobose, surface smooth to papillate or tuberculate. 



240 FIELDIANA: BOTANY 

A genus of 15 species, chiefly of the cold temperate zone of the Northern 
Hemisphere; centers of diversity are Europe and eastern Asia. Our species is a 
Eurasian introduction which has become established at higher elevations in 
Mexico, Guatemala, and Costa Rica. 

Sagina procumbens L., Sp. PI. 128. 1753. Figure 41. 

Herbs, perennial, usually procumbent and very small (less than 10 cm tall), much 
branched from the base, stems to 15 cm long, glabrous throughout. Leaves of the stems 
opposite and sessile, basal leaves 4-15 mm long, distal leaves 2.5-7 mm long, less than 1 
mm broad (dry), linear and entire, apiculate to aristate at the tip, united at the base to form 
a short (0.5 mm) scarious sheath. Flowers borne on slender pedicels (3) 5-10 (13) mm long, 
perianth usually 4-parted, sepals 4 (5), elliptic to orbicular, 1.5-2.5 mm long, ca. 1 mm 
wide, margins white, petals usually 4, 0.7-1.4 mm long, often half as long as the sepals, 
orbicular to obovate or elliptic; stamens 4 (8), filaments 1-1.5 mm long, anthers 0.3 mm 
long; ovary 1-2 mm long, styles ca. 0.6 mm long. Fruit 2-3 mm long, enclosed by the 
persisting sepals which open out as the capsule dehisces; seeds brown, reniform to 
obliquely triangular, with a distinct dorsal groove, ca. 0.4 mm broad, smooth. 

A weedy species of open, often gravelly or sandy, sites, flowering throughout 
the year in Central America at altitudes from 1,100 to 3,700 m elevation. This 
species is a native of Eurasia and has only been found around the eastern edge 
of the Meseta Central in Costa Rica and along the Interamerican Highway. 

Sagina procumbens is recognized by its very small habit and its little linear 
opposite leaves forming a sheath at their base, the solitary pedicellate flowers 
with sepals larger than the petals and the small capsular fruit with minute 
somewhat triangular seeds. 

SAPONARIA Linnaeus 

Herbs, annual or perennial, the stems erect or spreading; stipules absent. Leaves op- 
posite, simple and entire. Inflorescence cymose, loosely flowered to capitate. Flowers 
bisexual, radially symmetrical, lacking an epicalyx, calyx united to form a tube with 5 teeth 
at the apex, many veined but the veins often obscure, petals 5, longer than the calyx, the 
base narrowed into a claw, the expanded distal blade of the petal entire or emarginate, 
appendages usually present on the base of the blade above the claw (adaxial surface); 
stamens 10, united at the base to form a short tube around the stipe; pistil borne on a short 
stipe, ovary 1-locular, many ovulate on a free-central placenta, styles usually 2 (3), free. 
Fruit a capsule opening only at the apex with 4 (6) short teeth, ovoid to oblong, smooth; 
seeds reniform and tuberculate. 

A genus of about 30 species of Europe and adjacent Asia, but most numerous 
in the Mediterranean area. The following species is occasionally cultivated in the 
highland tropics and is widely naturalized in north temperate North America. 

Saponaria officinalisL., Sp. PI. 408. 1753. 

Perennial herbs, stems erect and stout but little branched, glabrous, nodes thickened 
and with an interpetiolar line formed by the connate opposing leaf bases. Leaves sessile 
or subsessile, laminae 5-9 cm long, 1-2.5 cm wide, ovate lanceolate to elliptic, acute at the 
apex, attenuate at the base and clasping the stem, entire, with 3 distinct primary veins 
impressed above. Inflorescences of opposing few-flowered dichasia clustered toward the 
ends of the branches, pedicels 1-3 mm long, their subtending bracts often leaflike. Flowers 
showy, calyx 15-25 mm long, tubular, calyx teeth ca. 5 mm long and with a mucronate (1 
mm) tip, petal claw 20-27 mm long, petal blade 10-15 mm long, emarginate and white to 
pale rose, 2 linear appendages ca. 1 mm long at the base of the blade above the claw; 
stamens 10, exceeding the petal claws in length; ovary to 15 mm long and 2 mm thick, 
styles 2, ca. 15 mm long, filiform. Capsule narrowly ovoid to ellipsoid, to 20 mm long and 



BURGER: FLORA COSTARICENSIS 241 

8 mm thick, dehiscing by 4 teeth ca. 0.5 mm long and becoming recurved, the calyx tube 
persistent and enclosing the fruit; seeds to 2 mm broad, reniform, surface with concentric 
rows of tubercles. 

Saponaria officinalisis a native of Europe and may be found in gardens at higher 
elevations in Central America. Both the Latin name and the English name 
"Soapwort" are derived from the fact that the leaves give a lather when rubbed 
with water. 

SCLERANTHUS Linnaeus 

Herbs, annual, biennial or perennial, procumbent to erect, usually densely branched, 
glabrous or minutely puberulent; stipules absent. Leaves opposite, clasping the stem at 
their base and with the opposing leaf bases often united to form a short sheath, laminae 
entire and narrow, small. Inflorescences dense terminal or axillary cymose clusters (in 
ours) or solitary flowers in leaf axils; flowers bisexual (often self-fertilizing), radially sym- 
metrical, very small, sepals 5 (4), borne on the apex of an urceolate hypanthium (some- 
times interpreted as a calyx tube with free distal lobes), petals absent; stamens 1-10, borne 
on the hypanthium (perigynous) just below the sepals, filaments free; ovary superior but 
tightly enclosed within the hypanthium, unilocular with usually 1 (2) basal ovule, styles 
2, separate. Fruit a 1-seeded utricle enclosed by the hardened hypanthium and persisting 
sepals; seed lenticular and smooth. 

A genus of perhaps 10 species native to Europe, Asia, South Africa, Australia, 
New Guinea, and New Zealand. The small size of the plants and crowding of 
flowers and axillary branches with condensed internodes produce a character- 
istic appearance similar to that of Spergula arvensis. 

Scleranthus annuusL., Sp. PI. 406. 1753. Figure 41. 

Herbs, annual, decumbent or ascending to 20 cm tall, much branched, leafy internodes 
0-30 mm long, sparsely puberulent. Leaves sessile and clasping the leaf at their base; 
laminae 3-10 (20) mm long, linear or subulate, the sheathing leaf base united with the 
opposing leaf base to form a very short sheath, entire, glabrous on the surfaces but the 
basal margins ciliate, venation obscure. Inflorescence a compact few-flowered cymose 
cluster exceeded by the leaflike bracts, flowers subsessile; sepals 5, 1.2-2.5 mm long, 
lanceolate with a thick midrib, borne at the apex of the urceolate or deeply cup-shaped 
hypanthium, the hypanthium ca. 1.5 mm long, glabrous, with 10 indistinct ribs; stamens 
ca. 0.5 mm long; ovary ca. 0.9 mm long and 0.5 mm thick, styles 2, ca. 0.7 mm long, linear. 
Fruit enclosed within the hardened hypanthium, 3-5 mm long (including the sepals), the 
persisting sepals erect to slightly incurved, ca. 1-2 mm long; seeds 0.7-1 mm long, 
ellipsoid to ovoid, pale yellowish, with a small projection at the apex and shallow vertical 
depressions on each of the 2 slightly flattened faces. 

Small weedy plants of open sites; collected by Brenes in June 1906 from along 
the Rio Reventado at 1,500 m and more recently on the slopes of Volcan Irazu at 
about 2,400 m, both in the province of Cartago. This species is native to north- 
western Europe and is now established in North America from Mexico to Can- 
ada and in the mountains of Ecuador. 

