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Full text of "Flora Costaricensis"

UNIVERSITY OF 

ILLINOIS LIBRARY 

AT URBANA CHAMPAIGN 

BIOLOGY 

JUL 1 1 1989 






DIANA 

Botany 

Published by Field Museum of Natural History 



Volume 40 



FLORA COSTARICENSIS 



WILLIAM BURGER, Editor 



*' 






The Library of 



,78 



i\tjnois 

sM 

\ l: 



November 11, 1977 



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



200 Acanthaceae 
136 Actinidiaceae 
67 Aizoaceae 
11 Alisnaataceae 
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 
96 Caesalpiniaceae, 
see Leguminosae 
114 Callitrichaceae 
207 Campanulaceae 
36 Cannaceae 
83 Capparidaceae 
203 Caprifoliaceae 
151 Caricaceae 
138 Caryocaraceae 
70 Caryophyllaceae 
40 Caauarinaceae 
120 Celastraceae 
72 Ceratophyllaceae 
63 Chenopodiaceae 
42 Chloranthaceae 
144 Cistaceae 
169 Clethraceae 
146 Cochlospermaceae 
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 


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 Gnetaccae 
15 Gramineae 
142 Guttiferae 
29 Haemodoraceae 
165 Halorrhagaceae 
93 Hamamelidaceae 
81 Hernandiaceae 
124 Hippocastanaceae 
121 Hippocrateaceae 
101 Humiriaceae, 
see Linaceae 
13 Hydrocharitaceae 
188 Hydrophyllacea* 
142 Hypencaceae, 
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 
24 Musaceae 
46 Myricaceae 
78 Myristicaceae 
174 Myrsinaceae 


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 Pontederiaceac 
68 Portulacaceae 
9 Potamogetonaceae 
175 Primulaceae 
55 Proteaceae 
158 Punicaceae 
140 Quiinaceae 
60 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 


16 Cyperaceae 
118 Cyrillaceae 


162 Myrtaceae 
10 Najadaceae 




112 Dichapetalaceae 
136 Dilleniaceae 


65 Nyctaginaceae 
71 Nympnaeaceae 




32 Dioscoreaceae 


137 Ochnaceae 




205 Dipeacaceae 


56 Olacaceae 




88 Droseraceae 


181 Oleaceae 




178 Ebenaceae 


164 Onagraceae 




1 56 Elaeagnaceae 


57 Opiliaceae 




130 Elaocarpaceae 
143 Elatinaceae 


39 Orchidaceae 
197 Orobanchaceae 




172 Ericaceae 


98 Oxalidaceae 




23 Eriocaulaceae 


17 Palmae 





FIELDIANA: BOTANY 

A Continuation of the 
BOTANICAL SERIES 

of 
FIELD MUSEUM OF NATURAL HISTORY 



VOLUME 40 




FIELD MUSEUM OF NATURAL HISTORY 
CHICAGO, U.S.A. 
1977 



FLORA COSTARICENSIS 



FIELDIANA 
Botany 

Published by Field Museum of Natural History 



Volume 40 



FLORA COSTARICENSIS 



FAMILY #42, CHLORANTHACEAE 

FAMILY #43, LACISTEMACEAE 

FAMILY #44, SALICACEAE 

FAMILY #45, GARRYACEAE 

FAMILY #46, MYRICACEAE 

FAMILY #47, JUGLANDACEAE 

FAMILY #48, BATACEAE 

FAMILY #49, BETULACEAE 

FAMILY #50, FAG ACE AE 

FAMILY #51, ULMACEAE 

FAMILY #52, MORACEAE 

FAMILY #52a, CANNABACEAE 

FAMILY #53, URTICACEAE 



WILLIAM BURGER, Editor 

Associate Curator, Vascular Plants 
Field Museum of Natural History 



Library of Congress Catalog Card Number: 78-1 72358 

US ISSN 0015-0746 
PRINTED IN THE UNITED STATES OF AMERICA 



TABLE OF CONTENTS 

CHLORANTHACEAE by William Burger 1 

LACISTEMACEAE by William Burger 11 

SALICACEAE by Luis D. Gomez P 14 

GARRYACEAE by William Burger 18 

MYRICACEAE by William Burger 21 

JUGLANDACEAE by Donald E. Stone 28 

BATACEAE by William Burger 54 

BETULACEAE by John G. Furlow 56 

FAGACEAE by William Burger 59 

ULMACEAE by William Burger 83 

MORACEAE by William Burger 94 

CANNABACEAE by William Burger 216 

URTICACEAE by William Burger 218 

Index . . . . 285 



Flora Costaricensis 1 

CHLORANTHACEAE 

WILLIAM BURGER 

Trees, shrubs, or herbs, usually aromatic when crushed. Leaves opposite and 
simple, petioles with thin adaxial margins sheathing the stem and connate to form 
a short or long tube at first including the shoot-apex, stipule-like structures often 
present on the leaf-sheath. Inflorescences terminal or axillary, spicate, thyrse-like, 
or capitate; flowers unisexual or bisexual, with or without a perianth, stamens 
1 or 3, free or adnate to the side of the pistil, anthers free or connate, 2-thecous or 
the lateral anthers 1-thecous, dehiscing longitudinally; pistil solitary, ovary enve- 
loped by a minutely 3-lobed perianth and inferior by adnation, 1-locular, ovule soli- 
tary and pendulous from the apex of the locule, stigma 1 and sessile or on a short 
style. Fruit a small drupe or drupe-like, seed with abundant oil-containing cellular 
endosperm and a minute embryo. 

A small family of five genera and about 50 species in the tropics 
and subtropics. The family is of phylogenetic interest because it 
contains one of the very few woody angiosperm genera lacking 
vessels in the xylem, Sarcandra of Southeast Asia. Hedyosmum 
is the only genus of the family native to the Americas. The female 
flowers of Hedyosmum mexicanum have recently been studied by 
Peter Endress (Bot. Jahrb. 91:39-60. 1971), who interprets the 
ovary to be monocarpic and compares the family with woody fami- 
lies of the ranalian alliance. 

HEDYOSMUM Swartz 

Bisexual or unisexual trees or shrubs, branches articulate at the nodes and 
exuding a gelatinous aromatic exudate when cut. Leaves evergreen, petioles 
grooved above and vaginate at the base with the adaxial margins united with those 
of the opposing leaf to form a tube sheathing the stem, with or without small stipule- 
like structures on the distal margin of the sheath; laminae generally elliptic and 
serrate, the serrations often with whitish tissue forming a disc-like gland near their 
apex (probably a hydathode), venation pinnate. Inflorescences terminal or axillary, 
sometimes united with the stem near the base, the individual inflorescence uni- 
sexual but the compound inflorescences often with female flowers above and male 
flowers on lower branches; male inflorescence of one to several spikes elongating at 

'Supported in part by National Science Foundation grants GB 28446, GB 42250, 
and BMS 74-08757. 



2 FIELDIANA: BOTANY, VOLUME 40 

anthesis, the male flower without a perianth or subtending bracts, each flower repre- 
sented by a solitary stamen, filament absent or very short, connective usually pro- 
duced beyond the two thecae; female inflorescence spicate, thyrse-like, or capitate, 
female flowers subtended by bracts, the perianth tubular and 3-lobed, adnate to the 
ovary and enlarging in fruit, stigma sessile or subsessile on a very short style, 
deciduous. Fruit drupe-like with the fleshy wall formed by the accrescent perianth 
in part, ellipsoid to globose or ovoid, usually trigonous, exocarp juicy, the 3 minute 
perianth lobes often persisting and whitish at the apex of the fruit. 

A genus with probably fewer than 30 species in the Neotropics 
and with a single species in southeastern Asia. The genus is primar- 
ily South American with several species in the West Indies and only 
one species reaching Mexico. The male flowers are perhaps the most 
reduced among angiosperms, lacking bracts and perianth, and 
represented by a single, almost sessile, anther. The expanded con- 
nective, usually broad and flat above, serves to protect the repro- 
ductive parts in early stages before expansion of the spike. Except 
for Hedyosmum mexicanum, our species are here interpreted as 
having rather narrow ecological limits. I believe that our collections 
are sufficiently large to indicate that these narrow patterns of dis- 
tribution are real and not merely artifacts of inadequate sampling. 
Our species are found only in areas that are quite moist throughout 
the year. No Costa Rican species is known to grow in the flat Carib- 
bean Coastal Plain; all species here appear to require the drainage 
of hilly sites. 

la. Leaf-sheath with conspicuous distal fimbriate structures 4-12 mm. long, leaves 
glabrous and smooth; plants unisexual with the female flowers in compact 
heads, male flowers (anthers) 3X1 mm. on spikes 3-16 cm. long; at elevations 
of 1100-2800 m. (in Costa Rica) H. mexicanum. 

Ib. Leaf-sheath entire or with subulate or very short ( 1-4 mm. ) fimbriate processes 
distally ; female flowers solitary or in small groups of 2 to 4 2a. 

2a. Leaves linear-lanceolate to very narrowly elliptic, leaf-sheath entire distally, 
leaves glabrous and smooth; plants bisexual with the female flowers sessile 
and solitary, often in a cincinnus-like form, male flowers (anthers) 1 X 0.7 mm.; 
1000-1300 m. on the Pacific slope (in Costa Rica) H. brenesii. 

2b. Leaves broader, plants of the wet Caribbean slopes and the Central Highlands 
and Cordilleras 3a. 

3a. Leaves with 12 to 20 (30) secondary veins on a side, glabrous and usually 
smooth; inflorescences free of the stem above the leaf-sheath, male flowers 
(anthers) 1.5 X 0.7 mm., the plants bisexual or (?) occasionally unisexual; 
900-1600 m H. costaricense. 

3b. Leaves with 5 to 10 secondary veins on a side, often scabrous; inflorescences 
usually united with the stem to above the leaf-sheath, plants unisexual 4a. 

4a. Female flowers solitary within a subtending cupulate or open bract, male 
flowers (anthers) 1.4 X 0.5 mm.; elevations of 500-1000 m. H. calloso-serratum. 




H. scaberrimum 



FIG. 1. Chloranthaceae: Costa Rican and Panamanian species of Hedyosmum; 
note the opposite leaves with tubular sheathing leaf -bases. 



3 



4 FIELDIANA: BOTANY, VOLUME 40 

4b. Female flowers usually in groups of 2 or 3 within the subtending bracts . . . . 5a. 

5a. Plants of higher (1800-2700 m.) elevations along the Caribbean side of the 
Central Highlands and in the Cordillera de Talamanca; male flowers (anthers) 
1.7 X 0.6 mm H. montanum. 

5b. Plants of lower (0-1000 m.) elevations on the Caribbean slopes of western 
Panama; male flowers (anthers) 2.5 X 0.5 mm H. scaberrimum. 

Hedyosmum brenesii Standl., Field Mus. Bot. 18:371. 1937. 
Figure 1. 

Bisexual shrubs 1-2 m. tall, often with many branches, leafy internodes (1)2-7 cm. 
long, 1-3 mm. thick, glabrous, leaf-scars inconspicuous and narrow around the stem. 
Leaves with the free portion of the petiole absent or very short ( 1-3 mm.), margins 
of the lamina continuous with the vaginate leaf-base, tube of the leaf-sheath 4-10 
mm. long with the distal margin usually entire; laminae 7-19 cm. long, 1-2 (3) cm. 
broad, linear-lanceolate to very narrowly elliptic, broadest at or below the middle, 
gradually long-acuminate at the apex, attenuate at the base, acutely serrate along 
the margins, laminae glabrous and drying chartaceous, smooth above and below, 
the 6 to 12 pairs of secondary veins obscure above and below with only the midvein 
prominent. Inflorescences usually unisexual with the male borne at nodes directly 
below those with female inflorescences; male inflorescence usually of opposite 
pedunculate spikes borne on an unbranched common peduncle 1-3 cm. long, 
peduncles of the spikes 5-12 mm. long and subtended by a bract, the spikes 5-15 mm. 
long and about 3 mm. thick, stamens becoming 1 mm. distant on the rachis, anthers 
sessile, 0.9-1.3 mm. long and 0.5-0.7 mm. thick, connective projecting acutely for- 
ward 0.5 mm. beyond the thecae; female inflorescence of paired or solitary flowers 
often on a cincinnus-like rachis, bracts subtending the lower inflorescence-branches 
1-3 cm. long and 2-4 mm. broad, each flower subtended by a bract 1-3 mm. long, 
female flowers sessile, 2-3 mm. long, 1-2 mm. thick, stigma very short. Fruit 3-4 mm. 
long and 2-3 mm. thick, ellipsoid and trigonous, drying brown. 

This species is known in Costa Rica only from the collections of 
Alberto Brenes (3731, 4027, & 4620 the type) made between 
August and November in the area of La Palma de San Ramon, 
Alajuela Province, at altitudes of 1150 to 1250 m. The species has 
also been collected in the Province of Bocas del Toro, vicinity of 
Chiriqui Lagoon, Panama, and near Lake Yojoa, Honduras. 

Hedyosmum brenesii is easily distinguished from our other 
species of the genus by the very narrow subsessile leaves, usual 
presence of a few male inflorescences below the female, and con- 
sistently solitary female flowers. This species is closely related to H. 
nutans Sw. of the West Indies. 

Hedyosmum calloso-serratum Oersted, Vidensk. Meddel. 
Kjoebenhavn 1856:40. 1857. Figure 1. 

Unisexual shrubs or small trees 3-12 m. tall, leafy internodes 2-10 cm. long, 1.5-6 
mm. thick, essentially glabrous, leaf-scars usually absent with the leaf-base per- 
sisting and encircling the stem. Leaves with the free portion of the petiole 5-25 mm. 



BURGER: FLORA COSTARICENSIS 5 

long and 1-2 mm. thick, glabrous or with irregular short or long hairs, tube of the 
leaf-sheath 1-2.5 cm. long, usually with 2 small (1-3 mm.) aculeate or distally fim- 
briate structures on each distal margin, usually remaining entire and not tearing 
distally; laminae 7-22 cm. long, 2.5-8.5 cm. broad, narrowly elliptic to oblong or 
slightly obovate, abruptly short-acuminate, acute to obtuse at the base, finely 
serrulate along the margins, drying stiffly chartaceous to subcoriaceous, glabrous 
and slightly rough to scabrous above, scabrous and often with irregular brownish 
hairs 0.2-1 mm. long on the midvein beneath, minute (0.1 mm.) epidermal projec- 
tions sparse or inconspicuous, the 6 to 9 pairs of major secondary veins flat above 
and prominent beneath. Inflorescences usually united with the stem to above the 
leaf-sheath; male inflorescence of spikes usually borne in 2 or 3 opposite pairs on a 
short ( 1-3 cm.) axis terminated by a single spike, subsessile or terminal on bracteate 
peduncles 4-12 mm. long, the subulate bracts 5-9 mm. long, spikes expanding to 
about 3 cm. long and 4-6 mm. thick, each anther subsessile or on a slight projection 
of the rachis, 1.2-1.6 mm. long and 0.4-0.6 mm. broad, the connective produced about 
0.2 mm. beyond the thecae, flat above and acute on one side (toward the apex of the 
spike); female inflorescences thyrse-like or racemose, 3-8 cm. long, branches of the 
inflorescence originating from the stem or from a short (1-2 cm.) common rachis, 
floral bracts opposite or alternate and pedicellate or subsessile, the floral bract 
cupulate or open on one side, 2-3 mm. long and usually 3-lobed, becoming white but 
drying brown, each bract subtending and partly enclosing a single female flower 
(rarely with more than one), female flower about 2 mm. long and 1.5 mm. thick with 
perianth-lobes about 0.3 mm. long. Fruit 2-3 mm. long and 1.4-2 mm. thick, ellipsoid 
and trigonous. 

Plants of the premontane wet forest and its transition to the 
tropical wet forest formation between (0) 500 and 1000 m. elevation 
in Costa Rica. The species ranges from the area of Ciudad Quesada, 
Alajuela, along the Caribbean slope to the Rio Grande de Orosi, 
Cartago, and from the General Valley on the Pacific slope to Central 
Panama; apparently flowering throughout the year, but collected 
most often between February and August. 

Hedyosmum calloso-serratum is distinguished by the usually 
solitary female flowers and the lowland habitats above the coastal 
plain (no Costa Rican collections are known from below 500 m. 
elevation). The type collection is described as having come from 
Volcan Irazu at an elevation of 9000 ft. (2760 m. ), but I am sure that 
this is incorrect. Type material very closely matches all the other 
material placed here, and none of this material was found at alti- 
tudes above 1000 m. This species is very closely related to H. 
scaberrimum and//, montanum; see the discussion under the latter 
species. 

Hedyosmum costaricense C. E. Wood in Burger, Phytologia 
26:132. 1973. Figure 1. 



6 FIELDIANA: BOTANY, VOLUME 40 

Bisexual or (?) unisexual shrubs and small trees 3-7 m. tall, essentially glabrous, 
leaf-scars absent with the leaf-base persisting and encircling the stem. Leaves with 
the free portion of the petiole 4-15 (25) mm. long, 0.8-2 mm. thick, tube of the leaf- 
sheath 3-8 ( 12) mm. long, the distal margins entire or with 2 minute ( 1 mm.) linear 
structures on each distal margin; laminae 7-16 cm. long, 2.5-5 (6) cm. broad, very 
narrowly to broadly elliptic or oblong, abruptly acuminate, obtuse to acute at the 
base, serrulate with teeth 4-8 mm. distant on the margin, laminae drying stiffly 
chartaceous to subcoriaceous, smooth and glabrous above and below, the 12 to 20 
(30) pairs of major secondary veins flat or becoming impressed above, serrulate with 
the teeth about (4) 8 mm. distant on the margin. Inflorescences occasionally bi- 
sexual (as in the type), usually free from the stem above the leaf-sheath; male 
inflorescences usually of spikes borne in 1 to 3 opposite pairs on an axis 3-8 cm. long, 
terminated by a pair of spikes, each spike subtended by an aculeate bract about 3 
mm. long, spikes sessile or occasionally short (15 mm.) pedunculate, 6-18 mm. long, 
4-5 mm. thick, stamens becoming 2 mm. distant on the expanded rachis, anthers 
sessile, 1.3-1.8 mm. long and 0.6-1 mm. broad, connective about 0.5 mm. broad and 
flat above; female inflorescences thyrse-like, racemose, or spicate with groups of ( 1 ) 
3 to 6 female flowers in opposite pairs, sessile or on short ( 1-8 mm.) peduncles, each 
group of flowers about 4-8 mm. long and 3-6 mm. thick, each flower subtended by a 
broad bract about 2.5 mm. long and united with the other bracts only at the very 
base, female flower about 2 mm. long with perianth-lobes about 0.5 mm. long, the 
lower half of the flower enclosed within the subtending bract. Fruit 2.5-4 mm. long, 
about 2 mm. thick, thickest at or above the middle, trigonous. 

Plants of the very wet lower montane (premontane wet and pre- 
montane rain) forest formations between 900 and 1600 m. elevation 
and known only from areas of the Central Highlands subject to the 
wet Caribbean winds ( see below) ; flowering and fruiting throughout 
the year. The species is endemic to Costa Rica. 

The leaf-venation, occasional bisexual inflorescence, and floral 
details readily distinguish this species from all our other species of 
the genus. The plants are uncommon and known only from the 
following collections: Los Angeles de San Ramon (Brenes 4772, 
13127, & 13589), below Zarcero (A. Smith H566, the type) in Ala- 
juela Province, near Tapanti (Lent 990), above Platanillo ( Wilbur & 
Stone 10627) in the Province of Cartago at 1,100 m. near Balsa de 
San Ramon (Lent 3502), and 1,100 m. from Rio Hondura-Rio Casc- 
ajal (Lent 3783). In addition, two rather unusual collections are 
placed here: J. Ledn 133 from Capellades and Valeria 1348 from 
Santa Cruz de Turrialba, Cartago. These differ from the others in 
having thicker leaves with many more ( 16-30 pairs) prominent sec- 
ondary veins and the closer (4 mm.) serrations, but I believe they 
are only an unusual form of the species; they lack well-preserved 
flowers. Vegetatively, the species and especially the latter two col- 



BURGER: FLORA COSTARICENSIS 7 

lections resemble H. scabrum (R.&P.) Solms of South America and 
H. arborescens Sw. of the West Indies. 

Hedysomum mexicanum Cordemoy, Adansonia 3:307. 1862-63. 
Figure 1. 

Unisexual shrubs or small trees 2-8 (12) m. tall, the stems strongly angled, leafy 
internodes 0.5-4 cm. long, 2.5-5 mm. thick, glabrous in all stages, older stems en- 
circled by leaf-scars at each node. Leaves with the free portion of the petiole 3-10 
mm. long, 1-2 mm. thick, adaxial margins continuous with the margins of the lamina 
and leaf-sheath, tube of the leaf-sheath 1-4 cm. long, widening apically to 14 mm. 
broad, usually with 2 fimbriate stipule-like structures 4-12 mm. long on each distal 
margin, the leaf-sheath not persisting after the leaves have fallen; laminae 9-18 
(27) cm. long, 2.5-4.5 (7) cm. broad, very narrowly elliptic to very narrowly oblong, 
broadest at the middle, gradually acuminate, acute to attenuate at the base, the 
laminae slightly succulent but drying stiffly chartaceous to subcoriaceous, glabrous 
throughout, smooth on both surfaces, the 12 to 20 pairs of major secondary veins 
often prominent beneath, conspicuously serrate with the blunt teeth 4-8 mm. dis- 
tant. Male inflorescences rare in collections, made up of spikes paired or terminal 
on short leafless axillary branches 3-20 mm. long, spikes 3-8 (16) cm. long, about 
8 mm. thick, stamens crowded but becoming 2 mm. distant on the rachis, anthers 
sessile, about 3 mm. long and 1 mm. thick, connective forming a flat disc-like apex 
0.5-1 mm. broad; female inflorescence capitate, 2-4 cm. long and 12-30 mm. thick, 
the numerous female flowers densely congested and free but appearing to be united 
basally, perianth about 4 mm. long with lobes 1 mm. long, style 2-4 mm. long and 
minutely papillate-puberulent. Fruit compound of basally united drupes, the seeds 
about 3 mm. long and partly immersed in the fleshy head. 

This is an uncommon species in Costa Rica, restricted to wet mon- 
tane forests between 1100 and 2800 m. elevation and collected only 
between Volcan Barba and the western edge of the General Valley 
in the Cordillera de Talamanca. The species flowers from February 
to May in Costa Rica and from December to August in northern 
Central America, ranging from Costa Rica to southern Mexico. 

The deciduous leaf-sheath, with its conspicuous fimbriate struc- 
tures distally, capitate female inflorescences, and elongate anthers, 
distinguishes this species from other Costa Rican members of the 
genus. The female flowers of this species have been studied recently 
by Peter Endress (1971), who states that these flowers are free. 
In herbarium material the flowers usually appear to be united 
basally. 

Hedyosmum montanum W. Burger, Phytologia 26: 133-135. 1973. 
Figure 1. 

Unisexual shrubs or trees 3-10 (20) m. tall, leafy internodes 2-6 cm. long, 2-5 mm. 
thick, essentially glabrous but with a very rough surface and occasional rows of 
hairs on the leaf-sheath, leaf-scars usually absent with the leaf-base persisting and 



8 FIELDIANA: BOTANY, VOLUME 40 

encircling the stem. Leaves with the free portion of the petiole 5-14 mm. long, 1.5-2.5 
mm. thick, glabrous or with irregular hairs 0.2-1 mm. long in rows, tube of the leaf- 
sheath 1-2.8 cm. long, with 2 (several) slender, often fimbriate, stipule-like struc- 
tures 1-3 mm. long on each distal margin, the distal margin occasionally becoming 
torn in age; laminae 6.5-13 (17) cm. long, 2-5 (7) cm. broad, narrowly elliptic to 
oblong, widest near the middle, gradually or abruptly short-acuminate, obtuse to 
acute or sometimes attenuate at the base, drying stiffly chartaceous to subcor- 
iaceous, slightly scabrous or smooth above, glabrous above and often with irregular 
brownish hairs 0.2-1 mm. long on the midvein beneath, minute (0.1 mm.) epidermal 
projections obscure or prominent on both surfaces, the 5 to 8 (10) pairs of major 
secondary veins flat above and slightly raised beneath, serrulate with the teeth 
2-4 mm. distant on the margin. Inflorescences usually united with the stem to above 
the leaf-sheath; male inflorescences usually of 1 or 2 pairs of opposite spikes and a 
solitary terminal spike on a short ( 1-2 cm.) rachis, opposing spikes subsessile, the 
terminal pedunculate, subtended by subulate bracts 3-6 mm. long, the spikes be- 
coming 3-6 cm. long, 4-6 mm. thick, stamens sessile and becoming 2-3 mm. distant 
on the rachis, anthers 1.4-1.8 mm. long, 0.6-0.7 mm. thick, connective produced 
0.1-0.2 mm. beyond the thecae, flat above and often acute on one side; female 
inflorescences of racemose or spike-like branches arising from the stem or from a 
short rachis in opposing pairs and thyrse-like in form, the female flower clustered in 
small sessile or short-pedunculate groups, each group with 1 to 4 flowers (usually 3) 
and about 4 mm. long and 4 mm. thick, each flower subtended and partly enclosed 
by a bract 3-4 mm. long, the bracts variously united at the base to form a cupulate 
involucre enclosing all the flowers of the group, flower about 2 mm. long with 
perianth-lobes about 0.5 mm. long, stigma 2-3 mm. long (? apically bifurcate) and 
soon deciduous. Fruit about 2.8 mm. long and 1.8 mm. thick, ellipsoid and trigonous 
with the apical perianth-lobes persisting. 

A species of the montane rain forest most often found on slopes 
subjected to the wet Caribbean weather and collected only between 
1800 and 2700 m. elevation in Costa Rica. The species ranges south- 
ward to the upper Rio Chiriqui Viejo in Panama and may be repre- 
sented at its northernmost limits by somewhat different plants 
(not included in these descriptions) on Volcan Mombacho and the 
Island of Ometepe in west-central Nicaragua. In Costa Rica the 
species has been collected from the area of Palmira (A. Smith A337, 
4186A, & 4187) and Alto Palomo (Lent 1829) in Alajuela Province, 
on the eastern slope of Volcan Barba (A. Jimenez 2269, Burger and 
Liesner 6366, the type, & 6416) and La Carpintera (Allen 639) in 
San Jose Province, and in the Cordillera de Talamanca near Em- 
palme (Burger 7919, A. Jimenez 2758, Williams et al. 25018) and 
below Chirripo (Burger and Gomez 8370) in the provinces of Car- 
tago and San Jose. The species appears to flower throughout the 
year; collections with male inflorescences are very rare. 

Specimens placed here were previously thought to be H. calloso- 
serratum, but the latter species has solitary female flowers and is 



BURGER: FLORA COSTARICENSIS 9 

separated, in Costa Rica, from H. montanum by an altitudinal dis- 
junction of about 800 m. I beb'eve that we have enough material to 
indicate that this ecological separation is real and not an artifact 
of poor sampling. Hedyosmum montanum is also closely related to 
H. scaberrimum, which differs in anther-size and lower elevation 
habitat. The lack of intermediates between these entities and a 
very consistent correlation between their morphology and habitat 
lead me to believe that these taxa are better treated as species than 
as subspecies or varieties. The material that I have seen from 
Nicaragua and have mentioned above (Friedrichsthal 1031, Grant 
795 &811) differs slightly in morphology from material placed here 
and occurs in a rather different habitat. Hedyosmum montanum 
has not been collected in the Cordillera de Guanacaste, where one 
might expect to find intermediates (if such exist) with the 
Nicaraguan material. I suspect that when the Nicaraguan popula- 
tion is better known, it will also prove to be worthy of specific rank. 

Hedyosmum scaberrimum Standl., Field Mus. Bot. 4:200-201. 
1929. Figure 1. 

Unisexual small trees 3-7 m. tall, leafy internodes 1-7 (10) cm. long, 1.5-5 (8) mm. 
thick, the surface muricate-scabrous and often with very short (0.3 mm) irregular 
hairs, leaf scars absent, with the persisting leaf-base encircling the stem. Leaves 
with the free portion of the petiole (3) 6-12 (22) mm. long, 1.3-3 mm. thick, muricate- 
scabrous and often irregularly torn on the adaxial margins, tube of the leaf-sheath 
1-2.5 cm. long, usually with 2 small (1-3 mm.) aculeate or fimbriate structures on 
each distal margin, the sheath often tearing and very irregular distally; laminae 
9-20 cm. long, 3-8 cm. broad, narrowly elliptic to broadly oblong or slightly obovate, 
acuminate at the apex, acute to obtuse at the base, finely serrate, the lamina drying 
stiffly chartaceous to subcoriaceous, conspicuously muricate and scabrous on both 
surfaces with a very few short hairs, the epidermal projections about 0.1 mm. broad, 
the 6 to 10 pairs of major secondary veins flat above and prominent beneath. 
Inflorescences often united to the stem above the leaf-sheath; male spikes usually 
in 2 or 3 opposing pairs on a short (2-4 cm.) rachis terminated by a single spike, 
lower spikes subtended by dentate bracts 12-18 mm. long and about 4 mm. broad, 
subsessile or the terminal pedunculate, spikes about 6 mm. thick and expanding to 
6 cm. long with the stamens becoming 1-2 mm. distant on the rachis, anthers sub- 
sessile, 2.3-2.8 mm. long, 0.4-0.6 mm. thick, connective produced about 0.5 mm. 
beyond the thecae, acute; female inflorescences thyrse-like, racemose, or spicate, 
flowering branches originating from the stem or from a common rachis 2-4 cm. long, 
floral bracts opposite or alternate and sessile or short-pedunculate, the floral bract 
cupulate or open on one side, 2-3 mm. long and usually 3-lobed, each bract subtend- 
ing and partly enclosing 2 (occasionally 4, 3, or 1) female flowers about 2 mm. long 
and 1.5 mm. thick, perianth-lobes about 0.3 mm. long. Fruit about 2.5 mm. long and 
2 mm. thick, ellipsoid and trigonous. 



10 FIELDIANA: BOTANY, VOLUME 40 

Plants of the wet Caribbean slopes and cloud forests of western 
Panama, between sea level and about 1000 m. elevation. This 
species has not been collected in Costa Rica but is known from 
adjacent Panama (Cooper 595, the type, from above Almirante and 
von Wedel 1943 & 2910 near Chiriqui Lagoon) in Bocas del Toro 
Province and also from near El Valle in Code Province (Allen 2148 
&22S4, Duke 121 19, and Wilbur etal 11139); apprarently flowering 
throughout the year. 

The larger male spikes with larger anthers, grouping of female 
flowers, and unusual surface on both leaves and stems serve to 
distinguish this species from the very closely related H. calloso- 
serratum and H. montanum. These three species could be con- 
sidered subspecific elements of a single taxon, but I prefer to keep 
them separate; see the discussion under H. montanum. 



LACISTEMACEAE 

WILLIAM BURGER 

Trees or shrubs. Leaves alternate and simple, petiolate, the lamina pinnately 
veined, stipules present. Inflorescence a spike, raceme, or paniculate, often fascicu- 
late in the leaf-axils, subtended by 2 bracts; flowers bisexual or unisexual, sub- 
tended by a bract or bracteoles or both, with or without a perianth, the perianth a 
single whorl of 6 or fewer parts free or variously connate below, a fleshy disc present 
and lobed or cleft; stamen solitary and arising from near the center of the disc, 
usually inflexed in bud, anthers 2-thecous, dehiscing longitudinally; pistil solitary 
and superior in the center of the disc, sessile or short- stipitate, ovary 1-locular with 
3 parietal placentas, the ovules 1 or 2 and pendulous on each placenta, style short or 
absent, stigmas 3 or solitary and 3-lobed; fruit capsular, ovoid or subglobose and 
opening by usually 3 valves, seeds usually 1 (3) by abortion. 

This small neotropical family has been recognized and placed 
among the Amentiferae by a number of authors. The family was 
recognized and so placed in the "Flora of Panama" (Nevling, Ann. 
Missouri Bot. Card. 47:84-87. 1960) and the "Flora of Guatemala" 
(Standley and Steyermark, Fieldiana Bot. 24, pt. 3:340-342. 1952). 
Diels, in reworking Engler's Syllabus der Pflanzenfamilien (llth 
edition, 1936), considered the plants placed here as no more than a 
tribe within the Flacourtiaceae. A superficial examination of the 
flowers of our species of Lozania leads me to concur with the view 
that these plants belong with the Flacourtiaceae. Even in the 
absence of flowers and fruit, the dried leaves and stems of Lozania 
bear a striking resemblance to herbarium material of Casearia and 
other members of the Flacourtiaceae. Our species of Lacistema, 
with its short spikes (aments) with minute flowers largely hidden 
by the imbricate bracts, appears to be very different from most 
Flacourtiaceae, but it is clearly related through Lozania. 

A key to the species and a figure is included here; these, together 
with full descriptions, will be provided under the account of the 
Flacourtiaceae in a future issue of this Flora. Lozania pittieri 
(Blake) L. B. Smith and Lozania mutisiana Roem. & Schult. are 
earlier names for L. pedicellata (Standl.) L. B. Smith and L. 



11 



LACISTEMA aggregatum 




LOZANIA pittieri 



LOZANIA mutisiana 



FIG. 2. Lacistemaceae: Costa Rican species of Lacistema and Lozania; plants 
closely related to the Flacourtiaceae. 



12 



BURGER: FLORA COSTARICENSIS 13 

monatana Standl., respectively, according to Getulio Agostini. 1 
Lacistema aggregation (Berg) Rusby is a very common small tree, 
more often encountered than the other two species in our flora ( see 
fig. 2). 



COSTA RICAN SPECIES ASCRIBED TO THE LACISTEMACEAE 

la. Flowers subsessile and partly hidden by the imbricate floral bracts; inflor- 
escences of short spikes borne in clusters of 4 to 12, less than 2 cm. long at 
anthesis, densely flowered and the rachis not visible; common plants of wet 
forest formations from sea level to 1600 m. elevation . . Lacistema aggregatum. 

Ib. Flowers clearly visible on distinct pedicels above the minute floral bracts; 
inflorescences of racemes 3-9 cm. long and 1 to 4 per axil, loosely flowered and 
the rachis easily visible from early stages ; uncommon plants of wet forest for- 
mations 2a. 

2a. Plants of montane areas between 1000 and 2000 m. elevation, leaves drying 
stiffly chartaceous; racemes 1 to 3 per axil, stamen with a very short broad 
filament Lozania mutisiana. 

2b. Plants of lowland areas between sea level and 500 m. elevation, leaves drying 
thinly chartaceous; racemes solitary, stamen with a slender filament. 

Lozania pittieri. 



'( Acta Bot. Venez. 8: 167-175. 1973). 



SALICACEAE 

Luis DIEGO G6MEZ P. 

Unisexual (rarely bisexual) trees and shrubs with light wood and bitter bark. 
Leaves alternate in a spiral, simple and stipulate, laminae entire or more often 
serrulate. Inflorescences dense spikes or racemes (catkins or aments) borne in the 
leaf-axils; flowers small and unisexual, each subtended by a thin bract, without 
sepals or petals and the perianth represented by a cup-like disc (in Populus) or by 
1 or 2 minute glands or scales (in Salix); male flower with 2 to many stamens, fila- 
ments borne on the base of the bract and free or united near the base, anthers 2- 
thecous, dehiscing longitudinally, a pistillode present or absent; female flower with- 
out staminodes, pistil solitary and sessile or stipitate, ovary unilocular, ovules many 
and erect on 2 to 4 parietal or somewhat basal placentas, style 1 with 2 to 4 stigmas, 
the stigmas simple or bifid. Fruit a capsule breaking into 2 to 4 parts, seeds small 
with a coma of long soft usually white hairs, endosperm little or none. 

A family of two genera and about 300 species, very common in the 
arctic and north temperate regions of both the Old and New World 
but represented in our area only by introduced species. Only one 
species is commonly encountered in Costa Rica; others are occasion- 
ally seen in cultivation. The family is quite isolated by virtue of the 
much-reduced flowers, but it is probably related to the Tamari- 
caceae. 

Laminae usually broad and on conspicuous, often flattened petioles, buds with 
several usually resinous scales; inflorescences usually drooping or pendulous, 
each flower with a basal cup-like disc; often planted in gardens and along streets. 

Populus. 

Laminae very narrow and on short terete petioles, buds with 1 scale; inflorescences 
usually erect, each flower with 1 or 2 minute basal glands; often planted or es- 
caped along streams and lakes and in wet cool areas Salix. 

POPULUS Linnaeus 

Trees, bark on young trunks often pale gray and quite smooth becoming rough 
and gray in age; buds at first enclosed by several imbricate scales, the scales usually 
resinous. Leaves persistent or deciduous, petioles usually long and flattened later- 
ally to form an adaxial groove, laminae often broadest below the middle and trun- 
cate to rounded at the base, usually serrate to sinuate along the edge; stipules 
narrow and deciduous. Inflorescences usually pendulous or drooping in anthesis 



14 



BURGER: FLORA COSTARICENSIS 



15 




FlG. 3. Salicaceae: Salix humboldtiana, twig with fruiting inflorescence. 

and fruit; each flower with a cup-like disc, the disc symmetrical or oblique, fleshy or 
membranous, edge of the disc entire to dentate or lobed; male flower with (4) 8 to 50 
or more stamens, filaments free; female flower with a sessile or stipitate pistil, style 
1 or none, stigmas 2 or 4. Fruit a 2- or 3-valved capsule. 

A genus of about 30 species of the northern hemisphere not 
ranging further south than Mexico (in North America) but occa- 
sionally planted as ornamental trees throughout the Neotropics. 
None of the introduced species is common in Costa Rica, but 
Populus alba L. with the laminae downy-white beneath is often seen 
in gardens. 

SALIX Linnaeus 

Shrubs or trees often growing near fresh water lakes and streams, young trunks 
with brown or dark gray bark; bud enclosed within a single scale, the scale with an 
inner adherent membrane. Leaves persistent or deciduous, usually short -petiolate 
and with very narrow and serrulate laminae; stipules persistent or deciduous, 
paired, scale-like or large. Inflorescences usually erect or spreading, floral bracts 
entire or minutely serrulate, each flower with 1 or 2 minute basal glands or scales; 
the male flowers with 1 to 2 or 3 to 12 stamens, filaments free or united; female 
flowers with a sessile or stipitate pistil, style 1 or none, stigmas 2 and simple or 
bifid; capsule usually 2-parted. 

A genus of more than 200 species but with only a few entering the 
tropics. The following is the only species commonly found in Costa 
Rica; several others, both native and introduced, have been re- 



16 FIELDIANA: BOTANY, VOLUME 40 

ported in Guatemala and are treated in the "Flora of Guatemala" 
(Fieldiana: Bot. 24, pt. 3:343-348. 1952). 



Salix humboldtiana Willd. inL., Sp. PL ed4, 4:657. 1806. Figure 3. 

Shrubs or trees becoming 10 ( 18) m. tall, branches often drooping, stems at first 
puberulent with crooked whitish hairs 0.1-0.3 mm. long, leafy internodes 3-18 mm. 
long, 0.4-1.8 mm. thick; bud scales 1-2 mm. long. Leaves evergreen, petioles 2-5 mm. 
long, about 0.5 mm. thick, puberulent; laminae 4-10 (15) cm. long, 4-8 (12) mm. 
broad, lanceolate to linear, tapering gradually to the slender and acute apex, acute 
at the base, each margin with 40 or more minute teeth 0.5-1.5 mm. distant, the 
laminae drying stiffly chartaceous, smooth and glabrous on both surfaces, venation 
pinnate with many slender secondary veins occasionally joining distally to form a 
submarginal vein; stipules vestigial. Inflorescences subtended by small leaves; 
( stamina te plants not known from Costa Rica and the description based on Central 
American material) male spikes 3-6 cm. long with the puberulent flowers crowded, 
bracts 1-2 mm. long and densely whitish tomentose at the base adaxially, each 
flower with 3 to 5 (7) stamens, filaments 2-3 mm. long, anthers about 0.4 mm. long 
and equally broad; female spikes 3-7 cm. long, peduncle about 4 mm. long and 0.8 
mm. thick, puberulent, the flowers 0.3-2.5 mm. distant on the rachis, bract 1-2 mm. 
long and densely white tomentose adaxially, pistil glabrous, 2-3 mm. long with a 
stipe about 1 mm. long, ovary narrowly ovoid, 0.5-0.8 mm. thick (dry), stigmas 0.4- 
0.7 mm. broad on a very short style or sessile. Fruit with valves 3-5 mm. long, 1.5-3 
mm. broad, seeds 0.5-1 mm. long with many soft whitish hairs 2-3 mm. long. 

This species is widely planted by vegetative propagation in the 
cool and wet areas of the country. Populations of this species have 
become established in the rivers of the Caribbean lowlands in 
nearby Nicaragua, and naturalized populations can be expected in 
Costa Rica throughout the wet and cooler areas of the country 
between sea level and 2000 m. elevation. The species ranges from 
Mexico southward to Costa Rica and from Colombia to Argentina 
and Chile. 