Scleranthus annuus is recognized by its small stature, narrow little leaves ex- 
panded and united across the stems at their base, flowers and fruit in dense little 
clusters, and the urceolate hypanthium with five distal sepals tightly enclosing 
the fruit. 

SILENE Linnaeus 

Herbs or small shrubs, glabrous to puberulent; stipules absent. Leaves opposite or 
whorled, sessile or petiolate, the sheathing bases connate or free, usually entire and 



242 FIELDIANA: BOTANY 

pinnately veined. Inflorescences cymes, racemes, dichasia or the flowers solitary, pedicels 
bracteate only at the base (an epicalyx absent). Flowers bisexual, radially symmetrical, 
calyx tubular with (5) 10-30 veins, ovoid to turbinate or campanulate in form, 5-toothed 
at the apex, petals 5, narrowed at the base to form a distinct claw and usually with 
appendages at the junction of claw and blade, the blade entire or more commonly lobed 
or toothed; stamens 10, usually borne at the apex of the androgynophore, filaments 
sometimes united at the base; pistil borne on the androgynophore, ovary 3-locular at the 
base but 1-locular above, with many ovules on a free-central placenta, styles 3 (rarely 4 or 
5). Fruit a capsule dehiscent only at the apex with 6 (3, 8, 10) short teeth, borne on a 
carpophore, calyx persisting in fruit and slightly inflated but little enlarged and often 
splitting; seeds reniform to subcircular, slightly flattened on 2 faces, minutely tuberculate. 

A genus of nearly 400 species, nearly all from the Old World. Both species 
included here are natives of Europe. They are distinguished by the lack of an 
epicalyx, three styles, and calyx tube with 10 or more veins. 

la Plants glabrous; grown in gardens for the showy flowers S. armeria 

Ib Plants densely pubescent; weeds of higher elevations S. gallica 



Silene armeria L., Sp. PI. 420. 1753. 

Erect, annual, mostly glabrous herbs to 70 cm. Leaves 4-8 cm long, 1-2.5 cm wide, 
sessile, lanceolate to ovate, apically acute to acuminate, clasping at the base and sometimes 
slightly connate. Inflorescence a crowded compound dichasium, many flowered; pedicels 
1-4 mm long (to 20 mm for the terminal flower), ebracteate; calyx 1.4-1.6 cm long, clavate 
at anthesis, becoming abruptly expanded in its distal half by the expanding stipitate fruit, 
10-nerved, 5-toothed, the teeth rounded; petals 5, blades entire or emarginate, the 2 
appendages ca. 2 mm long, linear, the blades pink to purple, the corolla ca. 15 mm in 
diameter. 

This species is called Llovizna and Espanola in Central America; the English 
common name is "Sweet William Catchfly." The glaucous and glabrous leaves 
are distinctive. 



Silene gallica L., Sp. PI. 417. 1753. S. anglica L., loc. cit. 416. 

Herbs, annual, erect or spreading, 15-50 cm tall, villous-puberulent throughout and 
glandular-pubescent on the distal portions of the plant, leafy internodes (3) 4-9 cm long, 
with short scurfy to longer translucent and crooked hairs (0.3-2.5 mm). Leaves sessile or 
short (0-5 mm) petiolate, the lower laminae 3-5 (7) cm long, spatulate, rounded at the apex 
and often mucronate, tapering to the connate base, upper laminae smaller and narrower 
with acute apices. Inflorescence a terminal 1-sided raceme, rachis glandular-pubescent, 
upper pedicels very short (0.5-5 mm), pedicels subtended by a pair of linear leaflike bracts 
8-20 mm long. Flowers with calyx tubes 7-10 mm long, becoming 5 mm in diameter in 
fruit, with 10 veins, calyx teeth ca. 2 mm long, linear, villous with crooked hairs to 3 mm 
long; petals bifid or toothed at the apex, entire below, white to pale purple, exceeding the 
calyx by ca. 1 mm, basal appendages oblong, ca. 1 mm long. Fruit a capsule 6-9 mm long, 
ovoid, dehiscent by 6 teeth, the teeth short (1 mm), acute, recurved; seeds ca. 1 mm broad, 
cochleate with rows of tubercles. 

This species is a native of southern and central Europe now widely naturalized 
in the New World. It is a plant of open weedy sites and cultivated fields in 
Central America. In Costa Rica it is found between 1,600 and 2,400 m around the 
Meseta Central; it flowers in the wet season between April and November. 

Silene gallica can be distinguished from our other members of the family by the 
viscid glandular hairs on distal parts, the one-sided inflorescence, the tubular 
calyx, and the capsule opening only at the apex with six small teeth. 



BURGER: FLORA COSTARICENSIS 243 

SPERGULA Linnaeus 

Herbs, annual, usually much branched from the base, the stems decumbent to as- 
cending, mostly glandular pubescent, rarely glabrous; stipules present and small. Leaves 
opposite or appearing verticellate by crowding of leafy axillary branches with condensed 
internodes, simple and entire, sessile or subsessile, linear or subulate. Inflorescences 
dichasial and terminal, small bracts present and subtending the slender pedicels; flowers 
bisexual, radially symmetrical, small, sepals 5, free and imbricate, petals 5, free, margins 
entire, white; stamens 5-10, filaments arising from a hypogynous ridge, free, anthers 
dehiscing longitudinally; ovary 1-locular, placentation basal with many ovules, styles 5, 
alternate with the sepals, free to the base. Fruit a capsule dehiscing by 5 valves, loosely 
enclosed within the persisting sepals, valves thin walled; seeds lenticular to subglobose, 
suborbicular in outline, with an acute or winged circumferential margin, surface often 
papillose. 

A genus of four species native to Europe and Asia; one species has become 
widely naturalized in the New World. The verticellate appearance of leaves at 
most all the nodes (because of the condensed axillary shoots) is very distinctive. 
Spergula arvensis is somewhat similar in appearance and habit to Polycarpaea 
corymbosa (L.) Lam. which is known to range from South America into southern 
Panama. However, the inflorescences of P. corymbosa are congested, and the 
cochleate seeds lack the thin winglike margin and minutely papillose surface 
found in Spergula. 

Spergula arvensis L., Sp. PI. 440. 1753. Figure 41. 

Erect to spreading much-branched herbs to 40 cm tall, stems and foliage glabrous below 
but often becoming glandular-viscid on the upper portions, internodes 1.5-6 cm long; 
stipules 0.8-1.5 mm long, triangular, acute to obtuse, scarious. Leaves congested at the 
nodes in verticellate-like clusters, sessile; laminae 1-3.5 cm long, 0.3-0.8 mm broad (dry), 
linear to subulate, entire, minutely puberulent with thin whitish hairs ca. 0.2 mm long. 
Inflorescences a compound dichasium with the terminal portions becoming racemose, to 
20 cm long, lax, 10- to 30-flowered, pedicels 1-1.5 cm long, slender, usually glandular- 
viscid; flowers ca. 3 mm long (dry), sepals 2.5-3.5 mm long, persistent in fruit and 
becoming 4 mm long, ovate, acute to obtuse, usually viscid, the margins thin; petals 2-3.5 
mm long, as long or slightly shorter than the sepals, entire, often persistent in fruit; 
stamens usually 10, 1-1.5 mm long; ovary ca. 2.5 mm long, subglobose, styles 5, ca. 0.5 
mm long, curved. Fruit a capsule 3.5-5 mm long, as long as or slightly exceeding the 
sepals, ovoid; seeds ca. 1 mm broad and 0.7 mm thick, subglobose, with a narrow whitish 
circumferential ridge, the broad surfaces brown to black and usually covered with minute 
yellowish clavate papillae. 

A native of Europe but now widely naturalized in North America and in the 
higher elevations of Guatemala and western Panama. Collections by Jorge 
Gomez-Laurito near Tierra Blanca, and by Robert Wilbur along the Carretera 
Interamericana, all in the province of Cartago, are the first recorded from Costa 
Rica. This species is a weed of open fields and also grows in sandy areas along 
rivers and streams, between 1,400 and 3,200 m elevation in Central America. The 
majority of Central American collections have been made in January and 
February, but the Costa Rican collections were made in June, July, and 
December. 



STELLARIA Linnaeus 

Herbs, annual or perennial, generally with slender procumbent or clambering, repent or 
ascending (occasionally pendent) stems, puberulent or glabrous; stipules absent. Leaves 



244 FIELDIANA: BOTANY 

opposite, sessile or petiolate, often clasping the stem at their base, laminae entire, broad 
or narrow, venation usually pinnate and with a slender submarginal vein. Inflorescences 
of distal dichasial cymes subtended by reduced sessile leaves (bracts) or the flowers solitary 
in axils of distal leaves, a progression of basal petiolate leaves to smaller sessile distal bracts 
often present on flowering stems, flowers usually subtended by slender pedicels. Flowers 
bisexual, radially symmetrical, small, sepals 4 or 5, free to the base, imbricate, petals as 
many as the sepals (rarely absent), 2-cleft (bifid and often giving the appearance of 8 or 10 
petals), white, lacking basal appendages; stamens 10 or fewer, free, staminodes absent; 
ovary superior and unilocular with basal, central or free central placentation, ovules few 
to many, styles 2 or 3 (rarely 4 or 5), free. Fruit a capsule, globose, ovoid, or oblong, 
dehiscing by as many or twice as many valves as there are styles, valves thin walled; seeds 
(1) few to many, cochleate to reniform or globose, usually reddish brown, the surface 
smooth to rugose, muricate, papillate, or tuberculate. 

A genus of about 100 species, most abundant in the cooler parts of both the 
northern and southern temperate zones and usually at higher elevations in the 
tropics. These plants can be mistaken for species of Cerastium or Drymaria, but 
our species of Stellaria can be distinguished by the presence of a slender sub- 
marginal collecting vein which unites the secondary veins near the edge of the 
leaf and runs parallel with the margin in the distal half of the lamina (but this 
is not always easy to see). 

la Laminae lanceolate to oblanceolate, to 8 mm long, drying stiff; stems conspicuously 
4-ridged, ridge continuous with the midvein of the leaf; internodes to 15 mm long; 
rare endemics of the eastern volcanoes; 1,600-2,600 m elevation S. nubigena 

Ib Laminae lanceolate to ovate, cordate or triangular, to 5 mm long, drying thin and 
membranous; internodes usually becoming more than 2 cm long, rarely with 4 longi- 
tudinal ridges 2a 

2a Sepals and petals 4, sepals to 2.5 mm long, inflorescence a compound dichasium; 
stems with ridges that are continuous with midveins of the leaves; leaves often 
broadly cordate; 1,500-3,300 m S. irazuensis 

2b Sepals and petals 5; stems usually terete and lacking ridges extending into the mid- 
vein 3a 

3a Inflorescence a compound dichasium; sepals and petals 2-3.5 mm long; leaves trun- 
cate to subcordate; mostly between 600 and 2,000 m elevation S. prostrata 

3b Flowers solitary in the axils of leaves or of large leaflike bracts 4a 

4a Sepals 2.5-4 mm long, petals to 4.5 mm long; petioles 0-5 mm long, laminae truncate 
to obtuse at the base; 50-1,800 (2,300) m S. ovata 

4b Sepals 4-6 mm long, petals 7-13 mm long; petioles 4-25 mm long, laminae subcordate 
to cordate at the base; (1,800) 2,400-3,200 m S. cuspidata 

Stellaria cuspidata Willd. ex Schlecht., Mag. Ges. Naturf. Freund. Berlin 
7:196. 1916. S. ciliataVahl ex Pers., Syn. 1:503. 1805, not Gilib., 1781. S. limitanea 
Standl., Publ. Field Mus. Nat. Hist., Hot. Ser. 22:74. 1940. 

Herbs, annual (perhaps perennials), much branched, stems procumbent to ascending, 
clambering and pendent, growing over other plants to 2 m high, internodes of the main 
stems to 14 cm long, mostly glabrous and becoming pale yellowish, internodes of the 
axillary shoots mostly 1-2 cm long, often villous, 0.5-1.5 mm thick (dry). Leaves opposite, 
sheathing bases of opposing leaves slightly connate, petioles 4-12 (25) mm long (in ours); 
laminae 5-16 (22) mm long, 3-14 (18) mm wide, deltoid to narrowly triangular, acute to 
acuminate at the apex and with a mucronate tip, abruptly truncate to cordate at the base 
and the basal lobes slightly unequal, margins entire, drying membranaceous to char- 
taceous, villous to glabrous, secondary veins usually obscure, the submarginal vein ca. 0.3 
mm from the edge. Flowers usually solitary and axillary, often with 1 or 2 flowers at distal 
nodes, pedicels (10) 20-40 mm long, sparsely to densely villous; sepals 5, 4-6 mm long, 
1.5-2.5 mm broad, narrowly ovate to elliptic, sparsely to densely villous, the margins 
membranous or scarious, expanding somewhat in fruit, petals deeply bilobed for over half 
their length (and often appearing as 10 petals), 7-13 mm long, white; stamens 4.5-7 mm 



BURGER: FLORA COSTARICENSIS 245 

long; ovary 2-2.5 mm long, cylindrical, styles usually 3, 2-3 mm long. Capsule 6-11 mm 
long, ovoid to ellipsoid; seeds ca. 1 mm broad, cochleate splitting into 3 valves, valves 
deeply bifid; seeds ca. 1.1 mm broad, cochleate, the tubercles rounded, reddish brown. 

Plants of high montane forest formations from (1,800) 2,400 to 3,200 m ele- 
vation (to 4,000 m in Guatemala). Central American flowering and fruiting 
collections have been made primarily from December through March (no col- 
lections have been seen from April and May). This species, whose name and 
circumscription are uncertain, ranges from the southernmost United States and 
Mexico through Central America to Colombia and Ecuador. 

Stellaria cuspidatais recognized by its long scrambling stems, relatively narrow, 
cordate to triangular, leaves, and relatively large flowers borne singly in the axils 
of leaves (or large leaflike bracts). The species is sometimes confused with speci- 
mens of S. prostrata, with usually broader leaves, smaller flowers, and from lower 
elevations; compare that species. 

It is difficult to see why these plants were placed under the European S. 
nemorum L. Plants of S. nemorum have thicker erect stems usually branched only 
in the distal inflorescence, basal leaves twice as large and with winged petioles, 
and the flowers are usually borne on distal inflorescence-like stems with greatly 
reduced leaves (i.e., bracts). Our use of the name S. cuspidata is consistent with 
its usage in the Flora of Guatemala. However, a photo said to be type material 
from Ecuador looks rather different from typical Mexican and Central American 
material placed here. The Ecuadorean specimen has larger leaves on longer 
petioles, and the flowers are on long pedicels, but the sepals appear to be the 
same as in our material. A type photograph of S. cilia ta Vahl and collections from 
northern South America placed under S. ciliata are very similar to our material; 
we follow the treatment in the Flora of Peru by considering all of these as 
variants of the same species. 

Stellaria irazuensis Donnell Smith, Bot. Gaz. 23:236. 1897. 