The first record of the genus Salix in the New World is probably 
that of Fernandez de Oviedo (Historia General y Natural de las 
Indias, Book 9, Chap. 32, 1535-1557.), who refers to the "salces so 
common in the southern lands of New Castile, which are very much 
like those seen in Europe." Nevertheless, it strikes one as rather 
awkward for a man of Oviedo's curiosity and fine insight, that 
although he described many trees peculiar to Central America, he 
does not mention "salces" nor "sauces" as occurring in places such 
as Guatemala. 

Salix humboldtiana is known only from sterile and pistillate col- 
lections in Costa Rica, and it is generally thought to have been 
introduced by the Spanish settlers. However, the species seems to 



BURGER: FLORA COSTARICENSIS 17 

be native in northern Central America and over a wide area in South 
America. The very narrow leaves, often slightly curved, and the wet 
habitat distinguish this species. 

The only other species of the genus that is commonly planted in 
Costa Rica is Salix babylonica L., with long hanging branches that 
may touch the ground. The name S. chilensis Molina ( Sagg. Storia 
Nat. Chil., 169. 1782) has been used for this species but is a nomen 
dubium, as according to Schneider (Bot. Gaz. 65:6. 1918) is based 
on material that may not be Salix. 



GARRYACEAE 

WILLIAM BURGER 

REFERENCE: Walther Wangerin in Engler, Pflanzenreich IV, 
56a. Garryaceae. 1-18. 1910. 

Unisexual shrubs and small trees, young stems somewhat quadrangular and with 
an interpetiolar ridge. Leaves opposite, simple and evergreen, petiolate; lamina 
usually coriaceous and entire, stipules absent but the leaf-bases continuous and 
united by an interpetiolar ridge. Inflorescence composed of 1 to 4 individual flowers 
in the axils of leaves or undeveloped leaves and often subtended by conspicuous 
bracts in a racemose or spicate form or occasionally producing a terminal thyrse- 
like inflorescence; male flowers usually pedicellate, sepals 4, valvate and separating 
or occasionally remaining connate at the apex, petals absent, stamens 4 and alter- 
nate with the sepals, filaments short and free, anthers 2-thecous, basifixed, 
dehiscing longitudinally and introrse, narrow, a minute pistillode present or absent; 
female flower without apparent parianth but 2 to 4 small lobes sometimes present 
at the apex of the ovary (and the ovary probably inferior by adnation), ovary 1-locu- 
lar with 2 ovules pendulous from the apex of the locule, styles and stigmas 2 and 
divergent. Fruit baccate, ovoid to globose, seeds 2 or 1 by abortion, seed ovoid to 
globose with a fleshy covering, embryo minute at the apex of the endosperm. 

This family, represented by a single genus, is closely related to 
the Cornaceae but has become adapted to wind pollination. While 
placement of the Garryaceae here (between the Salicaceae and 
Myricaceae) is clearly incorrect, it is perhaps easier for most people 
to associate these reduced unisexual flowers with those of the amen- 
tiferous families. The Garryaceae follow the Cornaceae in the "Flora 
of Guatemala" (Fieldiana: Bot. 24, pt. 8:69-72. 1966). 

GARRYA Douglas 

A genus of about 15 species restricted to North America and 
ranging from Oregon to the western United States southward 
through Texas and Mexico to Costa Rica with a single species 
(G. fadyeni Hook.) in Jamaica and eastern Cuba. The following is 
the only species known from Costa Rica; an additional species is 
known in Guatemala. They are not known to be useful in Central 
America, but members of the genus are occasionally planted as 
ornamental shrubs in California. 



18 



BURGER: FLORA COSTARICENSIS 



19 



GARRYA laurifolia 




FlG. 4. Garryaceae: Garrya laurifolia with fruiting female specimen (left) and male 
twig (right). 



Garrya laurifolia Hartweg ex Bentham, PI. Hartw. 14. 1839. 
Figure 4. 

Dioecious shrubs or small trees 2-6 ( 12) m. tall, often branched from near the base 
and with many vertical stems, leafy internodes 5-30 mm. long, 1.5-5 (7) mm. thick, 
with slender whitish hairs 0.3-0.7 mm. long or glabrescent, usually drying dark, 
interpetiolar ridges prominent. Leaves in decussate pairs, often held erect, petioles 
4-18 mm. long, 1-2 mm. thick, minutely puberulent but becoming glabrous, sulcate 
above with the adaxial ridges continuous with both the lamina-margin and the 
interpetiolar ridge; laminae (2) 4-11 cm. long, (0.8) 1.5-4 cm. broad, elliptic to oblong 
or occasionally narrowly obovate, rounded to abruptly obtuse (rarely acute) at the 
apex, occasionally minutely ( 1 mm. ) mucronate at the tip, acute to attenuate at the 
base, margins entire and revolute on drying, the lamina coriaceous to subcoriaceous, 
smooth and often lustrous above, sparsely puberulent above and very sparsely 
puberulent beneath with straight appresed and ascending whitish hairs 0.1-0.3 mm. 
long, becoming glabrous in age, the 5 to 9 pairs of major secondary veins slightly 
impressed above. Inflorescences axillary or apparently terminal, spicate, thyrse- 
like, or rarely racemose, the flowers solitary and terminal or in opposite axillary 
pairs, the rachis and branches of the inflorescence probably representing stems with 
reduced leaves subtending the opposed flowers, branches and rachis often densely 
whitish sericeous in early stages; each male flower subtended by a narrow bract 
4-7 mm. long, sepals (tepals) 2-4.5 mm. long and 1-2.5 mm. broad, usually remaining 
connate at the apex, stamen with very short (0.5 mm.) filaments, anthers 1.5-2.5 
mm. long, about 0.8 mm. thick; each axillary female flower subtended by a small 



20 FIELDIANA: BOTANY, VOLUME 40 

leaf-like bract 3-15 mm. long and about 3 mm. broad, the terminal flowers subtended 
by 2 bracts or without bracts, each flower sessile or on a short (1-4 mm.) pedicel, 
perianth and perianth-lobes not apparent, pistil about 6 mm. long and 3 mm. thick, 
surface of the ovary sparsely and very minutely puberulent with slender whitish 
hairs 0.2-0.5 mm. long, style branches 1-3 mm. long, 1 mm. broad at the base, 
minutely papillate-puberulent on the inner stigmatic surface. Fruit globose or 
ellipsoid, becoming about 10 mm. long and 8 mm. thick, dark olive-green but drying 
very dark gray or black. 

Plants of the high montane rain forests and paramo formations 
between 2200 and 3400 m. elevation in Costa Rica; flowering and 
fruiting throughout the year but most commonly in flower in the 
wet season, May through December. This species has only been col- 
lected along the Caribbean watershed of the Central Highlands and 
in the western part of the Cordillera de Talamanca along the Inter- 
american highway and on Cerro Chirripo in Costa Rica. The species 
ranges northwards to Mexico. 

These unisexual woody plants are easily recognized by the very 
stiff opposite leaves with interpetiolar ridges, reduced flowers, and 
high montane habitat. This species exhibits what may be tran- 
sitional stages in the development of complex inflorescences from 
what were originally solitary flowers in the axils of leaves. 



MYRICACEAE 

WILLIAM BURGER 

REFERENCE: T. S. Elias, The genera of the Myricaceae in the 
Southeastern United States, Journ. Arnold Arb. 52:305-318. 1971. 

Small trees, shrubs, or suffruticose, unisexual or bisexual, usually aromatic and 
often pellucid-punctate; roots often with nitrogen-fixing nodules. Leaves alternate 
in a spiral, evergreen or deciduous, simple, entire to dentate or rarely pinnatifid; 
with or without stipules. Inflorescences spicate to paniculate, axillary or from a 
short-shoot; flowers unisexual, small and lacking both sepals and petals, solitary in 
the axil of a large bract, with or without smaller bracteoles; male flowers with 2 to 30 
anthers borne on short, free or united filaments, anthers 2-thecous and dehiscing 
longitudinally, a pistillode usually absent; female flowers with a solitary pistil and 
unilocular ovary with a single ovule, style short with 2 (3) style-branches, stigmas 
2 (3). Fruit drupaceous or nut-like, endocarp hard, exocarp often producing wax, 
embryo straight with plano-convex cotyledons. 

A small family of three genera and probably fewer than 50 species 
widely distributed in the north-temperate zone and in Africa and 
Southeast Asia but usually restricted to highland habitats in 
Central and South America. The family has an extensive fossil 
record dating from the late Cretaceous and is an old and phylo- 
genetically isolated family. Relationships with the Juglandaceae, 
Fagaceae, Casuarinaceae, and Hamamelidaceae have been sug- 
gested by various authors. 

MYRICA Linnaeus 

Small shrubs to small or medium sized (12 m. ) trees, unisexual or less often bi- 
sexual, often branching near the ground, stems usually with pale grayish lenticels 
broadly elliptic and bisected by a longitudinal depression; roots usually with nitro- 
gen-fixing nodules. Leaves simple and with pinnate venation (in ours), short- 
petiolate, laminae stiffly chartaceous to coriaceous, subentire to dentate or serrate, 
aromatic when crushed; stipules absent. Inflorescence a simple stiff spike arising 
in the leaf-axils (in ours), flowers alternate in a spiral on the rachis; male flower sub- 
tended by 1 broad bract and usually with 2 linear bracteoles, stamens (2) 4 to 8 (20) 
with free or variously united filaments, the thecae often slightly unequal and diver- 
gent on the short thick connective; female flower subtended by a single broad bract 
with or without smaller bracteoles, the ovule erect from the base of the locule. Fruit 



21 



22 FIELDIANA: BOTANY, VOLUME 40 

drupe-like with a surface of tubercles or projections which usually become covered 
with whitish wax in late stages. 

The genus may be represented in Central America by no more 
than the species listed here. Of these, M. cerifera (as here inter- 
preted) is very unusual in its wide geographic range. The relation- 
ship of these plants with nitrogen-fixing bacteria is an important 
element in determining their ecological amplitude and role in forest 
succession. Our species possess the yellowish pellucid peltate 
glands, concave above, that are so characteristic of the genus. The 
wax extracted from the fruit has been used for making candles that 
burn with a pleasing aroma, but this use of the wax is becoming rare 
in Central America. The ability to grow in poor soils makes these 
plants useful in erosion control. The names Bayberry or Myrtle 
(in English) andArrayan or Arbol de la cera (in Spanish) are com- 
monly used for the genus. 



la. Plants bisexual, spikes usually with male flowers beneath and female flowers 
distally, fruit on the distal part of the spike; leaves usually densely puberulent 
beneath with 10 to 25 major secondary veins on each side; plants of montane 
wet forest formations from 1300 to 2800 m. elevation M. pubescens. 

Ib. Plants unisexual or rarely with terminal male flowers on a female spike; leaves 
sparsely puberulent to glabrous beneath 2a. 

2a. Laminae usually oblanceolate, entire or with 3 or 4 blunt teeth distally on 
each margin, major secondary veins usually less than 9 on each side and often 
obscure, minute pellucid dots numerous on both surfaces (X20); plants rarely 
found above 1800 m. elevation M. cerifera. 

2b. Laminae elliptic to narrowly oblong, usually with more than 4 conspicuous 
teeth on each side, secondary veins prominent beneath and becoming im- 
pressed above; plants commonly found above 1800 m. elevation 3a. 

3a. Lamina lacking pellucid peltate glands above or very sparsely glandular, the 
laminae usually less than 5 cm. long and broadly elliptic; plants endemic to 
Central Costa Rica M. phanerodonta. 

3b. Lamina with numerous yellowish peltate glands on the upper surface (X20), 
the laminae often becoming more than 7 cm. long and narrowly elliptic to nar- 
rowly oblong; plants not recorded from Costa Rica ( see discussion under M. 
cerifera) , M. lindeniana. 

Myrica cerifera L., Sp. PL 1024. 1753. M. mexicana Humboldt & 
Bonpland ex Willd., Enum. PI. 2:1011. 1809, fide auctores. M. 
xalapensis H.B.K., Nov. Gen. & Sp. 2: 16. 1817, ex char. Figure 5. 

Unisexual shrubs or trees, (0.5) 1-5 (9) m. tall, leafy internodes 2-10 ( 15) mm. long, 
0.8-3 (5) mm. thick, densely to sparsely puberulent with soft gray or brown straight 
and crooked hairs 0.3-1 mm. long, peltate pellucid glands present but the stems be- 
coming glabrescent and dark brown in age with lenticels 0.3-1 mm. long. Leaves 



MYRICA 



M. phanerodonta 



M. cerifera 




M. pubescens 



FIG. 5. Myricaceae: the Costa Rican species of Myrica; note the peltate pellucid 
glands (left-center). 



23 



24 FIELDIANA: BOTANY, VOLUME 40 

evergreen; petioles 1-3 (8) mm. long, about 0.8 mm. thick, terete or flattened 
adaxially; laminae 2-7 (9) cm. long, 1-2 (3) cm. broad, oblanceolate to narrowly 
obovate or less often elliptical, abruptly acute or obtuse at the apex, acute to at- 
tenuate at the base, distal half of each margin with 3 to 6 teeth or entire, often 
revolute on drying and stiffly chartaceous to subcoriaceous, the 4 to 9 pairs of major 
secondary veins often obscure above and below, smooth and occasionally slightly 
lustrous above, puberulent on the midvein above and below or essentially glabrous 
but with peltate pellucid glands about 0.1 mm. broad on both surfaces and these 
sometimes drying black. Inflorescences unisexual, arising and maturing in the axils 
of leaves or fallen leaves, peduncle and rachis about 0.8 mm. thick, puberulent and 
often densely pellucid-glandular; male spike 1-3.5 cm. long with 15 to 40 flowers, 
usually borne in the axils of persisting leaves, the superposed flowers usually less 
than 2 mm. distant on the rachis, male bracts about 1 mm. long and 1.5 mm. broad, 
sparsely puberulent and pellucid-glandular abaxially, anthers 3 to 5 ( 12) on usually 
very short (0.5 mm.) filaments, thecae 0.8-1.2 mm. long; female spike 1-3 cm. long 
with 8 to 30 flowers, usually maturing in the axils of fallen leaves, superposed 
flowers becoming 2-4 mm. distant on the rachis, female bract about 1.2 mm. long 
and equally broad, sparsely puberulent and densely pellucid-punctate abaxially, 
pistil about 3 mm. long with the style-branches 2 mm. long and the ovary about 1 
mm. Fruit becoming 2.8-4 mm. long and usually equally thick, globose, the tubercles 
0.2-0.5 mm. broad and often remaining contiguous when dried. (Measurements 
based on Central American material but excluding material ascribed to M. 
lindeniana. ) 

Plants of seasonally dry evergreen montane forest formations be- 
tween (500) 800 and 1800 (2000) m. elevation in Costa Rica; 
probably flowering throughout the year. The species, as here under- 
stood, ranges from New Jersey in the eastern United States to the 
West Indies, western Panama, and possibly to Colombia. 

This species is recognized by the generally small oblanceolate 
leaves entire or serrulate only in the distal half and often clustered 
at the ends of branches, aromatic parts, and small unisexual spikes. 
This species possesses an extraordinary geographic and ecological 
range for a perennial woody plant. The plants are known to grow in 
montane bogs and in well-drained pine forests in Guatemala 
(Standley, Fieldiana: Bot. 24, pt. 3:349-350. 1952). Populations are 
known from near sea-level along the Caribbean coast from 
Nicaragua northward, but it is apparently an uncommon occurrence 
and the material that I have seen lacks flowers and fruit. Plants 
from the West Indies bearing this name differ from ours by the 
much narrower leaves usually without serration. The material from 
the United States differs from Central American collections in the 
usually less serrulate leaves and the female spikes more often 
maturing in the axils of persisting leaves. These geographic dis- 
tinctions may be worthy of subspecific rank but the species and its 
relations are not well understood ( see below). 



BURGER: FLORA COSTARICENSIS 25 

There are two taxa in Central America that are very closely re- 
lated to M. cerifera: M. lindeniana C.DC. and M. phanerodonta 
Standley. With the variation and range ascribed to M. cerifera, it 
may seem inconsistent to consider these closely related taxa as 
separate species. In the case of M. phanerodonta, the plants are 
easily separable ecologically and morphologically with no real evi- 
dence of intergradation. However, the situation with M. tindeniana 
is not as clear. Material referable to M. lindeniana occurs through- 
out much of the range of M. cerifera in Central America and appears 
to grow in moister situations and at higher altitudes. Typical 
material of M. lindeniana has conspicuously longer (6-12 cm.) 
laminae than M. cerifera with more numerous (9-16 pairs) and more 
prominent secondary veins and serrations. The ecological and 
morphological distinctions are bridged by some collections that 
appear to be intermediate, but these collections are few in number 
and may prove to be unusual variants rather than true inter- 
mediates. Because there is a correlation between ecology and 
morphology, and until the species are actually studied in the field, 
I prefer to treat them as separate. Myrica pringlei Greenman is 
probably a small-leaved form of M. cerifera. 

Myrica phanerodonta Standley, Journ. Wash. Acad. Sci. 17: 164. 
1927. Figure 5. 

Unisexual or rarely bisexual shrubs and small trees 1-5 (7) m. tall, stems with 
minute peltate glands and sparsely to densely puberulent with short (0.3 mm.) 
gray or yellowish-brown hairs, becoming glabrous and dark brown with conspicuous 
lenticels 0.5-1.8 mm. long, leafy internodes 2-10 ( 15) mm. long, 1-6 mm. thick. Leaves 
evergreen, petioles (1) 2-7 mm. long, about 1 mm. thick, slightly sulcate adaxially; 
laminae 1.8-5 (8) cm. long, 0.8-2 (2.8) cm. broad, broadly elliptic to oblong or 
obovate, abruptly obtuse or rounded at the apex, acute to attenuate at the base, 
each margin with 4 to 12 teeth, teeth with a gland -like tip about 0.5 mm. thick, 
slightly revolute on drying, subcoriaceous. the major secondary veins (4) 6 to 10 
(14) on each side, usually impressed above and prominent beneath, smooth and 
slightly lustrous above, puberulent on the proximal half of the midvein above, 
sparsely puberulent or glabrous on the midvein beneath, hairs about 0.2 mm. long, 
peltate pellucid glands about 0.1 mm. broad, absent or very sparse above, present 
but often inconspicuous beneath, small dark pits or depressions often present on 
both surfaces. Inflorescences unisexual but rarely the female with a terminal male 
flower (as in Gomez 2292 and Molina et aL 17115), axillary, peduncle and rachis 
about 1 mm. thick, densely to sparsely puberulent, the flowers at first congested 
but becoming distant; male spike 1-3.5 cm. long with 15 to 40 flowers, bracts of the 
male flowers 2 mm. long and equally broad, very sparsely puberulent but with 
pellucid glands abaxially. anthers 4 to 6 (8) on filaments becoming 1 mm. long and 
variously united beneath, thecae 0.8-1.4 mm. long; female spike becoming 2-5 cm. 
long with 10 to 40 flowers, superposed flowers becoming 3-8 mm. distant on the 



26 FIELDIANA: BOTANY, VOLUME 40 

rachis, female bracts 2-3 mm. long and 0.5-1 mm. broad at the base, sparsely puber- 
ulent and pellucid-glandular abaxially, pistil about 2 mm. long with style-branches 
1-2 mm. long. Fruit becoming 3-4 mm. thick and equally long or slightly longer, 
globose to broadly ellipsoid, tubercles 0.2-0.4 mm. thick and usually remaining 
contiguous on drying. 

Plants of montane rain forests between 1800 and 2700 m. eleva- 
tion and apparently restricted to those areas subject to the wet 
Caribbean winds between Zarcero, Alajuela, in the west and the 
Cerros de Zurqui, Heredia. Probably flowering throughout the year 
but most commonly collected in flower or fruit between September 
and February. The species is known only from the small area 
described above and is common near the summit of Volcan Poas. 

Myrica phanerodonta is characterized by its small, conspicuously 
serrate leaves with prominent venation and restricted range. It is 
very closely related toM. lindeniana C.DC. but differs in its usually 
much shorter leaves and the apparent lack of intermediates with 
typical M. cerifera. I believe that this species has become differ- 
entiated fromM. cerifera (sensu lato) in a way that is more complete 
than but very similar to the differentiation of M. lindeniana ; both 
are adapted to higher elevations and both possess serrulate leaves 
with rather conspicuous venation. A similar situation may exist in 
Colombia, where several taxa are found that are closely related to 
M. cerifera (sensu lato) but that differ in their smaller leaves and 
high-altitude habitats. 

Myrica pubescens Humboldt & Bonpland ex Willd., Sp. PL 4: 746. 
1806. M. arguta H.B.K., Nov. Gen. & Sp. 2: 17, tab. 98. 1817. Figure 
5. 

Bisexual shrubs or trees 1.5-7 (10) m. tall, leafy internodes 3-15 mm. long, 1.5-4 
(6) mm. thick, densely soft-puberulent with straight and crooked gray or brown 
hairs 0.2-0.8 mm. long, pellucid glandular, becoming glabrescent and dark brown in 
age with conspicuous lenticels 0.5-1.3 mm. long. Leaves evergreen, petioles 3-8 mm. 
long, about 1 mm. thick, deeply grooved adaxially, densely puberulent; laminae 
4-14 cm. long, 1-3 cm. broad, narrowly elliptic to narrowly oblong or rarely ob- 
lanceolate, acute at the apex, acute to the base, margins serrate or doubly serrate 
with 6 to 26 small or prominent teeth on each side, drying stiffly chartaceous to 
subcoriaceous, upper surface smooth and sparsely puberulent, more densely puber- 
ulent on the veins beneath with gray or pale brown hairs 0.1-0.4 mm. long, pellucid 
glands about 0.1 mm. broad, present on both surfaces, the 10 to 25 pairs of major 
secondary veins becoming slightly impressed above. Inflorescence usually bisexual, 
12-46 mm. long, arising in the axil of a leaf and often persisting after the leaf has 
fallen, peduncle and rachis 0.6-1 mm. thick, densely puberulent, the superposed 
flowers becoming 1-4 mm. distant on the rachis, the 3 to 7 male flowers borne below 
the 6 to 12 female flowers, floral bracts densely puberulent and pellucid-punctate 



BURGER: FLORA COSTARICENSIS 27 

abaxially; bracts of the male flowers 2-3 mm. long and about 1.5 mm. broad at the 
base, anthers 4 to 9, thecae 0.6-1.2 mm. long; bracts of the female flowers 2-5 mm. 
long and 1-2 mm. broad at the base or occasionally leaf-like and larger, the lateral 
bracteoles about 1 mm. long, pistil 1-2 mm. long with 2 style-branches 0.5-1 mm. 
long, slender but soon becoming globose. Fruit globose to ellipsoid, 2.5-3.5 mm. 
thick and 3-4 mm. long (dry), tubercles about 0.3-0.5 mm. long and equally broad, 
sparsely puberulent, often becoming quite separate on drying. 

The species is common on and around the western parts of the 
Cordillera de Talamancana and in the higher parts of the Central 
Highlands as far west as Palmira, Alajuela, between 1300 and 
2800 m. elevation. Usually growing in or at the edge of montane 
rain forests or in open bogs and secondary growth; collected in 
flower from January to August. The species ranges from Costa Rica 
and Colombia southward to Bolivia. 

This species, often called encinillo in Costa Rica, is easily recog- 
nized by the narrow puberulent leaves with many secondary veins 
and the presence of bisexual spikes. In plants with poorly developed 
spikes or with fruiting spikes, the bisexual condition may be diffi- 
cult to see, but a few clearly bisexual spikes can usually be found by 
careful searching. The stamens appear to come into anthesis while 
the pistils are still quite small. A small seedling collected by 
Margery Carlson (3502, F) in a sphagnum bog on the Cerro de la 
Muerte clearly shows the root nodules so characteristic of the 
genus. 



JUGLANDACEAE 1 

DONALD E. STONE 2 

REFERENCES: T. S. Elias, The genera of Juglandaceae in the 
Southeastern United States, Journ. Arnold Arbor. 53:26-51. 1972. 
J. F. Leroy, Etude sur les Juglandaceae, Mem. Mus. Nat. Hist. 
Nat., Ser. B, Hot. 6:1-246. 1957. W. E. Manning, The morphology 
of the flowers of the Juglandaceae: I. The inflorescence. Amer. 
Journ. Bot. 25:407-419. 1938; II. The pistillate flowers and fruits. 
Amer. Journ. Bot. 25:407-419. 1941; III. The staminate flowers. 
Amer. Journ. Bot. 35:606-621. 1948. W. E. Manning, Juglandaceae, 
In Flora of Guatemala, Fieldiana, Bot. 24:352-359. 1952. W. E. 
Manning, Juglandaceae, In Flora of Panama, Ann. Missouri Bot. 
Card. 47: 90-92. 1960. P. C. Standley, Juglandaceae, In Flora of 
Costa Rica, Field Mus. Nat. Hist., Bot. Ser. 18:372-373. 1937. 
D. E. Stone & C. R. Broome, Juglandaceae A. Rich, ex Kunth. 
World Pollen and Spore Flora 4: 1-35. 1975. 

Trees or rarely large shrubs; bark tight or exfoliating, pith solid [or chambered]; 3 
buds naked [or protected). Leaves evergreen [or deciduous], opposite, whorled, or 



'Field work for this project has received generous financing from the National 
Science Foundation, beginning with my first trip to Costa Rica in January, 1963. 
Over the years the Organization for Tropical Studies has played a crucial role in 
providing logistic support, and for this help I particularly wish to thank the Resi- 
dent Director, Jorge Campabadal. I am indebted to William H. Hatheway, Leslie 
R. Holdridge, Paul Opler, and Luis Poveda for information about local field sites. 
Many of the fieldtrips benefitted from the companionship of my good friend Arthur 
L. Welden and my wife Beverly Larson Stone. Also to my wife I pay thanks for her 
encouragement and forbearance, at a time when family life would have enjoyed a 
resident father. William Louis Culberson kindly provided the Latin diagnoses and 
Wayne E. Manning, as always, lent his expertise to a review of the manuscript. 
Thomas Daniel has been most helpful in bringing the manuscript into its final form. 
The drawings are the artistry of Susan Carlton Smith and they were sponsored by 
the Duke University Council on Research. 

'Department of Botany, Duke University, Durham, North Carolina 27706. 
3 Bracketed descriptions apply to species not found in Costa Rica. 



BURGER: FLORA COSTARICENSIS 29 

alternate, estipulate, even-pinnate [or odd-pinnate]; leaflets sessile or petiolulate, 
margins entire or serrate, dotted below with peltate scales [sometimes aromatic]. 
Trees monoecious (bisexual) [or dioecious]. Infloresencences of several types: ter- 
minal androgynous panicle with central female catkin subtended by 1-6 male catkins 
or, rarely, with central male catkin subtended by several female flowers; terminal 
female catkin solitary; terminal cluster of 1-10 male catkins [or lateral solitary or 
clustered male catkins]. Flowers unisexual. Male flowers with 3-lobed [or unlobed] 
primary bract; floral segments 4-7 [to 14]; stamens 6-19 [or 3-100] in 1-2 series [or 
many?]; receptacle round to elongate; filaments short; anthers basifixed, erect, 
2-locular, longitudinally dehiscent; rudimentary pistil occasionally present. Pollen 
grains tripororate-isopolar [stephanopororate to anizonipororate], non-pseudocol- 
pate [pseudocolpate], subtriangular [triangular to spheroidal]; pores circular 
[meridionally elongate]; exine tectate; sculpturing spinulose. Female flowers con- 
sisting of a floral cup formed by an abaxial 3-lobed [or unlobed] primary bract that is 
fused with 2 adaxial bracteoles [or variously fused and divided]; sepals 4 [to 7], fused 
below and free above as oblong-linear lobes [or modified into a stigma tic disk], 
adnate at base to bract-bracteolar cup and ovary; syncarpous gynoecium of 2 [rarely 
3 or 4] carpels, ovary inferior, 1-8 [l-4]-locular; ovule with single integument, ortho- 
tropous, erect at apex of incomplete septa; style obsolete to long tapering, 
bifurcate, stigma 4[2]-parted, carinal [or commissural]. Fruit a drupaceous nut with 
3[l]-lobed [or unlobed] primary bract expanded to form persistent leathery wings, 
or reduced to a small circular tab at base of nut [or fused with floral parts to form the 
husk]; pair of bracteoles adnate to circular tab or fused to form protective lobe 
over nut in species with winged fruits [or fused with floral parts to form the husk]; 
husk thin to thick, fleshy or hardened, indehiscent [or dehiscent], formed from fused 
sepals [or various combinations of primary bract, bracteoles, and sepals]; nut 
8[2, 4]-chambered at equator, septa without lacunae [or with]. Seed solitary and 
large [or small], 8[2, 4]-lobes; endosperm absent; nut-meat has bitter [or sweet] 
taste. Seedling with hypogeous [or epigeous] cotyledons; first two aerial leaves 
opposite or alternate, simple or compound [or reduced to scale leaves], leaves and 
leaflets entire or serrate. Chromosome number n = 16[or 32]. 

The family of seven genera and approximately 60 species is con- 
centrated in the temperate regions of Asia and North America, but 
extends southward into the montane areas of southeastern Asia, 
Central and South America, and the West Indies. Members of the 
Juglandaceae have a well-marked Tertiary history (Berry, 1912), 
and there is good evidence that several of the genera now confined 
to Asia were well represented in North America and Europe prior 
to the Pleistocene (Nichols, 1973). Three genera (Engelhardia, 
Platycarya, Pterocarya) are extant in the Old World. The Costa 
Rican representatives of Alfaroa and Oreomunnea are strictly 
tropical American elements, whereas the hickories (Carya) and 
walnuts (Juglans) have a north temperate concentration in the 
Americas and Asia. The 13 New World species of Carya extend only 
as far south as the State of Veracruz in Mexico. Juglans, on the 
other hand, is distributed more or less continuously from Canada 



30 FIELDIANA: BOTANY, VOLUME 40 

south through the West Indies and Central America to Argentina 
(Manning, 1957a, 1960a), but is conspicuous by its absence from 
Costa Rica and Panama. Juglans boliviano, (C.DC.) Dode was intro- 
duced into cultivation at the Institute Interamericano de Ciencias 
Agricolas (IICA) in Turrialba in 1948 (Manning, 1957b), and more 
recently was established successfully in San Jose. Evidence from 
fossil walnuts from Ecuador suggests that the southward migra- 
tion reached South America only in late Neogene time (Brown, 
1946). 

The family is coherent and natural with a striking similarity 
in vegetative characters (de Candolle, 1862), including peltate 
scales and pinnately compound, estipulate leaves, and a diversity 
of floral and fruiting features (Manning, 1938, 1941, 1948) that are 
readily interpretable in terms of evolutionary shifts in the mode of 
pollination ( Whitehead 1969), and seed dispersal and establishment 
(Conde and Stone, 1970; Stone, 1970, 1973). The monotypic 
Rhoipteleaceae from China appears to be a primitive member of the 
Juglandales (Cronquist, 1968; Stone and Broome, 1971; Takhtajan, 
1969; Withner, 1941). Recent suggestions (Hutchinson, 1959; 
Cronquist, 1968) of close affinity with the Picrodendraceae are 
unfounded (Stone, 1973), though Thome's placement of the two 
families near the Anacardiaceae-Burseraceae-Sapindaceae (Rutales 

Opposite: 

FIG. 6. Vegetative and floral features of two wide-spread species of Alfaroa. a-d, 
A. costaricensis: a, shoot with opposite, pinnately-compound leaves, pubescent 
stem, petiole, rachis and midrib, leaflets numerous, serrate, truncate and revolute 
at base, female inflorescence terminal, bearing numerous, alternate flowers (Stone 
2174) X 1/3; b, adaxial view of male flower, pubescent, pedicel elongate (1.9 mm. 
long), 6 stamens subtended by 6 floral segments (mainly obscured), segments most- 
ly flat (Stone 3621 ), X5; c, female flower pubescent, 3-lobed bract sessile, bracteolar 
rim essentially obsolete, sepal lobes broad, elongate style deeply cleft, stigma lobes 
horseshoe shaped (Stone 2352), X 4; d, fruit ellipsoid, pubescent, calyx beak persis- 
tent at apex, bract-bracteolar cup obscure at base (Stone 2173), X 3/4. e-i, A. 
wilUamsii subsp. tapantiensis: e, shoot with opposite, pinnately-compound leaves, 
glabrous, leaflets 8, mostly entire, occasionally with a small tooth on margin, obtuse 
and flat at base (Stone 3633), X 1/3; f, adaxial view of male flower, glabrous, sessile, 
8 stamens subtended by 4 floral segments, segments tend to cup around tips of 
anthers, proximal segment not reflexed as in 6 (Stone 3633), X 5; g, female flower 
glabrous, sepal lobes broad, elongate style deeply cleft, stigma lobes horseshoe 
shaped (Stone 3633), X 4; h, fruit ellipsoid, glabrous, sculptured with faint longitu- 
dinal ridges, calyx beak persistent at apex, bract-bracteolar cup obscure at base 
(Stone 2678 A), X 3/4; i, fruit ovoid, similar to h in other aspects (Stone 3624), X 
3/4. 




31 



32 FIELDIANA: BOTANY, VOLUME 40 

of Thome, 1973; Sapindales of Cronquist, 1968) seems to be gaining 
acceptance (Stebbins, 1974; Wolfe, 1973). 

Costa Rica is the center of species diversity for the two native 
genera. Four of the six species of Alfaroa and the two species of 
Oreomunnea grow within a 50 km. radius of San Jose. Cartago 
Province, the type locality for both genera, has the richest concen- 
tration of species. The possibility of finding new species of Juglan- 
daceae is certainly good. The disjunct mountain tops and isolated 
valleys provide many suitable habitats for local endemism. Costa 
Rica should be a haven for alpha and omega taxonomists for many 
years to come. This is particularly true insofar as both genera have 
had such special significance in interpretation of the phylogeny of 
the family, because of their possession of a host of primitive fea- 
tures: long vessel members and occasional presence of scalariform 
perforations (Heimsch and Wetmore, 1939); terminal androgynous 
panicles (Manning, 1938); and small pollen grains that are basically 
tripororate, isopolar, suboblate in equatorial view, and sub- 
triangular in polar view (Whitehead, 1965; Stone and Broome, 
1975). 

In the following treatment, the species Alfaroa and Oreomunnea 
are keyed under the family. 



Opposite: 



FIG. 7. Vegetative and floral features of two endemic species of Alfaroa from 
Costa Rica, a-g, A. guanacastensis: a, sterile shoot with opposite, pinnately-com- 
pound leaves, leaflets subopposite, entire, decurrent on petiole, revolute at base 
with a few stiff hairs between the margin and midrib (Stone 3259), X 1/3; b, female 
flower, floral cup well developed, style obsolete, sepal lobes partially reflexed to 
expose stigma (Stone 3259, Miravalles), X2; c, young fruit, bract-bracteolar rim of 
floral cup split by enlarged ovary, sepal lobes arched over stigma from flowering 
through fruit maturation (Stone 2753, San Ramon), X 2; d, fruit spheroid, faint 
longitudinal ridges (Stone 2716, San Ramon), X 3/4; e, ellipsoid fruits, faint longi- 
tudinal ridges (Stone 3259, Miravalles), X 3/4; /, inflorescence with oblong fruits, 
faint longitudinal ridges (Stone 2167, Tenorio), X 3/4; g, transverse section of fruit 
at equator, secondary partition oriented in north-south direction, husk thin, shell 
thick, 8-chambered (Stone 2167, Tenorio), X 3/4. h-j, A. manningii: h, adaxial view 
of male flower, sessile, 4 hooded floral segments each enclosing 3 stamens (Stone 
2220, Platanillo), X5; i, young female flower, floral cups not fully elongated, style 
obsolete, sepal lobes arched over stigma (Stone 2170, Platanillo), X4; j, obloid fruit 
with deeply corrugated surface, large basal bract-bracteolar tab (Stone 21 70, Plata- 
nillo ),X 3/4. 




33 



34 FIELDIANA: BOTANY, VOLUME 40 

KEY TO JUGLANDACEAE 

la. Leaflets serrate on seedlings, and serrate to entire on saplings and sucker 
shoots of adult trees; female flowers sessile (except 5) 2a. 

Ib. Leaflets always entire; female flowers pedicillate on an elongate bract- 
bracteolar floral cup 4a. 

2a. Outer bark exfoliating, inner bark orange; leaflets commonly with basal 
auricles; male flowers compact, hooded with 4 floral segments, each tightly 
cupped around a pair of stamens, 8 stamens total; female flowers pedicillate, 
subtended by a bract-bracteolar floral cup with a well-developed 3-lobed 
bract and adaxial bracteolar lobe; fruit medium size, 3-winged, lateral wing 
span to 5 cm 5. Oreomunnea mexicana subsp. costaricensis. 

2b. Outer bark tight, inner bark pink to red; leaflets without auricles; male 
flowers elongate, not hooded, 4-7 floral segments only loosely enclosing 6-11 
stamens, female flowers sessile, bract small, acutely 3-lobed, bracteolar rim 
obsolete; fruit medium size (1.5-3 cm.), wingless nut with obscure, circular 
bract-bracteolar tab at base 3a. 

3a. Petiole short, 0.4-2(3.5) cm.; petiole and rachis densely pubescent; leaflets 
(8)12-18(30), sessile or nearly so, mainly truncate at base; basal leaflets 
moderately to greatly reduced, often less than one-fourth the length of the 
longest leaflets; male flowers with short but conspicuous pedicels, 1-2(8) 
mm.; fruit pubescent l.Alfaroa costaricensis. 



Opposite: 



FlG 8. Vegetative and floral features of the Costa Rican species of Oreomunnea. 
a-f O. pterocarpa: a, terminal shoot displaying decussate phyllotaxy, leaflets revo- 
lute at base, secondary veins curve upward toward tip and end without conspicuous 
branching (Stone 1016), X 1/3; b, portion of male catkin (Stone 1346), X 3; c, abax- 
ial view of male flower with 5 floral segments subtending 19 stamens (Stone 1346), X 
5; d, female flowers with well-developed bract-bracteolar floral cup, sepal lobes 
linear, style elongate and stigma horseshoe shaped (Stone 1346), X 3; e, fruit with 3- 
lobed bract, primary vein nearly continuous to tip, pair of lateral secondary veins 
parallel for shore distance, forming looping connections distally, adaxial bracteolar 
lobe enclosing nut (Stone 1346), X 1/4; f, transverse section of fruit at equator, 
secondary partition oriented in north-south direction, husk thin, shell thin, cartila- 
ginous, 8-chambered (Stone 1346), X 2. g-j, O. mexicana subsp. costaricensis: g, 
leaflet with auricles at base, slightly revolute, secondary veins curve upward toward 
tip, then branch and fuse near margin (Stone 2680), X 3/4; h, adaxial view of sessile 
male flower with 4 hooded floral segments (proximal segment removed), aborted 
pistil in center, and 8 stamens borne in one series removed to expose slightly raised, 
rectangular receptacle (Stone 2680), X 10; i, female flowers with spreading sepals, 
essentially obsolete style, and horseshoe shaped stigma (Stone 2680), X 5; j, fruit 
with 3-lobed bract, central lobe with primary and two secondary veins extending 
nearly to the tip, secondaries looping only in the distal one-third, two lateral lobes 
with strong primary vein and faint, looping secondaries, adaxial bracteolar lobe 
enclosing nut (Stone 3632), X 1/2. 




pterocarpa 



35 



36 FIELDIANA: BOTANY, VOLUME 40 

3b. Petiole long, (1.4)2.5-5.5 cm.; petiole and rachis glabrous; leaflets (6)8- 
12(16), short-petioluled (1-3 mm.), obtuse at base; basal leaflets smaller 
than median ones, but never less than one-fourth their length; male flowers 
sessile, pedicel (if present) less than 0.75 mm. ; fruit glabrous. 

4. Alfaroa williamsii subsp. tapantiensis. 

4a. Petiole often hairy at base; leaflets ( 4 )6-8, petiolules 5-15 mm. ; male flow- 
ers elongate, with 3-4 floral segments only loosely subtending 16-19 
stamens; fruit large, 3-winged, lateral wing span to 13 cm. 

6. Oreomunnea pterocarpa. 

4b. Petiole glabrous; leaflets 6-12(18), petiolules 1-5(10) mm.; male flowers 
compact, hooded, with 4 floral segments each tightly cupped around 3 
stamens, 12 stamens total; fruit large (to 3 cm.), wingless nut with 
prominent circular tab at base 5a. 

5a. Petiole (4)5-9(11) cm.; leaflets (6)8-12(18); fruits medium size (to 3.5 
cm.), obloid, surface deeply corrugated with pronounced longitudinal 
ribs and grooves and thick husk ( 1-7.5 mm.) .... 3. Alfaroa manningii. 

5b. Petiole (1)2-5(7.5) cm.; leaflets (6)8-10(16); fruits variable in size, 
spheroid (2.5) cm.) to oblong (1.7 x 3.8 cm.), surface nearly smooth, 
faint longitudinal ribs and thin husk (0.3-1.5 mm.) 

2. Alfaroa guanacastensis. 

ALFAROA Standley 

REFERENCES: P. C. Standley, Alfaroa, a new genus of trees of 
the family Juglandaceae from Costa Rica, Journ. Wash. Acad. 
Sci. 17:77-79. 1927. W. E. Manning, The genus Alfaroa, Bull. 
Torrey Bot. Club 76:196-209. 1949. W. E. Manning, Alfaroa and 
Engelhardtia in the New World, Bull. Torrey Bot. Club 86: 190-198. 
1959. 

Trees or rarely large shrubs; bark tight, or with small chips exfoliating, surface 
reddish-brown with congested lenticels, interior of bark pink with white streaks or 
orange-yellow ; sap wood white, heartwood pink, fine, straight grained ; buds glabrous 
or pubescent. Leaves glabrous or pubescent, decussate, occasionally whorled, 
infrequently alternate; petioles short to long; leaflets 6-18(30), sessile to short 
petiolulate, margins entire, or serrate on young plants and sucker shoots. Inflor- 
escences borne terminally with flush of new growth of pink leaves, or occasionally 
terminal on axillary shoots of old wood; female and male inflorescences either 
separate and terminal, or combined into an androgynous panicle with central female 
catkin flanked by one or more pairs of male catkins, or rarely with central male 
catkin subtended by female flowers. Male flowers numerous, alternately arranged, 
compact or elongate; floral segments 4-7, flat or hooded; stamens 6-12 in one series. 
Pollen tripororate (2-8), isopolar, suboblate-oblate; amb triangular to rounded 
triangular, 20 -2 6 /mm in diameter, pores circular, nexine thick, from one-third to 
equalling tectum in thickness. Female flowers numerous, alternately arranged; 
floral cup sometimes elongated into a pedestal consisting of a 3-lobed abaxial bract 
and an adaxial bracteolar rim; calyx tube fused to floral cup at base, distinct above, 



BURGER: FLORA COSTARICENSIS 37 

4 broad sepal lobes reflexed at time of pollination to expose stigma, or arched to 
form sheltered chamber; style obsolete to long tapering, bifurcate with shallow to 
deep cleft separating stylar arms; stigma weakly 4-parted, horseshoe shaped, 
carinal, verrucose stigmatic surface confined to rim and outer surface. Fruit medium 
to large drupaceous nut, ellipsoid to obloid, without wings, 8-chambered at equator; 
calyx and style persistent at apex; bract-bracteoles persisting as a small to large 
circular tab at base; husk leathery or hard, indehiscent, sometimes with pronounced 
corrugations; shell brittle to hard. Seedling with hypogeous cotyledons; first two 
aerial leaves alternate or opposite, simple or compound, leaves and leaflets entire 
or serrate. Chromosome number n= 16. 

Four Costa Rican species of Alfaroa are recognized, including 
one new species (A. guanacastensis) and subspecies (A. williamsii 
subsp. tapantiensis). A. costaricensis, which is the most distinctive 
member of the genus, has the widest range, extending from Mexico 
to Panama. It is sympatric in Costa Rica with the closely related 
A. williamsii. A. williamsii Molina subsp. williamsii is the only 
species of Alfaroa reported from Nicaragua. In addition, Alfaroas 
are known from Mexico (A mexicana Stone), Guatemala [A. 
guatemalensis (Standley) Williams], and Honduras (A. hondurensis 
Williams). A single immature specimen from Colombia (Killip & 
Smith 19285) was tentatively identified by Manning (1959) as A. 
manningii. However, the surface of the fruit is not deeply cor- 
rugated and ridged as that of A. manningii, and it seems likely that 
the South American collection represents a new, undescribed 
species. 

The species of Alfaroa in Costa Rica are trees of mid-elevations 
occurring in the premontane rainforests that extend from the 
borders of Nicaragua to Panama. Their disjunct distribution coin- 
cides with the many volcanoes and well-defined mountain ranges in 
northwest and central Costa Rica. The trees are often locally abun- 
dant, and they are readily recognized in the growing season by 
flushes of pink or dull red shoots. Locating Alfaroas in virgin rain- 
forest is aided considerably by the distinctive saplings in the under- 
story. The leaves are even-pinnate and at first are alternately 
arranged, but the later formed leaves have a distinctive decussate 
phyllotaxy. During the growing season the central leader displays 
a terminal apex with golden-yellow buds flanked by a pair of reddish 
young leaves with conduplicate leaflets. The adult trees are charac- 
terized by moderate size buttresses, tight bark with congested 
lenticels, generally pink interior, and fine grained wood that is white 
to pink. The lumber is of cabinet quality, so this is often one of the 
first species to be logged when new roads are opened. The flowers 



38 FIELDIANA: BOTANY, VOLUME 40 

are inconspicuous in the field, though a thorough search of the 
litter often uncovers dried remains of male catkins. The fruits are 
walnut-like with a thin or thick fibrous husk and a cartilaginous to 
hard shell. The fruits are similar to those of Oreomunnea in having 
a distinctive 8-chambered nut. 

The Costa Rican species of Alfaroa fall into two groups: (1) A. 
costaricensis and A. williamsii subsp. tapantiensis leaflets entire 
or serrate, the first pair of aerial seedling leaves opposite, pinnately 
compound, and leaflets serrate, young leaflets conduplicate at first 
but flattening out in primoidal stage (leaflet less than 1.5 mm. 
wide); (2) A. guanacastensis and A. manningii leaflets always 
entire, the first pair of aerial seedling leaves alternate, or opposite 
and simple or compound, young leaflets conduplicate throughout 
early stages of leaf expansion (leaflet over 10 mm. wide). There is 
probably sufficient additional evidence to recognize these groups 
formally, but I am postponing a decision on this matter until more 
collections are available. 

1. Alfaroa costaricensis Standley, Journ. Wash. Acad. Sci. 17: 78. 
1927. Figure 6a-d. 

Trees, or large shrubs, to 23 m. tall and 90 cm. dbh; buttresses small or absent; 
bark tight, to 1 cm. thick, interior pink with white streaks or infrequently pale 
orange; buds and shoot usually covered with long (1.5 mm.), coarse hairs, wearing 
thin as season progresses. Leaves mainly decussate, occasionally alternate, or 
whorled; petioles 0.4-2(3) cm., pubescent; rachises 10-15(30) cm., pubescent; leaf- 
lets (8)12-24(30), opposite to subopposite, lower ones conspicuously reduced, mainly 
entire, sometimes serrate on apical portion, coarsely serrate on sucker shoots and 
seedlings, truncate to obtuse and flat to broadly revolute at base, waxy green and 
glabrous above, except along costa, dull green below, hirtellous along nerves and 
often puberulent between, sessile or essentially so. Female inflorescences terminal 
on new growth, stiff and erect, with or without male catkins or individual male 
flowers at base, to 65 flowers per spike, often found persisting in dried state several 
weeks after flowering; male catkins alternate or decussate, to 16 cm. long and 10 
catkins per branch, up to 40 or 50 forming congested terminal panicle on new 
growth; androgynous panicles less common, female spike central, subtended by 
1-4 short (5-7.5 cm.) lateral male catkins, or with a few sessile male flowers at base 
or, rarely, with a central male catkin subtended by female flowers. Male flowers 
with a conspicuous pedicel, 1-2(8) mm.; 3-lobed bract short and blunt to tapered; 
floral segments 4-7, reflexed at maturity and not enfolding the stamens; stamens 
6-11. Pollen subtriangular in amb (polar) view, 24.8/tm in diameter. Female flowers 
sessile; 3-lobed bract not elongated into pedestal, central lobe pronounced, acute to 
tapered; adaxial bracteolar rim essentially obsolete; sepal lobes 4, reflexed to 
expose stigma at pollination; style elongate, bifurcate with deep cleft; stigmatic 
lobes rounded to horseshoe shaped, bright red at maturity. Fruit ellipsoid to ovoid, 
sometimes slightly compressed in the plane of carpel fusion, up to 2 cm. diameter 



BURGER: FLORA COSTARICENSIS 39 

and 3 cm. long; calyx beak 2-5 mm. long, persistent at apex; bract-bracteolar tab 
small (3-5 mm.), appressed to nut at base, the bract sometimes distinguished by re- 
tention of a tapered central lobe (up to 2 mm. long) flanked by 2 blunt (less than 1 
mm. long) lateral lobes; husk essentially absent, less than 0.5 mm. thick, surface hir- 
tellous (2 mm. long hairs), becoming glabrous and smooth on weathering; shell ex- 
tremely thin, less than 1 mm., cartilaginous. Seedling with first two aerial leaves 
opposite, compound, leaflets coarsely serrate; succeeding several leaves alternate, 
pinnately compound with serrate leaflets; leaves becoming decussate with mostly 
entire leaflets in sapling stage. 

This species is distributed more widely than any other member of 
the genus. It is known from Mexico, Guatemala, Costa Rica, and 
Panama, and has an elevational range in Costa Rica from 600 m. 
(Turrialba, Keith 371) to 2220 m. (Rio Negro, Mora CMV-21). 
Several local names are used goalin in Turrialba (Keith 371), 
gualin at Muneco (Standley 33501), and campano chile on the Rio 
Negro (Mora CMV-21). Herbarium records indicate that this 
species was once a fairly common forest tree in Costa Rica. Collec- 
tions have been made in the Provinces of Alajuela, Cartago, 
Guanacaste, Heredia, and San Jose. The tree, which is prized for its 
timber, is often the first removed when virgin forests are logged. 
Attempts to relocate early collection sites have been partially suc- 
cessful. Trees from "La Palma de San Ramon," Alajuela, were 
sampled in 1928 (Brenes 6300) and again in 1966 (Stone 2326). Most 
of the area around San Ramon has been converted to pasture and 
farmland for sugarcane. Only two remnant trees were located on a 
windswept ridge-top about 10 km. north of the city. Records by 
Skutch from Heredia (Skutch 4684, 4686) have been confirmed by 
repeated visits to Vara Blanca from 1967 (Stone 21 73) through 1975 
(Stone 3621). The trees are scattered in broken pastures and virgin 
forest at approximately 1700 m. elevation. The record from San 
Jose Province was first recorded by Stork 1 700 from Santa Maria de 
Dota. I relocated a few trees south of the city in 1968 (Stone 
2679) on a steep mountain ridge above a pasture broken with oaks, 
dogwoods, and tree ferns. The report from Guanacaste is based on 
my 1972 collection (Stone 3383) from the exquisite cloud forest 
near the Quaker community at Monteverde. Some of the largest 
trees that I have seen once formed stately groves in the mountains 
south of Muneco in Cartago Province, but extensive logging in the 
past several years has reduced the population considerably. 

Vivid reddish flushes of new growth appear in January at the 
beginning of the dry season. February seems to be the month for 
peak flowering, though at least sporadic flowering occurs in 



40 FIELDIANA: BOTANY, VOLUME 40 

March, June, and November. Immature to mature fruits have 
been collected in February, March, April, June, and August. While 
the trees are monoecious, there is some evidence that one sex may 
predominate in a particular season, and often whole branches will 
display either congested panicles of male flowers or elongate female 
spikes with highly reduced male catkins at the base. 

Alfaroa costaricensis is the most distinctive member of the genus. 
The Mexican and Guatemalan trees tend to have longer petiolules 
and a somewhat less truncate leaflet than the Costa Rican and 
Panamanian specimens, but the taxon is easily identified by its 
highly reduced petiole and lower leaflets, and the pubescent stems, 
leaves, and fruits. This species is most closely related to A. 
williamsii. Plants of both taxa produce at least some leaflets with 
toothed margins. The first pair of aerial leaves of the seedlings are 
normally opposite and pinnately compound with coarsely serrate 
leaflets. The male and female flowers also have much in common, 
though there are subtle, distinctive differences. A. costaricensis 
has a short to long pedicel supporting the male flower, and the 
female flower is hirsuite. A. williamsii has staminate flowers with 
an extremely short pedicel; the female flowers are covered with 
peltate scales but are without hairs. The two species also have 
several distinctive vegetative differences. The former has a pubes- 
cent petiole and rachis, an extremely short petiole, and leaflets 
that are mainly truncate at the base, whereas the latter is glabrous 
throughout, the petiole is relatively long, and the leaflets are mainly 
obtuse at the base. Intermediates between these species have been 
collected. Hybridization, which is suspected, is discussed under A. 
williamsii. 

2. Alfaroa guanacastensis D. Stone, sp. nov. Figure 7a-g. 

Arbor usque ad 27 m. alta. Folia pinnata decussate; foliola (6)8-10(16), coriacea, 
elliptica vel oblongo-lanceolata, basi symmetrica, indumento in pagina inferiore 
saepe preaesenti sed sparsissimo, petiolulis 2-7(10) mm. longis. Inflorescentiae 
masculinae et femineae terminales sed separatae. Flores masculini ca. 3 mm. lati, 
bracteis 3-lobatis, perianthio 4-partito, staminibus 12. Flores feminei 7-8 mm. longi, 
perianthio 4-partito, lobi perianthii cucullati, stylo obsoleto, stigmate subglobosa. 
Fructus sphaerici (ad 2.5 cm. diam.) vel ellipsoidi (1.7 x 3.8 cm.), in longitudinem 
dilute parcati, pagina fere laevi, vagina aliquantum tenui (0.3-1.5 mm. crassa). 
Germinatio hypogaea. HOLOTYPUS: Stone 2167, Duke University; ISOTYPI: 
A.CR, F.US. 

Trees to 27 m. tall and 90 m. dbh; buttresses small to large, extending to 3 m. or 
more up trunk; bark tight or with small chips exfoliating, to 1 cm. thick, reddish- 
brown exterior, interior pink throughout or pink toward surface and orange toward 



BURGER: FLORA COSTARICENSIS 41 

center; buds and shoot glabrous. Leaves decussate, glabrous; petioles (1)2-5(7.5) 
cm.; rachises commonly 4-16(22) cm.; leaflets (6)8-10(16), opposite to subopposite, 
entire, obtuse at base, symmetrical, slightly decurrent on petiolule, flat to moder- 
ately revolute, glabrous except for occasional presence of a few short hairs at base 
between midrib and margins; petiolules 2-7(10) mm. Female inflorescences terminal 
on new growth, stiff and erect up to 45 flowers per spike; male catkins 2-6 per 
branch, forming congested terminal panicle on new growth, or arising from axillary 
buds on old wood; terminal androgynous panicles with 1-2 decussate pairs of male 
catkins subtending 1-4 female flowers in a terminal catkin. Male flowers with 
gardenia-like odor, sessile or essentially so; 3-lobed bract short, wide, and blunt; 
floral segments 4, hooded, each segment partially enclosing 3 stamens; stamens 12. 
Pollen subtriangular in amb (polar) view, 21.8 /j.m in diameter. Female flowers 
stalked; pedestal formed by fusion of a faintly 3-lobed abaxial bract with an adaxial 
bracteolar rim; sepal lobes 4, arched over stigma to form sheltered chamber at 
pollination (Stone 2167) or reflexed (Stone 3629); style essentially obsolete to short; 
stigma lobes horseshoe shaped. Fruit variable in shape, spheroid (to 2.5 cm.) to 
oblong (1.7 X 3.8 cm.); calyx beak (4-6 mm.) persistent at apex; bract-bracteolar 
tab large (8-10 mm.), appressed to nut at base; husk relatively thin, 3 mm. or so in 
fresh state, 0.3-1.5 mm. dried, surface nearly smooth, faint longitudinal grooves 
and ridges; shell 1-2 mm. thick, hard even in fresh state. Seedling with first two 
aerial leaves variable, opposite to subopposite, simple (Stone 2716) or opposite- 
compound (Stone 3254), leaflets entire (Stone 2716), rarely with a few minute teeth 
(Stone 3254); succeeding several leaves alternate, pinnately compound with entire 
leaflets; leaves becoming decussate in the sapling stage. 

Alfaroa guanacastensis is known only from the Cordillera de 
Guanacaste, including Volcan Orosi, Volcan Miravalles, Volcan 
Tenorio, and the San Ramon area on the southeastern terminus of 
the Cordillera de Tilaran. This species is present in the premontane 
rainforest, 650-1000 m., occurring at the lower elevations on the 
wet Caribbean slopes and nearer the crest and in mountain passes 
where the moist eastern air spills over to the Pacific side. Peak 
flowering occurs from February (Stone 3629) through May (Stone 
3259); fruits develop in May (Stone 3259) and June (Stone 2753) 
and mature in January (Stone 2327), April (Stone 2167), and 
November (Stone 2327, 2716). 

Populational differences among the four collection sites are 
apparent. At one time I had considered describing at least one addi- 
tional species from this complex, but then decided that the vegeta- 
tive material was too similar for routine identification. In addition, 
the various fertile collections which look different may, in fact, 
represent slightly different developmental stages. The leaflets of 
trees from Orosi, Tenorio, and San Ramon are on the average larger 
and more coriaceous than those from Miravalles. The sepal lobes 
are reflexed at pollination (and through fruit maturation) in the 



42 FIELDIANA: BOTANY, VOLUME 40 

Miravalles specimens (Stone 3629), whereas they are arched over 
the stigma in trees at the other sites (e.g., San Ramon, Stone 2753). 
The mature fruits are variable in shape: those from Orosi and 
Tenorio are more oblong; fruits from Miravalles vary from oblong 
to spheroid, but tend to be compressed in the plane of carpel fusion; 
the trees from San Ramon produce spheroid fruits of uniform size. 
The seedlings were at first thought to be highly distinctive in the 
Miravalles population. The first aerial leaves are uniformly opposite 
and compound, a condition previously encountered only in A. cos- 
taricensis and A. williamsii, although the latter two have serrate 
instead of entire leaflets. The single seedling from Tenorio (Stone 
2167B) has opposite-simple first leaves as found in A. manningii. 
Somewhat later I discovered that Orosi seedlings from under the 
same parental tree may have either opposite-compound (Stone 
2333) or opposite-simple leaves (Stone 2553). Greenhouse-ger- 
minated seed confirmed this condition for the San Ramon popula- 
tion (Stone GH-117). The type of variability witnessed in A. 
guanacastensis is probably commonplace in tropical trees, but not 
often realized because of the paucity of samples. 

This species is closely related to A. manningii and is vegetatively 
very similar to A. guatemalensis and A. mexicana. The leaves are 
generally smaller, the petioles shorter, and the leaflets fewer than 
those of A. manningii. The fruits are also reasonably distinctive. 
In contrast to the thick, deeply corrugated husks of A. manningii, 
fruits of A. guanacastensis are basically smooth in outline with 
faint longitudinal ridges and a relatively thin husk. 

3. Alfaroa manningii Leon, Ceiba 4:44. 1953. Figure 7h-j. 

Trees to 24 m. tall and 90 cm. dbh; buttresses small to medium; bark tight, reddish 
brown exterior, pink interior, becoming orange to yellow toward center; buds and 
shoots glabrous. Leaves decussate, glabrous; petioles (4)5-9(11) cm.; rachises com- 
monly (50)90-230(290) cm.; leaflets (6)8-12(18), opposite to subopposite, entire, 
obtuse at base, symmetrical, decurrent on petiolule, very slightly revolute, 
glabrous; petiolules (1)2-5(10) mm. Female inflorescences terminal on new growth, 
stiff and erect, up to 40 or 50 flowers per spike; male catkins alternate or decussate, 
1-6 per branch, forming congested terminal panicle on new growth or arising from 
axillary buds on old wood, up to 18 cm. long and pendent at maturity; androgynous 
panicles less common, terminal on new growth, female spike central with 1-4 lateral 
male catkins at base. Male flowers with gardenia-like odor, compact, sessile or 
essentially so; 3-lobed bract subtending 4 hooded floral segments, each of which 
partially encloses 3 stamens; stamens 12. Pollen subtriangular in amb (polar) view, 
21.7 /urn in diameter. Female flowers stalked; pedestal formed by fusion of a faintly 
3-lobed abaxial bract with an adaxial bracteolar rim; sepal lobes 4, arched over 
stigma to form sheltered chamber at pollination; style essentially obsolete; stigma 



BURGER: FLORA COSTARICENSIS 43 

lobes horseshoe shaped. Fruit obloid, up to 3.5 cm. in diameter and 3 cm. long, apex 
slightly concave; calyx beak (4-5 mm.) persistent; bract-bracteolar tab at base 
large (to 16 mm.), more or less circular; husk of irregular thickness, 1-7.5 mm., 
surface deeply corrugated, 8-12 pronounced longitudinal ribs or flanges that extend 
from apex to equator, diminishing toward base; shell 1-2 mm. thick, hard even in 
fresh state. Seedling with the first two aerial leaves simple, alternate or opposite, 
and entire; succeeding several leaves compound; later formed leaves decussate with 
entire leaflets. 

Gavilan Colorado is a valued lumber tree of the Platanillo area of 
northeastern Cartago Province. This species grows to be a very 
large tree (up to 90 cm. dbh) in the premontane rainforest between 
650-1,200 m. Fertile specimens are recorded only from the vicinity 
of Rio Platanillo. Oreomunnea pterocarpa, gavilan bianco, is a 
common associate in this area. Sterile samples of what appear to 
be the same species, along with Oreomunnea mexicana, have been 
collected near the headwaters of the Rio Sapo, about 28 km. north- 
east of the village of Platanillo. Peak flowering occurs in March and 
April, though the presence of a range of fruit sizes in April as well 
as August suggests a more prolonged flowering period. Occasion- 
ally, trees bear only male flowers (Stone 2220, 25 March 1967), but 
most commonly both sexes are present. These trees appear to be 
truly bisexual, rather than polygamodioecious as reported by 
Skutch (in Manning, 1949). The exclusive production of male 
flowers is encountered in young trees, whereas adults display a 
great deal of variability in the type of inflorescence that is produced 
on a particular branch. I suspect also that the same tree shows 
seasonal and yearly differences in the frequency of production of 
male and female flowers. 

This narrow Costa Rican endemic has characteristics in common 
with A. guanacastensis. The leaves of A. manningii are generally 
larger with longer petioles and often have more leaflets. The fruits 
are also large, quite heavy, and deeply corrugated with 8-12 longi- 
tudinal ribs or flanges, and they bear a persistent calyx beak at the 
apex and a large, more or less circular, bract-bracteolar tab at the 
base. Manning (1959) tentatively referred a Colombian collection 
(Killip & Smith 19285) to this species, but has since changed his 
mind (pers. comm. ). Though the fruits are small and possibly 
immature, they do not display the prominent ridges characteristic 
of the Costa Rican species. Besides Juglans, the Killip & Smith 
collection of Alfaroa is the only member of the family known from 
South America. 



44 FIELDIANA: BOTANY, VOLUME 40 

4. Alfaroa williamsii Molina subsp. tapantiensis D. Stone, subsp. 
nov. Figure 6e-i. 

Arbor usque ad 30 m. alta. Folia pinnata decussata vel alterna, glabra, petiolis 
(1.4)2.5-5.5 cm. longis; folia 6-12 (16), basi obtusa, petiolulis stamina includentes. 
Fructus glabri. Germinatio hypogaea. HOLOTYPUS: Stone 3119, Duke Univer- 
sity; ISOTYPI: A, CR, F, US. 

Trees to 30 m. tall and 90 cm. dbh; buttresses small to moderate; bark tight, 
interior pink; buds glabrous, or rarely with a few coarse trichomes. Leaves mainly 
decussate or alternate; petioles (1.4)2.5-5.5 cm., glabrous; rachises 7.5-12 cm., 
glabrous; leaflets (6)8-12(16), opposite to subopposite, approximately of equal 
size, lower ones greatly reduced only rarely, mainly entire, occasionally with a few 
small teeth on apical end, coarsely serrate on sucker shoots and seedlings, mainly 
obtuse at base, sometimes truncate, often asymmetrical with basiscopic side decur- 
rent on petiolule, only slightly revolute if at all, glabrous on both surfaces; 
petiolules 1-3 mm. Female inflorescences terminal on new growth, stiff and erect, 
to 15 cm. long, 27 or more alternate flowers; male catkins alternate or decussate, 
6-9 catkins per branch, more or less erect, to 8.5 cm., forming congested terminal 
panicle on new growth; androgynous panicles terminal on new growth of two kinds; 
female catkin central with 1-2 individual male flowers sessile at base of inflores- 
cence, or, more commonly, central female spike flanked at base by 1-11 male catkins. 
Male flowers sessile or essentially so (pedicel not exceeding 0.75 mm. long); 3-lobed 
bract short and blunt, or moderately tapered; floral segments 4, each one slightly 
curved at the tips to enfold (1)2(3) stamens, (6)8(9) stamens total. Pollen subtri- 
angular in amb (polar) view, 23.9 /Am. in diameter. Female flowers sessile; 3-lobed 
bract not elongated into pedestal, central lobe pronounced, acute to tapered; 
adaxial bracteolar rim essentially obsolete; sepal lobes 4, reflexed to expose stigma 
at pollination; style elongate, bifurcate, shallow to deep cleft; stigmatic lobes 
rounded to horseshoe shaped. Fruit ellipsoid (1.5 cm. X 2 cm.) to ovoid (1.5 cm. 
diameter), sometimes compressed in the plane of carpel fusion; calyx beak 2-3 mm. 
long, persistent at apex; bract-bracteolar tab inconspicuous at base; husk essen- 
tially absent, less than 0.1 mm. thick, surface nearly smooth, with 8 or so very faint 
ridges; shell extremely thin, less than 0.5 mm., cartilaginous. Seedling with first 
two aerial leaves opposite to subopposite, simple or, more commonly, compound 
leaves or leaflets coarsely serrate; succeeding several leaves alternate, pinnately 
compound with serrate leaflets; leaves becoming decussate with mainly entire 
leaflets in sapling stage. 

Sterile trees and one fruiting specimen have been observed above 
Monteverde (1300 m.) on the Cordillera de Tilaran (Stone 3384, 
3627, 3628). The best representation comes from the terminus of the 
Cordillera de Talamanca south of the city of Cartago where Alfaroa 
williamsii subsp. tapantiensis is associated with A. costaricensis 
and Oreomunnea mexicana. Flowering specimens have been col- 
lected in March (Stone 3119, 3633) and April (Poveda 851a); how- 
ever, since green fruit has also been observed at these times, the 
initiation of flowering probably coincides with the flush of new 
growth in mid-January. Germination occurs immediately following 



BURGER: FLORA COSTARICENSIS 45 

fruit maturation, as evidenced by the range of green fruits to seeds 
with exposed radicles found nestled in the rich litter on the moist 
forest floor. 

Until now Alfaroa williamsii has been reported only from the 
Departments of Jinotega and Matagalpa in central Nicaragua. The 
recent Costa Rican collections from Tapanti (Stone 3119} and the 
vicinity of San Isidro de Cartago (Poveda 851, 851a; Stone 3630, 
3631, 3633), correspond closely to the Nicaraguan specimens 
(Williams et al 20143, 23176, 23717; Stone 2178, 2179a, 2180, 3249, 
3250). The new Costa Rican subspecies is distinguished from A. 
williamsii subsp. williamsii primarily on the basis of the male 
flower. Subspecies tapantiensis has a well defined, oblong recep- 
tacle bearing (6)8(9) stamens. Each pair of stamens is subtended by 
a floral segment (4 total) that forms a partial hood over the tips of 
the anthers at anthesis. Subspecies williamsii has a more or less 
elongate receptacle with 6-11 stamens, subtended by 4-7 floral seg- 
ments that are variable in position and shape; they open flat and do 
not enfold the stamens at maturity. Because no male flowers have 
been collected at Monteverde, the assignment of these specimens to 
subsp. tapantiensis is speculative at this time. Field identification 
of the species is based on the glabrous leaves, long petiole (on the 
average somewhat longer in subsp. williamsii than in subsp. 
tapantiensis}, lower leaflets approximating upper leaflets in size, 
and occasional serrations on the leaflet margins. 

A discussion of the close relationship of Alfaroa williamsii to A. 
costaricensis is included under the latter species. Not surprising 
perhaps is the discovery of a putative hybrid between these species 
from Estrella, Cartago Province (Stone 3379: 6 July 1972; 2 
January 1973). The tree was sterile, even though it was reasonably 
large with a 23 cm. dbh and a height of 15 m. The specimen appears 
intermediate in several respects: the shoots range from glabrous 
(cf. A. williamsii} to moderately pubescent (cf. A. costaricensis); 
the petioles are of medium-length (ca. 2-3.5 cm.); leaflet number is 
most commonly 10 (8-14; cf. A. williamsii); the leaflets range from 
obtuse to truncate at the base (cf. A. costaricensis); the lowermost 
leaflets may be reduced, but are never less than one-fourth the size 
of the upper leaflets (cf. A. williamsii). The "Alto de la Estrella" 
was visited by Standley in 1924 at a time when A. costaricensis 
was a common tree of the "wet forest" (Standley 39122, 39217}. The 
putative hybrid was located on cut-over land on the lower reaches of 
the mountain. A. williamsii subsp. tapantiensis grows today within 



46 FIELDIANA: BOTANY, VOLUME 40 

2 km. of Estrella, and both putative parents might still be sym- 
patric on the upper slopes. Alfaroa costaricensis Standley var. 
elongata Manning, which was described by Manning (1949) from 
a single male-flowered collection (Skutch 4685), is probably a hybrid 
also. Manning had questioned the taxonomic placement of the 
variety and correctly pointed out that it differs from the species 
by having glabrous foliage, distinctly petioled leaves, and sessile 
stamina te flowers with hooded floral segments (cf. A. williamsii ; 
see Manning, 1949, Figs. 1, 16, 17: Skutch 4685), but does have the 
truncate leaflet bases as in A. costaricensis. In contrast to Stone 
3379, specimens from this tree have a larger number of leaflets 
(14-18[22]), as in A. costaricensis. If Skutch 4685 is, in fact, a 
hybrid, the enormous size of the tree (90 m. dbh and 30 m. tall: 
Skutch, in Manning, 1949) indicates that the hybridization occurred 
when the forest was virgin. Attempts to relocate "elongata" at 
Vera Blanca have not been successful. A. williamsii has not been 
collected in this area, although A. costaricensis is still fairly com- 
mon in the open pastures at 1700 m. elevation. This is the first 
report of hybridization in Alfaroa. 



OREOMUNNEA Oersted 

REFERENCES: P. C. Standley, The American species of Engel- 
hardtia, Trop. Woods 12: 12-15. 1927. D. E. Stone, New World 
Juglandaceae, III. A new perspective of the tropical members with 
winged fruits. Ann. Missouri Bot. Card. 59:297-321. 1972. 

Trees or rarely large shrubs; buttresses moderate to well developed; bark ex- 
foliating or tight, surface reddish-brown, interior bright orange to yellow-orange; 
wood white throughout or heartwood sometimes pink, fine, straight grained; buds 
studded with yellow peltate scales, without hairs. Leaves occasionally puberulent in 
young shoots but glabrous at maturity, mainly decussate, occasionally alternate; 
petioles short to long; leaflets 4-12, generally long petiolulate, mainly entire, or 
serrate on young plants and sucker shoots. Inflorescences borne terminally with 
flush of new growth of yellow-red or pink leaves, or occasionally terminal on axillary 
shoots of old wood; female and male inflorescences either separate, or combined in 
androgynous panicles with central female catkin flanked by 1-6 male catkins. Male 
flowers numerous, alternately arranged, sessile or essentially so, compact or elon- 
gate, floral segments 4-6, flat or hooded; stamens 8(9) in one series, or 16-19 
stamens in two series. Pollen tripororate (2-8), isopolar, suboblate-oblate; amb 
triangular to rounded-triangular, 20-26 /u,m in diameter; pores circular; nexine 
thick, from one-third to equalling tectum in thickness. Female flowers numerous, 
alternately arranged, sessile or nearly so; bract-bracteolar floral cup forms a pedes- 
tal with 3-lobed bract abaxial, bracteolar rim adaxial, calyx tube fused to floral cup 



BURGER: FLORA COSTARICENSIS 47 

at base, forming distinct tube above; sepal lobes 4, narrow or broad, extending to 
summit of stigma or beyond, reflexed at time of pollination, or arched to form 
sheltered chamber; style short or long-tapering, bifurcate with deep clett separating 
stylar arms; stigma weakly 4-parted, horseshoe shaped, carinal, verrucose stigmatic 
surface confined to rim and outer surface. Fruit medium to large, 3-winged; adaxial 
bracteolar lobe covering nut at maturity; nut small, globose, 8-chambered at 
equator; husk essentially obsolete; shell cartilaginous. Seedling with hypogeous 
cotyledons; first two aerial leaves opposite and simple or compound, with leaves or 
leaflets entire or serrate. Chromosome number JV=16. 

The genus Oreomunnea is extant in the New World with two 
species: O. pterocarpa, an endemic to Costa Rica; and O. mexicana, 
which ranges from southern Mexico to Costa Rica. This genus 
superficially resembles the Old World taxon Engelhardia and is 
treated by some taxonomists as Engelhardia Sect. Oreomunnea 
(de Candolle, 1862, 1864, 1914; Standley, 1927a; Manning, 1959; 
Jacobs, 1960). However, in spite of the disparity between the 
winged fruit in Oreomunnea and the nut-like fruit inAlfaroa, these 
two genera have more characters in common with each other than 
either one does with the southeastern Asian Engelhardia (Oersted, 
1870; Stone, 1972). 

In Costa Rica, Oreomunnea is a tree restricted for the most part 
to the rainforests of Cartago Province. O. pterocarpa is apparently 
endemic to the Rio Reventazon Valley and its tributaries, although 
there is one unconfirmed report of O. pterocarpa from Laguna Hule 
in Alajuela Province (see Stone, 1972). O. mexicana, which occurs in 
scattered sites at higher elevations in Cartago Province, grows as 
far west as the Pan American Highway, extending into San Jose 
Province. Surprisingly, there are no reports of this species occurring 
between Jinotega, Nicaragua, and Cartago, Costa Rica, a distance 
of about 650 km. Fruiting material of both species is distinctive 
because of the 3-winged bract. Sterile trees are less easily iden- 
tified, though the exfoliating platelets of bark found in O. mexicana 
are not common in tropical forests. As in Alfaroa, seedlings and 
saplings of the understory give the best clues. O. mexicana has 
pinnately compound leaves, alternate at first, later opposite, and 
leaflets that are coarsely serrate and vivid pink when first un- 
folding. Seedlings and saplings of O. pterocarpa are less distinctive. 
However, the leaves are glaucous below, often hairy on the petiole 
base, alternate-simple-entire in the early stages, becoming opposite- 
compound with entire leaflets. 

5. Oreomunnea mexicana (Standley) Leroy, Bull. Mus. Hist. Nat. 
(Paris) Ser. 3. 23: 127. 1951. Engelhardtia mexicana Standley, Trop. 



48 FIELDIANA: BOTANY, VOLUME 40 

Woods 12:15. 1927. . nicaraguensis Molina, Fieldina, Bot. 31:358. 
1968. 

Oreomunnea mexicana (Standley) Leroy subsp. costaricensis 
Stone, Ann. Missouri Bot. Card. 59:320. 1972. Figure 8g-j. 

Trees to 32 m. tall and 76 cm. dbh; buttresses moderately developed; bark ex- 
foliating, reddish-brown surface, bright orange interior; buds and shoots studded 
with bronzy-yellow, peltate scales, without hairs. Leaves decussate, puberulent in 
bud, glabrous at maturity; petioles 1-3 cm.; rachises 2-12 cm.; leaflets 4-12, opposite 
to subopposite, mainly entire, coarse serrations on distal half of stump sprouts and 
some shoots on the upper branches, symmetrical to asymmetrical at base, revolute 
on one or both margins, but most pronounced on basiscopic side, auricles often 
present on one or both margins; petiolules to 3 mm. Female inflorescence terminal 
on new growth, one to several in a cluster, erect at anthesis, with 30 or more flowers 
per catkin, becoming pendent at maturity with cluster of fruits; male inflorescence 
forming congested terminal panicle with 1-6 pendent catkins ; terminal androgynous 
panicles common, with central female spike flanked at base by 1-3 pairs of decussate 
catkins. Male flowers small; 3-lobed abaxial bract cupped; floral segments 4 (rarely 
5), hooded, each segment partially enclosing 2, or rarely 3 stamens at anthesis; 
stamens 8(9) in one series. Pollen not examined. Female flowers sessile or nearly so, 
oriented at 45 to axis of catkin; floral tube short, sepal lobes and stigma not raised 
much beyond floral cup at anthesis; sepal lobes 4, broad, spread at maturity, ex- 
tending well beyond style and exposing stigma at pollination; style short with deep 
cleft separating stylar arms. Fruit of medium size, 3-winged, lateral wing spread to 
4.5 cm., central wing to 3.5 cm. long; adaxial bracteolar lobe covering small (to 10 
mm.), globose nut; husk papery thin (.03 mm.); shell cartilaginous, thin (.11 mm.). 
Seedling with first two aerial leaves opposite and pinnately compound, with 
coarsely serrate leaflets; succeeding several leaves alternate, pinnately compound, 
with serrate leaflets; leaves becoming decussate in sapling stage with leaflets 
mostly entire in more mature trees. 

This species, along with Alfaroa costaricensis, ranges from 
Mexico southward to Costa Rica. As presently defined, Oreomun- 
nea mexicana subsp. mexicana is known from Mexico, Guatemala, 
and Nicaragua. O. mexicana subsp. costaricensis has been reported 
only from Costa Rica, although the Boquette area in Chiriqui Pro- 
vince, Panama, is a promising locality for future investigation. This 
subspecies ranges from 1100 to 1860 m. (Stone 3620) in the pro- 
vinces of Cartago and San Jose. Trees from the virgin forests above 
Tapanti and El Muneco are situated on fog-shrouded ridges. A few 
trees are still standing on the steep, hillside pastures above the Pan 
American Highway just south and west of the city of Cartago 
(Stone 3632). This subspecies is often sympatric with Alfaroa 
williamsii subsp. tapantiensis and is occasionally associated with 
A. costaricensis (Tapanti, Cartago) and A manningii (Valle Escon- 
dido, Cartago). Field identification is relatively simple. Seedlings 



BURGER: FLORA COSTARICENSIS 49 

and young saplings have odd-pinnate leaves that are at first alter- 
nate, later opposite. The new leaves are pale to vivid pink, and the 
narrow leaflets are numerous (18-20) and coarsely serrate. Shoots 
from saplings can be confused with A. costaricensis. However, the 
petiole and rachis of O. mexicana are puberulent, rather than pubes- 
cent, tiny auricles may be evident; and, particularly, the upper leaf- 
let surface is light green and the lower one almost silvery, rather 
than dull green. Large trees show a flush of new leaves in March- 
June, August, and again in November. The new leaves on older trees 
are more of a yellowish-red than the vivid pink shoots of its saplings 
or trees of Alfaroa, but, most distinctively, large, reddish-brown 
platelets of bark exfoliate from the larger trunks (over 45 cm.). 
Smaller trees have relatively smooth bark on the lower trunk and 
evidence of incipient exfoliation in the vicinity of the first major 
branches. Flowering occurs with a flush of new growth; records are 
available for 29 April (Stone 2177B), 1 June (Stone 3287), and 29 
August (Stone 2680). The only record of fruiting material of this 
species in Costa Rica was made on 1 March (Stone 3632), though 
young seedlings with the cotyledons still attached have been collect- 
ed on 20 January (Stone 2335), 29 April (Stone 2177A), 8 June 
(Stone 2746), and 13 November (Stone 271 8A ). 

The two subspecies of Oreomunnea mexicana that are recognized 
(Stone, 1972) apparently cannot be separated on the basis of vegeta- 
tive characters, and even the diagnostic floral differences are subtle. 
The Costa Rican subspecies has female flowers that are sessile, or 
nearly so, and oriented away from the floral axis (45 angle), and the 
sepal lobes are spread at anthesis. Subspecies mexicana has female 
flowers with conspicuous pedicels to 3 mm. long, the bract-bract- 
eolar cup is somewhat recurved so that the flower is oriented more 
or less parallel to the axis of the catkin, and the sepal lobes are 
incurved to form a chamber around the stigma at pollination. The 
mature fruits are also very similar: those of subsp. costaricensis 
are sessile or have pedicels reaching a maximum of 2 mm. and the 
sepals, enclosed by the bracteolar lobe, are spread; the pedicels of 
subsp. mexicana commonly range to 3 or 4 mm. and the sepals arch 
over the stigma. This species is quite different from the only other 
member of the genus, O. pterocarpa. In some respects O. mexicana 
combines certain vegetative features of Alfaroa costaricensis (i.e., 
serrate leaflets) with floral features characteristic of Engelhardia 
roxburghiana (floral morphology). 



50 FIELDIANA: BOTANY, VOLUME 40 

6. Oreomunnea pterocarpa Oersted, Vidensk. Meddel. Dansk 
Naturhist. Foren Kjdbenhavn 3:34. 1856. Engelhardtia pterocarpa 
(Oersted) Standley, Trop. Woods 12: 15. 1927. Figure 8a-f. 