Herbs, perennial, prostrate or spreading, usually much branched, leafy internodes 1-10 
cm long, 0.4-2 mm thick, glabrous, becoming pale yellowish when dry. Leaves opposite, 
usually evenly spaced along the stems, petioles 6-25 mm long, sparsely villous with 
slender crooked translucent hairs ca. 1 mm long; laminae 10-20 (40) mm long, 7-15 (25) 
mm broad, deltoid to triangular or ovate, acuminate to abruptly attentuate at the apex, 
rounded at the truncate to cordate base, margin entire, laminae drying membranaceous 
and light green, sparsely villous, with 2 or 3 pairs of major secondary veins and a slender 
submarginal vein running parallel with the edge of the lamina ca. 0.5 mm from the margin. 
Inflorescences to 25 cm long, terminal or appearing to be axillary, of open dichotomously 
branching cymes, a pair of bracts at each dichotomy with the basal pair of bracts leaflike 
and sessile and the successive bracts becoming smaller, primary peduncle 4-15 cm long, 
each succeeding peduncle becoming shorter by l /3- l /2, pedicels sparsely to densely 
glandular-villous. Flowers 4-parted, sepals 1.2-2.5 mm long, 0.5-1 mm broad, elliptic, 
acute to obtuse, glabrous; petals 4, 2-4 mm long, deeply cleft, the lobes 1.5-3.5 mm long, 
white; stamens 4-8, ca. 1.5 mm long, ovules 3-6 on basal placentae. Capsule ellipsoid, 
1.5-2.5 mm long, subtended by the persisting sepals and petals, dehiscing by 4 valves; 
seeds 1-1.3 mm broad, cochleate, dark reddish brown, with a tuberculate surface. 

Plants of wet evergreen montane formations between 1,500 and 2,800 m ele- 
vation (to 3,300 m in Guatemala). Flowering collections have been made primar- 
ily between June and January, with a few collections made in February and 
March. This species ranges from Chiapas, Mexico, to Guatemala, Nicaragua, 
Costa Rica, and the westernmost highlands of Panama (we have seen no col- 
lections from El Salvador or Honduras). 



246 FIELDIANA: BOTANY 

Stellaria irazuensis is distinguished by its very small four-parted flowers, the 
open inflorescences with long peduncles and widely spaced cymes, and the 
deltoid to cordate leaves that dry thin and translucent green. This species is 
apparently a close relative of S. venezuelana Steyerm. 

Stellaria nubigena Standley, J. Wash. Acad. Sci. 17:250. 1927. 

Herbs, perennial, much branched and often forming clumps or mats, stems to 15 cm 
long, leafy internodes 5-15 mm long, glabrous, sharply 4-angled (in cross section), drying 
pale yellowish. Leaves opposite, decussate and sessile, clasping the stem at their base and 
the bases of opposing leaves arising close together; laminae 4-8 mm long, 1-2.5 mm wide, 
lanceolate to oblanceolate, apex acute and with a calloused tip, margin entire, blades thick, 
stiff, drying yellow to yellow-green, distally glabrous and villous near the base, midvein 
continuous with the ridges of the stem, secondary veins inconspicuous, submarginal veins 
obscure. Inflorescence few-flowered cymes or the flowers solitary, peduncles 2.5-5 mm 
long and subtended by a pair of scarious bracts 1.5-2 mm long, pedicels 4-10 mm long, 
glabrous, subtended by a pair of scarious bracts 1-1.5 mm long. Flowers 5-parted, sepals 
ca. 2 mm long at anthesis (up to 3 mm in fruit), lanceolate, glabrous, green with a scarious 
margin, petals 5, shorter than the sepals (ca. 1 mm at anthesis to 2 mm in fruit), 2-cleft 
nearly to the base, white; stamens apparently 8, unequal, the largest to 1 mm long; ovary 
ovoid, ca. 1 mm long, styles 3, 0.7-0.9 mm long. Capsule ca. 3 mm long, ovoid, splitting 
into 6 valves; seeds ca. 0.7 mm broad, cochleate-reniform, tuberculate, reddish brown. 

Stellaria nubigena is endemic to Costa Rica and known only from collections by 
Paul Standley on Volcan Turrialba (35344, the type, US) and on the slope of 
Volcan Irazu near Las Nubes, San Jose (numbers 38736, 38784, and 38829) 
collected in February and March of 1924 between 1,600 and 2,600 m elevation. 
This species is easily distinguished from our other species of Stellaria by its stiff 
little sessile lanceolate leaves, short internodes,- and four-angled stems. 

Stellaria ovata Willd. ex Schlecht., Mag. Ges. Naturf. Freund. Berlin 7:196. 
1816. Figure 42. 

Herbs, perennial, prostrate or spreading to 60 cm long, much branched from the base, 
leafy internodes 0.4-6 cm long, 0.5-1.5 mm thick, glabrous to densely hirtellous, the 
trichomes thin and translucent, to 1 mm long, stems green to pale yellowish when dry, 
and longitudinally ridged. Leaves opposite and usually evenly spaced along the stem, 
petioles 0-5 mm long, with lateral margins continuous with the lamina margins; laminae 
5-25 (30) mm long, 7-14 mm wide, ovate to triangular, acute to obtuse at the apex and 
with a minute (0.7 mm) mucronate tip, attenuate at the base and decurrent on the winged 
petiole, drying yellowish or greenish, hirtellous, with 2-4 pairs of major secondary veins, 
submarginal vein 0.2-0.4 mm from the margin and often obscure. Flowers solitary in the 
axils of leaves, borne on long (6-25 mm) slender (0.3 mm) ebracteate hirtellous pedicels 
(rarely glabrous); sepals 5, 2.5-4 mm long, ovate to obovate, apically acute to obtuse, often 
hirtellous, petals 5, 3.5-4.5 mm long, bilobed, lobes to 1 mm long, white; stamens 10, ca. 
3 mm long; ovary ovoid 2.5-3.5 mm long, with numerous ovules on a basal placenta, styles 
3. Capsule 3-4 mm long, ovoid; seeds 1 mm broad, subreniform to subcircular in outline, 
dull reddish brown, with rows of prominent tubercles to 0.2 mm high. 

Plants of moist or shaded areas in regions of evergreen vegetation formations 
between 50 and 1,800 (2,300) m elevation, having been collected on the Carib- 
bean slopes and lowlands, the Central Highlands, the General Valley, and the 
Golfo Dulce area in Costa Rica. Flowering collections have been made through- 
out the year. The species ranges from Mexico southward through Central Amer- 
ica to Venezuela and Peru. 

Stellaria ovata is distinguished from other species of the genus by its combina- 
tion of nearly sessile ovate leaves, solitary axillary flowers, and lower elevation 
habitat. 



BURGER: FLORA COSTARICENSIS 247 

Stellaria prostrata Baldwin, in Elliott, Bot. South Carol. & Georgia 1:518. 1821. 

Herbs, annual or perennial, stems procumbent to subscandent, to 60 cm long, leafy 
internodes 1-7 (12) cm long, 0.5-3 mm thick, minutely puberulent to villous with tri- 
chomes to 0.5 mm long. Leaves opposite and usually evenly spaced on the stems, petioles 
10-25 mm long, with lateral wings, glabrous to sparsely villous along the margins of the 
wing; laminae 5-30 (40) mm long, 5-20 (35) mm broad, ovate to deltoid, acute to acuminate 
at the apex, truncate to subcordate at the base, slightly decurrent on the petiole, drying 
membranaceous and pale green, glabrous or sparsely villous along the entire margins, 
with 2-4 pairs of major secondary veins, submarginal vein difficult to see. Inflorescences 
dichasial, lax, with few to many flowers, moderately to densely villous or villous-glandular 
with hairs 0.1-0.5 mm long, bracts subtending the inflorescence 6-20 mm long and 
petiolate (leaflike), each succeeding pair of bracts becoming smaller, often villous. Flowers 
5-parted, sepals 2-3.5 mm long (becoming 4.5 mm long in fruit), ovate to elliptic- 
lanceolate, glabrous to villous-glandular, petals 5, 2-3.5 mm long, deeply lobed, the lobes 
1.3-2.5 mm long, white; stamens 1.5-2 mm long; ovary ca. 1.5 mm long, styles 3 or 4, ca. 
1 mm long. Capsule 4-5.5 mm long, ellipsoid to ovoid, splitting into 6 valves, the valves 
thin walled and strongly revolute at the tip; seeds 0.7-1 mm broad, cochleate-reniform, 
with rows of minute cylindrical capitate tubercles, reddish brown. 

Plants of moist and shaded sites in areas of evergreen vegetation formations 
between 600 and 2,000 m elevation in Costa Rica (to 4,000 m elevation in Gua- 
temala); flowering and fruiting throughout the year, but with most collections 
made from December through March. The species ranges from the southern 
United States (Texas to Georgia and Florida) through Mexico and Central Amer- 
ica to Colombia. 

Stellaria prostrata is very similar to S. irazuensism vegetative characteristics, but 
it is distinguished from that species by its larger five-parted flowers and capsule 
valves revolute at the tip. It has been confused with certain forms of what is here 
called S. cuspidata and can be distinguished from that species by the capitate 
tubercles on the seeds, the sepals usually less than 4 mm long (at anthesis), the 
petals usually equal to the sepals in length, and the strongly revolute capsule 
valves. These differences appear to be consistent with ecological differences: S. 
prostrata is most commonly found between 1,200 and 1,800 m elevation (extremes 
of 700 to 2,000 m), while S. cuspidata is usually found between 2,500 and 3,200 
m (extremes of 1,900 to 4,000 m) in northern Central America. (Specimens 
identified as S. prostrata by Standley and Steyermark from over 2,000 m elevation 
in Guatemala are sterile.) See the discussion under S. cuspidata. 



INDEX 

The index includes all accepted names (in roman typeface), synonyms (italics ), 
common English names (roman) and vernacular names (italics). Page numbers 
of illustrations are in boldface. Hyphenated words and multiple words are 
alphabetized letter by letter. 



Abanico 162 
Acelga 139 
Acetosella 132 
Achyranthes 144 

altissima 165 

aspera 144, 146 

bettzickiana 148 

brasiliana 148 

calea 173 

costaricensis 151 

indica 145, 146 

laguroides 151 

lehmannii 153 

megaphylla 151 

panamensis 153 

prostrata 167 

stenophylla 153 

williamsii 154 
Adorno de nino 176 
Aethanthus nodosus 47 
Agdestis clematoides 203 
Agonandra 15, 28 

brasiliensis 29 

macrocarpa 15, 28 

obtusifolia 29 

racemosa 29 
Agrostema coronaria 238 
Aguacatia 11 

Aizoaceae 213, 223, 225, 226 
Algodoncillo 174 
Allionia 180 

violaceae 192 
Alternanthera 145, 149, 152 

bettzichiana 148, 149 

bettzickiana 148 

brasiliana 148 

caracasana 149, 150 

costaricensis 151, 152 

ficoidea 153, 156 

laguroides 151, 152 

lanceolata 153 

lehmannii 153 



Alternanthera panamensis 153 

paronychioides 149, 153 

polygonoides 154 

pubiflora 152, 154 

repens 150 

sessilis 155 

stenophylla 153 

tenella 149, 155 

williamsii 154 
Amaranthaceae 142-180, 146, 149, 152, 

158, 163, 171, 223 
Amaranthus 156, 158 

caudatus 159 

cruentus 158, 159 

dubius 157, 158 

hybridus 157, 158 
subsp. cruentus 159 

hypochondriaceus 157 

scariosus 158, 159 

spinosus 158, 160 

tristis 157 

viridis 158, 161 
Amor seco 162 
Andripetalum suaveolens 11 
Anredera vesicaria 222 
Antidaphne 32, 37 

viscoides 32, 37 
Antigonon 100, 104 

cordatum 106 

grandiflorum 101 

guatemalense 101, 104 

leptopus 104, 106 

macrocarpum 101 
Ant-plant 137, 138 
Apinagia 3 

myriophylla 6 
Apodantheae 90 
Apodanthes 37, 90 

caseariae 37, 91 

flacourtiae 91 

panamensis 91 

tribracteata 91 



248 



BURGER: FLORA COSTARICENSIS 



249 



Arenaria 225, 226, 229 

alsinoides 229 

guatemalensis 229 

lanuginosa 225, 226, 229 
ssp. guatemalensis 226, 229-231 

lanuginosum ssp. saxosa 229, 230 

nemorosa 229 

quirosii 231 

saxosa 229 
Aristolochia 79, 80, 81, 82 

anguicida 81, 82 

bicolor 84 

bilabiata 82 

chapmaniana 85 

constricta 80, 83 

costaricensis 85 
var. zamorensis 85 

gigantea 81, 83 

grandiflora 81 

linearifolia 82 

littoralis 84 

loriflora 82 

maxima 80, 84 

odoratissima 81, 84 

pandurata 84 

pilosa 81, 85 

ringens 85 

schmidtiana 86 

securidata 83 

sylvicola 83 

tonduzii 80, 85 

translucida 80, 86 

trilobata 81, 86 

veraguensis 80, 87 
Aristolochiaceae 79, 80, 81 



Baby's Breath 238 
Balanophoraceae 93, 94, 95 
Banksia 8 
Basella alba 222 
Basellaceae 222, 224 
Batchelor's button 169 
Bdallophyton 90, 91, 92 

americanum 91, 92 

andreuxii 91 

bambusarum 91 

cerantantherum 91 

oxylepis 91 
Beets 139 
Bejuco de ajo 203 
Bellisima 106 
Beta 139 

vulgaris 139 
Bilderdykia 104, 106 

aubertii 104, 106 
Black Man wood 24 
Blandowia myriophylla 6 
Bledo 156 
Boerhavia 181 



Boerhavia coccinea 183, 187 

diffusa 183, 188 

erecta 183, 188 

paniculata 188 
Bogambilla 189 
Boldoa 199 

ovatifolia 199 

purpurascens 199 
Boria 162 
Bougainvillea 182, 189 

buttiana 189 

glabra 190 

spectabilis 189 
Boussingaultia 222, 224 

ramosa 222, 224 
Brandesia lanceolata 153 

pubiflora 154 
Bugambilla 189 
Buguenvitia 189 



Calandrina megarhiza 218 

Caldasia cayennensis 97 

Calalu 206 

Callite 138 

Campderia floribunda 120 

mexicana 120 
Camron 176 
Canilla de Mula 138 
Caraxeron 177 

vermicularis 177 
Carnation 234 

Caryophyllaceae 225, 226, 227 
Caryophyllales (families 63-70) 138-247 
Casearia 91 
Celosia 161, 163 

argenta 162, 163 

var. cristate 162 

paniculata 165, 175 

pleiogyna 178 

virgata 162, 163 

Centrospermae (families 63-70) 138-247 
Centrostachys aspera 144 

indica 145 
Cephalotomandra 180 

fragrans 180 

panamensis 180 
Cerastium 226, 231 

caespitosum 233 

fontanum ssp. trivale 233 

glomeratum 232 

guatemalense 226, 232 

holosteoides 233 

trivale 233 

viscosum 232 

vulgatum 233 
Chamissoa 163, 164 

acuminata 165 

altissima 163, 165 

macrocarpa 165 



250 



FIELDIANA: BOTANY 



Chard 139 
Chaunochiton 16, 18 

kappleri 16, 18 
Chenopodiaceae 138, 202 
Chenopodiales (families 63-70) 138-247 
Chenopodium 140, 202 