Trees to 46 m. tall and 83 cm. dbh; buttresses well-developed; bark tight, surface 
gray or reddish-brown, interior yellow-orange; buds studded with butter-yellow pel- 
tate scales, without hairs. Leaves decussate, generally glabrous, pubescent at base 
of petiole and nodal area in saplings and sucker sprouts; petioles 3.5-6 cm.; rachises 
7-10 cm. ; leaflets (4)6-8, long petiolulate (5-15 mm. ), opposite to subopposite, always 
entire, symmetrical to asymmetrical at base, revolute on one or both margins, but 
most pronounced on basiscopic side, auricles absent. Inflorescences borne laterally 
on old wood or at junction of old and new wood; androgynous panicles with central 
female catkin of 15-20 flowers, erect at anthesis, becoming pendent at maturity with 
cluster of fruits, flanked at base by 2-3 pairs of decussate male catkins. Male flowers 
with 3-lobed abaxial bract long, narrow, and flat; floral segments 5-6, flat, irregu- 
larly positioned, stamens 16-19 in two disorganized series. Pollen subtriangular in 
amb (polar) view, 22.0 /tm in diameter. Female flowers sessile or nearly so, oriented 
at 45 to axis of catkin; floral tube elongate, sepal lobes and stigma raised well above 
floral cup at anthesis; sepal lobes 4, narrow, spread at maturity, extending to level 
of stigma but not beyond; stigma exposed at pollination; style elongate, with deep 
cleft separating stylar arms. Fruit large, 3-winged, lateral wing spread to 13 cm., 
central wing to 11 cm. long; adaxial bracteolar lobe covering medium size (to 15 
mm.), globose nut; husk papery thin; shell cartilaginous. Seedlings with first two 
aerial leaves opposite, simple and entire; succeeding several leaves alternate, simple 
and entire; followed by transition to compound leaves, and later abrupt shift to 
decussate phyllotaxy and entire leaflets. 

Gavilan bianco, as it is known locally in the Plantillo area, is 
endemic to the Atlantic watershed of Costa Rica, occurring along 
tributaries flowing into the Rio Reventazon in Cartago Province 
(Pittier, 1957). The tree has been reported to range from 200 to 
1500 m. elevation. Herbarium vouchers, however, only verify collec- 
tions between 550 and 820 m., although a cultivated tree in the 
Botanic Garden of the Universidad de Costa Rica in San Jose (1168 
m. ) is healthy and producing flowers, fruits, and viable seeds. This 
species is sympatric with Alfaroa manningii. Trees of the rainforest 
around Platanillo and Tuis commonly have plank buttresses extend- 
ing to 2.5 m. in diameter at the base. The bark is tight, often gray 
and the leaves are dark green above. The lower leaflet surface, 
rachis, petiole, and stems of new growth are glaucous. Flushes of 
new growth are usually vivid pink. Flowering overlaps with fruit 
maturation. Male and/or female flowers are recorded for the months 
of January (Stone 1346), March (Stone 1346), April (Leon 1523), 
and September (Leon 1819), while mature fruits are present in 
January (Stone 1016, Stone 1346), March (Stone 2222), April (Leon 
1523, Tonduz 18000), and July (Lankester, Stevens 468a, Stork 
2808). 



BURGER: FLORA COSTARICENSIS 51 

Oreomunnea pterocarpa is a very distinctive species and not 
easily confused with other members of the family. The fruits are 
three-winged as in its closest relative, O. mexicana, but the wing 
span is 2-3 times larger. Certain aspects of the male and female 
flowers are characteristic ofAlfaroa costaricensis, in much the same 
way that the latter species shows certain vegetative similarities to 
O. mexicana. 

REFERENCES FOR JUGLANDACEAE 

BERRY, E. W. 

1912. Notes on the geological history of the walnuts and walnuts and hickories. 
Plant World 15: 225-240. 

BROWN, R. W. 

1946. Walnuts from the Late Tertiary of Ecuador. Amer. Journ. Sci. 243:554-556. 
CANDOLLE, C. de 

1862. Memoire sur la famille des Juglandees. Ann. Sci. Nat. Bot. IV. 18:5-48. 
1864. Juglandaceae. In Prodromus systematis universalis regni vegetabilis 16: 

134-146. 

1914. Engelhardtia Oreomunnea C. DC. Une espece remarquable du Costa-Rica. 
Bull. Soc. Bot. Geneve II, 6: 165-170. 

CONDE, L. F., and D. E. STONE 

1970. Seedling morphology in the Juglandaceae, the cotyledonary node. Journ. 
Arnold Arbor. 51:463-477. 

CRONQUIST, A. 

1968. The evolution and classification of flowering plants. Houghton, Mifflin Co., 
Boston. 

ELIAS, T. S. 

1972. The genera of Juglandaceae in the Southeastern United States. Journ. 
Arnold Arbor. 53:26-51. 

HEIMSCH, C., and R. H. WETMORE 

1939. The significance of wood anatomy in the taxonomy of the Juglandaceae. 
Amer. Journ. Bot. 26:651-660. 

HUTCHINSON, J. 

1959. Juglandales. In Hutchinson, J. The familes of flowering plants. I. Dicoty- 
ledons. 2nd ed. 194-197. Clarendon Press, Oxford. 

JACOBS, M. 

1960. Juglandaceae. In van Steenis, C.G.G.J., Fl. Malesiana. I, 6: 143-154. 

LEON, J. 

1953. Alfaroa manningii, una nueva Juglandacea de Costa Rica. Ceiba 4:42-47. 

LEROY, J. F. 

1951. Pour la rehabilitation du genre Oreomunnea Oersted (Juglandaceae). Bull. 
Mus. Hist. Nat. (Paris) Ser. 2, 23: 126-127. 



52 FIELDIANA: BOTANY, VOLUME 40 

1957. Etude sur les Juglandaceae. Mem. Mus. Nat. Hist. Nat., Ser. B, Bot. 6: 

1-246. 

MANNING, W. E. 
1938. The morphology of the flowers of the Juglandaceae. I. The inflorescence. 

Amer. Journ. Bot. 25:407-419. 

1941. The morphology of the flowers of the Juglandaceae. II. The pistillate flowers 
and fruits. Amer. Journ. Bot. 25:407-419. 

1948. The morphology of the flowers of the Juglandaceae. III. The staminate 
flowers. Amer. Journ. Bot. 35:606-621. 

1949. The genus Alfaroa. Bull. Torrey Bot. Club, 16: 196-209. 

1952. Juglandaceae. In Flora of Guatemala. Fieldiana, Bot. 24:352-359. 

1957a. The genus Juglans in Mexico and Central America. Journ. Arnold Arbor. 

38:121-150. 

1957b. A Bolivian walnut from Peru growing in Costa Rica. Brittonia 9: 131. 
1959. Alfaroa and Engelhardtia in the New World. Bull. Torrey Bot. Club 86: 

190-198. 
1960a. The genus Juglans in South America and the West Indies. Brittonia 12: 

1-26 
1960b. Juglandaceae. In Flora of Panama. Ann. Missouri Bot. Card. 47:90-92. 

MOLINA, A. 
1968. Two new Nicaraguan Juglandaceae. Fieldiana, Bot. 31:357-359 

NICHOLS, D. J. 

1973. North American and European species of Momipites ("Engelhardtia") 
and related genera. Geoscience and Man 12: 103-1 17. 

OERSTED, A. S. 

1856. Plantae novae centroamericanae. Vidensk. Meddel. Dansk Naturhist. 
Foren. Kjdbenhavn. 3:33-43. 

1870. Bidrag til Kundskab om Valdnodplanterne. Vidensk. Meddel. Dansk Natur- 
hist. Foren. Kjrfbenhavn. 1870:159-173. 

PITTIER, H. 

1957. Plantas usuales de Costa Rica. 2nd ed. rev. Univ. Costa Rica, Ser. Ciencias 
Nat. 2: 121, Fig. 20. 

STANDLEY, P. C. 

1927a. The American species of Engelhardtia. Trop. Woods 12: 12-15. 

1927b. Alfaroa, a new genus of trees of the family Juglandaceae from Costa Rica. 

Journ. Wash. Acad. Sci. 17:77-79. 
1937. Juglandaceae. In Flora of Costa Rica. Field Mus. Nat. Hist., Bot. Ser. 18: 

372-373. 

STEBBINS, G. L. 

1974. Flowering plants evolution above the species level. Harvard Univ. Press, 
Cambridge. 

STONE, D. E. 

1969. Documented plant chromosome numbers 1969:2. Sida 3:352-355. (includes 
Alfaroa costaricensis Standley from Guatemala, n=16). 



BURGER: FLORA COSTARICENSIS 53 

1970. Evolution of cotyledonary and nodal vasculature in the Juglandaceae. 
Amer. Journ. Bot. 57: 1219-1225. 

1972. New World Juglandaceae, III. A new perspective of the tropical members 
with winged fruits. Ann. Missouri Bot. Gard. 59:297-321. 

1973. Patterns in the evolution of amentiferous fruits. Brittonia 25:371-384. 
STONE, D. E., and C. R. BROOME 

1971. Pollen ultrastructure: evidence for relationship of the Juglandaceae and the 
Rhoipteleaceae. Pollen et Spores 13:5-14. 

1975. Juglandaceae A. Rich, ex Kunth. World Pollen and Spore Flora 4: 1-35. 

TAKHTAJAN, A. 

1969. Flowering plants origin and dispersal (translated by C. Jeffrey). Smith- 
sonian Institution Press, Washington, B.C. 

THORNE, R. F. 

1973. The "Amentiferae" or Hamamelidae as an artificial group: a summary 
statement. Brittonia 25:395-405. 

WHITEHEAD, D. R. 

1965. Pollen morphology of the Juglandaceae, II: survey of the family. Journ. 
Arnold Arbor. 46:369-410. 

1969. Wind pollination in the angiosperms: evolutionary and environmental con- 
siderations. Evolution 23:28-35. 

WITHNER, C. L. 

1941. Stem anatomy and phylogeny of the Rhoipteleaceae. Amer. Journ. Bot. 
28:872-878. 

WOLFE, J. A. 
1973. Fossil forms of Amentiferae. Brittonia 25:334-355. 



BATACEAE 

(Batidaceae) 

WILLIAM BURGER 

Glabrous much-branched little shrubs to 1.5 m. tall with both prostrate horizontal 
and erect succulent stems, the plants unisexual or bisexual. Leaves opposite and 
decussate, simple and sessile, fleshy and entire; stipules minute and caducous, 
represented by gland-like bodies. Inflorescences of cone-like spikes or short-shoots, 
floral bracts with minute stipule-like appendages; male flowers in the axils of decus- 
sate bracts or terminal and arranged in cones, each flower with a perianth-like tube 
opening irregularly into 2 to 4 parts, 4 spathulate petal-like structures alternating 
with the stamens and often referred to as staminodes, stamens 4, filaments free, 
anthers dorsifixed and introrse, center of the flower raised and possibly a pistillode; 
female flowers sessile and axillary, solitary or grown together at the base, each 
flower with 1 pistil subtended by a single bract and without perianth, ovary 4- 
loculed with a single epitropous ovule borne from the base of each locule on enlarged 
placentas (perhaps parietal in origin), stigmas 2 and sessile. Fruit drupaceous or 
compound, seeds without endosperm, embryo straight, cotyledons large. 



BATIS Linnaeus 

The family is represented by the solitary genus with two species: 
Batis maritima L. on the tropical and subtropical coasts of the 
Americas and B. argillicola van Royen on the southern coast of New 
Guinea. The systematic position of the genus is not clear, and a wide 
variety of relationships have been suggested. Modern phylogenists 
have considered this family related to the Chenopodiaceae (Centro- 
spermae or Gary ophy Hales) but Batis lacks betacyanins and 
betaxanthins (T. J. Mabry and B. L. Turner, Taxon 13:197-200. 
1964), which suggests that they are not related to the Centro- 
spermae. More recently the detection of "Myrosinase" in extracts 
of Batis maritima has suggested a relationship with the Cappari- 
dales (Schraudolf, Schmidt, & Weberling in Experientia 27:1090- 
1091. 1971). The floral diagrams in our illustration are from Eckardt 
(Ber. Deut. Botan. Gesell. 72:416. 1959). 

54 



BURGER: FLORA COSTARICENSIS 



55 




BATIS maritima 



FIG 9a. Bataceae: Batis maritima, male parts on the left and female parts on the 
right. 



Batis maritima L., Syst. edit. 10, 1289. 1759. Figure 9a. 

Unisexual little shrubs or subshrubs 0.3-1.5 m. tall, stems becoming woody, leafy 
internodes 1-10 (15) mm. long, 0.7-2.8 mm. thick, glabrous, succulent and drying 
pale green or grayish. Leaves almost terete, petioles absent, laminae 8-30 (40) mm. 
long, about 2 mm. thick (dry), linear or linear oblong, abruptly obtuse at the apex, 
slightly narrowed and prolonged basally about 1 mm. below the point of attachment 
to the stem, the two basal lobes becoming recurved on drying, venation not visible. 
Male spikes sessile or very short pedunculate, 5-10 mm. long, bracts about 2 mm. 
broad, tightly imbricate in 4 ranks, persistent with usually more than 12 bracts and 
flowers per spike, filaments about 2 mm. long, anthers about 1.2 mm. long; female 
spikes on short stalks, becoming 15 mm. long, bracts and flowers 4 to 12, bracts 
round and peltate, 2-2.5 mm. broad, separate and deciduous, pistil about 6 mm. 
long and 2.5 mm. thick, united below with the free apices bearing the minutely 
papillate-puberulent 2-lobed stigmas. Fruit fleshy and compound by the union 
beneath of the pistils, the compound fruit (spike) about 8 mm. long, and 6 mm. 
thick. 

Batis maritima is a strand plant ranging along the ocean shores 
from Florida and Texas in the United States to the West Indies and 
southward to Brazil along the Atlantic and from California to Peru 
on the Pacific. While the species has not been recorded from Costa 
Rica or adjacent countries, it is known from both the Caribbean and 
Pacific coasts of Honduras. Because the species grows both on 
sandy shores and near mangrove formations, it very likely is to be 
found in Costa Rica. 



BETULACEAE 

JOHN J. FURLOW 

Trees and shrubs, leaves alternate and simple; stipules present, free, and deci- 
duous. Plants unisexual, monoecious; inflorescences usually composed of reduced 
cymules in a spiral on an elongate axis forming aments (catkins) or in congested 
dichasia; staminate flowers usually in pendulous aments, the flowers subtended by 
large bracts with or without bracteoles, perianth of 1 whorl or absent, free or united, 
often of 4 separate parts, the stamens (1) 2, 4, 5, or 6 (20), borne on slender fila- 
ments or sessile, anthers 2-thecous, the thecae separate or connate; pistillate 
flowers usually in groups of 2 or 3 within a subtending bract with or without 
bracteoles, the perianth absent or adnate with the ovary, pistil with a 2- or 3-locular 
ovary (sometimes 1-locular above) with 2 pendulous ovules, styles and stigmas 2 
(3). Fruit a nut, often winged, sometimes with the perianth persisting above or sub- 
tended by the persistent bracts, seed 1 by abortion, endosperm absent. 

The Betulaceae are a family of six genera and about 100 species of 
the north temperate zone with a few species reaching Central and 
South America at higher elevations. The family is represented by a 
single native species in our area; two other genera, Carpinus and 
Ostrya, have their southern limits in El Salvador and Honduras. 
The family is characterized by the very reduced flowers in complex 
inflorescences and is adapted to wind pollination. Recent studies 
(Endress, 1967) show that this family is very closely related to the 
Hamamelidaceae. 

ALNUS Miller 

Monoecious trees and shrubs, leaf buds usually stalked and with few scales, roots 
often with nodules of nitrogen-fixing endophytes. Leaves alternate, simple, petio- 
late, and pinnately-veined, usually at least somewhat pubescent and glandular 
below. Staminate aments in terminal clusters or solitary in the axils of leaves, pro- 
duced during the previous growing season or on growth of the present season; 
staminate flowers usually in groups of 3 (rarely 6) on each short-stalked peltate 
bract, bracteoles present, the perianth of 4 (1-6) free or basally connate parts, sta- 
mens usually 4 and opposite the perianth parts, anthers with 2 partially separate 
thecae, dehiscing longitudinally. Pistillate inflorescences congested, ovoid to ellip- 
soid or cylindrical, solitary or racemose, arising from leaf axils, sometimes on special 
short shoots, produced during the previous or present growing season, the bracts 



56 



BURGER: FLORA COSTARICENSIS 



57 




ALNUS acuminata 



FIG 9b. Betulaceae: Alnus acuminata with enlarged view of male flower (right) 
and individual fruit (left). 

thick, each subtending 2 flowers and 4 bracteoles, perianth absent or reduced to 
small adnate glands, ovary laterally compressed. Fruit a small flattened nut, usually 
with 2 winged margins, 1-locular by abortion; the fruiting spike cone-like, with per- 
sistent 5-lobed woody scales derived from the bracts and bracteoles. 

A genus of about 20 species, mainly of the Northern Hemisphere 
but extending into South America along the Andes. Several species 
occur in northern Central America and Mexico. 

Alnus acuminata H.B.K. Nov. Gen. Sp. 2: 20. 1817. A. arguta 
(Schlecht.) Spach, Ann. Sci. Nat. ser. 2, 15: 205. 1841. A. jorullensis 
auct., non H.B.K. Nov. Gen. Sp. 2: 20. 1817. Figure 9b. 

Trees 5-20 (30) m. tall, leafy internodes 0.5-2.5 cm. long, 1-4 mm. thick, glabrous 
or sparsely puberulent with slender whitish to yellowish hairs 0.2-0.5 mm. long or 
with minute brownish peltate glands or both, becoming glabrescent in age, often 
dark brown and lustrous, lenticels yellowish, oval to circular, 0.5-2.0 mm. long, 0.3- 
1.0 mm. wide. Buds with 2 or 3 resinous-coated stipular scales, obtuse to acuminate 
at the apex, stalked, body 4-8 mm. long, 2.0-3.5 mm. thick, stalk 2-8 mm. long, 1-2 
mm. thick. Leaves borne in a spiral, petioles 7-25 mm. long, 1-2 mm. thick, deeply 
grooved adaxially, glabrous or with hairs, glands, or both; laminae 5-17 cm. long, 3-9 
cm. wide, broadly elliptic to oblong or somewhat ovate, obtuse or abruptly short- 
acuminate to acuminate at the apex, acute, abruptly obtuse, and rounded to trun- 
cate at the base, unequally doubly serrate along the margin, the teeth smaller near 



58 FIELDIANA: BOTANY, VOLUME 40 

the apex and base than at mid-leaf, closer near the apex and more distant near the 
base than at mid-leaf, larger teeth terminating the veins, margin moderately to 
strongly revolute, lamina drying stiffly chartaceous and usually much darker above, 
smooth and glabrous to very sparsely pubescent along the veins above, sparsely to 
moderately glandular above, sparsely to densely puberulent with slender yellowish 
to brownish hairs 0.2-0.6 mm. long beneath, sparsely to densely covered with whit- 
ish to yellowish-brown peltate glands below, the lower surface becoming glabrescent 
in age, venation often impressed above, secondary veins in 9-16 pairs, 4-9 mm. apart 
at mid-leaf, prominent beneath with the tertiary veins often conspicuous and sub- 
parallel. Staminate aments in racemose clusters of 3-6, produced the previous grow- 
ing season, 4-12 cm. long, 5-9 mm. thick, borne on short glabrous peduncles 4-12 
mm. long, 1-2 mm. thick, each cluster (cymule) of flowers subtended by a bract 
about 1.5 mm. broad, the 3 flowers congested and difficult to distinguish, perianth 
about 1.3 mm. long, anthers 1.0-1.5 mm. long, 0.8-1.1 mm. broad on filaments 0.4-1.0 
mm. long; pistillate spikes (cones) in racemose clusters of 3-6, produced the previ- 
ous season, 7-10 mm. long, 6-8 mm. thick at anthesis, on short peduncles 0.4-0.7 mm. 
long, bracts thick and fleshy, tightly imbricate, 3-4 mm. broad distally, pistil about 
2 mm. long, styles 0.5-1.0 mm. long. Fruit a 2-winged nutlet (samara), thin and 
slightly obovate or obcordate, body 2.2-3.0 mm. long, 1.0-1.5 mm. broad, each wing 
0.8-2.1 mm. long, 0.5-0.7 mm. broad, the fruiting cones becoming 1.2-2.5 cm. long, 9- 
12 mm. thick, peduncles 1-10 mm. long, 1.2-1.5 mm. thick, scales 3.5-4.5 mm. long, 
3.5-4.5 mm. broad at the widest point. 

Plants of montane forest formations from 1500 to 3100 m. eleva- 
tion and often occurring in almost pure stands, perhaps as second- 
ary growth on old clearings and landslides. In Costa Rica the 
species has only been collected between the slopes of Volcan Barba 
and the Cordillera de Talamanca as far eastward as the slopes above 
San Isidro del General. It is found in the highlands of Western 
Panama and ranges northward through central Mexico and south- 
ward into South America. 

Distinctive plants because of the cone-like infructescences, pen- 
dulous staminate aments, unusual glands on the lower leaf surface, 
and tendency to be found in stands. 

The taxonomic status of this species has long been confused. Al- 
though the Costa Rican alders show considerable affinity with 
Alnus acuminata of South America, they nevertheless appear some- 
what more similar to A. arguta of Mexico and Guatemala. Both of 
these species may be better considered the same species, however, 
which is the view taken here, in which case A. acuminata is the valid 
name. They are markedly distinct from A. jorullensis H.B.K. of 
Mexico, which name has frequently been misapplied to them. The 
name commonly used in Costa Rica is Jaul. 



FAGACEAE 

WILLIAM BURGER 

REFERENCE: Thomas Elias, The Genera of Fagaceae in the 
Southeastern United States. Journ. Arn. Arb. 52: 159-195. 1971. 

Trees or shrubs, bisexual or rarely unisexual (in Nothofagus). Leaves simple, 
deciduous or evergreen, usually alternate in a spiral, entire to deeply lobed, pin- 
nately veined; stipules present and deciduous. Flowers unisexual (rarely bisexual); 
male flowers with 4 to 8 perianth parts (tepals) united basally, stamens usually 6 or 
12 (4 to 40), filaments slender, anthers 2-thecous, dehiscing longitudinally, a pistil- 
lode usually absent; female flowers subtended by bracts forming an involucre or 
cupule, flowers 1 to 3 per involucre or cupule, perianth 3- to 8-lobed and adnate to 
the ovary, staminodes usually absent, ovary inferior with 2 or 3 (6) locules, each 
locule with 2 pendulous ovules, placentation axile, styles and stigmas as many as 
the locules. Fruit 1 to 3 and subtended by or enclosed within an involucre or cup, 
each fruit a single-seeded nut, endosperm absent, embryo with thick cotyledons. 

A family of eight genera with around 500 species in the temperate 
zones of both northern and southern hemispheres and in the tropical 
highlands, but absent in Africa south of the Sahara. The family has 
had a long and independent history but appears to be related to the 
Betulaceae and Hamamelidaceae. The Fagaceae are represented in 
Central America by the genus Quercus. The chestnut or castafio 
(Castanea sativa Miller) is occasionally planted in the Valle Central; 
its narrowly oblong leaves with many (12-20) pairs of secondary 
veins and prominent serration are distinctive. 

QUERCUS Linnaeus 

REFERENCES: William Trelease, The American Oaks. Mem. 
Nat. Acad. Sci. 20. 1924. Cornelius Muller, The Central American 
species of Quercus. U.S. Dept. Agric. Misc. Publ. no. 477. 1942. 

Shrubs or trees, older bark pale in color and scaly or dark and furrowed, the wood 
usually hard, new growth from buds enclosed by imbricate brownish bud-scales. 
Leaves deciduous or persisting, arising in a spiral, petiolate or subsessile, the lamina 
entire to deeply lobed, veins often extending beyond the margin as bristles; stipules 
associated with the bud-scales below the leaves, narrow, and usually deciduous. In- 
florescences axillary and emerging with the new leaves, male inflorescences long- 



59 



60 FIELDIANA: BOTANY, VOLUME 40 

pendulous spikes (aments) from the axils of leaves or the inner bud-scales, male 
flowers solitary or in clusters of 2 or 3 on the rachis, bracts present or absent, 
perianth of 3 to 6 tepals united below, stamens (2) 4 to 12 from a slightly raised 
receptacle, filaments free; female flowers solitary and pedicellate or several on erect 
spikes and arising from the axils of leaves of the current season, each flower en- 
closed by an involucre of many appressed scales, perianth difficult to distinguish, 
minutely 6-lobed and adnate to the ovary, pistil with usually 3 locules and styles. 
Fruit a nut (acorn, or bellotd) enclosed or subtended by the cupulate involucre and 
developing to maturity in 1 or 2 years, ovoid to subglobose or turbinate, flattened 
and with a circular scar basally, pericarp hard, glabrous or with appressed whitish 
hairs on the interior surface. 

The oaks (Quercus spp.) are not represented by many species in 
Costa Rica, but they are often a dominant group in our highland 
forests, achieving both great individual size and great numbers. 
They form large stands in the Cordillera de Talamanca above 2500 
m. elevation and occasionally at lower elevations on some of the 
slopes of the Pacific watershed. Only one species (Q. oleoides) is 
found below 500 m. elevation, while several occur above 3000 m. (Q. 
costaricensis, Q. copeyensis, and Q. seemannii). Our knowledge of 
these trees is still poor as their size makes collecting difficult and 
the populations are poorly sampled. The hard wood has had many 
uses, but it is especially prized for making charcoal in Costa Rica. 
The production of charcoal has caused the destruction of many oak 
forests containing large trees. 

The genus is usually easy to recognize because of the buds, 
covered by bud-scales, and crowded toward the ends of the often 
fluted stems, the stipules associated with the buds rather than the 
leaves (but often caducous), the leaves in a spiral, the male flowers 
on slender pendant spikes (catkins), and the small often obscure 
female flowers in leaf-axils. The hard wood usually with distinct 
rings of larger pores, rough light gray to dark gray bark, and the 
very characteristic acorn and acorn-cup further distinguish the 
genus. Some species may become more than 30 m. tall, and many 
species regularly produce trunks more than 1 m. thick. 

The North American species of the genus Quercus fall into two 
natural subgenera. Species of the subgenus Quercus (formerly 
called subgenus Lepidobalanus) are often referred to as white oaks 
because of the pale color of their bark and branchlets. Species of 
subgenus Erythrobalanus are endemic to North and Central Amer- 
ica and are referred to as black oaks because of their dark bark and 
branchlets. The two full-page figures illustrate the Costa Rican 
species of the two subgenera. The following dichotomy outlines the 
major differences between the two subgenera, but the distinctions 



BURGER: FLORA COSTARICENSIS 61 

are often difficult to see in herbarium specimens. The key to species 
does not use this dichotomy in its early parts. 

KEY TO THE SUBGENERA (Figures 10 and 11) 

1 A. Bark of the trunk usually gray and forming flat scales, relatively soft, branch- 
lets usually rough and grayish after the first year, wood pale yellowish; leaves 
entire to lobed and the lobes rounded or if serrate then with short mucronate 
tips; styles short and abruptly diverging; fruit produced in one year, interior 
surface of the pericarp glabrous subgenus Quercus. 

IB. Bark of the trunk usually very dark and furrowed longitudinally, relatively 
hard, branchlets usually smooth, lustrous, and dark after the first year, wood 
often reddish; leaves entire to lobed and the lobes acute or if serrate then 
usually with arista te tips; styles longer and gradually diverging; fruit pro- 
duced in one or two years, interior surface of the pericarp tomentose. 

subgenus Erythrobalanus. 

Both subgenera have closely related species that are often dif- 
ficult to identify. In our white oaks (subgenus Quercus}, Q. insignis, 
Q. oocarpa, and Q. pilarius may present problems unless properly 
identified herbarium material is available for comparison. Among 
our black oaks (subgenus Erythrobalanus}, Q. seemannii and its 
close allies, Q. gulielmi-treleasei and Q. rapurahuensis, may be 
impossible to separate convincingly without mature acorns. All 
these species, within the same subgenus, are probably capable of 
hybridizing and this factor may account for the difficulty in sepa- 
rating them. 

Dr. Cornelius Muller has recently mentioned (pers. comm.) his 
intention of reviewing the oaks of Costa Rica. At present, his view 
of the Costa Rican species differs from the one presented here in the 
following ways. Dr. Muller believes that Q. gulielmi-treleasei and 
Q. rapurahuensis are not distinguishable from Q. seemannii. He 
also believes that what are here called Q. insignis and Q. pilarius 
are both elements of Q. oocarpa. Dr. Muller interprets Q. tonduzii 
as a local population of Q. eugeniaefolia. He also recognizes Q. 
panamandinea and an undescribed species. Thus, Dr. Muller finds 
ten species of Quercus in Costa Rica, of which eight represent the 
twelve species recognized in the treatment given here. The student 
of Costa Rica's flora should not be disturbed by these differences in 
interpretation. As mentioned, the oaks are notorious for their 
ability to hybridize, and they produce populations of considerable 
variability. Also, these large trees have been poorly sampled, and 
mature fruit are rare in collections. These factors contribute to 
differing species-concepts in the work of different authors. Actual- 
ly, all the species in this Flora should be viewed as scientific hypo- 




FIG 10. Fagaceae: the Costa Rican species of Quercus, subgenus Quercus, the 
white oaks. 



62 




FIG. 11. Fagaceae: the Costa Rican species ofQuercus subgenus Erythrobalanus, 
the black oaks. 



63 



64 FIELDIANA: BOTANY, VOLUME 40 

theses that have to be revised as we learn more about the plants 
themselves and the populations of which they are a part. 

KEY TO THE SPECIES 

1A. Trees of the lowland deciduous forest formations of Guanacaste Province 
between 50 and 500 m. elevation; the lower leaf-surface with minute (0.1 mm.) 

canescent hairs forming a dense covering between the veins Q. oleoides. 

IB. Trees of evergreen or semideciduous forest formations between 600 and 3400 
m. elevation; the lower leaf -surf aces not covered by a dense tomentum of 

minute whitish hairs 2A. 

2 A. Laminae narrowly elliptic to oblong with a conspicuously serrate margin of 
blunt or aristate teeth, becoming glabrous or very sparsely puberulent; trees 

not found above 2000 m. altitude 3A. 

2B. Laminae with entire margins or broadly elliptic to obovate when serrate; 

trees of 1000 to 3400 m. altitude 5A. 

3 A. Serrations aristate with slender tips 1-5 mm. long, laminae 1-3 cm. broad, 
stipules caducous; year-old stems remaining dark and smooth (a black 
oak); acorns about 16 mm. long and 14 mm. thick; trees of the Pacific slope 
of west-central Costa Rica between 600 and 1500 m. elevation . . Q. brenesii. 
3B. Serrations blunt or with very short ( 1 mm.) rounded tips, laminae 2-6 cm. 
broad; stems becoming rough and grayish after a year (white oaks); acorns 
becoming more than 25 mm. thick at maturity; trees growing between 

1000 and 2000 m. elevation 4A. 

4 A. Petioles (4) 8-25 mm. long and the laminae usually drying stiffly 
chartaceous, stipules caducous; trees of apparently drier evergreen 
forest formation on the Pacific slope between 1200 and 1900 m. eleva- 
tion Q. corrugata. 

4B. Petioles 1-6 (9) mm. long and the laminae often drying thin chartaceous, 
stipules often persisting; trees of the moister evergreen forest forma- 
tions on both the Pacific and Caribbean slopes between 1000 and 1800 

m. elevation Q. pilarius. 

5 A. Laminae usually bluntly serrate and obovate in general form, commonly 10-25 
cm. long; stipules usually persisting; acorns becoming more than 3 cm. thick 

at maturity; white oaks with the year-old stems usually pale gray 6A. 

5B. Laminae rarely serrate and not usually obovate; acorns more than 3 cm. thick 

only in Q. costaricensis with the year-old stems smooth and dark 9A. 

6A. Lower surface of the laminae with hairs persisting only along the midvein, 

petioles 1-6 (9) mm. long 7A. 

6B. Lower surface of the laminae with persisting stellate hairs or occasionally 

with the hairs persisting only in the axils of the secondary veins 8 A. 

7A. Laminae drying stiffly chartaceous to subcoriaceous, with both stellate 
and simple hairs beneath or glabrous; acorns not more than 2.5 cm. 

thick; trees of higher montane forests ( 1800-3000 m.) Q. copeyensis. 

7B. Laminae often drying thin-chartaceous, with only a few simple ascend- 
ing hairs persisting along the midvein beneath; acorns probably exceed- 
ing 3 cm. at maturity; trees of middle elevations ( 1000-1800 m.) 

Q. pilarius. 



BURGER: FLORA COSTARICENSIS 65 

8A. Petioles 1-6 (10) mm. long, and the laminae usually cuneate at the base, 
drying stiffly chartaceous; trees of wet forests between 1100 and 2300 m. 

altitude Q. oocarpa. 

8B. Petioles 5-25 mm. long and the laminae usually aburptly truncate to 
cordulate at the petiole, drying stiffly chartaceous to subcoriaceous; trees 

of wet forests between 1000 and 1800 m. elevation Q. insignis. 

9 A. Stipules usually persisting, stems becoming rough and grayish after a year 
(a white oak) ; laminae variable but often cuneate at the base and bluntly acute 
or rounded apically, drying stiffly chartaceous to subcoriaceous; trees of high 

( 1800-3000 m.) montane rain forests Q. copeyensis. 

9B. Stipules caducous, stems often remaining smooth and very dark in color after 

one year (black oaks) 10A. 

10 A. Laminae drying subcoriaceous to coriaceous and usually with the venation 
impressed above to give a somewhat bullate appearance, apex of the lamina 
blunt to rounded (rarely acute), densely puberulent to glabrous beneath, 
petioles 0-4 (8) mm. long; acorns becoming 20-35 mm. thick; trees of very 

high (2200-3300 m.) montane forest formations Q. costaricensis. 

10B. Laminae drying thin chartaceous to subcoriaceous and usually flat above, 
apex of the laminae acute to acuminate or rarely blunt and rounded .... 1 1 A. 

1 1 A. Acorns becoming 14-22 mm. thick at maturity 12A. 

11B. Acorns becoming 10-14 mm. thick at maturity 13A. 

12A. Trees endemic to Volcan Poas above 2200 m. elevation; petioles 2-8 mm. 
long, laminae, generally 4-11 cm. long and 1.5-4 cm. broad, often drying 

subcoriaceous Q. tonduzii. 

12B. Uncommon trees between 1000 and 2500 m. elevation on the Pacific side of 
the Cordillera de Talamanca; petioles (4) 8-26 mm. long, laminae generally 
9-18 cm. long and 3-7 cm. broad, usually drying stiff -chartaceous. 

Q. rapurahuensis. 

13A. Laminae often drying stiff-chartaceous to subcoriaceous, gradually or 
abruptly narrowed to both base and apex, (2.5) 4-10 (16) cm. long and (1) 
1.5-3 (4) cm. broad on petioles 1-6 ( 10) mm. long; trees of wet and very wet 

forests from 1100 to 3100 m. elevations Q. seemannii. 

13B. Laminae usually drying thin chartaceous, very gradually narrowed to both 
base and apex, (6) 9-18 (25) cm. long and (2) 3-6 (8) cm. broad, on petioles 
0-5 mm. long; trees of very wet forests between 1500 and 2500 m. elevation. 

Q. gulielmi-treleasei. 

Quercus brenesii Trel., Mem. Nat. Acad. Sci. 20:186, pi. 377. 
1924. Figure 11. 

Trees 8-25 m. tall, leafy internodes 1-20 (40) mm. long, (0.7) 1-3 mm. thick, glab- 
rous or pale yellowish-brown tomentulose in early stages, twigs dark and smooth 
with small (0.5 mm.) but conspicuous lenticels, becoming grayish after 1 or 2 years; 
buds 2-5 mm. long, becoming narrowly ovoid, bud scales glabrous or puberulent and 
ciliolate along the edge. Leaves said to be deciduous, petioles 1-7 mm. long, 0.7-1.5 
mm. thick, glabrous or puberulent, terete or slightly winged; laminae 5-17 cm. long, 
1-3 cm. broad, very narrowly elliptic to lanceolate, linear-lanceolate, or occasionally 



66 FIELDIANA: BOTANY, VOLUME 40 

oblanceolate, tapering to the long-acuminate or acute apex, aristate at the tip, acute 
to attenuate at the base, margins entire along the basal half and usually with 2 to 5 
diverging aristate teeth on each side distally, the aristae as much as 5 mm. long, the 
lamina drying stiffly chartaceous and grayish-green, smooth and slightly lustrous 
above and below, quickly becoming glabrous on both surfaces, the hairs on young 
parts yellowish-brown stellate tomentulose, about 0.1-0.2 mm. long, midvein slight- 
ly raised above with 5 to 11 pairs of major secondary veins, the secondary and 
tertiary veins often becoming slightly raised on drying; stipules ligulate and 
caducous. Male spikes to 8 cm. long, the flowers becoming 2-10 mm. distant on the 
glabrescent rachis, perianth densely and persistently tomentulose, filament equal- 
ing the anthers in length, anthers about 1.5 mm. long and 0.5 mm. thick, the connec- 
tive produced beyond the thecae into a slender tip about 0.2 mm. long, glabrous; 
female flowers solitary or paired on short (3-12 mm.) thick (2 mm.) axillary 
peduncles, female flowers about 4 mm. long becoming thickened above the middle 
during development (10 mm.). Fruit produced in a year, solitary or paired on short 
peduncles, the cup about 10 mm. long and 16 mm. broad, saucer-shaped and 
abruptly narrowed to the base, puberulent within, the scales densely puberulent 
with minute grayish-brown hairs but with glabrescent brown margins, the nut 
(acorn) about 16 mm. long and 14 mm. thick, ovoid but abruptly narrowed at the 
base, densely puberulent with grayish-brown hairs but these rubbing off, the nar- 
rowed apex of the fruit to 4 mm. long (with the persisting styles), basal scar about 
8 mm. in diameter (description of the fruit based on Molina 22979 from Nicaragua). 

This species is found in the seasonally dry evergreen (premontane 
and lower montane moist and wet) forest formations on the Pacific 
slope between 600 and 1500 m. elevation. Collections have been 
made from the area between Monteverde (Puntarenas) and San 
Ramon (Alajuela); flowering in January and fruiting in November. 
This species was thought to be endemic to Costa Rica but recent 
collections by Williams et al. (23936, 24728, & 27862) and Molina 
(20127 & 22979) from the Cordillera Central de Nicaragua appear to 
be this species. 

Quercus brenesii is a species of the subgenus Erythrobalanus. 
The very narrow leaves with slender aristate teeth distally and the 
lower altitude habitat on the Pacific slope separate this oak from all 
the other Costa Rican species of the genus. The recent collections 
from Nicaragua and Costa Rica have given us a better idea of varia- 
tion within the species. However, this expanded concept of Q. 
brenesii may prove to be conspecific with material from northern 
Central America that has been referred to Q. anglohondurensis 
Muller, gracilior Muller, Q. tenuiaristata Trel., and Q. trichodonta 
Trel. This group is in turn related to Q. conspersa Benth. and Q. 
skinneri Benth. with larger acorns and characteristically long 
petioles. 



BURGER: FLORA COSTARICENSIS 67 

Quercus copeyensis C. H. Muller, U.S.D.A. Misc. Publ. 477:30, 
pis. 31 & 32. 1942. Q. costaricensis f. kuntzei Trel., Mem. Nat. Acad. 
Sci. 20: 146, pi. 283 b. 1924. Q. copeyensis Muller emend E. L. Little, 
Carib. Forest. 9:348. 1948. Q. aaata auctores in herb, as to Costa 
Rica. Figure 10. 

Trees 8-35 m. tall, trunk becoming more than 1 m. thick, leafy internodes 1-16 
(30) mm. long, 2-4 (6) mm. thick, sparsely stellate puberulent or glabrous, pale 
brown becoming grayish in age; buds 3-5 mm. long, ovoid, bud-scales glabrous or 
puberulent distally. Leaves deciduous and often clustered at the ends of branch- 
lets, petioles 1-6 (8) mm. long, 1-2.5 mm. thick, simple or stellate puberulent or 
glabrous, sulcate adaxially; laminae quite variable, 4-10 (15) cm. long, 2-5 (6.5) 
cm. broad, elliptic to oblong, obovate, or occasionally oblanceolate, bluntly acute 
to rounded at the apex, tapering to the obtuse, cuneate, or slightly rounded base, 
often truncate or cordulate at the petiole, margin entire or slightly undulate 
distally (rarely obscurely dentate), the lamina drying stiffly chartaceous to sub- 
coriaceous, smooth and often lustrous above and becoming glabrous, persistently 
puberulent along the midvein beneath or occasionally glabrous, the hairs both 
simple and stellate, 0.2-0.8 mm. long, major veins often raised in slight depres- 
sions above, prominent beneath, the (4) 6 to 12 pairs of major secondary veins 
arising at angles of 35-55 degrees; stipules often persisting, 7-12 mm. long and 
1-2 mm. broad, ligulate, sparsely puberulent. Male spikes (3) 4-8 (12) cm. long, 
flowers becoming distant on the glabrous or sparsely puberulent rachis, perianth 
2-2.5 mm. long, ciliolate distally, filaments 1-2 mm. long, anthers 0.8-1.5 mm. 
long (dry); female spikes 2-6 cm. long and about 2 mm. thick, each spike with 
4 to 10 flowers, flowers about 4-6 mm. long. Fruiting spikes 2-8 cm. long, cup 
about 10-16 mm. long and 20 mm. broad at the apex, tapering gradually to the 
base and thin at the edge, said to enclose one-third to one-half of the mature 
acorn, cup-scales densely puberulent on the basal umbo but glabrescent apically, 
nut (acorn) 22-28 mm. long and 18-22 mm. thick, ovoid, glabrous or persistently 
puberulent apically, basal scar about 10 mm. in diameter, area above the basal 
scar occasionally drying dark. 