album 140 

ambrosioides 141, 202 

anthelminticum 141 

quinoa 140 
Chile de perm 129 
Chivito 174 
Chivo 174 
Cladocolea 35, 38 

oligantha 35, 39 
Clavel 234 
Clavel Imperial 234 
Clavellina 235 
Clauellina mantes 215 
Claytonia paniculata 221 
Coccoloba 107, 108, 109, 110, 111 

acapulcensis 109, 113 

acuminata 110, 114 

allenii 116 

belizensis 111, 114 

browniana 113 

caracasana 108, 115 

cardiophylla 113 

changuinolana 116 

floribunda 120 

guanacastensis 111, 116 

hirsuta 114 

lehmannii 110, 116 

molinae 120 

obovata 109, 117 

padiformis 111, 119 

riparia 117 

roseiflora 118 

standleyana 115 

tuerckheimii 109, 118-119 

uvifera 108, 119 

venosa 110, 120 

wercklei 113 

williamsii 116 
Colacion 106 
Colchbn de nino 148 
Comenternero 174 
Commicarpus 180 
Confite 106 
Confitillo 106 
Conopholis 93 
Coqueta 148 
Cordia alliodora 75 
Corynaea 95, 96 

crassa 95, 96 

sphaerica 95, 97 
Cottage Pinks 235 
Coyontura 174 
Coyontura de polios 176 
Cresta de gallo 162 
Cricamola 24 



Crillo 24 

Cyathula 146, 166 

achyranthoides 146, 166 
prostrata 146, 167 

Cynomorium cayennense 97 

Cytineae 90 

Cytinus americanum 91 



Danto hediondo 13 
Dendrophthora 60, 61 

ambigua 61, 64 

biserrula 65 

costaricensis 61, 64 
subsp. poasensis 64 

geniculata 65 

squamigera 61, 65 

terminalis 61, 66 
Desmochaeta achyranthoides 166 
Dianthus 233 

barbatus 234 

caryophyllus 234 

chinensis 234 

plumarius 235 
Dioscorea 82 

calyculata 222 
Drymaria 226, 235 

cordata 226, 236 

diandra 236 

hirsuta 237 

multiflora 236 

villosa 237 

ssp. villosa 237 
Dufourea hypnoides 7 

trifaria 7 



Eremolepidaceae 31, 37 
Eriogonum 99 
Escambron 124 
Escambron negro 124 
Espanola 242 
Espaholita 238 
Espinaca 141, 142, 213 
Eubrachion 31 



Fallopia aubertii 107 
Flor de corona 174 
Flor de mano 162 
Flor de San Miguel 106 
Flor de Verano 189 
Flares de palo 50 
Flowering stones 213 
Four-o'clock 192 



Gaiadendron 34, 39 

poasense 39 

punctatum 34, 39 
Gateador 121 



BURGER: FLORA COSTARICENSIS 



251 



Gipsofila 238 
Glinus 213, 226 

radiatus 214, 226 
Golondrina 154 
Gomphrena 168 

brasiliana 148 

decumbens 169 

disperse 169 

elegans 168 

ficoidea 153 

filaginoides 168 

globosa 168 

latifolia 173 

paniculata var. hookeriana 176 

serrata 149, 169 

sessile 155 

tuerckheimii 168 

vermicularis 177 
Grain amaranths 156, 157-159 
Grevillea 9, 10 

banksii 9 

robusta 9, 10 
Guapira 184, 190 

costaricana 184, 190 

linearibracteata 190 

standleyanum 190 
Gypsophila 237 

elegans 238 

paniculata 238 

Hebanthe hookerianus 176 
Heisteria 17, 18 

acuminata 18, 19, 20 

acuta 23 

cocinnea 20 

concinna 18, 20 

costaricensis 18, 20 

cyanocarpa 18, 21 

eurycarpa 22 

fatoensis 22 

kappleri 16 

latifolia 22 

longipes 21 

macrophylla 18, 22 

scandens 18, 22 
Helosis 94, 95, 97 

cayennensis 94, 95, 97, 98 
var. cayennensis 98 
var. mexicana 97, 98 

guyanensis 97 

mexicana 97, 98 
Hierba de gato 176 
Hilleria 203 

subcordata 203 
Holosteum cordatum 236 

diandrum 236 

Homalocladum platydadum 121 
Hongo 98 
Hormigo 138 
Howardia costaricensis 85 

hoffmanni 84 



Hydnora 87 
Hydnoraceae 87, 88 



Inmortal 169 

Insect-plant mutualism 138 

Iresine 170, 171 

acicullaris 176 

angustifolia 171, 172 

argenta 173 

arrecta 171, 172 

calea 171, 173 

celosia 175 

celosoioides 175 

costaricensis 171, 174 

diffusa 171, 175 

elatior 172 

frutescence 176 

grandiflora 176 

hassleriana 175 

latifolia 173 

paniculata 175 

spiculigera 176 



Jaboncillo 206 

Jamesbondia costaricensis 151 

Lads schiedeanum 6 

foeniculacea 4 
Langsdorffia 94, 98 

hypogaea 94, 99 
Lechugon 134 
Lengua de caballo 134 
Lengua de vaca 134 
Lewisia 218 

megarhiza 218 
Llovizna 238, 242 
Lora malodora 13 
Loranthaceae (sensu lato) 29,. 30, 33, 

34- 37, 57-63 

Loranthaceae (sensu stricto) 33, 34- 37 
Loranthus aduncus 45 

alveolatus 41 

amplexicaulis 41 

angustifolius 69 

calyculatus 47 

cansjeraefolius 56 

chordocladus 55 

leptostachyus 52 

marginatus 53 

nodosus 47 

occidentalis 42 

oerstedii 54 

orbicular is 55 

paniculatus 45 

piperoides 75 

punctatus 39 

pyrifolius 44 

auadrangularis 75 

auercicola 56 



252 



FIELDIANA: BOTANY 



Loranthus ramiflorus 48 

retroflexus 45 

schiedeanus 49 

spicatus 43 

theobromae 45 
Lustrosa 189 
Lychnis 238 

coronaria 238 



Manglillo 17 
Mono de lebn 162 
Manto de Jesus 189 
Mann 24 
Marathrum 2, 3 

allenii 5 

cheiriferum 4, 5 

flexuosum 6 

foeniculaceum 4 

indifferens 5 

leptophyllum 5 

minutiflorum 5 
forma allenii 5 
forma diversifolium 5 
forma indifferens 5 
forma intermedium 5 

oxycarpum 5 

pusillum 5 

schiedeanum 2, 6 

tenue 2, 6 

utile 2, 7 
Maravilla 192 

Medicinal uses 82, 134, 140-141 
Melanocarpum sprucei 179 
Mesembryanthemum 213 
Microtea 200, 204 

debilis 200, 204 
Minquartia 15, 23 

guianensis 15, 23 
Mirabilis 182, 191 

jalapa 182, 192 

violaceae 182, 192 
Mitrastemma 93 
Mitrastemon 90, 93 

matudai 93 
Mitrostemonaceae 93 
Mollugo 214, 225 

radiata 214 

tetraphylla 239 

verticellata 215, 225 
Mono 162 
Mono de reina 162 
Monte negro 148 
Mosotillo 145 
Mozote 145 
Muehlenbeckia 104, 121 

platyclada 121 

tamnifolia 104, 122 

volcanica 123 
Mulato 138 



Napoleon 189 

Neea 185, 186, 193 
acuminatissima 195 
amplifolia 186, 194, 195 
belizensis 195 
delicatula 185, 196 
elegans 186, 194, 195 
latevirens 185, 195, 1% 
orosiana 194 
pittieri 186, 195 
popenoei 185, 195, 196 
psychotrioides 185, 195, 1% 
pycnantha 195 
urophylla 194 
xanthina 195 