A dominant species of the wet evergreen montane (premontane 
and lower montane rain) forest formations between (1800) 2000 and 
2800 (3000) m. altitude; flowering collections have been made 
between December and March, fruit have been collected in May 
(immature?), August, and November. The species, as here under- 
stood, ranges from Central Costa Rica to Chiriqui, Panama. In 
Costa Rica the species is found in the Cordillera Central from near 
Zarcero and Palmira (Alajuela) to Irazii and from the areas of 
Escazu and Tarbaca (San Jose) eastward along the central part of 
the Cordillera de Talamanca. The species is commonly collected 
along the Interamerican Highway but is not known from Sta. 
Maria de Dota and is apparently uncommon on Volcan Poas and 
Volcan Barba. 



68 FIELDIANA: BOTANY, VOLUME 40 

This species is recognized by its stiff, usually obovate and blunt 
leaves often lustrous above with few persistent hairs beneath, thick 
grayish twigs often retaining stipules and bud-scales, and the aver- 
age-size acorns. The bark grayish and forming flat scales marks 
Q. copeyensis as a white oak ( Subgenus Quercus ) and distinguishes 
it from Q. costaricensis, a black oak with rather similar foliage. 
See the article concerning this species by E. L. Little in the Carib- 
bean Forester, vol. 9:345-353. 1948. 

As I understand it, Q. copeyensis is an extremely variable species 
often found in dominating stands. Little is known about the flowers 
and fruit; I have only seen three fruiting collections: Burger & 
Burger 8181 (Fila Cedral, San Jose), Little 20043 (Volcan Irazu, 
Cartago), and Allen 3491 (Chiriqui, Panama). The species possesses 
considerable variety in leaf-form, leaf-texture, leaf-pubescence, and 
venation. These characters can vary on the same branch, or (more 
often) they may be quite uniform on an individual tree. Present 
collections give little evidence of correlations between these vari- 
able characters, and they are not correlated with geographic locale 
or habitat, except that the very small thick-leaved collections ap- 
pear to come from exposed sites at high altitudes. The narrowly 
obovate and thinner laminae characterizing material previously 
referred to as Q. aaata Muller is, I believe, no more than an unusual 
form found in individual trees or groups of trees. There are all man- 
ner of intermediates between this form and the thick shorter and 
broader laminae with few secondary veins characteristic of other 
trees and groups of trees. The two forms appear to have much the 
same ecological range. In the absence of more fertile material, it is 
impossible to say whether Q. aaata in a restricted sense ( Guatemala 
and Honduras) and with leaves of very thin texture is conspecific 
with the material placed here. 

Quercus corrugata Hooker, Icones Plant 5: pi. 403-404, 1842. Q. 
pilgeriana Seemen, Bull. Herb. Boissier, 2 ser. 4:655. 1904. Figure 
10. 

Trees 6-20 m. tall, the trunk becoming 70 cm. thick with dark brown bark peeling 
off in large flat pieces, leafy internodes (1) 4-30 (50) mm. long, 2-5 mm. thick, glab- 
rous or minutely stellate-tomentulose at the nodes, brown and soon becoming gray 
or yellowish-brown; buds 3-5 mm. long, globose to ovoid, bud-scales glabrous or 
minutely ciliolate along the distal margin. Leaves said to be deciduous, petioles 
(4) 8-25 mm. long, 0.7-1.8 mm. thick, terete or slightly sulcate adaxially, glabrous 
or very minutely (0.2 mm.) puberulent with yellowish hairs simple or branched from 
the base; laminae (5) 8-18 (25) cm. long, 2-5.5 cm. broad, very narrowly obovate to 



BURGER: FLORA COSTARICENSIS 69 

lanceolate or narrowly elliptic, usually tapering gradually to the acuminate or acute 
apex, abruptly obtuse or occasionally cordulate or truncate at the narrowed base, 
often unequal with the margins of the lamina 1-3 mm. distant on the petiole, margin 
entire below the basal third or fourth and with 4 to 12 blunt or serrate teeth on each 
side (rarely entire throughout), the lamina drying stiffly chartaceous, smooth and 
lustrous above, glabrous or with a few longer (0.5-1 mm.) hairs persisting basally 
or along the midvein, larger veins often raised within slight depressions on the 
upper surface, the 8 to 14 pairs of major secondary veins prominent below and aris- 
ing at angles of 40-70 degrees; stipules immediately caducous. Male spikes not seen 
from Costa Rica, said to be 5-6 cm. long and loosely flowered with the anthers much 
exserted; female flowers not seen from Costa Rica, said to be solitary or paired on 
short (5 mm.) peduncles. Fruit produced in one year, solitary on a thick (4 mm.) 
peduncle 0.5-3 cm. long, cup about 15 mm. long and 3 cm. broad but said to become 
as much as 6 cm. broad, cup- or bowl-shaped (but not seen at maturity and com- 
pletely mature fruit not seen from southern Central America), densely velutinous 
on the walls within, scales thickened basally and tightly appressed, densely puberu- 
lent with minutely, yellowish-white hairs, nuts (acorns) subglobose to ovoid or 
cylindrical, ours 2.5 cm. long and 1.5 cm. thick but said to become 3-5 cm. thick, 
longitudinally corrugated or smooth (dry), often puberulent distally, the basal scar 
(8) 12-16 mm. in diameter, area above the scar usually drying dark and contracting 
somewhat on drying. 

Plants of evergreen montane (premontane wet) forest formations 
between 1200 and 1900 m. elevation and apparently confined to the 
somewhat drier Pacific slope in Costa Rica. Our collections range 
from the southern slopes of Volcan Poas (Alajuela) in the west to 
Boruca (Puntarenas) in the southeast, and though a number of 
collections have been made from the area of Santa Maria de Dota, 
none have been made from the somewhat moister areas along the 
Interamerican Highway on the Cerro de la Muerte. The species 
ranges from Chiapas, Mexico, to western Chiriqui in Panama. 

The usually narrow leaves conspicuously bluntly serrate on rela- 
tively long slender petioles, generally glabrous parts, restricted 
habitat, and large acorns easily separate Q. corrugata from our 
other white oaks ( Subgenus Quercus). 

Quercus costaricensis Liebmann, Overs. Danske Vidensk. Selsk. 
Forhandl. 1854:184. 1854. Q. irazuensis Kuntze, Rev. Gen. PI. 
2:641. 1891. Q. endresi Trel., Mem. Nat. Acad. Sci. 20:145, pi. 280. 
1924, ex char. Figure 11. 

Trees 8-30 m. tall, the trunk becoming as much as 1 m. thick, the crown often 
dense and rounded, bark smooth, leafy internodes 1-30 mm. long, 2-8 mm. thick, 
very densely stellate-tomentose in early stages or glabrous, the pale brownish hairs 
about 0.5 mm. long and rubbing off, twigs becoming glabrescent and very dark 
brown changing to dark gray; buds about 6 mm. long and 4 mm. thick, ovoid, bud- 
scales puberulent apically. Leaves deciduous, petioles 0-4 (8) mm. long, 1-3 mm. 



70 FIELDIANA: BOTANY, VOLUME 40 

thick, densely puberulent to glabrous; laminae 3-10 ( 18) cm. long, 2-6(9) cm. broad, 
broadly oblong to elliptic-oblong or obovate or rarely ovate, rounded at the apex or 
occasionally bluntly obtuse to acute, obtuse to rounded and cordulate at the base, 
the margin entire to undulate or slightly lobed distally and becoming revolute, the 
lamina drying coriaceous to subcoriaceous and pale grayish-green, smooth and 
lustrous above, glabrous or with hairs persisting along the midvein above, densely 
tomentulous beneath with pale brownish stellate hairs falling off in age (laminae 
almost completely glabrous in material formerly ascribed to Q. irazuensis), venation 
strongly impressed above with the larger veins prominent within the depressions, 
the 4 to 7 (8) pairs of major secondary veins often dividing distally and very promi- 
nent beneath, lower surface often becoming minutely bullate; stipules caducous. 
Male inflorescences becoming 4-9 cm. long, the flower crowded or 1-6 mm. distant on 
the densely stellate-tomentulose rachis, perianth campanulate and about 2.5 mm. 
long, puberulent, filaments becoming 2-3 mm. long, anthers 1.8-2.3 mm. long and 
1 mm. broad, glabrous, female spike with (1) 3 to 10 flowers, to 5 cm. long, the 
flowers about 6 mm. long. Fruit produced in a year, solitary or paired and subsessile 
or on a short (1-10 mm.) thick (3-4 mm.) peduncles near the apex of the stem, the 
shallow cup 10-15 mm. long and 15-35 mm. broad, abruptly constricted and flat- 
tened beneath, the scales sparsely puberulent and minutely ciliolate distally, usually 
lustrous brown and the apices becoming free, mature nut (acorn) enclosed less than 
one-fourth by the cup, 15-30 mm. long, 20-35 mm. thick, hemispheric to ovoid, glab- 
rous or puberulent near the apex, pale brown, basal scar 10-15 mm. in diameter. 

This species is restricted to high montane wet forest and rain 
forest formations between (2200) 2700 and 3300 m. elevation. Flow- 
ering collections have been made from November to August and 
fruit has been collected from January to June. The species is known 
only from a small area bounded on the west by the slopes of Volcan 
Irazii and extending eastward along the Cordillera de Talamanca as 
far as Cerro Chirripo. 

Quercus costaricensis belongs to the subgenus Erythrobalanus, 
the red or black oaks. However, this species is most easily mistaken 
for a white oak, Q. copeyensis, among our species, and the two are 
often found together in high montane forests. The dark twigs and 
the very stiff, usually short subsessile leaves rounded apically with 
impressed venation above and persistent tomentum beneath, that 
dry pale yellowish-brown or gray-green distinguish this species. 
Material previously placed under Q. irazuensis is distinguished by 
having glabrous leaves narrowed at both ends, but these have never 
been collected with flowers or fruit and represent, I believe, no more 
than an unusual form of this very well-defined and quite variable 
species. 

Quercus guglielmi-treleasei C. H. Muller, U.S.D.A. Misc. Publ. 
477:58, pi. 79, 80. 1942. Figure 11. 



BURGER: FLORA COSTARICENSIS 71 

Trees 8-30 m. tall, trunk to over 1 m. in diameter, leafy internodes (0) 2-30 mm. 
long, 1.5-4 (5) mm. thick, usually only sparsely floccose in early stages and soon 
glabrous, very dark brown or grayish-black with conspicuous (0.5-1 mm.) lenticels; 
buds 3-4 mm. long, ovoid, bud-scales sparsely puberulent and slightly lustrous. 
Leaves probably deciduous, petioles 0-5 (12) mm. long, 1.5-3 mm. thick, densely 
stellate-floccose to glabrate, the winged margins prominent and flat or forming an 
adaxial groove, swollen at the base; laminae (6) 9-18 (25) cm. long, (2) 3-6 (8) cm. 
broad, narrowly elliptic-oblong to lanceolate or oblanceolate, often asymmetrical 
and curved to one side, tapering gradually to the long-acuminate or less often short- 
acuminate or acute apex, the tip only occasionally aristate, usually tapering 
gradually to the acute or attenuate base, the margin entire, becoming undulate and 
slightly re volute on drying, continuous with the wings of the petiole, the lamina 
drying chartaceous and usually dark gray-green or brownish above, slightly lust- 
rous, glabrous and smooth above, glabrous beneath or persistently puberulent near 
the base and along the midvein, the 9 to 18 pairs of major secondary veins branching 
distally, impressed above but raised within the grooves, prominent beneath, the 
smallest reticulate veins usually raised on the upper surface (dry); the ligulate 
stipules early caducous. Male inflorescence and flowers unknown; female flowers 
unknown. Fruit probably formed in one year, solitary to several on a peduncle 1-4 
cm. long and 1.5-3 mm. thick, the cups 5-10 mm. long and 13-18 mm. broad, saucer- 
shaped to goblet-shaped and abruptly narrowed at the base, scales sparsely puberu- 
lent and tightly appressed, umbonate at the base and often lustrous brown, nuts 
(acorns) 7-15 mm. long, 11-15 mm. thick, hemispheric to broadly ovoid, apex round- 
ed or flat (? immature), minutely sericeous but becoming glabrous, enclosed one- 
third or less within the cup, basal scar 7-9 mm. in diameter. 

Trees of wet montane (premontane and lower montane rain) 
forest formations between (1100) 1500 and 2600 m. altitude. The 
species as presently known ranges from the wet Caribbean slopes 
near Zarcero (Alajuela) to the Chiriqui highlands in Panama. The 
two fruiting collections from Chiriqui were made between April 
and July. 

Quercus gulielmi-treleasei is a poorly understood species of the 
subgenus Erythrobalanus and appears to intergrade with the very 
closely related Q. seemannii. The relatively long and narrow leaves, 
which are tapered at both ends and often subsessile, and which dry 
thin and dark in color, are important but very variable characteris- 
tics. This species is often very difficult to separate from Q. seeman- 
nii and may be no more than an ecotype form of that species com- 
monly found in wetter montane forests. A collection by Alfonso 
Jimenez (1276E) from Monteverde in the Cordillera de Tilaran 
(Puntarenas) may be this species or an unusual juvenile form of 
Q. brenesii. 



Quercus insignis Mart. & Gal., Bull. Acad. Brux. 10:219. 1843. Q. 



72 FIELDIANA: BOTANY, VOLUME 40 

schippii Standley, Cam. Inst. Wash. Publ. 461:53. 1936. Q. seibertii 
Muller, U.S.D.A. Misc. Publ. 477: 19, pi. 6 & 7. 1942. Figure 10. 

Trees 15-30 (40) m. tall, trunk exceeding 1 m. in diameter, bark dark brown to 
grayish brown and often peeling in strips to appear shaggy, leafy internodes 5-30 
mm. long, 2-6 mm. thick, densely covered with yellowish or orange (fulvous to 
rufous) stellate hairs 0.3-0.9 mm. long, becoming glabrescent after 1 or 2 years and 
grayish or brown with conspicuous lenticels; buds 2-5 mm. long (expanding to 15), 
globose to ovoid, bud-scales distally glabrous. Leaves probably deciduous, petioles 
5-25 mm. long, 1.5-3 mm. thick, densely stellate tomentose and terete; laminae 10- 
24 cm. long, 3.5-9 (12) cm. broad, quite variable in shape, most often oblong to 
obovate, tapering abruptly to the bluntly obtuse apex or occasionally acute or 
rounded, often gradually narrowed below the middle and then abruptly truncate or 
cordulate at the petiole (rarely subcordate), margins entire to undulate or bluntly 
short-serrate, revolute (dry) and the lamina stiffly chartaceous to subcoriaceous, 
smooth and lustrous above, persistently puberulent on the midvein above, densely 
to sparsely puberulent on all surfaces beneath, the orange or yellowish stellate hairs 
0.2-0.6 mm. long, primary and secondary veins often raised within depressions on 
the upper surface, the 9 to 18 pairs of major secondary veins arising from the mid- 
vein at angles of 40-60 degrees, very prominent beneath, tertiary veins subparallel 
and occasionally impressed above; stipules often persisting, 8-12 mm. long, ligulate, 
densely appressed sericeous on the abaxial surface. Male inflorescences 3-8 cm. 
long, the flowers remaining crowded on the densely puberulent rachis, perianth 
about 2 mm. long, apically ciliolate, filaments very short ( 1 mm.), anthers 1-1.5 mm. 
long (based on Shank 13954); female spike 1-3 cm. long with 1 to 3 globose female 
flowers about 4 mm. long (based on J. Leon 1165). Fruit produced in 1 year and 
usually solitary, the cup becoming 2-3 cm. long and 4-8 cm. broad, broadly saucer- 
shaped and abruptly narrowed beneath or occasionally tapering to the base, cup- 
scales densely and minutely sericeous, the free apex 4-6 mm. long and about 2.5 mm. 
broad; nuts (acorns) said to become 3-5 cm. long and 3-7 cm. thick, ovoid to globose 
and flattened above, longitudinally striate, basal scar about 25 mm. in diameter, 
tissue above the scar-edge often contracting on drying. 

This species is known only from lower montane (and premontane) 
wet forest formations between 1000 and 1800 m. elevation in Costa 
Rica; collected at Zarcero (A. Smith 141, 177, & 2769), Alajuela, 
south of Guatuso (Lent 1165), Cartago, Las Lajas above El General 
(J. Leon 1165), San Jose, and Agua Buena (Shank 13954), Pun- 
tarenas. In our area, flowering material has been collected in 
January and fruit in July. The species ranges from Veracruz, Mexi- 
co, to Chiriqui, Panama. 

Quercus insignis is an unusual oak distinguished by its rather 
thick, persistently yellowish puberulent laminae, usually truncated 
at the base and borne on prominent petioles. The usual leaf-shape 
and very large acorns indicate that this species is very closely re- 
lated to Q. oocarpa, and the species do not differ greatly in habitat, 
though they have not been collected at the same sites in Costa Rica. 
The type collection of Q. seibertii (Seibert 225 from Chiriqui) has 



BURGER: FLORA COSTARICENSIS 73 

unusually broad and entire leaves that are subcordate at the base. 
A review of our recent collections leads me to believe that this is 
only an unusual leaf-form and not specifically distinct. The type of 
Q. davidsoniae Standley (Davidson 864 from Chiriqui) has charac- 
teristics of both Q. insignis and Q. oocarpa, and I believe that it is 
either a hybrid or a backcross between the two. Our present 
sampling of Quercus populations is so poor that we can not clearly 
define the parameters of these species, and assignment of unusual 
collections is no more than guesswork. 

Quercus oleoides Schlecht. & Cham., Linnaea 5:79. 1830. Q. 
retusa Liebm., Overs. Danske Vidensk. Selsk. Forhandl. 1854:187. 
1854. Q. oleoides var. australis Trel., Mem. Nat. Acad. Sci. 20:114, 
pi. 192 & 193. 1924. Figure 10. 

Trees 5-15 m. tall, often much branched and with a dense crown, leafy internodes 
2-15 (30) mm. long, 2-4.5 mm. thick, pale grayish-white with minute stellate hairs, 
remaining puberulent or becoming glabrous; axillary buds 2-3 mm. long, ovoid, 
sparsely puberulent and reddish-brown. Leaves persisting, petioles 4-8 (10) mm. 
long, 1-1.8 mm. thick, subterete, pale grayish with minute canescent stellate hairs; 
laminae 3-11 cm. long, 2-5 (6) cm. broad, oblong or elliptic to slightly obovate, ob- 
tuse to rounded and emarginate at the apex, abruptly obtuse to acute or cuneate at 
the base, the margin entire or rarely with a few blunt or mucronate lobes distally 
and becoming slightly revolute, the lamina drying stiffly chartaceous to sub- 
coriaceous, dark green but drying pale gray-green or pale buff above and very pale 
gray beneath, smooth, lustrous, and becoming glabrous or remaining puberulent on 
the midvein above, becoming sparsely puberulent on the veins beneath but densely 
appressed puberulent between the veins with canescent stellate hairs about 0.1 mm. 
long, the 4 to 7 pairs of major secondary veins flat above, reticulum of the tertiary 
veins usually visible and slightly raised on the upper surface; stipules immediately 
caducous. Male spikes becoming 3-4 cm. long, the -achis puberulent and the flowers 
approximate, anthers about 1 mm. long on very short filaments, thecae with short 
(0.1 mm.) whitish hairs; female spikes 3-30 mm. long, with 1 to 6 (8) flowers, flower 
about 7 mm. long. Fruit produced in one year, solitary or several on a short ( 5-50 
mm.) thick (1-3 mm.) peduncle, the cup 7-12 mm. long and 12-17 mm. broad, taper- 
ing gradually to the base and turbinate to hemispheric in shape, the scales relatively 
flat and covered with canescent hairs, the interior of the cup with similar hairs, 
mature nut (acorn) 15-28 mm. long and 10-14 (18) mm. thick, narrowly ovoid to 
ellipsoid, glabrous and drying light to dark brown, enclosed less than one-third by 
the cup, often elevated about 1 mm. on the base, basal scar about 5-7 mm. in dia- 
meter. 

This species is restricted in Costa Rica to a small area in the 
northern part of Guanacaste province between 50 and 500 m. alti- 
tude in the deciduous (tropical dry and premontane moist) forest 
formations. Flowering material has been collected during the dry 
period, December to May, and mature fruit have been collected from 



74 FIELDIANA: BOTANY, VOLUME 40 

July to January. The species ranges northward in a series of dis- 
junct populations to Tamaulipas, Mexico. 

Quercus oleoides is a member of the subgenus Quercus and is 
easily separated from all our other oaks by the restricted low-alti- 
tude habitat and by the very pale-colored lower leaf-surfaces. This 
species is not closely related to other Central American white oaks ; 
its relationships lie with species of the southern United States and 
northern Mexico. The type of Q. retusa Liebmann, not Q. retusa 
Rafinesque, (Oersted s.n. in C) has the locality as Volcan Barba 
7000 ft. but I am sure that this is incorrect and the species is re- 
stricted in Costa Rica to Guanacaste. See the excellent discussion 
of the phytogeography of this species by J. M. Montoya Maquin in 
Turrialba 16:57-66, 1966. 

Quercus oocarpa Liebm., Overs. Danske Vidensk. Selsk. For- 
handl. 1854:184. 1854. Figure 10. 

Trees 8-30 m. tall, trunks with dark brown bark coming off in strips, leafy inter- 
nodes 0-2 (4) cm. long, 3-5 mm. thick, densely and usually persistently tomentulose 
for the year with yellowish or yellowish-brown hairs 0.5-1.5 mm. long, becoming pale 
gray or whitish gray after a year or two, the hairs stellate (often difficult to see); 
buds globose to ellipsoid, 4-8 mm. long and obscured by the stipules. Leaves decidu- 
ous, petioles 1-6 (10) mm. long, 2-3 mm. thick, densely yellowish tomentulose, 
apparently terete; laminae (8) 12-25 (30) cm. long, 4-9 (11) cm. broad, usually obo- 
vate but occasionally elliptic to oblong, tapering abruptly to the acute or short 
acuminate apex, tapering gradually below the middle to the cuneate base, occasion- 
ally acute or slightly rounded at the petiole, margin serrate above the basal half or 
third (rarely subentire or undulate), the 5 to 15 ( 18) teeth on each side quite variable 
from blunt to curved or with a tip 0.5 mm. long, the lamina drying stiffly char- 
taceous and the edge slightly revolute, smooth and often slightly lustrous above, 
usually densely and persistently stellate-puberulent on the major veins above and 
sparsely puberulent to glabrous between the veins, persistently puberulent beneath 
especially on the veins, major veins prominent above in slight depressions, the 12 
to 18 pairs of major secondary veins arising from the midvein at angles of 40-70 
degrees, secondary and tertiary veins prominent beneath; stipules usually persist- 
ing, 8-4 mm. long and ligulate, sericeous on the abaxial surface. Male spikes 3-7 cm. 
long, flowers remaining crowded distally on the densely tomentulose rachis, 
perianth about 2 mm. long with conspicuous pale yellowish hairs about 0.5 mm. long 
on the edge, anthers barely exserted on filaments less than 1 mm. long, thecae 1-1.5 
mm. long, glabrous, the connective not usually prolonged; female flowers on a short 
(5-30 mm.) spike, about 5 mm. long. Fruit usually solitary, cup 2-3 cm. long and 3-4 
cm. broad but probably becoming larger, gradually tapering and bowl-shaped but 
probably becoming saucer-shaped at full maturity, sericeous on the walls within, 
apices of the cup-scales about 4 mm. long and loosely appressed, persistently puber- 
ulent, nut (acorn) 3-4 cm. long and 2-3 cm. thick but said to become 5 cm. thick and 
4-5 cm. long at full maturity, cylindrical to globose and depressed above (not fully 
mature ?), remaining minutely puberulent at the apex, one-half to one-fourth 



BURGER: FLORA COSTARICENSIS 75 

enclosed by the cup, basal scar 12-18 mm. in diameter, with a darkened and 
contracted ring just above the scar on drying. 

Trees of wet evergreen montane (lower montane wet, lower mon- 
tane rain, and premontane rain) forest formations between (700) 
1100 and 2300 m. elevation in Costa Rica. Flowering material has 
been collected in January and March and fruiting material (im- 
mature ?) in July in our area. The species, as here understood, 
ranges from Vera Cruz, Mexico, to Chiriqui, Panama. It has been 
collected in Costa Rica from Monteverde (Puntarenas) in the Cordil- 
lera de Tilaran, along the Cordillera Central, near Escazu (San 
Jose), Mufieco (Cartago), and along the Cordillera de Talamanca. 
This species has not been collected along the Interamerican high- 
way, though the highway crosses the Cordillera de Talamanca not 
far from some areas where the trees are common. 

Quercus oocarpa is recognized by the yellowish or orange-brown 
pubescence on younger parts, very short petioles, larger obovate 
laminae usually cuneate at the base with distinct low serrations dis- 
tally, numerous secondary veins, and the leaves usually clustered at 
the ends of branchlets. The male flowers are distinctive; the fruit 
are poorly known but apparently become very large. This species is 
part of a difficult complex of Central American white oaks (sub- 
genus Quercus). Quercus oocarpa is very closely related to Q. 
insignis and the fact that they share much the same habitat in 
Costa Rica and much the same range may indicate that the two are 
not really different species; see the discussion under Q. insignis. 
Quercus tomentocaulis Muller from Honduras is probably synony- 
mous with the concept of Q. oocarpa described here. 

Quercus pilarius Trel., Mem. Nat. Acad. Sci. 20:44, pi. 19. 1924. 
Figure 10. 

Trees 8-25 m. tall, trunk becoming more than 1 m. thick, leafy internodes 2-20 mm. 
long, 1.2-3 (4) mm. thick, sparsely to densely puberulent but soon becoming glabres- 
cent and grayish, the hairs simple or stellate, 0.5-1 mm. long; buds 2-4 mm. long, 
globose to ovoid and usually obscured by the stipules, glabrous abaxially and 
minutely ciliolate. Leaves deciduous or persisting during the new growth, petioles 
1-6 (9) mm. long, 0.6-2 mm. thick, sparsely puberulent or glabrous, slightly winged 
at the lamina and terete basally; laminae (6) 10-26 cm. long, 2-6 (9) cm. broad, 
oblanceolate to very narrowly obovate or elliptic, gradually tapering to the acumi- 
nate or acute apex, very gradually narrowed below the middle to the cuneate or sub- 
cuneate base and acute or slightly rounded at the petiole, conspicuously serrate 
along the distal margins, the slightly mucronate serrations 4 to 11 on each side and 
curved forward, the lamina drying chartaceous or stiffly chartaceous with the edge 
slightly revolute, usually smooth and slightly lustrous on both surfaces, soon be- 



76 FIELDIANA: BOTANY, VOLUME 40 

coming glabrous or with a few persisting hairs on the midvein beneath, these hairs 
usually simple, straight, and ascending, 0.5-1 mm. long and whitish, secondary 
veins slightly raised above and prominent beneath, the 10 to 16 pairs of major secon- 
daries arising at angles of 40-60 degrees; stipule 4-10 mm. long and often persisting, 
ligulate, short strigose on the abaxial surface; flowering material not seen. Fruit 
said to become about 5 cm. thick and 4 cm. long, subglobose, the cups unknown, 
nuts ( acorns) and cups probably very similar to those of Q. oocarpa. 

Plants of wet evergreen montane (premontane wet, premontane 
rain, and montane rain) forest formations between 1000 and 1800 m. 
elevation in Costa Rica and known from the following areas: near 
Monteverde (Burger and Gentry 8585), Cataratas de San Ramon 
(Brenes 13437} and near La Laguna (Molina et al. 17528) in 
Alajuela, east of Turrialba (Barbour 1013) and near Moravia 
(Williams 16197) in Cartago, and around Sta. Maria de Dota 
(Standley 42425 & 42842} in San Jose. The species ranges from 
Chiapas, Mexico, to Chiriqui, Panama. 

Quercus pilarius, a member of subgenus Quercus, is closely re- 
lated to Q. oocarpa, but the former is easily distinguished by the 
glabrescent parts and the thinner leaves that are much narrower 
with the midvein beneath retaining only a few simple ascending 
whitish hairs. The wood is said to be extremely hard and durable, 
and good for heavy construction. A collection from Boquete, 
Chiriqui (Davidson 497), appears to be a collection of Q. oocarpa 
with some of the characteristics of Q. pilarius and may indicate that 
these species hybridize. 

Quercus rapurahuensis Pittier ex Trelease, Mem. Nat. Acad. Sci. 
20:143, pi. 275. 1924. Q. baruensis Muller, Trop. Woods 108:75. 
1958. Figure 11. 

Trees 10-30 m. tall, trunk becoming more than 1 m. thick, leafy internodes 2-20 
(30) mm. long, 1.2-5 mm. thick, stellate tomentulose but quickly becoming glabrous, 
dark brown or reddish-brown with small (0.5 mm.) but conspicuous lenticels; buds 
3-4 mm. long, ovoid, bud-scales glabrescent abaxially and ciliolate. Leaves said to 
be deciduous, petioles (4) 8-26 mm. long, 0.8-1.8 mm. thick, terete or flattened and 
slightly winged adaxially, glabrescent or becoming so; laminae (6) 9-18 cm. long, 
3-7 cm. broad, narrowly ovate or lanceolate to elliptic or oblong (rarely obovate), 
acute to short-acuminate at the apex, acute to abruptly obtuse and occasionally 
unequal at the base, margin entire or undulate and slightly revolute on drying, 
lamina drying stiffly chartaceous and often pale grayish above and yellowish-brown 
beneath, often slightly lustrous on both surfaces, becoming glabrous above, persis- 
tently tomentulose in the axils of the veins beneath, the stellate hairs pale or yellow- 
ish-brown and 0.2-0.4 mm. long, midvein prominent above, the (7) 9 to 12 pairs of 
major secondary veins prominent beneath and often forking distally, tertiary veins 
becoming slightly raised on the upper surface (dry) and the smallest veins usually 



BURGER: FLORA COSTARICENSIS 77 

easily seen above (X10); stipules immediately caducous. Male spikes probably be- 
coming 4-5 cm. long with the flowers distant on the sparsely puberulent rachis, 
perianth 1-1.5 mm. long, free to near the base, minutely ciliolate, anthers on very 
short filaments and about 1.2 mm. long (before anthesis), glabrous; female spikes 
with 1 to 4 flowers on short (3-16 mm.) thick (1-2 mm.) peduncles, flowers about 
4-6 mm. long, style-branches 2 mm. long and recurved. Fruit usually 2 or 3 on short 
(1-2 cm.) thick peduncles, the cup 8-13 mm. long, 16-20 mm. broad and abruptly 
narrowed beneath and saucer-shaped, bud-scales tightly appressed and often thick- 
ened basally, pale brown with minute appressed buff colored hairs, the nut (acorn) 
15-20 mm. long and 14-20 mm. thick, ovoid to ellipsoid, densely pale brownish 
sericeous but becoming glabrous in age, the mature nut enclosed less than one-third 
by the cup, basal scar 10-14 mm. in diameter. 

Trees of the wet evergreen montane (lower and premontane wet 
and lower and premontane rain) forest formations between 1000 and 
2500 m. elevation. The species is known in Costa Rica from the areas 
of Sta. Maria de Dota, Copey, and in the Cordillera de Talamanca on 
the northern slopes of the General Valley ; collected in flower from 
December to April and with fruit from May to July. The species 
ranges from Central Costa Rica to Chiriqui, Panama. 

Quercus rapurahuensis is a black oak (subgenus Erythrobalanus) 
whose leaves usually dry pale-colored, are often long-petiolate, and 
with only 2 or 3 fruits on. short thick peduncles. The acorns are con- 
siderably larger than those of the closely related Q. seemannii (see 
discussion under that species). There are two type sheets of Tonduz 
11795 at the U.S. National Herbarium, and I suspect that they 
represent a mixed collection. I take sheet 930372 to be the type, as 
illustrated by Trelease, and sheet 93067 to be a specimen of Q. see- 
mannii. Outside of our flora, Q. rapurahuensis is most closely re- 
lated to Q. benthamii A. DC. of Guatemala, which differs in the 
longer and narrower buds and the secondary veins arising more 
acutely from the midvein. The wood is said to be good for firewood 
but not for lumber. 

Quercus seemannii Liebmann, Overs. Danske Vidensk. Selsk. 
Forhandl. 1854:188. 1854. Q. eugeniaefolia Liebm., I.e. 185. Q. 
granulata Liebm., I.e. 186, not Q. granulata Raf. Q. citri folia 
Liebm., I.e. 187. Q. bumelioides Liebm., I.e. 188, fide Trelease. 
Q. borucasana Trel., Mem. Nat. Acad. Sci. 20:161, pi. 315. 1924. 
Q. eugeniaefolia f . petiolata Trel., I.e. 161, pi. 316b. Q. boquetensis 
Standl., Field Mus. Bot. 22:13. 1940. Q. panamandinaea Muller, 
U.S.D.A. Misc. Publ. 477:29, pis. 21 & 22. 1942, pro parte: as to 
stems and leaves only. Q. sapotaefolia auctores as to Costa Rica. 
Figure 11. 



78 FIELDIANA: BOTANY, VOLUME 40 

Trees 6-15 (25) m. tall, the trunk becoming over 1 m. thick with relatively smooth 
gray or brownish bark; leafy internodes 1-30 mm. long, 1.2-6 mm. thick, sparsely 
puberulent with yellowish stellate hairs about 0.3 mm. long but soon becoming 
glabrescent, often dark reddish brown and lustrous in the first year; buds narrowly 
ovoid 4-7 mm. long, bud-scales puberulent only on the edges. Leaves deciduous or 
persisting (for a short period?) after the new flush of growth, petioles 1-6 ( 10) mm. 
long, 0.8-2 mm. thick, sulcate above with adaxial ridges or wings continuous with 
the margins of the lamina, soon glabrescent; laminae (2.5) 4-10 (16) cm. long, (1) 
1.5-3 (4) cm. broad, narrowly oblong to elliptic, lanceolate, or narrowly obovate, 
usually tapering gradually to the acute and aristate apex or occasionally blunt and 
rounded (on the same stem or on different trees), tapering to the acute base or rarely 
obtuse and contracted abruptly at the petiole, margin entire and usually becoming 
revolute, the lamina drying thick chartaceous to subcoriaceous, usually becoming 
glabrous and lustrous above, becoming glabrous beneath or with a few brownish 
stellate hairs persisting along the midvein, midvein prominent above with the secon- 
daries flat or slightly impressed, the 5 to 13 pairs of major secondary veins arising 
from the midvein at angles of 45-80 degrees; stipules 6-12 mm. long, 0.5-1.5 mm. 
broad, translucent brown, caducous. Male inflorescences 3-10 cm. long, flowers 
usually separate on the minutely and sparsely puberulent rachis, male flowers 
sessile or very short (0.5 mm.) pedicellate, perianth parts 1-1.5 mm. long, filaments 
1.5-2 mm. long, anthers 0.8-1.4 mm. long (dry); female flowers solitary or 2 to 4 on 
peduncles 1-5 mm. long, flowers narrowed at the base, 5-7 mm. long, bracts (scales) 
minutely brownish puberulent. Fruit maturing within a year, subsessile on very 
short (0-2 cm.) peduncles, solitary or 2 to 4, the cup 8-12 mm. broad and 6-8 mm. 
long, deeply cup- or goblet-shaped, larger cup-scales about 2 mm. broad at the base, 
narrowed to a rounded apex, becoming glabrescent on the upper abaxial surface, nut 
(acorn) 10-18 mm. long, (8) 10-12 (14) mm. thick, usually with an abruptly narrowed 
tip 1-2 mm. long and the persisting style-base 1-2 mm. long, broadly ovoid to hemis- 
pheric but often very narrowly ellipsoid in early stages, persistently minutely seri- 
ceous, the basal scar 6-8 mm. broad. 

This species is commonly found in both premontane and montane 
wet forest and rain forest formations between 1400 and 2400 m. ele- 
vations, but occasional collections have been made as low as 1100 m. 
and as high as 3100 m. (on Cerro Chirripo). Male flowers have been 
collected in November and December with a single collection in 
April, while mature acorns have been collected between April and 
August. The species ranges in our area from San Ramon and 
Zarcero, Alajuela, in the west through the Central Highlands and 
along the Cordillera de Talamanca to the Chiriqui highlands in 
Panama. 

Quercus seemannii is a species of considerable but not unusual 
variability. It is characterized by its small acorns, generally small 
lustrous leaves often acute at both apex and base, and its glabre- 
scent parts. This species probably intergrades with Q. gulielmi- 
treleasei, and it may hybridize with Q. rapurahuensis and Q. ton- 
duzii. These species may be difficult to separate in the absence of 



BURGER: FLORA COSTARICENSIS 79 

acorns and comparative material. Quercus seemannii and its close 
relatives in Costa Rica are, in turn, related to the entire-leaved black 
oaks (subgenus Erythrobalanus) of middle and northern Central 
America. These species together make up the most difficult com- 
plex in Central America's oaks. Though many names and distinc- 
tions have been proposed to separate them, I believe that no 
adequate treatment of these plants is presently available and that 
they are in need of careful study in the field. The following com- 
ments deal with a few names applicable to this group that have been 
in use in Costa Rica and Panama. 

The name Q. sapotaefolia has been used for oaks of this species 
with small oblong leaves blunt at the apex. This type of leaf-form is 
very rare in Costa Rica (Lems 630714, Opler 147, Pittier 2036), and 
it can occasionally be found together with aristate leaf-tips on the 
same branchlet (A. Jimenez 2782, Lent 774, Williams & Molina 
13851 ). These are merely variants in Q. seemannii of Costa Rica and 
I am sure that the name sapotaefolia does not apply. Liebmann 
describes the tvpe (Skinner in herb. Hooker) as being from Guate- 
mala, not Costa Rica (Trelease 1924, Muller 1941), and I am sure 
that he is correct. The holotype sheet of Q. panamandinaea ( Wood- 
son & Schery 360 in MO) possesses foliated stems that match per- 
fectly with some material that I have included under Q. seemannii. 
The acorns associated with the specimen, but detached, appear to 
be those of Q. corrugata though not quite mature. I believe this 
name is based on a mixed collection. Type material of Q. citrifolia 
(Oersted 3461, 3 sheets in C) has distinctly petiolate laminae 
abruptly narrowed at the base. I had at first thought that this was 
the same as Q. rapurahuensis but examination of the type material 
leads me to believe that it represents only an unusual form of Q. 
seemannii. 

I prefer to use the name Q. seemannii because of the excellent 
illustration presented by Liebmann and Oersted in Chenes de 
1'Amerique Tropicale (plate 20) and presence of type material in the 
Hookerian herbarium at Kew (fide Trelease 1924). Type material of 
Q. eugeniaefolia, said to have been at Berlin, is probably destroyed. 

Quercus tonduzii Seemen, Bull. Herb. Boissier, ser. 2, 4:656. 
1904. Q. wesmaeli Trel., Mem. Nat. Acad. Sci. 20:172, fig. 344a. 
1924, as to type only. Figure 11. 

Trees (6) 10-30 m. tall, leafy internodes (0) 1-15 (25) mm. long, 1.5-4 mm. thick, 
densely stellate-floccose, the hairs 0.4-1 mm. long and rubbing off quickly, the older 



80 FIELDIANA: BOTANY, VOLUME 40 

twigs retaining only a few scattered yellowish hairs; buds narrowly ovoid, 3-8 mm. 
long, bud scales puberulent on the edges and apex but glabrous on the abaxial sur- 
face. Leaves usually deciduous before the new flush of growth, petioles 2-8 mm. 
long, 1-2 mm. thick, slightly sulcate above with narrow adaxial ridges (wings) con- 
tinuous with the margins of the lamina, floccose at first but soon glabrescent; 
laminae (3) 4-10 (11) cm. long, 1.5-3.5 (4) cm. broad, elliptic to oblong or slightly 
obovate, acute and aristate to rounded and blunt at the apex (on different plants or 
on the same branch), tapering gradually or abruptly to the acute or obtuse base, 
often slightly rounded at the petiole, margin entire and drying revolute, the lamina 
drying stiffly chartaceous to subcoriaceous, upper surface becoming glabrous and 
lustrous in age, lower surface with a mat of soft stellate hairs sloughing off and per- 
sisting only along the midvein, secondary veins becoming slightly impressed in age 
and the midvein prominent above, the 4 to 8 pairs of major secondary veins arising 
at angles of 45-70 degrees; stipules 5-10 mm. long, 0.3-1 mm. broad, immediately 
caducous. Male inflorescences 3-7 cm. long, the flowers usually separate on the per- 
sistently puberulent rachis, male flowers sessile or short ( 1 mm. ) pedicellate, peri- 
anth parts about 2 mm. long and 1 mm. broad, filaments 1.5-2.5 mm. long, anthers 
1.3-2 mm. long; female inflorescences 0.5-2 cm. long with 2 to 5 flowers, the female 
flower about 4 mm. long and subtended by thin puberulent bracts. Fruit on very 
short (0-2 cm.) peduncles, solitary or 1 to 4, the cup becoming about 20 mm. broad 
and 10 mm. long, deeply saucer-shaped, bud-scales about 3 mm. broad at the base 
and with a long (2-3 mm.) narrow apex, persistently puberulent, nut (acorn) be- 
coming about 20 mm. long and 20 mm. thick, broadly ovoid to subglobose, basal 
scar about 8 mm. broad. 