Negro 24 

Neolacis myriophylla 6 

New Zealand Spinach 213 

Nispero 24 

Notanthera 29 

Nyctaginaceae 180, 182-186 



Olacaceae 14, 15, 18 
Opiliaceae 15, 27 
Oreobroma megarhiza 218 

mexicanum 218 
Oryctanthus 33, 37, 40, 41 

alreolatus 37, 41 

botryostachys 41 

cordifolius 37, 42 

florulentus 43 

guatemalensis 43 

occidentalis 37, 42 

spicatus 37, 43 
Oxybaphus 191 

violaceus 192 



Palo de papa 11 
Panopsis 9, 10 

costaricensis 11 

suaveolens 10, 11 
Papa 11 

Papaturro 112, 120, 121 
Papaturro Blanco 116 
Papaturro de Playa 121 
Papaturro Negro Macho 121 
Papaturro Rastero 121 
Pasacarne 3 
Perico 148 

Peristethium leptostachyum 52 
Petiveria 202, 205 

alliacea 202, 205 
Pfaffia 152, 176 

grandiflora 152, 176 

hooker iana 176 

forma glabriuscula 176 
Philoxerus 177 

vermicularis 177 



BURGER: FLORA COSTARICENSIS 



253 



Phoradendron 61, 62, 63, 66, 67 

acinacifolium 63, 68 

a/feni'i 64 

angustifolium 69 

annulatum 62, 69 

auriculatum 72 

biolleyi 75 

ceibanum 75 

conzattii 70 

cooperi 77 

corynarthron 61, 70, 76 
var. seibertii 75 

crassifolium 63, 71 
var. pittieri 71 

crispum 64 

davidsoniae 70 

dichotomum 62, 71 

dipterum 62, 72 

dodge/ 76, 77 

ensifolium 69 

falcifolium 76 

flavens 63, 73 

flavescens 64 

gracilispicum 78 

herrerense 75 

mucronatum 73 

navae-helvetiae 77 

obliquum 63, 74, 77 

paquitanum 75 

pergranulatum 76 

piperoides 63, 75 

quadrangulare 61, 75 

auinquenervium 73 

rensonii 75 

robaloense 68 

robustissimum 63, 76 

seibertii 75 

sonarum 75 

sp. aff. undulatum 62 

sauamigerum 65 

supravenulosum 73 

tonduzii 62, 77 

undulatum 62, 78 

venezuelense 75 

woodsonii 73 
Phrygilanthus 33 

panamensis 55 
Phthirusa 33, 35, 44 

adunca 45 

paniculata 45 

pittieri 52 

pyrifolia 35, 44 

retroflexa 35, 45 
Phytolacca 201, 206 

costaricensis 208 

icosandra 201, 207 

meziana 206 

octandra 206 

purpurascens 206 

rivinoides 201, 206, 207 

rugosa 201, 208 



Phytolaccaceae 199, 200-202, 203 
Pilostyles 90, 93 

covillei 93 

globosa 93 

thurberi 93 
Pisonia 184, 1% 

aculeata 184, 197 

var. macranthocarpa 197 

fasciculata 197 

grandifolia 197 

macranthocarpa 197 

sylvatica 184, 198 
Pleuropetalum 163, 178 

calospermum 179 

costaricensis 179 

pleiogynum 163, 178 

sprucei 163, 179 

standleyi 178 

tucurriquense 179 
Podopterus 105, 123 

mexicanus 105, 123 
Podostemaceae 1 
Polycarpaea corymbosa 243 
Polycarpon 238 

tetraphyllum 239 

Polygonaceae 99, 102-105, 108-111 
Polygonum 102, 124 

acuminatum 102, 125 

aubertii 106, 107 

aviculare 126 

baldschuanicum 106 

grandiflorum 101 

guatemalense 125 

hispidum 102, 126 

hydropiper 129 

hydropiperoides 102, 127 

meisnerianum 102, 128 

mexicanum 129 

pennsylvanicum 130 

persicaria 128 

persicarioides 128 

platycladum 121 

punctatum 102, 128, 129 

segetum 102, 129 

tamnifolium 122 

uvifera 119 

volcanicum 123 
Pomonce 189 
Pompilla 189 
Portulaca 218, 225 

coronata 220 

denudata 220 

grandiflora 219 

lanceolata 220 

marginata2l9 

oleracea 219, 223 

paniculata 221 

patens 221 

pilosa 220, 225 
plano-operculata 220 

portulacastrum 215 



254 



FIELDIANA: BOTANY 



Portulaca umbraticola 220 
Portulacaceae 217, 223-225 
Primavera 189 
Prosopanche 87, 88 

americana 89 

costaricensis 88, 89 
Protea 8 
Proteaceae 8 
Psittacanthus 34, 46 

allenii 48 

calyculatus 34, 47 

chrismarii 47 

dilatatus 48, 49 

lateriflorus 48 

mayanus 47 

nodosus 34, 47 

ramiflorus 34, 48 

scheryi 34, 48 

schiedeanus 34, 49 
Purselane 220 



Rabo de Chanco 145 
Rabo de gato 162 
Rafflesiaceae 89, 90, 92 
Rainbow Pinks 235 
Remolacha 139 

Rhaptostylum acuminatum 19 
Rheum 130 

rhabarbarum 130 

rhaponticum 130 
Rhubarb 130 
Ribbon Bush 122 
Rivina 200, 208 

humilis 200, 209 

octandra 211 

polyandra 212 
Rosas de pah 50 
Rose Campion 238 
Roupala 10, 11 

borealis 13 

complicata 13 

glaberrima 10, 12 

loranthoides 10, 13 

montana 10, 13 
var. dentata 14 

panamensis 13 
Ruibarbillo 132 
Ruibarbo 130 
Rumex 103, 131 

acetosella 103, 132 

costaricensis 103, 132 

crispus 103, 133 

peruanus 133 

tolimensis 133 
Ruprechtia 105, 134-135 

costata 105, 135 

cumingii 136 

deamii 135 

kellermanii 135 

nepalensis 103, 134 



Ruprechtia obtusifolius 103, 134 
pringlei 136 



Sagina 225, 239 

procumbens 225, 240 
Salpianthus 183, 198 

purpurascens 183, 199 
San Andres 106 
San Diego 169 
San Miguel 106 
Santalaceae 14 

Santalales (families 56-58) 14-79 
Santa Rita 189 
Saponaria 240 

officinalis 240 
Schoepfia 15, 24 

americana 25 

arborescens 25 

obliquifolia 26 

schreberi 15, 25 

species A 15, 26 

vacciniiflora 15, 25 
Scleranthus 225, 241 

annuus 225, 241 
Sea Grape 120 
Sempre Lustrosa 189 
Sesuvium 215, 223 

portulacastrum 215, 223 

scandens 210 
Siempreviva 169 
Siete pellejos 174, 176 
Silene 241 

anglica 242 

armeria 242 

gallica 242 
Soapwort 241 
Solitaria 122 
Spergula 225, 243 

arvensis 225, 243 
Spergulastrum lanuginosum 229 
Spinacea oleracea 142 
Spinach 141, 142 