Quercus tonduzii is endemic to the summit of Volcan Poas, 
Alajuela, above 2100 m. altitude in montane rain forest and as- 
sociated vegetation; flowers have been collected in March and fruit 
in November. 

This species is closely related to Q. seemannii sensu lato and dif- 
fers in the relatively broader leaves more abruptly tapered at the 
apex and in the larger fruit and anthers. Only one collection of 
mature fruit is known (Tonduz 10788, the type), but other collec- 
tions with immature acorn-cups have the same large cup-scales as 
the type and together differ in this regard from Q. seemannii. The 
leaves of this species are quite variable with those of the type re- 
sembling material of Q. seemannii. Collections with mature acorns 
are rare in this and the related species; because of this, the species 
concepts themselves are quite hypothetical. 



INDEX TO EXSICCATAE 

QUERCUS OF COSTA RICA AND PANAMA 

Acronyms refer to species 

Allen, P. H. 302 GUL; 303 OOC; 672 COS; 1595 RAP?; 1596 OOC; 3464 RAP; 



BURGER: FLORA COSTARICENSIS 81 



3465 SEE; 3467 RAP; 3491 COP; 3496, 3523 RAP; 4683 OOC; 4722, 4731 SEE; 
16480 GUL. 

Harbour, W. R. 1013 PIL. 

Brenes, A. M. 5178 BRE; 5194 BRE?; 5566, 6010, 6224 BRE; 6704 SEE; 11602 
BRE; 13437 PIL; 14520 TYPE BRE; 15590 OLE; 16966 BRE. 

Burger, W. C. et al. 5940 COP; 6001, 7385 COS; 7386 SEE; 7387, 7486 COS; 7911 A, 
B, C, D, E, F, 7967 COP; 8169 SEE; 8172, 8181 COP; 8236 A, B COS; 8380 A, 
C COP; 8380 B RAP?; 8386 RAP; 8390, 8415 SEE. 

Cohn, G. G. 44 RAP? 

Cuatrecasas, J., & Leon, J. 26533 COS. 

Davidson, M. E. 133 COP; 437 SEE; 497 OOC; 677, 721, 780 SEE; 864 TYPE Q. 
davidsoniae, INS x OOC?; 909, s.n. SEE. 

Dayton, W. A. 3084 COS. 

Dodge, C. W., & Thomas, W. S. 6232 OLE. 

Ebinger, J.E.814COR. 

Frostal4lCOR. 

Gonzalez M., R. RGM-3 COS; RGM-18-X-3 SEE; RGM-19-X-4 COP; RGM-20-X-6 
COS; RGM-25-X-12, RGM-40-X-40 COP. 

Hatheway, W. H. 1276 SEE ; 1308 COS. 
Hunter, J. R. 8 OLE. 

Jimenez M., A. 194 TON; 292, 293 SEE; 296 COR; 462 TON; 478 OOC; 550, 585 
OLE; 602 SEE; 1276 A, B BRE; 1276 C OOC; 1276 D BRE; 1276 E GUL?; 
1276 G BRE; 1419 COP; 1430, 1488, 2610, 2782 SEE; 3359 OLE; 3986 COS; 
s.n. BRE. 

Jimenez, O. 20 COS; 21 COP; s.n. OLE; s.n. RAP. 
Kukachka, B. F. s.n. BRE. 

Kuntze. O. 22826 TYPE COP in part, COS in part. 
Lankester, C. H. 214 COR. 

Lems, K. 63071302 COS; 630714, 63071401 SEE; 63071402 COR; 630726 TON?; 
64090604 GUL?; 640909 COP; s.n. SEE. 

Lent, R. W. 390 COS; 774 TON; 1116 INS; 1756 BRE. 

Leon, J. 847 COR; 1099, 1105, COP; 1165 INS?; 1178 SEE; 1271, 1294 COP. 

Little, E. L., Jr. 6001, 6002, 6003, 6004, 6005, 6008 COP; 6009 SEE ; 6010 COP; 6011 
SEE; 6035 COP; 6036 OOC; 6038, 6039 COP; 6045 SEE; 6054 RAP; 6055 PIL; 
20043 COP. 

Madriz V., A. AMV-1 COS; AMV-15 COP; AMV-16, AMV-17 SEE; AMV-18 COP; 
AMV-21-X-2 COS; AMV-24 SEE. 

Merker, C. A., Scholten, J. A., & Dayton, W. A. 3153 COP; 3154 COS. 

Molina R., A. 15029 OLE; 17045, 17105 COP; 17113 OOC; 17528 PIL; 17809 GUL?; 
17831 COP; 17838 SEE; 20127, 22979 BRE. 



82 FIELDIANA: BOTANY, VOLUME 40 

Opler, P. A. 120, 121 TON; 122 GUL; 126 TON; 127 COS; 128, 130 COP; 147, 148 
SEE; 149 COP; 150 GUL. 

Pittier, H. 871 COS; 2036 TON; 2197 COR; 2262, 5305, 10553 SEE; 14120 COS; 
s.n. COR. 

Quin6s, M. 187 BRE. 

Raven, P. H. 20952 COP; 20971 COS; 20976 COP. 

Rodriguez, R. L. 549 OOC. 

Rowlee, W. W., & Stork, H. E. 940 COS. 

Seibert, R. J. 225 INS?; 226 GUL; 317 OOC. 

Shank, P. 13954 INS; 13963 GUL?. 

Skutch, A. F. 3584 COP. 

Smith, A. A141 INS; A464, H370, P.C.198 SEE; 177 INS; 2742 COR; 2756 COP; 
2769 INS; 2828, 2877 SEE; 2878 OOC; 2879 COP; 10082 SEE. 

Soels, K. KSW-1, KSW-2 COP. 
SolaneJ., I. ISJ623SEE. 

Standley, P. C. et al. 9550, 9584 SEE?; 9993 BRE; 10335, 10375, 10385 SEE?; 
32619, 33869 OOC; 33875 GUL; 34181 SEE; 34186 OOC?; 34395 COP; 34561 
COR; 35958, 39798, 41459 OOC; 41611 SEE; 41707 COR; 42220 SEE; 42425 
PIL; 42558 SEE?; 42573, 42583, 42629 COP; 42834 COR; 42842 PIL; 42876, 
42985, 42988, 43046 SEE; 43403 COR; 43564, 43671, 43752, 43789, 43972 COS; 
43982, 50546 COP; 50588 SEE; 50651 COP; 50707 SEE; 50921 GUL; 51147 
OOC; 51223 GUL; 51270 OOC; 51382 GUL; 52178, 52194 COP. 

Stern, W. L., & Chambers, K. L. 52 GUL; 76 RAP. 
Stern, W. L. et al. 1124 INS; 1998 SEE. 

Stork, H. E. 347 COS; 1042 GUL; 1129 OOC; 1130 SEE; 1365 COP; 1500 SEE; 
1745 RAP; 2089 COS; 2420 RAP; 2591 BRE x SEE?; 3052 COS?; 3131 RAP. 

Taylor, B. W. 4533 OLE. 
Terry 1258, 1337 SEE. 
Tessene, M. F. 1568 TON. 

Tonduz, A. 7871 SEE; 10788 TYPE TON; 11697, 11795 RAP; 11827 SEE; 12231 
RAP; 17693 OOC. 

Tyson, E. L. 802 SEE. 

Valerio, M. 179 SEE. 

Wilbur, R. L., & Stone, D. E. 8743 COS. 

Williams, L. O. et al. 13803 OOC; 13819 COS; 13845 COP; 13851 SEE; 13854, 13886 
COP; 16008 COS; 16197 PIL?; 16268 COP; 16271 COS; 16308 OOC; 16623 
COP; 16664 SEE; 20114 OOC; 23909 SEE?; 23936 BRE; 24455 COS; 24657 
OOC; 24728, 24850 BRE; 26373 OLE; 27862 BRE; 28122, 28209, 28515 COP; 
28637 GUL; 28848 COS; 28898 OOC. 

Woodson, R. E., Jr., & Schery, R. W. 206 OOC; 318 SEE; 360 SEE in part; 868 
SEE. 



ULMACEAE 

WILLIAM BURGER 

REFERENCE: T. Elias, The genera of the Ulmaceae in the South- 
eastern United States. Journ. Arn. Arb. 51: 18-40. 1970. 

Trees or shrubs (rarely climbers in Celtis), bisexual or unisexual, the wood usually 
hard, the sap transparent; stipules usually present. Leaves simple and alternate or 
rarely opposite (in Lozanella), usually distichous, laminae often inequilateral. In- 
florescences basically cymose and often fasciculate or the female flowers solitary, 
axillary on growth of the same or previous year; flowers small and bisexual or uni- 
sexual, radially symmetrical or slightly bilaterally symmetrical, perianth of a single 
whorl with 4 to 6 (rarely 2 to 9) sepals (tepals) free or united below, stamens the 
same number as the sepals and opposite them or rarely twice as many (in Ampelo- 
cera), erect in bud, anthers 2-thecous and dehiscing longitudinally, dorsifixed and 
often somewhat versatile, a pistillode usually present in male flowers; staminodes 
present or absent in female flowers, pistil solitary, ovary superior and sessile or 
stipitate, 1-locular or rarely 2-locular (in Ulmus spp.), ovule 1 and pendulous from 
near the apex of the locule, styles (style-branches) 2 and simple or bifurcate. Fruit 
drupaceous or dry and flattened, often winged when dry, seed usually lacking endo- 
sperm. 



A family of about 15 genera and 150-200 species best represented 
in the north temperate zone. The Ulmaceae are very closely related 
to the Moraceae and Urticaceae, forming the natural order Urti- 
cales. 



KEY TO THE GENERA OF ULMACEAE 

la. Leaves opposite, stipules united and ligulate, leaving an interpetiolar line 
across the stem; fruit drupaceous, slightly flattened and ribbed along the edge, 
2-3 mm. long (in ours); very wet montane forests between 1400 and 2300 m. 

Lozanella. 

Ib. Leaves alternate, stipules free, paired and lateral, not leaving an interpetiolar 
scar 2a. 

2a. Fruit very flat, ciliate edged and samara-like; laminae with 8 to 16 pairs of 
secondary veins; becoming very tall trees, between 1000 and 2000 m. . . Ulmus. 

2b. Fruit drupaceous and fleshy, seed rounded; laminae with fewer than 7 pairs of 
major secondary veins 3a. 

83 



ULMUS mexicana 




LOZANELLA enantiophylla 



FlG 12. Ulmaceae: Central American species of Ulmus (or Chaetoptelea), Trema, 
and Lozanella ( with opposite leaves). 



84 



CELTIS iguanaea 



C. schippii 




AMPELOCERA hottlei 



FIG. 13. Ulmaceae: Costa Rican species of the genera Ampelocera andCeltis. 



85 



86 FIELDIANA: BOTANY, VOLUME 40 

3a. Fruit less than 3 mm. long with narrow cotyledons; leaves and stems usually 
covered by grayish pubescence (in ours), common and wide ranging shrubs and 
trees from sea level to 2000 m Trerna. 

3b. Fruit more than 5 mm. long with broad cotyledons; trees, shrubs, and climbers 
not found above 1200 m 4a. 

4a. Stamens equal in number to the sepals, the two styles (style-branches) deeply 
bifid; spines often present Celtis. 

4b. Stamens twice as many as the sepals, the two styles (style-branches) simple; 
spines absent Ampelocera. 

AMPELOCERA Klotzsch 

Bisexual trees, the stems lacking spines; stipules paired and lateral. Leaves 
alternate on short petioles, laminae slightly inequilateral, entire to distantly serrate, 
pinnately veined. Inflorescences fasciculate or solitary in the axils of the current 
year's growth, subtended by dry scales; flowers bisexual or functionally male, the 
bisexual flowers with 4 or 5 imbricate sepals, united near the base or for part of their 
length to form a short tube or cup, stamens usually twice as many as the sepals 
(rarely more or only 4 or 5), exserted; pistil sessile, ovary 1-locular, styles or style- 
branches 2 and united at the base, divaricate and persisting; male flowers with a 
pistillode. Fruit a small drupe or somewhat berry-like. 

A genus of four or five species, one Central American and the 
others found in South America and the West Indies. 

Ampelocera hottlei (Standl.) Standley, Trop. Woods 51:11. 1937. 
Celtis hottlei Standl., I.e. 20:20. 1929. Figure 13. 

Bisexual trees 10-30 m. tall, the trunk becoming 70 cm. thick with a smooth pale 
colored bark, leafy internodes (1) 2-6 cm. long, 1.2-3.5 mm. thick, glabrous or 
sparsely and very minutely puberulent with grayish white hairs 0.1-0.2 mm. long; 
stipules 2-4 mm. long, triangular and 2 mm. broad at the base, minutely puberulent 
with appressed whitish hairs 0.1-0.2 mm. long. Leaves distichous, petioles 3-12 mm. 
long, 1-3 mm. thick, terete; laminae (6) 10-19 (26) cm. long, (3) 5-9 (12) cm. broad, 
elliptic to ovate or oblong, gradually or abruptly acute or acuminate at the apex, 
obtuse or subtruncate and slightly rounded at the subequal or unequal base, margin 
entire, revolute and sometimes dark on drying, lamina drying stiffly chartaceous to 
subcoriaceous, smooth, glabrous and often lustrous above, dull and usually gla- 
brous below, the young laminae said to be bluish or purplish in color, primary and 
secondary veins slightly raised above, the 3 to 6 pairs of major secondary veins 
usually distant along the midvein and arising at angles of 30-50 degrees, the lower- 
most pair of secondaries often arising at the petiole and very prominent. Inflores- 
cences axillary and only 1-2 cm. long, flowers crowded and sessile, bisexual, sub- 
tended by bracteoles; sepals 4- or 5-lobed, about 2 mm. long with the lobes about 1 
mm. long, puberulent abaxially, stamens apparently 8 or 10, filaments 1-2 mm. long, 
anthers about 1.3 mm. long; pistil with the ovary about 2 mm. long, globose to 
ovoid, style-branches about 2.5 mm. long, simple and densely brownish-puberulent 
adaxially. Fruit ellipsoid to ovoid or globose, 8-10 mm. long, densely velutinous with 
short (0.1-0.2 mm.) stiff yellowish hairs. 



BURGER: FLORA COSTARICENSIS 87 

A species of the wet forests between sea level and 300 m. altitude, 
and ranging from central Mexico and Belize along the Caribbean 
side of Central America to Panama and Colombia. This species is 
apparently common on the Caribbean side of Guatemala and Hon- 
duras and is known from a single collection in Panama (Pittier 
4319). I have seen no collections from Nicaragua or Costa Rica, 
though the species undoubtedly grows in the wet forests of the 
Caribbean coastal plain. 

The species is characterized by the stiff lustrous usually glabrous 
leaves, distichous and often in a single plane, the pale smooth bark, 
and the very small inflorescences. Common names used areAchote 
de Monte andAepito in Colombia, andManteca in Honduras. 

CELTIS Linnaeus 

Trees, shrubs or rarely climbers, bisexual, the branches with or without spines; 
stipules paired and lateral. Leaves alternate and distichous, persistent or deciduous, 
pinnately or palmately veined, often inequilateral, entire or serrate. Inflorescences 
axillary, usually on the growth of the current year, male inflorescences cymose or 
fasciculate, female inflorescences solitary or fasciculate and few-flowered; flowers 
small and usually pedicellate, bisexual flowers with 4 or 5 imbricate sepals united at 
the base, stamens equal in number to the calyx lobes, exserted at maturity, anthers 
versatile, extrorse, a small disc present, pistil sessile and 1-locular, styles (or style- 
branches) 2 and simple or bifid, sometimes united at the base, reflexed in age; male 
flowers with a small pistillode; female flowers without staminodes. Fruit a drupe, 
ovoid to globose or ellipsoid, with a thin succulent exocarp and hard endocarp, em- 
bryo curved, cotyledons broad, conduplicate or rarely flat, variously folded. 

A genus of temperate and tropical regions with about 100 species 
in both hemispheres. The species are quite variable and often dif- 
ficult to segregate taxonomically. 

Climbers, shrubs, or small trees of both evergreen and deciduous vegetation, stems 
usually armed with short spines; laminae usually drying thin-chartaceous, 3-13 
cm. long; fruit puberulent C. iguanaea. 

Rare trees of the Caribbean lowlands, stems lacking spines; laminae usually drying 
stiff -char taceous, 6-22 cm. long; fruit glabrous C. schippii. 

Celtis iguanaea (Jacq.) Sargent, Silva N. Amer. 7:64. 1895, as 
iguaneus. Rhamnus iguaneus Jacq., Enum. PI. Carib. 16. 1762. 
Figure 13. 

Bisexual climbers, lianas, shrubs or occasionally small trees 2-6 (12) m. tall, 
usually armed with straight or recurved axillary spines, 4-10 mm. long, leafy stems 
straight or zig-zag, leafy internodes (0.5) 1-3 (5.5) cm. long, 1-3 (4) mm. thick, 
minutely (0.1-0.3 mm.) puberulent, becoming glabrous and lenticellate, brown to 
pale gray, lenticels ellipsoid and longitudinally 2-parted; stipules caducous, about 3 



88 FIELDIANA: BOTANY, VOLUME 40 

mm. long and 1 mm. broad at the base. Leaves distichous, apparently deciduous and 
growing in flushes, petioles 5-14 mm. long, 0.6-1.5 mm. thick, minutely strigose with 
whitish hairs 0.1-0.7 mm. long, terete; laminae (3) 5-13 cm. long, 2-6 cm. broad, 
ovate to elliptic or oblong, acute to short-acuminate at the apex, obtuse to rounded 
and subcordate at the equal or subequal base, margin bluntly to sharply serrate 
with teeth 3-6 mm. distant, lamina drying thin- to stiff-chartaceous, smooth or 
slightly rough to the touch on either surface, puberulent above and below in early 
stages with yellowish hairs 0. 1-0.3 mm. long, becoming glabrous, primary and secon- 
dary veins becoming impressed above in age, venation palmate or pinnate with 2 or 
3 pairs of major secondary veins prominent beneath, the basal pair often arising at 
the petiole. Inflorescences usually produced with the new leaves from the axils of 
new or fallen leaves, cymose and fasciculate but occasionally borne in alternate 
groups on a leafless rachis, 1-4 cm. long; male flowers sessile and in compact 
clusters, perianth about 1.2 mm. long, filaments about 1.5 mm. long, anthers 0.8 
mm. long; bisexual flowers short-pedicellate or terminal, usually only 1 or 2 per in- 
florescence, perianth ciliate, about 1.5 mm. long and early deciduous, sepals usually 
5, stamens 5, ovary about 2 mm. long and 1 mm. thick, puberulent, the 2 style 
branches becoming 4 mm. long and bifurcate, densely papillate-puberulent. Fruit 
12-15 mm. long, about 8 mm. thick (dry), ellipsoid to ovoid, fleshy and puberulent. 

Plants of wet or seasonally dry evergreen and deciduous forest 
formations of both the Caribbean and Pacific watersheds between 
sea level and 1200 m. elevation in Costa Rica; collected with flowers 
from February to June and with fruit from August to January. The 
species ranges from the southernmost parts of the eastern United 
States southward through the West Indies, Mexico, and Central 
America to southern South America. 

Celtis iguanaea is noteworthy for its very wide geographical range 
and for the variety of its growth forms. The usual presence of 
spines, thin subpalmate distichous leaves, and small inflorescences 
with minute flowers helps to distinguish this species. The species is 
commonly called cagalera in Costa Rica and Nicaragua. See the dis- 
cussion under Celtis schippi. 

Celtis schippii Standley, Field Mus. Bot. 12:409. 1936. Figure 13. 

Trees 10-20 m. tall, spines absent, leafy internodes 0.8-4 cm. long, 1.5-3 mm. thick, 
glabrous and usually pale gray; stipules apparently minute and caducous. Leaves 
distichous, petioles 5-10 mm. long, 0.8-1.6 mm. thick, glabrous, sulcate adaxially; 
laminae 6.5-22 cm. long, 4-10 cm. broad, ovate to elliptical, tapering gradually to the 
acuminate apex, abruptly narrowed to the obtuse or somewhat rounded base, mar- 
gin entire, lamina drying stiffly chartaceous, smooth or very slightly scabrous on 
either surface, glabrous above and below or very minutely (0.05-0.1 mm.) puberulent 
on the midvein beneath, primary and secondary veins raised above and prominent 
beneath, the 3 to 5 (6) pairs of major secondary veins usually quite distant on each 
side of the midvein and arising at angles of 30-50 degrees, the lowermost pair of 
secondaries arising at the petiole, very prominent, and strongly ascending. In- 
florescences 4-8 mm. long, flowers few and sessile, perianth 5-parted, about 1.5 mm. 



BURGER: FLORA COSTARICENSIS 89 

long and united only near the base, not seen at anthesis. Fruit about 15 mm. long 
and 8 mm. thick, ellipsoid, fleshy and drying dark, glabrous. 

A species of the Caribbean lowlands, and known only from British 
Honduras and from a recent collection (Molina et al 17656) near 
Los Angeles, Llanura de San Carlos, Alajuela, in Costa Rica. The 
species has been collected in fruit in February (Costa Rica), March, 
July, and September; probably flowering throughout the year. 

This species is closely related to Celtis iguanaea but differs in 
having the glabrous fruit, larger and stiffer leaves with entire 
margin and somewhat different venation, and the larger consistent 
tree-form. Our knowledge of the trees of the Caribbean lowland is 
very poor; I doubt that the Costa Rican collection represents a true 
disjunction. 

LOZANELLA Greenman 

Unisexual shrubs or trees, the branches often opposite; stipules united to form a 
single ligule-like structure on the petiole and united near the leaf-base with the 
ligulate stipule of the opposing leaf, deciduous and leaving an interpetiolar scar. 
Leaves opposite and decussate, the leaves of a pair often unequal, long petiolate, 
laminae pinnately veined but with prominent secondaries from near the base, sides 
of the laminae occasionally slightly unequal, serrate. Inflorescences cymose or with 
some of the flowers in terminal clusters on lateral branches of the inflorescence, 
axillary on growth of the current year or in the axils of fallen leaves, minute 
bracteoles present; flower unisexual, male flowers pedicellate with 5(6) imbricate 
sepals united near the base, stamens as many as the sepals and arising below a 
pilose disc with a central pistillode; female flowers sessile and in clusters or 
separate, sepals 5 (6), imbricate and united near the base, staminodes absent, ovary 
sessile, 1-locular, terete, styles 2, spreading and persistent. Fruit a small drupe sub- 
tended by persistent sepals, with succulent exocarp and hard endocarp, embryo 
and cotyledons slightly curved. 

A genus of two or three species, the others South American. The 
genus is unique in the family because of its opposite leaves and 
unusual stipules that have become ligule-like and are basally united 
to form an interpetiolar ridge. 

Lozanella enantiophylla (Donn.Sm.) Killip & Morton, Journ. 
Wash. Acad. Sci. 21:339. 1931. Trema enantiophylla Bonn. Smith, 
Bot. Gaz. 33:259. 1902. Lozanella trematoides Greenm., Proc. 
Amer. Acad. Sci. 41:236. 1905. Figure 12. 

Unisexual trees or shrubs 3-10 (20) m. tall, leafy internodes 1-5 cm. long. 1-4 (6) 
mm. thick, densely strigulose with minute (0.1-0.4 mm.) grayish or pale-brown hairs, 
becoming glabrous and reddish brown, terete, an interpetiolar scar or ridge pro- 



90 FIELDIANA: BOTANY, VOLUME 40 

duced between the leaf-bases; stipules of the same leaf united above the petiole to 
form a ligulate structure about 3 mm. long, fused stipules (ligules) of opposing 
leaves united at the base and leaving an interpetiolar scar or ridge. Leaves opposite 
and usually decussate, both laminae and petioles of an opposing pair often unequal, 
petioles (6) 15-45 (65) mm. long, 0.7-1.8 mm. thick, minutely strigulose, deeply 
sulcate adaxially; laminae 5-18 cm. long, 1.5-7 (9) cm. broad, lanceolate (in small 
leaves) to broadly ovate, tapering gradually to the acute or acuminate apex, acute 
to obtuse or rounded at the equal to subequal base, margin serrulate with the teeth 
2-6 mm. distant, lamina drying thin-chartaceous and scabrous on both surfaces, 
minutely (0.1-0.2 mm. ) strigulose above and below, hairs of the upper surface broad- 
based, hairs narrower and less conspicuous on the lower surface, venation becoming 
impressed above only in age, the 3 to 5 pairs of major secondary veins arising at 
angles of 20-50 degrees, the lower pair of secondaries often very prominent and the 
venation subpalmate. Male inflorescences 2-3 cm. long, 2 per axil (4 per node), rachis 
slender (0.2-0.3 mm.) and minutely strigulose, male flowers sessile or short (0-2 
mm.) pedicellate, subtended by small (0.7 mm.) bracteoles, perianth usually 5- 
parted and separate to near the base, about 2 mm. long, filaments 2-2.5 mm. long, 
anthers 1-1.5 mm. long, disc with conspicuous whitish hairs, pistillode about 1 mm. 
long; female inflorescences 3-5 cm. long, 2 per axil, flowers subsessile or short pedi- 
cellate, subtended by small (0.7 mm.) bracteoles and clustered or separate on the 
slender rachis, perianth 1.5-2.2 mm. long, ovary lenticular and green, 1.5 mm. long, 
style-branches 0.7-1.5 mm. long, densely brownish papillate-puberulent. Fruit len- 
ticular, ellipsoid or subglobose, 2-3 mm. long, 2-keeled and often with prominent 
ribs on the edges, becoming yellow or orange. 

Plants of the very wet (premontane rain and lower montane rain) 
forest formations along the Caribbean side of the Central Highlands 
and along the Cordillera de Talamanca to the highlands of Chiriqui 
at elevations from 1400 to 2300 m. The species has only been 
collected between the areas of Zarcero (Alajuela) in the west and 
above San Isidro del General (San Jose) toward the east within 
Costa Rica; flowering material has been collected from January to 
March, while the collections between June and September are 
largely fruit. This species ranges from Southern Mexico to Peru. 

Plants of open or partly shaded sites often found along stream 
edges. The opposite leaves are very unusual and make separation 
from other Ulmaceae easy, but they give the plants the appearance 
of some Urticaceae. Leaf-form is quite variable, often on the same 
branch. The fused ligule-like stipules forming an interpetiolar ridge 
are distinctive. 

TREMA Loureiro 

Bisexual trees or shrubs, lacking spines but often with stiff hairs; stipules paired 
and lateral. Leaves alternate and usually distichous, short-petiolate and pinnately 
or palmately veined, usually unequilateral, mostly serrate. Inflorescence cymose, 



BURGER: FLORA COSTARICENSIS 91 

fasciculate or solitary in the axils of leaves or fallen leaves, flowers and inflores- 
cences bisexual or unisexual, the bisexual flowers with 4 or 5 sepals connate at the 
base, stamens as many as the sepals and opposite them, anthers dorsifixed and 
introrse, pistil sessile, ovary 1-locular, styles 2 and united near the base; male 
flowers with a minute pistillode and the sepals usually induplicate valvate; female 
flowers without staminodes and the sepals usually slightly imbricate. Fruit a small 
ovoid to globose drupe with persisting styles, exocarp succulent and the endocarp 
hard, embryo curved with thick cotyledons. 

A genus widely distributed in the tropics and subtropics. The 30 
to 55 species are often quite variable and taxonomically difficult. 
A single species is found in Central America. 

Trema micrantha (L.) Blume, Ann. Mus. Bot. Lugd. Bat. 2:58. 
1853. Rhamnus micranthus L., Syst. Nat. ed. 10, 2:937. 1759. 
Figure 12. 

Trees 4-12 (20) m. tall, trunk becoming 70 cm. thick with smooth gray or brown 
bark, usually with a single straight axis and distant horizontal branches spreading 
widely to form a broad open crown, leafy internodes 6-20 (40) mm. long, 1.2-4 mm. 
thick, densely strigulose with pale grayish hairs 0.3-0.9 mm. long or rarely gla- 
brescent, often somewhat zig-zag and branching in a horizontal plane; stipules 
about 5 mm. long, lanceolate. Leaves distichous, petioles 3-10 mm. long, 0.8-2 mm. 
thick, densely strigulose, sulcate above; laminae 4-14 (17) cm. long, 1.4-5 (7) cm. 
broad, lanceolate to narrowly ovate or triangular, tapering gradually to the acute or 
acuminate apex, rounded at the unequally truncate or cordulate base, margin 
usually serrulate and revolute (dry), teeth about 1 mm. distant, lamina drying 
stiffly chartaceous, very scabrous and hirsutulous above, occasionally lustrous, 
densely to sparsely strigulose beneath with pale grayish hairs 0.2-0.7 mm. long, 
major veins becoming impressed above, the 2 to 4 pairs of major secondary veins 
arising at angles of 20-40 degrees with the lowermost pair often arising at the 
petiole, very prominent, and the venation subpalmate. 'Inflorescences Bisexual or 
unisexual, male inflorescences 5-30 mm. long, with short branches, flowers sessile or 
very short pedicellate and often in crowded clusters, perianth usually puberulent 
and about 1.5 mm. long, valvate or slightly imbricate, anthers 0.6-1 mm. long, pis- 
tillode about 0.7 mm. long and 2-lobed; .female inflorescences 5-35 mm. long, female 
flowers borne on pedicels 1-3 mm. long, perianth 0.7-1.5 mm. long and usually 
sparsely puberulent, ovary globose to ovoid, narrowed at the base, style branches 
(styles or stigmas) 1.5 mm. long and densely papillate-puberulent. j^ruit globose or 
ellipsoid, becoming about 2 mm. thick and orange or yellowish, subtended by per- 
sisting but minute perianth. 

A common species usually found in open or partly shaded sites 
and secondary growth on well drained soils in a wide variety of 
ecological zones, ranging from sea level to 2100 m. elevation and 
from the semi-deciduous forests of Guanacaste to the very wet 
highland forests of the Caribbean slope, but rare at lower elevations 
on the Caribbean side in Costa Rica ; flowering throughout the year. 
The species is found on Cocos Island and ranges from Mexico to 
southern South America and the West Indies. 



92 FIELDIANA: BOTANY, VOLUME 40 

The scabrous leaves often with palmate venation^and grayish 
pubescence, distichous foliage and branching, open crown, and 
minute flowers in small inflorescences distinguish this species. 
Young specimens may be mistaken for plants belonging to the 
Urticaceae, Euphorbiaceae, or Malvales. The bark has been used as 
a source of fibers, and the trees are known by a variety of common 
names, such as: Bara blanca, Capulin bianco, Capaslan, andJuco. 
The plants are quite variable, both in pubescence and form of the 
inflorescence, but these variations do not seem to be correlated with 
each other or with the environment. 

ULMUS Linnaeus 

Bisexual trees or shrubs; stipules paired and lateral, caducous. Leaves alternate 
and usually distichous, deciduous or persistent, pinnately veined and serrate, the 
laminae usually inequilateral and oblique at the bases. Inflorescence racemose or 
fasciculate, borne in the axils of the previous year's growth and at first covered with 
imbricate scales, the flowers numerous and bisexual or rarely unisexual, sepals 4 to 
9, imbricate and united near the base, stamens as many as the sepals and opposite 
them, becoming exserted, pistil sessile or stipitate, 1 or rarely 2-locular and com- 
pressed longitudinally, styles 2, stigmatic on the inner face, recurved and usually 
persisting. Fruit a samara or dry drupe, lenticular or flattened and usually with thin 
winged lateral margins (but these lacking in our species), embryo straight with flat 
cotyledons, endosperm absent. 

A genus of about 45 species of the Northern Hemisphere. Our 
species has been placed in the genus Ulmus by some authors and in 
its own genus, Chaetoptelea, by others. Sweitzer, who has recently 
studied the comparative anatomy of the Ulmaceae (Journ. Arn. 
Arb. 52:523-571. 1971), finds that the wood anatomy does support 
the segregation of Chaetoptelea as a distinct genus. I believe that 
these distinctions in wood anatomy and in the lack of winged fruit 
may be worthy of subgeneric rank but are not so unusual that they 
are worthy of separating this species as a distinct genus; in general 
aspect, this species is just another elm. 

Ulmus mexicana (Liebm.) Planch, in DC., Prodr. 17:156. 1873. 
Chaetoptelea mexicana Liebm., Kjoeb. Vidensk. Meddel. 77. 1850. 
Figure 12. 

Trees 10-40 m. tall, the crown becoming more than 20 m. high and up to 20 m. 
broad but usually narrower, trunk becoming more than 1 m. thick with scaly gray 
bark, leafy internodes 1-2 cm. long (to 6 cm. long on sprout shoots), 1-2 (4) mm. 
thick, glabrous or puberulent with thin whitish hairs 0.1-0.3 mm. long, often dark 
reddish-brown, buds 2-5 mm. long and enclosed in several bud-scales minutely 
ciliolate along the edge; stipules 6-8 mm. long, narrowly triangular, occasionally 



BURGER: FLORA COSTARICENSIS 93 

persisting. Leaves distichous and produced in flushes, petioles (2) 5-14 mm. long, 
0.6-1.8 mm. thick, minutely canescent or less often glabrous, terete; laminae 4-12 
(16) cm. long, 1.8-5 (7) cm. broad, lanceolate or narrowly ovate to ovate-oblong, 
tapering gradually to the usually acuminate apex, very unequal (oblique) at the base 
with one side often rounded and cordulate and the other attenuate, margin sharply 
serrate with teeth 2-5 mm. distant, lamina drying stiffly chartaceous, smooth or 
scabrous above, scabrous beneath, often slightly lustrous on both surfaces, 
glabrous or minutely puberulent only along the midvein above, glabrous or 
puberulent beneath with very thin whitish hairs 0.2-0.7 mm. long, major veins be- 
coming impressed above, the 8 to 16 pairs of major secondary veins arising at angles 
of 30-60 degrees, and very prominent beneath. Inflorescences emerging from buds 
in the axils of fallen leaves, the 2 or 3 pairs of decussate bud-scales glabrous, rachis 
of the inflorescences usually unbranched, 2-6 cm. long; flowers borne in whorls of 3 
or 4, pedicels 2-5 mm. long, perianth 1-2 mm. long, united more than half and usually 
campanulate, stamens 5, exserted, filaments 2-4 mm. long, very slender, anthers 
about 1 mm. long and equally broad; pistil with style-branches about 2 mm. long, 
minutely brownish puberulent. Fruit becoming 10 mm. long including stipe and 
style-branches, body of the fruit lenticular and ellipsoid to obovoid in outline, about 
2 mm. broad, ciliate along the edges with whitish hairs 0.7-1.5 mm. long. 

Trees of wet montane forest formations between 900 and 1900 m. 
elevation in Costa Rica; flowering material has been collected be- 
tween February and April. I have only seen the following collections 
from Costa Rica: Brenes 22687 along the Rio Jesus de San Ramon 
(Alajuela), Tonduz 11792 near El Copey (San Jose), J. Leon 180 
along the Rio Reventazon (Cartago). The species ranges from 
Mexico to Chiriqui, Panama. 

The great size attained by these trees probably accounts for the 
very few flowering collections found in herbaria. The small leaves 
with rough surfaces, toothed margin, asymmetric base, and many 
veins are produced from scale-covered buds and make vegetative 
material easy to identify (but leaves on sprout shoots can be as 
much as 16 cm. long). Cenizo (-a) is a common name reported frpm 
Panama. 



MORACEAE 

WILLIAM BURGER 

REFERENCES: E. J. H. Corner, The Classification of Moraceae. 
Card. Bull. Singapore 19:187-252. 1962. C. C. Berg, Olmediae and 
Brosimeae. Flora Neotropica, Monog. 7: 1-229. 1972. 

Trees, shrubs, or rarely climbers (Ficus spp.) and herbs (Dorstenia) bisexual or 
unisexual, latex present and usually whitish; stipules present, paired at the node or 
solitary by connation. Leaves alternate and simple (in ours), distichous or in a 
spiral, usually petiolate, the lamina entire, serrate, or lobed to deeply incised (in 
Artocarpus, Cecropia, and Pourouma) capitate or subcapitate multicellular micro- 
scopic hairs (X150) often present. Inflorescences axillary, often paired at the node, 
unisexual or bisexual, extremely variable in the family and ranging from cymose- 
paniculate or simple racemes and spikes to condensed heads, discoid structures or 
urceolate with the flowers enclosed (as in Ficus); flowers small and unisexual, peri- 
anth of a single whorl of usually 4 (0-8) free or united parts, imbricate or valvate, 
persistent; stamens as many as the perianth parts and opposite them or variously 
reduced and occasionally the male flowers not organized with the stamens and in- 
terspersed bracts arising directly from the rachis, filaments straight or bent inward 
in bud, anthers usually 2-thecous, dehiscence longitudinal to circumscissile, pis- 
tillode present or more often absent; pistil often adnate to the perianth, ovary 1- 
locular (very rarely 2-locular), superior to inferior by adnation of the perianth-tube, 
or often imbedded within the receptacle, style and style-branches (or stigma tic 
arms) 2 or less often 1, stigmas usually linear, very rarely capitate or peltate, ovule 
1, pendulous from near the apex of the locule and anatropous or campylotropous or 
basal and erect in Cecropia, Coussapoa, and Pourouma. Fruits usually fleshy, the 
tissue of the ovary, perianth, or receptacle becoming succulent, or the endocarp 
crustaceous to woody, often connate in fleshy syncarps, seeds small to large, cotyle- 
dons various and equal or unequal. 

The Moraceae are commonly present in lowland evergreen tropi- 
cal forests, but they are very poorly represented in herbaria. Short 
flowering-period, inconspicuous inflorescences, and the tree habit 
probably account for the paucity of collections. The family can often 
be recognized by the white sap, alternate leaves (distichous or in a 
spiral), stipules that are sometimes united and often surround the 
stem, small flowers often in capitate or discoid inflorescences, 
stamens opposite the perianth parts (when present), and the usually 
2-branched style. Members of the family are easily mistaken for 



94 



BURGER: FLORA COSTARICENSIS 95 

species of Euphorbiaceae, Flacourtiaceae (including Laciste- 
maceae), and the closely related Ulmaceae and Urticaceae. 

Corner (Gard. Bull. Singapore 19:187-252. 1962) has stated that 
the genera of the subfamily Conocephaloideae are more closely re- 
lated to genera of the Urticaceae than to other genera of the Mora- 
ceae. The Conocephaloideae have erect basal ovules and they often 
lack whitish sap, as do most Urticaceae. However, an equally valid 
argument can be made for their inclusion in the Moraceae or for 
separation in a family of their own. Because this is a reference work, 
we are placing our genera of the Conocephaloideae (Cecropia, Cous- 
sapoa, and Pourouma) among other genera of the Moraceae where 
they have been placed traditionally and where most readers will 
look for them. 

The genus Madura is represented in Central America by Madura 
brasiliensis (Martius) Endlicher (= Chlorophora scandens Standl. 
& L. Wms.), which is naturalized in small areas of the Dept. of 
Olancho, Honduras. 

KEY TO THE GENERA OF MORACEAE 

la. Plants herbaceous, stems less than 0.4 m. tall and not woody, with whitish 
sap; inflorescences disc-like with a flattened apical surface, the minute flowers 

imbedded in the disc Dorstenia. 

Ib. Trees or shrubs, stems becoming more than 2 m. tall and woody 2a. 

2a. Stipules only partly encircling the stem, stipule-scars not united around the 

stem (as seen on younger stems), the stipules always paired at the node .... 3a. 

2b. Stipules completely encircling the stem, stipule-scars forming a ring around the 

stem on younger stems, the stipules paired or united and solitary at each node 

24a. 

3a. Inflorescences spicate or racemose, long and narrow 4a. 

3b. Inflorescences capitate, discoid, or of a few closely crowded or solitary 

flowers 13a. 

4a. Inflorescences with anthers, the flowers male 5a. 

4b. Inflorescences with pistils or fruit, female lOa. 

5a. The flowers not definitely organized and the stamens apparently inter- 
spersed with bracts or with a minute perianth and a single stamen, 
anthers minute (0.5 mm.), flowering parts sessile on the slender spikes, 

tall trees 6a. 

5b. The flowers with a definite 4-parted perianth and each with usually 4 
stamens, inflorescence spicate with sessile flowers or racemose with pedi- 
cellate flowers 7a. 

6a. Flowers not definitely organized, the spikes usually paired at a node 

Clarisia. 



MORUS insignis 




FIG. 14. Moraceae with the flowers often in spikes and racemes: Chlorophora, 
Clarisia, Morus, Sorocea, and Trophis. 



96 



ssp aiicastrum/ 1 
sscxbolivarense 



BATOCARPUS 

costaricensis 




FIG. 15. Moraceae with the flowers usually in globose heads, lacking an involucre 
of bracts at the base: Batocarpus, Brosimum, and Poulsenia. 