Spinach-like vegetables 217, 220-222 
Spinacia 141 
Stegnosperma 202, 210 

cubense 202, 210 

scandens 210 
Stellaria 226, 243 

ciliata 244, 245 

cuspidata 245 

irazuensis 245 

limitanea 244 

nemorum 245 

nubigena 246 

ovata 226, 246 

prostrata 247 

venezuelana 246 
Struthanthus 35, 36, 50 

aff. dichotrianthus 57 

belizensis 55 



BURGER: FLORA COSTARICENSIS 



255 



Struthanthus cansjeraefolius 56 

chordocladus 55 

costaricensis 36, 52 

guatemalensis 43 

leptostachyus 35, 42 

macrostachyus 58 

marginatus 36, 53, 57 

oerstedii 36, 54 

oliganthus 39 

orbicularis 36, 55 

panamensis 33, 35, 55 

papillosus 57 

polystachyus 52 

quercicola 36, 56, 57 

retroflexus 45 

rotundatus 36, 57 

woodsonii 35, 58 
Sweet William 234 
Sweet William Catchfly 242 



Trichilia scandens 210 
Trichostigma 200, 211 

octandrum 200, 211 

polyandrum 200, 211 
Trinitaria 189 
Triplaris 108, 136 

cumingiana 137, 138 

macombii 137 

melaenodendron 105, 137 
Tristicha 2, 7 

hypnoides 7 
Tsu-Kra 27 
Turi-Svan-Kra 138 



Ullucus tuberosa 222 
Una de Tigre 198 
Uva 120 
Uva de Playa 120 



Tabaco 138 
Tabaco de Monte 138 
Tabacon 127, 138 
Taba de gueguecho 176 
Tacuquelite 174 
Talinum 221, 224 

paniculatum 221, 224 

patens 221 

triangulate 221, 222 
Tandonia ramosa 222 
Tapeworm Plant 122 
Telanthera bettzichiana 148 
Tenia 122 
Terciopelo 162 
Tetragonia expansa 213 
Thonningia 98 
Tinta 206 
Tobaquillo 127 
Torrubia 190 

costaricana 190 
Tres Marias 189 
Trianthema 216, 223 

portulacastrum 216, 223 



Vegetables 134, 141, 142, 156, 217, 220, 221 

Velasquezia melaenodendron 137 

Velo de gueguecho 176 

Velo de princesa 176 

Veranera 189 

Verdolaga 217, 220, 221 

Viscaceae 57-63 

Viscum angustifolium 69 

cordifolium 42 

crassifolium 71 

dichotomum 71 

ensifolium 69 

/toens 73 

mucronatum 73 

squamigerum 65 
Vomi'ta 203 



Ximenez, Francisco 27 
Ximenia 15, 26 
americana 15, 27 



Families of seed plants known or expected to occur in Costa Rica and adjacent ai 
numbered according to the sequence oiEngler'sSv//a6u,s der Pflanzenfamuien, edi 
11, reworked by L. Diels (1936). 



areas 
tion 



1 Cy cad no 

3 Podocarp 

iceae 

5 Pinaceae 

6 Cupressaceae 

7 Cm-: 

8 Typhaceae 

mogetonaceae 

10 Najadaceae 

11 A! 

12 Butom.i' 

13 Hydroch;u 

14 Triuridaceae 

15 Gramineae 

16 Cypenu 

ilmae 
* lanthaceae 

19 Araceae 

20 Lemnaceae 

iceae 

23 Eriocaulaceae 

24 Bromeliaceae 

25 Commelinaceae 

26 Pontederiaceae 

27 Juncaceae 

28 Liliaceae 

29 Haemodoraceae 

30 Amaryllidaceae 

.lloziaceae 

32 Dioscoreaceae 

33 Indaceae 

34 Musaceae 

35 Zingiberaceae 

36 Cannaceae 

37 Marantaceae 

38 Burmanniaceae 

39 Orchidaceae 

40 Casuarinaceae 

41 Piperaceae 

42 Chloranthaceae 

43 Lacistemaceae 

44 Salicaceae 

45 Garryaceae 

46 Myncaeeae 

47 Juglandaceae 

48 Batidaceae 

49 Betulaceae 

50 Fagaceae 

51 Ulmaceae 

52 Moraceae 

53 Urticaceae 

54 Podostemonaceae 

55 Proteaceae 

56 Olacaceae 

57 Opiliaceae 

58 Loranthaceae 

59 Aristolochiaceae 
60a Hydnoraceae 
60b Rafflesiaceae 

61 Balanophoraceae 

62 Polygonaceae 

63 Chenopodiaceae 

64 Amaranthaceae 

tagmaceae 

66 Phytolaccaceae 

67 Aizoaceae 

68 Portulacaceae 

69 Basellaceae 

70 Caryophyllaceae 

72 Ceratoph - 

73 Ranunculaceae 

74 Berberidaceae 

75 Menispermaceae 

tgnoliaceae 
\nonaceae 



82 P> 

incl t 

iceae 
iceae 
iceae 

91 Brunei!: 

92 Cunoni. 

uelidaceae 

94 Re 

95 Connaraceae 

96 I.egumn. 

97 Kramenaceae 

98 Oxalidaceae 

99 Geraniaceae 

i opaeolaceae 

101 Linaceae, 

incl. Humiriaceae 

102 Erythroxylaceae 

103 Zygophyllaceae 

104 Rutaceae 

105 Simarubaceae 

106 Burseraceae 

107 Meliaceae 

108 Malpighiaceae 

109 Trigoniaceae 

110 Vochysiaceae 

111 Polygalaceae 

112 Dichapetalaceae 

113 Euphorbiaceae 

114 Callitrichaceae 

115 Buxaceae 

116 Coriariaceae 

117 Anacardiaceae 

118 Cyrillaceae 

119 Aquifoliaceae 

120 Celastraceae 

121 Hippocrateaceae 

122 Staphyleaceae 
loacinaceae 

124 Hippocastanaceae 

125 Sapindaceae 

126 Sabiaceae 

127 Balsaminaceae 

128 Rhamnaceae 

129 Vitaceae 

130 Elaeocarpaceae 

131 Tiliaceae 

132 Malvaceae 

nmbacaceae 
't-rculiaceae 

135 Dilleniaceae 

136 Actinidiaceae 

137 Ochnaceae 

138 Caryocaraceae 

139 Marcgraviaceae 

140 Quiinaceae 

141 Theaceae 

142 Guttiferae, 

incl. Hypericaceae 

143 Elatinaceae 

i-ae 
\aceae 

146 Cochlospermaceae 
Violaceae 

149 Turner: 

150 Passifloi 

ceae 
152 Loasaceae 



154 Cactiiceae 

155 Thymelaeaceae 

156 Elaeagnaceae 

157 Lythraceae 

.ceae 

163 Melastomataceae 

164 Onagraceae 

165 Halorrhagaceae 

eae 

167 Umbelliferae 

168 Cornaceae 

169 Clethraceae 

'lotropaceae 

171 Pyrolaceae 

172 Ericaceae 

i-ophrastaceae 

174 Myrsinaceae 

175 Primulaceae 

176 Plumbaginaceae 

177 Sapotaceae 

178 Ebenaceae 

mplocaceae 

180 Styracaceae 

181 Oleaceae 

182 Lopaniaceae 

ntianaceae 

184 Apocynaceae 

. lepiadaceae 

186 Convolvulaceae 

187 Polemoniaceae 

188 Hydrophyllaceae 

189 Boraginaceae 

190 Verbenaceae 

191 Labiatae 

192 Solanaceae 

193 Scrophulariaceae 

194 Bignoniaceae 

195 Pedal iaceae 

196 Martyniaceae 

197 Orobanchaceae 

198 Gesneriaceae 

199 Lentibulariaceae 

200 Acanthaceae 

201 Plantaginaceae 

202 Rubiaceae 

203 Caprifoliaceae 

204 Valerianaceae 

205 Dipsacaceae 

206 Cucur'oitaceae 

207 Campanulaceae 

208 Compositae 



UNIVERSITY OF ILLINOIS-URBANA 




30112028176011 




Field Museum of Natural History 
Roosevelt Road at Lake Shore Drive 
Chicago, Illinois 60605-2496 
Telephone: (3 1 2) 922-9410 



UNIVERSITY OF ILLINOIS-URBANA