97 



St ' P ' PSEUDOLMEDIA 
sc 




FIG. 16. Moraceae with usually disc-like inflorescences: Castillo., Helicostylis, 
Maquira, Naucleopsis, Olmedia, Perebea, and Pseudolmedia. 

98 



drakena 
20cm Jft contrajerva 




2cm 

) for figs 



OJ673 



FIG. 17. Moraceae: Dorstenia and species of Ficus, subgenus Urostigma with 
larger, long-petiolate leaves, and sessile figs. 

99 




FIG. 18. Moraceae: Ficus, species of subgenus Urostigma with smaller leaves or 
acuminate leaf-tips, the figs mostly pedicellate. 



100 




morazaniana 



FIG. 19. Moraceae: Ficus, species of subgenus Urostigma with puberulent figs or 
blunt-tipped leaves. 



101 




FlG. 20. Moraceae: Ficus, species of subgenus Urostigma with sessile figs and 
large bracts or with unusual leaves. 



102 



FICUS 




FIG. 21. Moraceae: FICUS, species of subgenus Pharmacosycea with only one fig at 
a node and usually three basal bracts. 



103 



1Ocm 




nymphaeifolia 




FlG. 22. Moraceae, subfamily Conocephaloideae: the Costa Rican species of 
Pourouma and the often epiphytic Coussapoa. 

104 



insignis 




FIG. 23. Moraceae, subfamily Conocephaloideae; the continental Costa Rican 
species of Cecropia. 

105 



10 6 FIELDIANA: BOTANY, VOLUME 40 

6b. Flowers with a minute 2- or 4-lobed perianth, spikes solitary at a node 

Batocarpus. 

la. Stamens with the filaments straight and the perianth decussate-imbri- 
cate in bud, perianth-parts often broadly sessile on the rachis. . . Sorocea. 

7b. Stamens with the filaments bent inward in bud, the filaments con- 
sequently usually longer than the perianth-parts 8a. 

8a. Inflorescences usually paired at a node; perianth-parts valvate in bud 

Trophis. 

8b Inflorescences solitary at the node; perianth-parts imbricate in bud 

9a. 

9a. Lowland trees common in deciduous areas, wood yellowish; spikes with- 
out peltate bracts Chlorophora. 

9b. Trees from between 1500 and 2200 m. altitude; spikes with peltate 
bracts ( in our species) Morus. 

lOa. Pistil free, enclosed within 4 separate perianth-parts, the flowers sessile 

and closely crowded; inflorescences solitary at a node Morus. 

lOb. Pistil free or united with the perianth, enclosed or subtended by a tubular 
(united) perianth, the perianth often very difficult to distinguish and 
often almost completely united with the pistil; inflorescences usually 

paired or of paired pedicellate flowers lla - 

lla. Inflorescences of pistils in distichous pairs on leafless stems, peltate 
bracts present at the base of the pistil above the pedicel; tall lowland 

trees Clarisia - 

lib Inflorescences spicate or racemose with few to many crowded or separate 
and sessile or pedicellate flowers, peltate bracts found only on the rachis 

of the inflorescence 12a - 

12a. Style-branches (or stigmas) slender; lower surface of the leaf lacking 

microscopic (X 150) capitate hairs Trophis. 

12b. Style-branches usually short and broad; lower leaf surface usually with 

microscopic capitate multicellular hairs Sorocea. 

13a. Inflorescences with anthers, male parts present 14a. 

13b. Inflorescences with pistil or fruit, female 17a - 

14a Inflorescences usually globose, with thin flat round peltate bracts on the 

surface Brosimum. 

14b. Inflorescences discoid and with subtending imbricate bracts usually 

forming an involucre 15a - 

15a. Flowers with the filaments curved inward in bud and opening elastically, 
perianth-parts valvate in bud; laminae scabrous and denticulate; 0-600 

m. elevation Olmedia. 

15b. Flowers with the filaments straight in bud and the perianth-parts decus- 

sate-imbricate; laminae smooth (in ours) 16a - 

16a Leaves sparsely to densely puberulent, usually drying dull above; 700- 

1500 m Helicostylis. 

16b. Leaves glabrous, usually drying lustrous above; 0-850 m Maquira. 

17a. Inflorescence usually globose and lacking an involucre of imbricate basally 

. 18a. 



BURGER: FLORA COSTARICENSIS 107 

17b. Inflorescence usually discoid to ovoid or occasionally with short lobes sub- 
tended by imbricate basally attached bracts forming an involucre or the 
flowers borne in pairs from the leaf-axil or on short-shoots 20a. 

18a. Inflorescences with thin flat round peltate bracts on the surface or near 

the base D 

Brosimum. 

18b. Inflorescences lacking thin round flat peltate bracts on the surface .... 19a. 
19a. Style branch or stigma 1 per pistil, fruiting inflorescence 1-2 cm. in dia- 
meter; trees of wet evergreen and seasonally dry deciduous areas 

Chlorophora. 

19b. Style branches ( stigmas ) 2 per pistil, fruiting inflorescence 4-5 cm. in dia- 
meter; trees of wet evergreen forests in the Golfo Dulce area 

Batocarpus. 

20a. Flowers distinctly pedicellate and paired in the axils of leaves or borne in 
alternate pairs on short (1-3 cm.) leafless stems, flat round peltate bracts 
borne at the base of the pistil above the pedicel; tall trees of the wet low- 
lands , . . 

Clansia. 

20b. Flowers sessile on the inflorescence, never pedicellate 21a 

21a. Inflorescence discoid, with more than 10 flowers; leaves entire usually dry- 
ing lustrous; 0-850 m Maquira. 

21b. Inflorescence with fewer than 5 flowers, usually less than 10 mm. long- 
leaves usually serrulate 22a 

22a. Inflorescence usually with 2 or 3 flowers; small treelets of lowland Carib- 
bean wet forest formations Tro his 

22b. Inflorescence usually with a single female flower 2 3a 

23a. Leaves scabrous above, 0-600 m Olmedia 

23b. Leaves smooth above, 700-1500 m '.''.' Helicostylis. 

24a. Stipules paired, 2 at a node, enclosing the shoot-apex and overlapping ( some- 
times difficult to distinguish as two different parts) 25a. 

24b. Stipule solitary at the node, a single structure enclosing the shoot-apex (but 
ateral buds and inflorescences may be enclosed by more than one stipule- 
like structure) . . . 

ola. 

25a. Flowers borne within an enclosed cavity in a rounded fruit-like structure 

(the syconium or fig) that is closed to the outside except for a small spical 

stiole with interleaved scales; the figs solitary or paired in the leaf-axils 

with 2 or 3 bracts near the base; small to very large trees, often beginning 

as epiphytes and strangling the host Ficus 

25b. Flowers not borne within an enclosed surface, the inflorescence not a 
globose fruit-like structure except in Brosimum and then with many peltate 
bracts on the surface 26 

26a. Inflorescences globose to ellipsoid or clavate, lacking a definite involucre of 

imbricate basally attached bracts at the base 27a 

26b. Inflorescence discoid or of only 1 or a few flowers, subtended by an in- 
volucre of imbricate basally attached stiff bracts 29a. 

27a. Inflorescences usually globose with few to many flat thin round peltate 
bracts on the surface, 1-5 cm. in diameter; plants lacking spines, leaves 

entire D . 

arosimum. 



108 FIELDIANA: BOTANY, VOLUME 40 

27b. Inflorescences lacking thin flat round peltate bracts 28a. 

28a. Plants usually with short spines on younger stems, leaves entire; inflor- 
escences globose, the male 1-1.5 cm. in diameter, fruiting heads 2-3 cm. in 
diameter Poulsenia. 

28 b. Plants lacking spines, leaves entire or large and deeply pinnately lobed; 
inflorescences globose to long and irregularly ellipsoid or clavate, 3-50 cm. 
in diameter Artocarpus. 

29a. Female inflorescence with only a single flower ( solitary pistil) ; stamens free 
among concentrically arranged bracts and not within definite 4-parted 
flowers; leaves with entire margins Pseudolmedia. 

29b. Female inflorescences with several to many flowers; stamens in flowers 
with 4-parted perianth 30a. 

30a. Leaves usually puberulent and denticulate; ovary mostly on the surface of 
the receptacle; male inflorescence open before anthesis, male flowers 

usually with 4 stamens Perebea. 

30b. Leaves glabrous and entire; base of the ovary immersed in the receptacle; 
male inflorescence closed before anthesis, male flowers usually with fewer 

than 4 stamens Naucleopsis. 

31a. Inflorescences globose with few to many thin flat round peltate bracts on the 

surface . . Brosimum. 

31b. Inflorescences lacking thin round peltate bracts 32a. 

32a. Inflorescences subtended by a conspicuous involucre of stiff imbricate basal- 

ly attached bracts, flattened at the top and discoid or folded Castillo. 

32b. Inflorescences lacking an involucre of stiff imbricate bracts, varying from 
cymose and branched to umbellate, capitate, or digitate; pistil with a single 
short penicillate stigma and erect basal ovule; plants usually lacking milky 

sap ( subfamily Conocephaloideae) 33a. 

33a. Leaves peltate with the petiole attached near the center of the lamina, 
palmately lobed; free standing trees with few major branches, biting ants 
often present in and on the stems; flowers in thick (4-14) spikes borne on a 

common peduncle and the inflorescence often digitate in form Cecropia. 

33b. Leaves never peltate, the petiole attached at the lamina base, flowers in 
cymose groups or heads, never in digitate spikes; biting ants absent .... 34a. 
34a. Trees, usually free-standing from early stages, fruit 10-30 mm. long; male 
flowers pedicellate, never in globose heads, with 4 stamens and 4 perianth- 
parts; leaves lobed or entire Pourouma. 

34b. Trees or shrubs, usually epiphytic in early stages; fruit 1-4 mm. long; male 
flowers sessile in globose heads, with 2 united stamens and 4 free or united 
perianth-parts; leaves entire Coussapoa. 

ARTOCARPUS J. R. & G. Forster 
Nomen conservandum 

Small to large trees with whitish milky sap; stipules paired, amplexicaul and 
leaving ring-like scars around the stem ( subgenus Artocarpus ) or smaller and lateral 
to interpetiolar, not leaving scars around the stem (subgenus Pseudojaca), 
caducous. Leaves alternate and in a spiral (subgenus Artocarpus) or distichous 



BURGER: FLORA COSTARICENSIS 109 

(subgenus Pseudojaca), simple (in ours) or rarely pinnately compound, entire to 
deeply pinnatifid, mature leaves often differing from the juvenile. Inflorescences 
axillary or on old wood, paired or solitary, unisexual and capitate, globose, ellipsoid 
or cylindrical, usually pedunculate, flowers tightly compacted and numerous, the 
single pistil or stamen enclosed by perianth and often with interspersed stalked 
bracts, pale flowers reduced to a single stamen, perianth tubular with 2-4 imbricate 
lobes, filament straight, pistillode absent. Female flowers with the tubular perianth 
thickened above and with a small orifice for the style, perianth often connate with 
the perianth of adjacent flowers above and forming a syncarp, staminodes absent; 
pistil with an apical or lateral style, style simple or with 2 style-branches (stigmas). 
Fruit a syncarp formed by the enlargement of the entire female head, the individual 
fruit (achenes) included within the succulent tissue of the syncarp. 

A genus of about 48 species, native to southern Asia and ranging 
from India to Southern China, the Philippines, Indonesia, New 
Guinea, and the Solomon Islands. The genus is now pan tropical be- 
cause of the distribution by man of two important food-plants: the 
Breadfruit and the Jack, or Jackfruit. These are the species com- 
monly encountered in Central America and both belong to the sub- 
genus A rtocarp us. 

Leaves deeply pinnately lobed; stipules 10-25 cm. long; inflorescences borne on the 
young branches, fruiting inflorescence usually globose A. communis. 

Leaves usually entire, stipules 1.5-5 cm. long; inflorescences borne on short shoots 
arising from thick branches and trunk, fruiting inflorescence ellipsoid or irregular 

A. heterophyllus. 

Artocarpus communis J. R. & G. Forster, Char. Gen. 101. 1776. 
Rademachia incisa Thunb., Vet. Acad. Handl. Stockholm 37:253. 
1776. Artocarpus incisus (Thunb.) L.f., Suppl. PI. 411. 1781. 

Trees to 20 (35) m. tall, leafy internodes 5-15 mm. thick, glabrous to sparsely 
puberulent at the stipule-scars; stipules 10-25 cm. long, sparsely to densely puberu- 
lent with slender ascending hairs about 2 mm. long. Leaves quite variable in size and 
lobing, petioles 2-4 cm. long; laminae of mature trees 30-100 cm. long, 25-65 cm. 
broad, rhomboid to elliptic in outline with 3 to 7 lobes on each side, acuminate at the 
apex, usually scabrous above, with 6 to 12 pairs of major secondary veins. Male in- 
florescences on peduncles 3-6 cm. long, head 7-30 cm. long, 1.5-4 cm. thick, long- 
cylindracal to clavate. Female inflorescences globose to ellipsoid, on peduncles 3-13 
cm. long, becoming 20-30 cm. in diameter, globose to ellipsoid; some varieties lack- 
ing seeds. Fruiting syncarp green to yellow with acute pyramidal projections. 

Introduced plants usually found only in hot lowlands with suffi- 
cient rainfall to support an evergreen vegetation. The species is not 
a commercially important fruit in Central America. See Standley's 
discussion in "Flora of Guatemala," Fieldiana Botany 24, 4:12. 
1946. This species is called palo de pan, breadfruit, or sometimes the 
bread-nut when seeds are present. 



110 FIELDIANA: BOTANY, VOLUME 40 

Artocarpus heterophyllus Lamarck, Encycl. Meth. Bot. 3:209. 
1789. A. integrifolius auctores non L.f. 

Trees to about 10 to 15 m. tall, leafy internodes 2-10 mm. thick, sparsely puberu- 
lent and becoming glabrous; stipules 1.5-5 (8) cm. long, minutely puberulent or gla- 
brous. Leaves not especially variable in mature plants, petioles 1-3 (4) cm. long; 
laminae 8-20 cm. long, 4-10 cm. broad, broadly elliptic to obovate, rounded to obtuse 
at the apex, unlobed on mature plants, drying coriaceous and smooth above, with 4 
to 8 pairs of major secondary veins. Male inflorescence on peduncles 1-5 cm. long 
borne in axils of leaves more distal than those subtending the female or cauliflorous, 
heads 2-7 cm. long and 8-28 mm. thick. Female inflorescences solitary or paired in 
axils of the lowest leaves or cauliflorous, on peduncles 5-10 cm. long, becoming 
heads 30-90 cm. long, 25-50 cm. thick, cylindrical to ellipsoid or clavate. Fruiting 
syncarp yellow and often with a sharp sweet unpleasant odor, the surface with small 
papillae. 

Introduced plants occasionally planted in areas of evergreen vege- 
tation between sea level and 1200 m. This species is called the Jack- 
fruit and probably originated in India. 

BATOCARPUS Karsten 

Trees, unisexual, without spines, sap yellow or white; stipules paired and free, 
lateral, caducous and leaving sm.all scars that encircle less than half the stem. 
Laminae distichous, petiolate, the lower surface with few microscopic (X200) 
globose-capitate hairs, very small hooked (uncinate) hairs and round transparent 
epidermal cells with sharp conical apex. Male inflorescences long slender spikes, soli- 
tary in the axils of leaves or several on leafless short-shoots, pedunculate, flowering 
portions of the spike usually long (5-12 cm.) and thin ( 1-4 mm.), male flower wiuh a 
minute 2- to 4-lobed perianth and a single stamen, anthers minute (less than 0.5 
mm.). Female inflorescences usually solitary and short-pedunculate, a globose to 
ellipsoid head of many compacted flowers and lacking an involucre; the female 
flowers with a tubular truncate fleshy perianth, the ovary free (superior) but en- 
closed within the perianth, style short, stigmas 2, short and reflexed. Fruit formed 
within the fleshy globose infructescence formed by the fleshy accrescent perianths 
closely crowded together on the fleshy receptacle, the perianths coherent but not 
grown together, seed with a thin coat. 

A very poorly known genus of three species ranging from south- 
western Costa Rica to Bolivia. The slender spikes of staminate 
flowers with single stamens tightly congested and the round heads 
of coherent female flowers are very distinctive. The male spikes re- 
semble those of Piper and the infructescences resemble those of 
Annona. The genus is probably closely related toAcanthinophyllum 
of South America; the male spikes are similar to those of Clarisia 
bi flora, among our species. 

This circumscription of the genus follows that of Fosberg ( Proc. 
Biol. Soc. Wash. 55:99-101. 1942), who synonomized Anonocarpus 



BURGER: FLORA COSTARICENSIS 111 

of South America under Batocarpus. Woodson (Ann. Missouri Bot. 
Card. 47: 134-136. 1960) mistook a collection ofMaquira costaricana 
(Cooper 601) for the male of Batocarpus orinocensis and concluded 
that Batocarpus and Anonocarpus differed in their male in- 
florescences. Our species of the genus is known from only two 
female collections. The genus has recently been revised by De Mello 
Filho in Bol. Mus. Nac. Rio de Janeiro Bot. 37: 1-15. 1968. 

Batocarpus costaricensis Standley & L. O. Williams, Ceiba, 3:25. 
1952. Figure 15. 

Trees to 30 m. tall, the trunk slender (45 cm.) and without buttresses, sap from the 
trunk pale yellowish-white, sap from the branchlets and fruit dull orange, leafy 
internodes 0.5-3 cm. long, 1.5-5 mm. thick, very minutely (0.05-0.2 mm.) puberulent 
with thin usually ascending hairs, dark brown but becoming glabrous and grayish; 
stipules about 5 mm. long and 2 mm. thick near the base, covered with thin ascend- 
ing brown or yellowish-brown minutely sericeous hairs, scars about 1-1.5 mm. broad, 
encircling less than half the stem. Leaves often asymmetric, petioles 4-8 mm. long, 
about 2 mm. thick, minutely and sparsely puberulent, the periderm flaking off in 
age; laminae 8-17 cm. long, 3-6.5 cm. broad, elliptic-oblong, often with one side 
broader than the other, gradually or more often abruptly narrowed to the short 
acuminate apex, obtuse to rounded or acute on one side at the usually unequal base, 
margin bluntly serrate to obscurely serrulate with 1 to 3 teeth per cm., the laminae 
drying stiffly chartaceous, smooth and glabrous above, glabrous or very sparsely 
and minutely puberulent beneath, the midvein flat or slightly impressed above, the 
8 to 12 pairs of major secondary veins irregularly loop-connected near the margin, 
microscopic globose-capitate hairs few or absent beneath, very small (X150) hooked 
hairs and round transparent epidermal cells with sharp conical apex present be- 
neath, the stomates readily visible. Male inflorescences and flowers not known ( see 
generic description). Female inflorescences subsessile globose, about 2 cm. thick, 
the many flowers tightly congested and only opening apically ; female perianth parts 
brownish velutinous, the rounded apices little projecting from the surface of the 
head, style and stigmas projecting about 2 mm. above the head. Fruit borne within 
the fleshy subsessile globose syncarp 4-5 cm. in diameter, green becoming brownish 
(dry), perianth and ovary coherent but not becoming fused in fruit, perianth parts 
fleshy and remaining rounded apically (on the surface of the smoothly globose 
head), seed about 10 X 5 mm. 

Plants of the wet evergreen forest formation of the Golfo Dulce 
area in southwestern Costa Rica between 50 and 500 m. elevation; 
collected with early and mature fruit in February. This species is 
known from only two collections made by Paul Allen (5948 & 5971 ) 
near Palmar Norte, Puntarenas. 

Batocarpus costaricensis is recognized by the serrulate often 
slightly asymmetric leaves, tall habit with slender trunk, small 
lateral stipules, globose heads of female flowers with thick perianth 
that remains separate in fruit, and (probably) the male flowers 



112 FIELDIANA: BOTANY, VOLUME 40 

tightly congested on slender spikes. Allen (Rain Forests of Golfo 
Dulce 136. 1956) states that the male flowers are in catkin-like 
spikes, but we have no collections of staminate material. The fruit- 
ing heads resemble those of Madura (Moraceae) or Annona (An- 
nonaceae). 

BROSIMUM Swartz 

REFERENCE: C. C. Berg, Brosimeae, Fl. Neotrop. Monog. 
7:161-208.1972. 

Bisexual or unisexual trees, without spines, usually with small uncinate hairs on 
the younger parts, the latex white or yellowish; stipules free and paired or united 
and solitary, fully encircling the stem or not, usually caducous. Leaves distichous, 
usually entire, the microscopic multicellular hairs of the lower leaf-surface globose- 
capitate or oblongoid-capitate. Inflorescences bisexual or unisexual, paired or soli- 
tary in the leaf-axils, pedunculate, the receptacle at first covered with round peltate 
bracts, capitate and globose to hemispheric, turbinate or convexly discoid; the male 
flowers several to many on an inflorescence, perianth 4-lobed or 4-parted (as in B. 
costaricanum ) or variously reduced in number and size or lacking, the stamens 4 to 
1, filaments straight in bud, anthers latrorse to extrorse (with circumscissle 
dehiscence in B. alicastrum), a pistillode absent; the female flowers usually 1 
(several) in an inflorescence, the flower immersed in and fused with the receptacle 
beneath, perianth vestigal and united with the ovary beneath, stigmas 2. Fruit 
borne within the enlarged and pulpy, yellowish or red receptacle, seed large, coty- 
ledons thick, equal or unequal. 

A genus of 13 species ranging from Mexico and the Greater Antil- 
les southward to southern Brazil. The globose to discoid head can 
be either unisexual or bisexual with one or a few female flowers 
imbedded centrally; the male flowers are usually found over a large 
part of the inflorescence surface. The peltate bracts, thin and flat 
distally and round in outline, cover the young inflorescence and 
probably indicate a relationship with other genera having similar 
bracts, such as Clarisia and Sorocea. Many species of Brosimum 
grow to be very tall (50 m.), have useful wood, potable sap, and 
edible fruit. These plants are very poorly represented in herbaria, 
perhaps because of their size. They are often called ojoche, ramon, 
and breadnut in Central America. These names also are applied 
occasionally to species of Trophis and Sorocea. 

la. Stipules of the same node completely united and thus solitary at a node, com- 
pletely encircling the stem, the stipule scar completely encircling the stem; 
heads usually bisexual 2a. 

Ib. Stipules of the same node free and paired, the stipule scars variable but not 
completely surrounding the stem; heads bisexual or unisexual 3a. 



BURGER: FLORA COSTARICENSIS 113 

2a. Laminae 15-30 (50) cm. long; heads becoming 3 cm. thick in fruit . . . . B. utile. 
2b. Laminae 2-13 cm. long; heads becoming 2 cm. thick in fruit . . . . B. rubescens. 

3a. Stipule scars of the same node encircling more than half the stem and almost 
joining on the leaf-opposed side of the stem; leaves usually glabrous; heads uni- 
sexual, stamens often with united anthers and circumscissile dehiscence 

B. alicastrum. 

3b. Stipule scars of the same node encircling less than half the stem 4a. 

4a. Stipule 3-15 mm. long and broad above the base with prominent raised fan-like 
venation; lamina with the midvein often deeply impressed above, 3-12 cm. 
broad, usually glabrous, tertiary venation prominent beneath . . . B. lactescens. 

4b. Stipule 2-7 mm. long but narrow and the venation not prominent; the midvein 
flat above, laminae rarely more than 5 cm. broad, usually puberulent beneath 
and the tertiary veins flat 5a. 

5a. Laminae with the midvein often minutely puberulent above, the lower surface 
usually with thin straight hairs and brownish in color; the heads usually glo- 
bose, unisexual, anthers about 1 mm. long B. costaricanum. 

5b. Laminae with the midvein glabrous above, usually very lustrous above, the 
lower surface with minute (0.2 mm.) hooked hairs and with a grayish color and 
microscopic (150X) projections on the epidermis; the heads often lobed, hemi- 
spheric to discoid, usually bisexual, anthers about 0.2 mm. long. . B. guianense. 

Brosimum alicastrum Swartz, Prod. Veg. Ind. Occ. 12. 1788. 
Helicostylis ojoche Schumann ex Pittier, PI. Usuales de Costa Rica 
119. 1908. Brosimum terrabanum Pittier, Contr. U.S. Nat. Herb. 
18:69. 1914. B. bernadetteae Woodson, Ann. Missouri Bot. Gard. 
47: 131. 1960. B. gentlei Lundell, Wrightia 3: 167. 1966. Figure 15. 

Trees to 45 m. tall, unisexual (rarely bisexual?), with buttresses, latex white to 
yellow, leafy internodes 0.5-5 cm. long, 1-4 mm. thick, glabrous or very sparsely 
puberulent; stipules paired, 3-15 mm. long, 1-2 mm. broad at the base, glabrous or 
very minutely (0.1 mm.) puberulent along the midrib. Leaves usually symmetrical, 
petioles (2) 4-14 mm. long, 1-2.5 mm. thick, narrowly sulcate above; laminae 4-20 
cm. long, 2-8 cm. broad, elliptic or oblong to somewhat ovate or obovate, acute to 
caudate-acuminate at the apex, acute to obtuse or rarely rounded at the base, mar- 
gin entire to slightly repand or drying undulate, laminae chartaceous to subcoria- 
ceous, smooth and glabrous above, glabrous or very minutely (0.1 mm.) puberulent 
beneath, midvein usually flat or slightly raised above, the 10 to 20 pairs of major 
secondary veins usually loop-connected near the margin, the tertiary veins often 
forming a parallel intermediate vein between adjacent secondaries, microscopic 
oblongoid hairs and hooked (uncinate) hairs present on the veins beneath. Male in- 
florescences usually 1 or 2 per axil, borne on peduncles to 16 mm. long, heads glo- 
bose to ellipsoid, 3-8 mm. in diameter, peltate bracts 0.2-2 mm. broad present and 
minutely puberulent, with usually 1 central non-functional female flower, male 
flowers not organized, the surface covered with many individual stamens; male peri- 
anth absent or minute, filaments 0.4-1.6 mm. long, anthers 0.4-0.5 mm. long, the 
thecae fused and with circumscissile dehiscence (in subspecies alicastrum) or the 
thecae free and dehiscing laterally (in subspecies bolivarense). Female inflores- 
cences usually 1 or 2 per axil, borne on peduncles to 14 mm. long (rarely subsessile), 



114 FIELDIANA: BOTANY, VOLUME 40 

globose to ellipsoid, 2-5 mm. in diameter, peltate minutely puberulent bracts 0.2-2 
mm. broad present on the surface of the receptacle, bracts near the base often 
basally attached, usually with 1 (2) functional female flowers; style 1.5-8.5 mm. 
long, stigmas 0.2-8 mm. long, unequal. Fruit borne within the globose succulent in- 
fructescence 1.5-2 cm. in diameter. 

Plants of deciduous, partly deciduous, or wet evergreen forest 
formations from sea level to about 700 m. altitude (in our area). 
The species is represented by subspecies alicastrum in the Pacific 
watershed of Costa Rica and by subspecies bolivarense (Pittier) 
Berg on the Caribbean watershed of Costa Rica and on both water- 
sheds in western Panama. The species ranges from Sonora, Mexico, 
to Venezuela and Guyana in eastern South America, and south- 
ward to Peru and the state of Acre in Brazil. The species is also 
found on Cuba, Jamaica, Trinidad, St. Vincent, and Carriacou 
islands. 

Brosimum alicastrum is recognized by the paired stipules almost 
completely encircling the stems, the almost glabrous leaves with 
unusual tertiary venation, the small globose inflorescences with flat 
thin round peltate bracts, the lack of organized male flowers (on the 
male head) and the very unusual anthers in subsp. alicastrum. This 
tree is often called ojoche, ojeche, berga, ramon, and breadnut. The 
foliage is often used to feed cattle, especially in the dry season. Sap 
and fruit are edible. 

Brosimum costaricanum Liebmann, Danske Vidensk. Selsk. 
Skrift. ser. 5,2:334. 1851. Helicostylis montana Pittier, Contr. U.S. 
Nat. Herb. 20:96. 1918. Brosimum sapiifolium Standl. & L. Wms., 
Ceiba 3:40. 1952. Figure 15. 

Trees to 30 m. tall, unisexual, latex white, leafy internodes 0.6-3 cm. long, 1-3 mm. 
thick, with thin straight or slightly crooked yellowish hairs 0.1-0.5 mm. long; 
stipules paired, 3-7 mm. long, with thin ascending hairs along the midrib, stipule- 
scars small (1 mm.) and encircling less than half the stem. Leaves usually sym- 
metrical, petioles 3-8 mm. long, 0.7-1.5 mm. thick, sparsely to densely puberulent 
with minute (0.1-0.3 mm.) often retrorse and hooked hairs, terete or very slightly 
sulcate above; laminae (4) 7-15 cm. long, 1.5-4.5 cm. broad, narrowly elliptic to 
elliptic-oblong or narrowly obovate, gradually narrowed to the acuminate apex, 
acute to obtuse and slightly rounded at the base, margin entire, the lamina drying 
stiffly chartaceous, smooth and essentially glabrous above except over the midvein, 
with thin whitish hairs about 0.2 mm. long beneath, midvein usually flat or slightly 
impressed above, the 7 to 19 pairs of major secondary veins loop-connected near the 
margin, microscopic globose-capitate hairs present beneath. Male inflorescences 
borne on peduncles 3-6 mm. long, globose, about 6 mm. in diameter, with many 
peltate or subpeltate bracts 0.5-1.5 mm. broad, with many flowers; male perianth 3 
or 4 parted, stamens 2 to 4 per flower, anthers about 1 mm. long and 0.4-0.5 mm. 



BURGER: FLORA COSTARICENSIS 115 

broad, connective narrow. Female inflorescences borne on peduncles and solitary or 
2 per node; female flower solitary. Fruit borne within the globose succulent in- 
fructescence about 15 mm. in diameter, fruiting peduncles 5-18 mm. long. 

Plants of evergreen or partly deciduous forest formations on the 
Pacific slope of central and southern Costa Rica and western 
Panama between sea level and about 1000 m. altitude; flowering 
material has been collected from December to March. The species is 
known only from the area between Central Costa Rica (Naranjo, 
Alajuela) and the eastern border of Chiriqui province. 

Brosimum costaricanum is recognized by the paired stipules 
leaving only small scars, the narrow leaves with thin short hairs, 
the small globose unisexual inflorescences with thin round peltate 
bracts, and the large anthers. 

Brosimum guianense (Aubl.) Huber, Bol. Mus. Emilio Goeldi 
5:337. 1909. Piratinera guianensis Aublet, PI. Guian. 2:888, t. 340. 
1775. P. panamensis Pittier, Contr. U.S. Nat. Herb. 20:100. 1918. 
Brosimum panamense (Pittier) Standl. & Steyer., Field Mus. Bot. 
23:40. 1944. Figure 15. 

Shrubs or trees to 30 m. tall, bisexual, with or without buttresses, latex white to 
yellow, leafy internodes 0.1-3 (6) cm. long, 0.8-3.5 mm. thick, very sparsely to 
densely puberulent with minute (0.2 mm.) thin often retrorse uncinate hairs, be- 
coming gray; stipules 2-5 mm. long, densely to very sparsely puberulent, scars en- 
circling less than half the stem. Leaves often asymmetric at the base, petioles 2-6 
mm. long, 0.5-1.5 mm. thick, with retrorse uncinate hairs about 0.2 mm. long; 
laminae (2) 4-10 (15) cm. long, (1) 2-4.5 (6) cm. broad, elliptic-oblong to obovate- 
oblong or less often narrowly ovate, abruptly narrowed at the acute or short-acumi- 
nate apex, acute to obtuse or somewhat rounded (often on only one side) at the base, 
margin entire, the lamina drying chartaceous to subcoriaceous, smooth, glabrous, 
and lustrous above, very sparsely to densely puberulent beneath with minute thin 
hairs, the midvein prominent above, the 6 to 14 pairs of secondary veins forming an 
arcuate submarginal vein, the lower surface often grayish with microscopic (150X) 
projections on the epidermis, thin transparent hairs, and few oblongoid-capitate 
hairs distally orange. Inflorescences usually bisexual usually solitary, subsessile or 
more often on peduncles to 20 (30) mm. long, the head hemispheric to broadly tur: 
binate or discoid, often lobed, 3-12 mm. in diameter, the peltate bracts many, 0.4-1 
mm. broad; male flowers few to many, male perianth 3- or 4-lobed, stamen 1 (per 
flower), filaments 0.3-0.8 mm. long, anthers 0.1-0.3 mm. long and almost equally 
broad, connective broad and swollen; female flower 1 to several (per head), style 
0.4-1 mm. long, stigmas 0.1-0.3 mm. long. Fruit borne within the succulent globose 
or subturbinate infructescence about 12 mm. in diameter or the infructescence lobed 
and up to 16 mm. in diameter when containing 2 or more fruits, reddish at maturity, 
seed about 8 by 5 mm. 

Plants of seasonally dry semi-deciduous forest or wet evergreen 
forest formations between sea level and 1000 m. elevation in both 



116 FIELDIANA: BOTANY, VOLUME 40 

primary and secondary vegetation. This species has a very dis- 
continuous distribution pattern and is known in Costa Rica only 
from the Osa peninsula (A. Jimenez 3044). It is known from south- 
ern Mexico and British Honduras and from southern Panama, 
northern Colombia, northwestern Venezuela and coastal Brazil in 
the state of Guanabara, but the main areas of distribution are the 
Amazon Basin, the Guiana Shield, and Trinidad. 

Brosimum guianense is recognized by its small paired stipules en- 
circling less than half the stem, the small leaves shiny above and 
with unusual surface beneath (X150), hemispheric to discoid heads 
with thin round peltate bracts, and male flower reduced to a single 
stamen. The larger trees of the neotropics have not been well 
sampled, and it is possible that this species does occur rarely in 
areas where it is presently thought to be absent. 



Brosimum lactescens (Moore) Berg, Acta Bot. Neerl. 19:326. 
1970 Brosimopsis lactescens S. Moore, Trans. Linn. Soc. ser. 2, 
4:473, t. 30 & 31. 1895. Brosimum ojoche Woodson, Ann. Missouri 
Bot. Card. 47: 126. 1960. Figure 15. 

Trees to 35 (50) m. tall, unisexual, with buttresses, latex white to yellowish or 
greenish, leafy internodes 5-35 mm. long, 1.8-4 mm. thick, minutely (0.1-0.5 mm.) 
and sparsely puberulent with thin whitish hairs, often with minutely hooked (unci- 
nate) hairs; stipules 3-15 mm. long, broad near the base, minutely puberulent along 
the midrib, with prominent fan-like venation. Leaves usually symmetrical, petioles 
(3) 4-14 mm. long, 1.3-3 mm. thick, very minutely (0.05-0.2 mm.) puberulent or 
glabrescent; laminae (3) 6-20 (32) cm. long, (2) 3-8 ( 12) cm. broad, elliptic to oblong- 
elliptic or occasionally somewhat ovate or obovate, gradually or abruptly narrowed 
to the acute or acuminate apex, acute to abruptly narrowed and somewhat rounded 
at the obtuse base, margin entire with the edge often revolute, the lamina drying 
very stiffly chartaceous to subcoriaceous, smooth above and often slightly scabrous 
beneath, glabrous or glabrescent above and below, midvein impressed above the 9 to 
20 pairs of major secondary veins usually weakly loop-connected near the margin, 
tertiary veins forming a slightly raised reticulum beneath, microscopic straight or 
hooked (uncinate) hairs on the veins beneath (150X). Male inflorescences usually 2 
per node, borne on peduncles 1-8 mm. long, usually with peltate bracts and small 
hooked hairs, the globose head 3-10 mm. in diameter with many flowers; and many 
peltate bracts 0.2-0.9 mm. broad; male perianth usually 4- (3-) parted, 1.5-2.5 mm. 
high, stamens 2 to 4, filaments 2-5 mm. long, anthers 0.6-1.5 mm. long and 0.2-0.7 
mm. broad, thecae often apiculate or hairy at the tip. Female inflorescences usually 
solitary at a node, borne on peduncles 1-8 mm. long, globose to ovoid, obovoid, or 
lobed, 2-6 mm. in diameter, receptacle often covered with minute uncinate hairs and 
few to many peltate bracts 0.2-0.5 mm. broad, with broader ( 1 mm.) bracts near the 
base, 1 to 5 (13) flowers per head; styles 1-3 mm. long, stigmas 2-9 mm. long, fili- 
form. Fruit borne within a globose infructescence when solitary or within a lobed in- 






BURGER: FLORA COSTARICENSIS 117 

fructescence when 2 or more, the infructescence 1-2 cm. in diameter, becoming 
yellow to reddish, seed 1 cm. long. 

Tall trees of the wet evergreen forest formations below 600 m. 
elevation (in our area) on the Caribbean watershed and in the Golfo 
Dulce area of Costa Rica; collected with flowers or fruit from 
December to May (in our area). The species ranges from Central 
Mexico to Costa Rica and in South America from the eastern Andes 
of Venezuela and Colombia to southern Brazil. 

Brosimum lactescens is recognized by the paired short but broad 
stipules with prominent fan-like venation, the midvein usually con- 
spicuously impressed above, the tertiary veins drying pale yellow- 
ish-brown and forming a fine reticulum beneath, the minute unci- 
nate hairs on many parts, and the small unisexual inflorescences 
with thin round peltate bracts. 

Brosimum rubescens Taubert, Bot. Jahrb. 12 (Beibl. 27):4. 1890. 
B. caloxylon Standl., Trop. Woods 17:11. 1929. Figure 15. 

Trees to 40 m. tall, usually bisexual, apparently without buttresses, latex white, 
leafy internodes (0.2) 0.6-7 cm. long, 0.8-3 mm. thick, glabrous to sparsely puberu- 
lent (in ours); stipules completely united and apparently solitary at the node, 5-28 
(40) mm. long, 1-2 mm. thick, very sparsely and minutely puberulent, drying dark 
reddish-brown. Leaves usually symmetrical, petioles 2-10 (13) mm. long, less than 1 
mm. thick, narrowly sulcate above, minutely (0.1-0.4 mm.) puberulent; laminae (2) 
4-13 cm. long, 1-3.5 (6) cm. broad, short -acuminate to abruptly long-acuminate, 
acute to obtuse at the base, margin entire, lamina drying stiffly chartaceous to sub- 
coriaceous, smooth and glabrous above, nearly glabrous to sparsely puberulent be- 
neath, the 10 to 22 pairs of secondary veins loop-connected near the margin, slender 
oblongoid-capitate hairs present or absent on the veins beneath. Inflorescences 
usually bisexual, solitary, subglobose to subturbinate, hemispheric, or somewhat 
irregular, 2-8 mm. in diameter, borne on peduncles 2-12 mm. long and 0.2-2 mm. 
thick, receptacle glabrous to puberulent; peltate bracts few to many, 0.2-1.2 mm. 
broad; male flowers few to numerous, perianth 3- to 5-parted, 0.1-0.5 mm. high, 
stamens 1 or 2 (3), filaments 0.2-1.5 mm. long, anthers 0.1-0.3 mm. long, connective 
narrow or broad; female flowers 1 to several, style about 1 mm. long, stigmas 0.1-0.8 
mm. long. Fruit borne within the succulent globose infructescence to 2 cm. in dia- 
meter, reddish at maturity. 

Plants of lowland wet evergreen forest formations and known in 
our area only from sterile material collected by Cooper (535 the type 
of B. caloxylon and 607) in the region of Almirante, province of 
Bocas del Toro, Panama; the species ranges disjunctly to the 
Guianas, the Amazon Basin, and near Rio de Janeiro, Brazil. 

Brosimum rubescens is recognized by the very slender stipules 
completely united and therefore solitary at the node and completely 



118 FIELDIANA: BOTANY, VOLUME 40 

encircling the stem, the small almost glabrous leaves with many 
veins (in ours), and relatively small usually bisexual heads with thin 
round peltate bracts. The tree has been called bloodwood cacique in 
Panama. The fact that our material is sterile and disjunct from 
other members of the species makes the assignment to this species 
somewhat tentative. 

Brosimum utile (H. B. K.) Pittier, Contr. U.S. Nat. Herb. 20:102. 
1918. Galactodendrum utile H.B.K., Nov. Gen. & Sp. 7: 125 (or 163). 
1825. Brosimum allenii Woodson, Ann. Missouri Bot. Card. 47: 
128. 1960. Figure 15. 

Trees to 50 m. tall, usually bisexual, latex white, leafy internodes 0.7-8 cm. long, 
3-7 mm. thick, very minutely puberulent and with sparse longer hairs, longer (0.5 
mm.) hairs usually present below the stipule-scar; stipules united and solitary at 
the node, 0.8-1.8 cm. long (in ours), usually with ascending thin hairs about 0.2 mm. 
long. Leaves usually symmetrical, petioles 6-12 (20) mm. long, 2-4 mm. thick, dark 
brown and deeply ridged on drying; laminae 15-30 (56) cm. long, 5-12 ( 18) cm. broad, 
narrowly ovate to oblong or elliptic, abruptly short-acuminate, obtuse to somewhat 
rounded and truncate or subcordate (rarely acute) at the base, margin entire to re- 
pand, the lamina drying very stiffly chartaceous to coriaceous, smooth and glabrous 
above or puberulent near the petiole, glabrous to very sparsely puberulent beneath, 
the 20 to 30 pairs of major secondary veins usually loop-connected near the margin, 
tertiary veins occasionally parallel with each other, microscopic oblongoid-capitate 
orange hairs present on the lower surface. Inflorescences bisexual (rarely unisexual) 
and solitary, borne on peduncles 2-10 mm. long, subglobose and 5-10 mm. in dia- 
meter, with peltate bracts often long-stipitate; male flowers many on the surface of 
the head, male perianth with 4 basally connate parts about 1 mm. high, stamens 2, 
filaments 1.5-2 mm. long, anthers 0.8-1 mm. long and about 0.5 mm. broad, connec- 
tive narrow, sometimes apiculate; female flower usually solitary in the distal center 
of the head, style about 1.5-2 mm. long, stigmas 0.5-3 mm. long. Fruit borne within 
the globose succulent head, the infructescence about 3 cm. in diameter at maturity 
and becoming brown. 

Very tall trees of the evergreen forest formations below 700 m. 
elevation and apparently restricted to the areas of the General 
Valley and Golfo Dulce region on the Pacific side of southern Costa 
Rica in our area; the species ranges from southwestern Costa Rica 
to northern South America, Peru, and the Amazon Basin in Brazil. 
The species is represented in Costa Rica by the endemic subspecies 
allenii (Woodson) Berg. 

Brosimum utile is recognized by the completely united (and there- 
fore solitary) stipules forming an unbroken scar around the young 
stems, the relatively large leaves with many secondary veins, bi- 
sexual globose heads with many stamens usually in twos, and thin 
round peltate bracts. The very great height of these trees may ac- 



BURGER: FLORA COSTARICENSIS 119 

count for the small number of collections: Allen 5813 (type of the 
subspecies), Echeverria 981, Marsh s.n., Williams et al. 24234. This 
species, as defined by Berg (Flora Neotropica, Monog. 7:1-229. 
1972), includes considerable variation in floral structure in the dif- 
ferent subspecies. More and better collections of the species 
throughout its range may require a reassessment of the importance 
of floral variations. 



CASTILLA Sesse 

REFERENCE: C. C. Berg, Olmedieae, Fl. Neotrop. Monog. 7:92- 
104. 1972. 

Trees, unisexual or bisexual, often with buttresses and self-pruning twigs; 
stipules united and fully encircling the stem, with distinct parallel venation, large 
and caducous. Leaves distichous and often large, short-petiolate, chartaceous to 
subcoriacous, the margin entire or undulate, puberulent and often with a number of 
short hairs around the base of the rigid unicellular hairs, microscopic multicellular 
hairs infrequent and globose-capitate or oblongoid-capitate. Male inflorescences of 
two kinds, the primary pedunculate, widening to a flabellate bivalvate disc with the 
receptacle covered with large imbricate bracts in the primary inflorescences, the 
secondary inflorescences (associated with female inflorescences) much smaller and 
infundibuliform to cyathiform, entire to 2-lobed, with few to many stamens; male 
flowers not definitely organized, the stamens solitary or pairs along radiating and 
branched ridges of the receptacle, interspersed with free or connate membranaceous 
interstaminal bracts, anthers basifixed or dorsifixed. Female inflorescences usually 
solitary but often accompanied by small male inflorescences, sessile, discoid to 
cupuliform or subglobose, the receptacle with broadly overlapping bracts, many- to 
several-flowered; female flowers free or basally united, perianth tubular and entire 
or 4- (5-) lobed, the ovary free, partly united with the perianth, or immersed in the 
receptacle, stigmas short. Fruit united near the base, the infructescence 1.5-4.5 cm. 
in diameter, seeds with thick equal cotyledons. 

A genus of three species ranging from Central Mexico to Peru and 
Brazil below 900 m. elevation but absent in northeastern South 
America and the West Indies except as introduced. These are very 
striking trees with relatively few wide-spaced branches and large 
distichous leaves borne on very short petioles. The stipules have 
become completely united and are therefore solitary at each node, 
surrounding and enclosing the shoot-apex in its early stages. In our 
area members of the genus are usually called hule or ule. Indian 
names used for members of the genus in Costa Rica are said to be 
gsi-kra (Brunka), quiri (Guatuso), seru and soro (Terraba), and 
tsini (Bribri and Cabecara). Castilla elastica has been used as a 
source of rubber in Costa Rica. 



120 FIELDIANA: BOTANY, VOLUME 40 

Laminae usually abruptly rounded and subcordate at the symmetrical base, margin 
usually minutely denticulate, often abruptly narrowed to the short-acuminate 
apex: stipules with white tomentellous hairs along the edges; Nicoya Peninsula 
and the Caribbean lowlands C. elastica. 

Laminae usually obtuse on one side of the asymmetric base, margin entire to un- 
dulate, often tapering gradually to the acuminate apex; stipules lacking white 
tomentellous hairs along the edges; common in the Golfo Dulce area but ap- 
parently rare on the Caribbean lowlands C. tunu. 

Castilla elastica Sesse in Cervantes, Suppl. Gaz. Lit. Mexico, 
1794. C. costaricana Liebm., Danske Vidensk. Selsk. Skrift. ser. 5, 
2:319. 1851. C. nicoyensis Cook, Science 18:438. 1903. C. pana- 
mensis Cook, loc. cit. Figure 16. 

Trees to 30 (40?) m. tall, with low buttresses, sap white and rubber-like, leafy 
internodes 1-8 (12) cm. long, 3-13 mm. thick, with slender ascending yellowish to 
brownish hairs 0.5-1.5 mm. long; stipules 2-11 cm. long, densely ascending strigose 
to sericeous, the yellowish hairs minutely stellate at the base. Leaves usually sym- 
metrical and the laminae in a single horizontal plane, petioles 5-20 mm. long, 1.5-4 
mm. thick, densely strigose; laminae (10) 18-38 (55) cm. long, (5) 7-18 (25) cm. 
broad, oblong to obovate-oblong or slightly pandurate, mostly broadest above the 
middle but occasionally broadest below the middle and ovate-oblong, caudate to 
abruptly short -acuminate, the slender tip about 1 cm. long, usually truncate to cor- 
dulate at the subequal base, occasionally deeply cordate with the lobes overlapping, 
margin obscurely to minutely denticulate with 5 to 12 teeth per cm. often marked by 
tufts of hairs, laminae drying stiffly chartaceous to subcoriaceous, scabrous or 
slightly scabrous above with scattered stiff hairs 0.2-0.6 mm. long between the veins 
and longer hairs more dense on the major veins, lower surface with strigose or hispid 
hairs grayish-white to yellowish-brown in color, the 14-22 pairs of major secondary 
veins not usually loop-connected near the margin, microscopic globose-capitate 
hairs present on the lower surface but often difficult to see, the larger hairs often 
echinate or stellate at the base(XlOO). Male inflorescences associated with the 
female flowers variable, 5-20 mm. broad, independent male inflorescences often 4 per 
node, borne on peduncles 3-15 mm. long, conduplicate-reniform and 2-valved or 2- 
valved and folded with a U-shaped apex ( a folded discoid structure with the stamens 
on the inner face), about 10-25 mm. broad and 7-25 mm. high, receptacle covered 
with 10 to 12 series (centrally) of many yellow strigose bracts often acuminate at the 
apex, interstaminal bracts irregular in shape, to 2.5 mm. long, puberulent; stamens 
numerous, solitary, filaments 0.5-3.5 mm. long, anthers mostly 0.5-1.2 mm. long, 
often irregular and unequal. Female inflorescences solitary (rarely paired) but often 
with small male inflorescences, sessile or subsessile, discoid to cupuliform, 1-2 cm. in 
diameter, receptacle covered with 5 to 10 series of many yellow strigose bracts acute 
to acuminate at the apex, with (10) 15 to 30 basally connate flowers; female peri- 
anth-tube 2-3 mm. high, 4-lobed, minutely velutinous, ovary partly united with the 
perianth, style short (to 1.5 mm.) with long (3-6 mm.) stigmas or the style longer 
(2-3 mm.) and with shorter stigmas, stigmas 2 (3). Fruit ellipsoid, 8-10 mm. long, 
borne within the velutinous accrescent perianth, united below and free (3-10 mm.) 
above, borne in the surface of the discoid infructescence 2.5-4.5 cm. broad, perianth 
ribbed and grooved. 



BURGER: FLORA COSTARICENSIS 121 

Trees of wet evergreen forest formations between sea level and 
850 m. elevation and also found in seasonally dry, partly deciduous 
forest formations; flowering throughout the year but collected most 
often between January and June. The species ranges from Mexico 
through Panama and the coastal regions of western Colombia to 
western Ecuador and is represented in our area by two subspeices 
(see below): ssp. elastica and ssp. costaricana (Liebm.) Berg. 

Castillo, elastica is recognized by the large distichous leaves often 
held in a horizontal plane, generally oblong laminae subcordate at 
the base and very abruptly narrowly acuminate at the apex, the 
yellowish strigose hairs on most parts (these often minutely echi- 
nate or stellate at the base), the 2-valved or doubly folded male in- 
florescences, the discoid female infructescence with fruiting peri- 
anth united basally, and the single large stipule enclosing the shoot 
apex. The species is represented in Costa Rica by two subspecies 
that are apparently geographically disjunct in our area. They can 
usually be separated in the following way: 

Hairs usually spreading (patent) on the secondary veins beneath; free part of the 
fruiting perianth much longer than the basal united part; styles 0-1.5 mm. long, 
stigmas 3-6 mm. long; Nicoya peninsula ssp. elastica. 

Hairs usually appressed or ascending on the secondary veins beneath; free part of 
the fruiting perianth much longer to less than the length of the basal united part; 

styles 1.5-3 mm. long, stigmas 2-3 mm. long; Caribbean lowlands 

ssp. costaricana. 

Castilla tunu Hemsley, Hook. Ic. PL 27:2651. 1900. C. fallax 
Cook, Science 18:438. 1903. Figure 16. 

Trees to 35 m. tall, with buttresses, latex yellow to dark brown and said to be gum- 
like not rubber-like, leafy internodes 1-7 cm. long, 4-12 mm. thick, densely covered 
with slender appressed-ascending yellowish hairs about 0.5 mm. long, often hollow; 
stipules 2-10 cm. long, densely strigose or sericeous with golden-brown hairs, com- 
pletely united and apparently solitary at the node. Leaves distinctly asymmetric at 
the base, petioles 6-18 mm. long, usually 3-4 mm. thick, densely sericeous or stri- 
gose; laminae 16-40 cm. long, 6-16 cm. broad, oblong to elliptic-oblong or slightly 
obovate, narrowed to the short-acuminate apex, the base usually oblique with one 
side acute and the other rounded to obtuse, margin entire or repand, the lamina 
drying stiffly chartaceous to subcoriaceous, somewhat scabrous above with scat- 
tered slender appressed hairs 0.2-0.8 mm. long (denser on the veins), slightly 
scabrous and more densely strigose beneath, the 16 to 20 pairs of major secondary 
veins not usually loop-connected near the margins, microscopic globose-capitate or 
oblongoid-capitate hairs often orange and difficult to see among the larger hairs 
with unusual rough surfaces (X 150). Male inflorescences paired in the axils of 
leaves, subsessile, 2-valved conduplicate-reniform (a folded discoid structure with 
the stamens on the inner faces), 12-20 mm. broad, 6-15 mm. high, receptacle covered 



122 FIELDIANA: BOTANY, VOLUME 40 

with 10 to 18 series of bracts (in the central area), the bracts yellowish or golden- 
brown strigose to sericeous; interstaminal bracts triangular, acute, puberulent; sta- 
mens many, often paired, filaments 1-3 mm. long, anthers 0.5-1 mm. long and equal- 
ly broad. Female inflorescences solitary and sessile, at leafy or leafless nodes, dis- 
coid, 1-1.5 cm. in diameter, receptacle covered with 6 to 8 series of yellowish strigose 
to sericeous bracts, flowers 15 to 30, usually free to the base; female perianth 
tubular, 2-3.5 mm. high, entire or dentate, densely puberulent, style 2-2.5 mm. long, 
stigmas 1-1.5 mm. long, twisted. Fruit ellipsoid, 7-9 mm. long, enclosed within the 
(free) 3- to 5-ribbed yellowish to orange sericeous perianth-tube, the 10 or more 
fruits borne on the discoid or oblate-globose infructescences 2.5-3.5 cm. in diameter. 

Plants of lowland wet evergreen forest formations between sea 
level and 200 m. elevation, apparently common in the Golfo Dulce 
area but rare in the Caribbean lowlands of Costa Rica; probably 
flowering throughout the year, but collected primarily between 
December and March in our area. The species ranges from British 
Honduras to northwestern Colombia. 

Castillo, tunu is recognized by the large oblong, often drooping 
leaves asymmetric at the base, the yellowish-brown sericeous or 
strigose hairs on many parts, the 2-lobed male inflorescences and 
the discoid female infructescence with separate (basally congested) 
angled and ellipsoid fruiting perianth, and the single stipule en- 
closing the shoot-apex. 

CECROPIA Linnaeus 

Unisexual trees, upper trunk and branches often hollow with transverse septa, 
primary branches usually few and often forming an open candelabra-like crown, 
bark smooth and usually very pale gray, most species often harbouring aggressive 
ants within the stems; stipules completely united and apparently solitary, fully en- 
closing the stem and leaving an encircling scar, usually large. Leaves borne in a 
spiral, simple, the first leaves unlobed and narrowly elliptic, often with a serrate 
margin, the subsequently formed leaves showing a gradual transition (first 3 lobes, 
then 5, etc.) to the typical adult foliage, peltate, petioles long and often enlarged 
beneath at the base (the pulvinus); laminae slightly to deeply lobed and usually 
eccentrically peltate in ours, tertiary veins usually subparallel. Inflorescences 
paired in the axils of leaves, each inflorescence of minute (ca. 1 mm. long) densely 
congested flowers in several to many spikes at first enclosed in a deciduous or 
caducous spathe at the apex of a common peduncle. Male flowers with a tubular 
perianth thickened and transversely split at the apex, anthers 2, usually exserted 
individually. Female flowers with a shredding tubular perianth, stigma one and 
minutely fimbriate, ovule basal in the locule. Fruit a minute achene, with glabrous 
surface. 

Cecropia, containing perhaps as many as 60 species, is one of the 
most characteristic genera of the American tropics. Some species 
are common in secondary growth, and their tall, few-branched habit 



BURGER: FLORA COSTARICENSIS 123 

with very large umbrella-like leaves produces a striking silhouette. 
Other species are found in mature forests and may reach 30 m. in 
height. The aggressive biting ants that are often present in these 
trees have apparently deterred botanical collectors, so that these 
common plants are poorly represented in herbaria and their species 
are very poorly understood. Knowledge of both male and female 
flowering parts is necessary for the effective delimitation of species. 
These plants are commonly called guarumo in Central America. 

Cecropia belongs to the subfamily Conocephaloideae and, like the 
other genera of that subfamily, is probably more closely related to 
genera of the Urticaceae than to other Moraceae. The Conocepha- 
loideae are retained in the Moraceae here for the sake of con- 
venience, though their basal ovules and lack of milky sap in leaves 
and inflorescences indicate their proper placement in Urticaceae 
(Corner, Gard. Bull. Singapore 19:187-252. 1962). Cecropia is 
closely related to Musanga of Africa and more distantly to Cous- 
sapoa andPourouma. 

The ants housed by a single Cecropia tree can reach very large 
numbers. They feed on minute food-bodies (Mullerian bodies) pro- 
duced among the short matted hairs of the pulvinus at the base of 
the petiole, as well as on the sugary exudate of associated coccid 
insects. Among our species, C. polyphlebia and C. pittieri have 
never been reported to be associated with ants. 



la. Laminae very shallowly lobed; plants endemic to Cocos Island C. pittieri. 

Ib. Laminae with sinuses one-third as deep as the adjacent primary veins or 
deeper; plants not found on Cocos Island 2a. 

2a. Laminae smooth to the touch above, primary veins 7 to 11 in mature foliage; 
male and female spikes 5-12 cm. long, 7-12 mm. thick, wet evergreen formations 
0-1500 m. elevation C. insignis. 

2b. Laminae scabrous above, male spikes usually more slender 3a. 

3a. Primary veins 11 to 13 (rarely 8 to 15) in mature foliage, longest primary vein 
with about 30 pairs of secondary veins, laminae very deeply lobed; female 
spikes 18-50 cm. long, male spikes 8-22 cm. long; wet evergreen formations, 
0-1200 m. elevation C. obtusifolia. 

3b. Primary veins usually 7 to 1 1 ; spikes usually shorter 4a. 

4a. Longest vein of the leaf with 14 to 20 pairs of major secondary veins, sinuses 
about half the length of the adjacent primary veins; common plants of secon- 
dary growth in wet and seasonally dry formations, 0-1200 m C. peltata. 

4b. Longest vein of the leaf with 30 to 40 pairs of major secondary veins, sinuses 
about three-fourths the length of the adjacent primary veins; plants with con- 
spicuous long whitish hairs and lacking ants, in very wet montane forests, 
1400-2400 m C. polyphlebia. 



124 FIELDIANA: BOTANY, VOLUME 40 

Cecropia insignis Liebmann, Danske Vidensk. Selsk. Skrift., ser. 
5, 2:318. 1851, e descr. C. eximia Cuatrecasas, Rev. Acad. Colomb. 
Cienc. 6:287. 1945, (female); descr. ampl. loc. cit. 9:326-327. 1956, 
(male). C. sandersoniana (standleyana) P. Allen, The Rain Forests 
of Golfo Dulce: 162 & 709. 1956. Figure 23. 

Trees 10-40 m. tall, the trunk becoming 90 cm. thick above the buttresses, young 
trunks said to be dark in color and without rings, stilt-roots becoming buttresses; 
stipules (12) 18-34 cm. long, about 6 cm. thick unopened, pink or reddish (live), 
sparsely to densely strigose with whitish hairs about 1 mm. long and rough to the 
touch. Leaves simple, petioles 40-90 cm. long, 1-2.5 cm. thick, sparsely to densely 
puberulent with whitish arachnoid hairs closely appressed to the surface, longitu- 
dinally ribbed, basal thickening (pulvinus) with a dense covering of small brownish 
scabrous or velutinous hairs and longer thin interspersed whitish hairs; laminae 
eccentrically peltate, 40-120 cm. long and almost as broad, with ( 7) 8 to 10 ( 1 1 ) lobes, 
sinuses two-thirds to seven-eighths as long as the adjacent primary veins, the 
longer lobes tapering to a bluntly obtuse apex, the shorter lobes rounded apically, 
margins entire and undulate, the lamina drying stiffly chartaceous to subcoria- 
ceous, smooth and glabrous or with slender stiff hairs above, glabrous or minutely 
puberulent on the veins beneath, areas between the veins greenish to densely 
whitish arachnoid-lanate, primary veins (7) 8 to 10 (11), longest primary vein with 
18 to 30 pairs of major secondaries, central secondaries arising at angles of 40-60 
degrees and 12-25 mm. distant, tertiary veins readily apparent. Male inflorescences 
with common peduncles about 10 cm. long and 12 mm. thick bearing 5 to 7 spikes, 
male spikes about 6 cm. long and 7-10 mm. thick, borne on individual peduncles 4-20 
mm. long and 4-6 mm. thick, the enclosing spathe 10-15 cm. long and 2-4 cm. thick 
before anthesis. Female inflorescences with common peduncles 8-12 cm. long and 5-8 
mm. thick, bearing 5 to 7 spikes, female spikes (6) 8-12 cm. long, 8-12 mm. thick, 
borne on individual peduncles 5-10 mm. long and about 6 mm. thick or occasionally 
subsessile. Fruiting spikes becoming 13 cm. long and 15 mm. thick, seeds 2-2.5 mm. 
long, about 0.8 mm. thick, longitudinally 2- or 3-angled, pointed at both base and 
apex, surface slightly muricate. 

This species occurs in both secondary and primary vegetation 
from near sea level to 1500 m. elevation in wet evergreen forest for- 
mations on both the Pacific and Caribbean sides of Costa Rica; 
flowering from January to June and fruiting through September. 
The species ranges southward to Colombia. 

Cecropia insignis is recognized by the deeply lobed leaves with 
relatively few primary and secondary veins and the very thick male 
spikes. The leaves vary from bright whitish to dull green beneath. 
Cecropia insignis is vegetatively very similar to C. sylvicola, a mon- 
tane forest species of Nicaragua to Guatemala, but the male in- 
florescences are very different. The description of the male spikes of 
this species (under C. eximia} in the "Flora of Panama" (Woodson, 
Ann. Missouri Bot. Gard. 47:175. 1960) is incorrect and, I believe, 
was based on a mixed collection from Costa Rica ( United Fruit Co. 



BURGER: FLORA COSTARICENSIS 125 

390) in the U.S. National Herbarium. Liebmann listed two species 
ofCecropia from Costa Rica: C. humboldtiana Klotzsch, apparently 
a synonym of C. peltata, and C. insignis. Both were based on collec- 
tions of Oersted along the Rio San Juan. The description of C. 
insignis, though it lacks flowering or fruiting parts, clearly refers to 
this large-leaved species. I thank Dr. Leslie Holdridge for pointing 
this out. 

Cecropia obtusifolia Bertoloni, Fl. Guatemal. 39. 1840. C. mexi- 
cana Hemsl., Biologia Cent. Amer. 3:151. 1883. C. panamensis 
Hemsl., loc. cit. 151. C. mexicana var. macrostachya Donn.-Smith., 
Bot. Gaz. 27:442. 1899. Figure 23. 

Trees 5-15 (20) m. tall, trunk becoming 25-50 cm. thick, bark gray to whitish, 
major branches few, leafy internodes 1.5-4 cm. thick, very scabrous, usually in- 
habited by biting ants; stipules 5-12 cm. long, sparsely whitish sericeous. Leaves 
simple, said to be 4-ranked, petioles 25-60 (90) cm. long, 10-15 mm. thick, minutely 
(0.1-0.3 mm.) grayish-white puberulent, longitudinally ridged, pulvinus at the 
petiole-base beneath with a dense covering of brown velutinous hairs and very few 
longer whitish hairs; laminae eccentrically peltate and deeply lobed, 35-75 cm. long 
and almost as broad, with (8) 10-13 ( 15) lobes, sinuses one-third to four-fifths as long 
as the adjacent primary veins, longer lobes with rounded, obtuse, or occasionally 
very short-acuminate apices, margins entire and undulate, the lamina drying very 
stiffly chartaceous or subcoriaceous, dark, scabrous, and sparsely puberulent 
above, very minutely (0.05-0.1 mm.) puberulent on the veins beneath or the hairs 
longer (0.5 mm.) and sparse, areas between the veins pale greenish to grayish-white, 
primary veins (8) 10-13 ( 15), longest primary with about 30 pairs of major secondary 
veins, central secondaries arising at angles of 30-60, an arcuate marginal vein and 
the tertiary veins usually readily visible. Male inflorescences with common ped- 
uncles (3) 5-25 cm. long and 3-6 mm. thick, glabrous or very minutely puberulent 
bearing 12 to 18 spikes emerging from a spathe 9-13 cm. long and 1.5-2 cm. thick; 
male spikes 8-22 cm. long, (2) 3-5 mm. thick, borne on individual peduncles 5-10 (25) 
mm. long, 0.5-1.3 mm. thick, often united above the spathe-scar. Female inflores- 
cences with common peduncles 6-23 (32) cm. long, 6-8 mm. thick, sparsely puberu- 
lent with thin whitish hairs 0.5 mm. long, bearing usually 4(3-5) spikes from within 
spathes 18-28 cm. long and about 2 cm. thick; female spikes 18-50 cm. long, 3-6 mm-, 
thick, subsessile or on individual peduncles 1-10 mm. long and 3-5 mm. thick. Fruit- 
ing spikes becoming 10 mm. thick; fruit about 2 mm. long and 1.2 mm. broad, 
usually flattened, abruptly rounded at base and apex, the surfaces smooth. 

Common plants of open secondary vegetation only rarely en- 
countered as tall prop-rooted individuals in mature forest in areas of 
wet evergreen formations between sea level and 1200 m. altitude on 
both the Caribbean and Pacific slopes of Costa Rica; probably 
flowering throughout the year. This species appears to be absent in 
the seasonally very dry (tropical dry) formations of the Pacific 
slope. The species ranges from central Mexico to northern South 
America. 



126 FIELDIANA: BOTANY, VOLUME 40 

Cecropia obtusifolia is recognized by the deeply lobed leaves, very 
long female spikes, long slender male spikes, and apparent prefer- 
ence for areas of high rainfall or high soil moisture. 

Cecropia peltata L., Syst. Nat. ed. 10, 2:1286. 1759. C. arach- 
noidea Pittier, Contr. U.S. Nat. Herb. 18:226. 1917. C. asperrima 
Pittier, loc. cit. 227. Figure 23. 

Trees 8-15 (20) m. tall, trunk and stems pale in color with encircling rings, leafy 
internodes and stems hollow and often harbouring biting ants; stipules 5-9 cm. 
long, about 2 cm. thick unopened, sparsely to densely puberulent with short ( 1 mm. ) 
stiff whitish hairs and scabrous. Leaves simple, petioles 15-50 cm. long, 5-12 mm. 
thick, densely to sparsely puberulent with crooked whitish hairs 0.1-0.5 mm. long, 
longitudinally ridged, the basal thickening (pulvinus) with a dense covering of 
brown velutinous hairs with usually few longer whitish hairs interspersed; laminae 
eccentrically peltate, 25-90 cm. long and almost as broad, with (8) 9 to 11 ( 12) lobes, 
distal lobes about twice the length of the basal lobes, largest lobes 6-12 cm. broad, 
sinuses one-third to two-thirds as long as the adjacent primary veins, the longer 
lobes tapering to an obtuse or rounded apex (rarely abruptly short-acuminate), 
margins entire and undulate, the lamina drying very stiffly chartaceous to sub- 
coriaceous, minutely puberulent, scabrous and dark above, minutely (0.1-0.3 mm.) 
puberulent on the veins beneath, sparsely to densely whitish arachnoid-villous 
between the veins, primary veins (8) 9 to 11 ( 12), longest primary vein with 14 to 20 
pairs of major secondary veins, central secondaries arising at angles of 30-60 
degrees, tertiary veins often obscured by the tomentum. Male inflorescences with 
common peduncles 3-14 (16) cm. long, 2-4 mm. thick, bearing 12 to 32 (40) spikes, 
at first enclosed in a spathe 4-8 cm. long and 1.5-3 cm. thick; male spikes (1.5) 3-7 
cm. long, 2-4 mm. thick, subsessile or borne on individual peduncles 1-8 mm. long 
and 1-2 mm. thick, male flowers tightly compressed. Female inflorescences with 
common peduncles 6-10 cm. long, 2-3 mm. thick, sparsely to densely puberulent and 
bearing (2) 3 to 4 (6) spikes, emerging from within a spathe 6-12 cm. long; female 
spikes (2.5) 4-10 cm. long, (4) 5-10 mm. thick, subsessile on the common peduncle, 
tomentum between the pistils whitish and evident in fruit. Fruiting spikes becoming 
10-12 mm. thick, fruit about 2 mm. long and 0.8 mm. thick, longitudinally 2-or 3- 
angled, ellipsoid, the surfaces muricate. 

Common plants of secondary growth ranging from sea level to 800 
m. altitude or less commonly to 1200 m., collected most often on the 
seasonally dry Pacific side and only rarely in the Caribbean lowlands 
in Costa Rica, probably flowering throughout the year. The species 
ranges from Mexico to Colombia, Venezuela, and the West Indies. 

Cecropia peltata is characterized by the leaves with lobes about 
half as long as the primary veins, the very short female spikes, the 
very large numbers of short male spikes on each common peduncle, 
and the tolerance of seasonally dry conditions. Cecropia maxonii 
Pittier from El Boquete, Chiriqui, is probably no more than an 
unusual specimen of C. peltata with rugose leaf-surfaces. 



BURGER: FLORA COSTARICENSIS 127 

Cecropia pittieri Robinson in Stewart, Proc. Calif. Acad. Sci. ser. 
4, 1:389. 1912. 

Trees 10-20 m. tall, leafy internodes 2-4 cm. thick, with short (0.5 mm.) stiff white 
hairs; stipules often persisting, 11-17 cm. long, 1.5-4 cm. thick unopened, whitish 
sericeous except along the margin abaxially. Leaves simple, petioles 20-40 cm. long, 
about 10 mm. thick, densely grayish-white puberulent with appressed arachnoid 
hairs, the basal pulvinus usually lacking short velutinous hairs and with scattered 
whitish hairs; laminae eccentrically peltate, 20-60 cm. long, with usually 9 or 10 
short lobes, sinuses about one-fourth to one-third as long as the adjacent primary 
veins, lobes broadly rounded at the apex, distal portion of the lamina (petiole to 
apex) about twice as long as the basal (petiole to base) portion, drying very stiffly 
chartaceous to subcoriaceous, smooth or slightly scabrous and very sparsely 
puberulent above, with slender whitish hairs 1-2 mm. long on the veins beneath, 
aereoles between the veins pale grayish with a very minute appressed tomentum, 
primary veins usually 9 or 10, longest primary vein with 18 to 22 prominent 
secondary veins, central secondaries arising at angles of 35-70 degrees. Male 
inflorescences with common peduncles about 8 cm. long and bearing about 19 sessile 
spikes emerging from a spathe 14-16 cm. long; male spikes about 10 cm. long and 3 
mm. thick. Female inflorescences with common peduncles 6-10 cm. long, with 
usually 4 spikes; the fem$le spikes 14-22 cm. long and 5-6 mm. thick, spikes usually 
subsessile. Fruiting spikes 6-10 mm. thick, fruit 1-1.5 mm. long, about 0.8 mm. 
broad, flattened on 2 sides and abruptly rounded at base and apex, surfaces smooth. 

This species is endemic to Cocos Island and common on that 
island's eastern and northern coasts, especially on steep slopes near 
the beach, to 150 m. elevation. 

Cecropia pittieri is characterized by its isolated island habitat and 
very shallowly lobed leaves. The species is not known to be as- 
sociated with ants, and the pulvinus at the petiole-base lacks the 
unusual brownish velutinous hairs characteristic of our continental 
species. 

Cecropia polyphlebia Donnell-Smith, Bot. Gaz. 27:442. 1899. 
Figure 23. 

Trees 8-25 m. tall, trunk becoming 40 cm. in diameter at breast height, leafy inter- 
nodes 2-5 cm. thick, with translucent or white slender hairs 2-10 mm. long; stipules 
9-30 cm. long, covered with long whitish hairs abaxially except along the margins. 
Leaves simple, petioles 25-55 cm. long, 6-14 mm. thick, longitudinally ridged, 
sparsely to densely tomentose or villous with whitish or translucent multicellular 
hairs 2-8 mm. long; base of the petiole beneath (pulvinus) with the very short velu- 
tinous brownish hairs obscured by the longer whitish hairs; laminae eccentrically 
peltate and deeply lobed, 30-80 cm. long, almost as broad, lobes 10 or 11, sinuses 
two-thirds to seven-eighths as long as the adjacent primary veins, lobes 6-12 cm. 
wide, the longer lobes obtuse to acute or short-acuminate at the apex, entire and 
somewhat undulate, drying very stiffly chartaceous to subcoriaceous, scabrous and 
with short ( 1 mm. ) slender hairs on the veins above, very sparsely to moderately 



128 FIELDIANA: BOTANY, VOLUME 40 

strigulose between the veins, very sparsely to densely soft villous on the veins be- 
neath with hairs 0.3-10 mm. long, aereoles between the veins whitish with a dense 
arachnoid tomentum, the primary veins 10 or 11, longest primary veins with 30 to 
40 pairs of prominent secondaries, central secondaries arising at angles of 30-50 
degrees, about 5-10 mm. distant, a loop-connected marginal vein often apparent, 
tertiary veins usually dark in contrast to the whitish surface. Male inflorescences 
solitary or paired, with common peduncles 4-7 cm. long and about 4 mm. thick, flat- 
tened and ridged on drying, glabrous except near base and apex, bearing 8 to 16 
spikes emerging from a caducous spathe 4-8 cm. long; male spikes 2.5-4.5 cm. long, 
5-8 mm. thick, borne on very short peduncles at the strigose apex of the common 
peduncle. Female inflorescence with common peduncles 1-4 cm. long and 4-7 mm. 
thick, bearing (3) 4 to 6 spikes emerging from a small (4 cm.) caducous spathe; 
female spikes (1.5) 3.5-6 (9) cm. long, 7-16 mm. thick, sessile on the common ped- 
uncle. Fruiting spikes 10-20 mm. thick, fruit 2.5-3 mm. long, 0.5-0.9 mm. thick, 
ellipsoid, with a muricate surface. 

Cecropia polyphlebia is known only from the very wet montane 
forest formations subject to the wet Caribbean weather between 
1400 and 2400 m. elevation; probably flowering throughout the 
year. The species has been collected from the areas of Monteverde 
(Puntarenas), La Palma and the Rio Para Blanco (San Jose), Cachi 
and Tapanti (Cartago), and near El Empalme on the Cerro de la 
Muerte (San Jose & Cartago) in Costa Rica and recently (Blum & 
Dwyer2600) on Cerro Horqueta in Chiriqui, Panama. 

This species is distinguished by the long whitish hairs on younger 
parts, leaves deeply lobed and white beneath with many secondary 
veins, short thick spikes, wet montane habitat, and the apparently 
consistent absence of resident ants. Only C. insignis shares some of 
the same wet highland habitats in Costa Rica. Cecropia polyphlebia 
appears to be closely related to C. palmatisecta Cuatr. of similar 
altitudes in Colombia and Venezuela. 



CHLOROPHORA Guadichaud 

Unisexual trees, occasionally armed with axillary spines, the sap white; stipules 
paired, lateral, caducous, leaving a scar on half the stem. Leaves alternate and dis- 
tichous, simple, entire to dentate. Inflorescences unisexual, solitary in the leaf axils, 
the male flowers crowded on long spikes, the female in globose capitular or on long 
spikes (in Africa); male flowers sessile, perianth segments 4, imbricate in bud, free, 
stamens 4, filaments inflexed in bud, anthers sub-basifixed, introrse, a pistillode 
often present; female flowers sessile and congested in the head, perianth 4-lobed or 
4-parted, thickened near the apex and covering the ovary, style usually simple and 
slender, sublateral near the apex of the ovary. Fruit with the perianth becoming 
slightly fleshy, forming a loosely coherent globose or oblong syncarp (in ours), fruit 
an achene, ovate and compressed. 

A genus of three species, with two others in western tropical 



BURGER: FLORA COSTARICENSIS 129 

Africa. This genus has been united with Madura by Corner ( Card. 
Bull. Singapore 19:187-252. 1962) and given the status of section 
within that genus. However, I believe it is better to retain the nar- 
rowly defined small genus until more intensive studies are done. See 
the recent study by R. C. Kaastra in Acta Botanica Neerlandica 
21:657-670.1973. 

Chlorophora tinctoria (L.) Gaudichaud in Freycinet ex Bentham 
& Hooker, Gen. PL 3:363. 1880; Gaudichaud in Freycinet, Voyage 
Uran. Physic. 509. 1830. Morus tinctoria L., Sp. PL 986. 1753. 
Figure 14. 

Shrubs or trees 5-30 m. tall, the bark light brown, wood yellowish, branches 
occasionally armed with sharp spines, leafy internodes 5-25 mm. long, 1-3 thick, 
minutely (0.1-0.2 mm.) puberulent with ascending whitish hairs; stipules 2-10 mm. 
long, subulate, caducous. Leaves often deciduous, petioles 4-14 mm. long, 0.6-1.4 
mm. thick, minutely puberulent or glabrescent, sulcate above; laminae often lobed 
on young branches, 4-13 cm. long, 1.5-5 cm. broad, narrowly ovate to ovate-elliptic 
or lanceolate, usually with a long-acuminate apex, obtuse to truncate (subcordate) 
at the usually inequilateral base, margin serrate to entire, drying chartaceous, 
smooth and glabrous above or with a few small hairs above the midvein, glabrous or 
sparsely and minutely puberulent on the veins beneath, the 4 to 8 pairs of major 
secondary veins often weakly loop-connected near the margin, central secondaries 
arising at angles of 45-65 degrees. Male spikes 4-12 cm. long, about 4 mm. thick, 
peduncles 4-10 mm. long, about 0.5 mm. thick, glabrous or very minutely (0.05 mm.) 
puberulent, perianth about 1 mm. long and minutely puberulent, filaments about 2 
mm. long (dry) anther 0.7 mm. long. Female capitula (heads) 2-8 mm. in diameter, 
borne on short (2-4 mm.) slender (0.5 mm.) peduncles, female flowers densely 
crowded, styles about 6 mm. long and papilla te-puberulent. Fruiting head becoming 
1-2 cm. in diameter, globose. 

Plants of the seasonally dry deciduous and semi-deciduous forest 
formations of the Pacific slopes between sea level and 1000 m. eleva- 
tion in Costa Rica ; flowering from the end of the dry season into the 
wet season, April to August. The species ranges from Central 
Mexico and the West Indies southward to Argentina. 

Chlorophora tinctoria is recognized by its solitary inflorescences, 
male catkins, female capitula, yellowish wood, and the seasonally 
dry habitat. The species was important in commerce as a source of 
yellowish dye from the wood. The strong durable wood has had 
many uses in Central America (see Standley in Fieldiana: Bot. 24, 
4:24. 1946, and Allen in Rain Forests of Golfo Dulce, 174. 1956). 
The common names mora, mora de espina, morillo brasil, macano, 
and fustic have been used for this species in our area. The sap is 
said to be used to ease the extraction of teeth. 



130 FIELDIANA: BOTANY, VOLUME 40 

CLARISIA Ruiz & Pavon 

Unisexual trees with milky sap, lacking spines; stipules paired and lateral, usually 
caducous, encircling less than half the stem. Leaves alternate and distichous, simple 
and entire, petiole sulcate above, venation pinnate. Inflorescences paired in the leaf 
axils or cauliflorous on older branchlets; male inflorescences in densely crowded 
sessile flowering parts on a spicate axis with bracts and stamens often lacking along 
a narrow line on one or two sides of the spike; male flowers of solitary stamens 
interspersed with bracts and perianth parts arising directly from the rachis, anthers 
sub-basifixed ; female flowers paired in the leaf axils (in ours) or on racemiform 
shoots, pedicellate with 3-7 suborbicular peltate bracts at the base of the receptacle 
(base of the ovary), the pedicel is probably the peduncle of a reduced inflorescence 
that now appears as a single pedicellate flower, ovary inferior by adnation of the 
tubular perianth, the perianth free only near the apex, ovary 1-locular with pendu- 
lous ovule, style branches 2, long and narrow. Fruit drupaceous, perianth accrescent 
and succulent. 

A genus of two or three species of tall trees ranging from Mexico 
to the Amazonian Basin. In ours, the male spikes and individual 
female flowers are usually borne in axillary pairs, but in the Ama- 
zonian species these are borne on long racemiform leafless shoots. 
The male flowers have lost their organization, and stamens and 
perianth parts are not regularly arranged. 

Clarisia biflora Ruiz & Pavon, Syst. Veg. Fl. Peruv. & Chil. 255. 
1798. C. panamensis Woods., Ann. Missouri Bot. Card. 47:123. 
1960. Figure 14. 

Trees to 35 m. tall, trunk becoming 1.2 m. in diameter with smooth brown bark, 
leafy internodes 2-4.5 mm. thick, sparsely appressed puberulent and soon becoming 
glabrous, lenticels inconspicuous; stipules 3-8 mm. long, narrowly to broadly 
cuneate, the scars inconspicuous. Leaves with petioles 6-22 mm. long, 1-2.5 mm. 
thick, minutely (0.1-0.2 mm.) and sparsely puberulent but becoming glabrous, peri- 
derm often breaking up into small flakes; laminae 8-25 cm. long, 2.5-9 cm. broad, 
narrowly oblong to elliptic-oblong or broadly elliptic, acuminate at the apex, acute 
to obtuse at the base, entire, drying thin to thickly chartaceous, smooth and gla- 
brous above, glabrous or very sparsely and minutely (0.1 mm.) puberulent beneath, 
the (4) 6 to 12 pairs of major secondary veins not clearly loop-connected near the 
margin, central secondaries arising at angles of 40-70 degrees. Male inflorescences of 
paired axillary spikes or rarely the spikes on leafless racemiform shoots, spikes 
2-10 cm. long and borne on peduncles 3-6 mm. long, sparsely puberulent, rachis with 
numerous spatulate to peltate bracts, stamens interspersed with the bracts (peri- 
anth in part?), filaments about 1 mm. long, anthers 0.4-0.8 mm. long, slightly apicu- 
late in ours. Female inflorescences of two axillary flowers or occasionally in alter- 
nate pairs on a leafless shoot, pedicels 0.5-6 mm. long, densely and minutely puberu- 
lent with 3 to 7 peltate bracts 0.6-1.4 mm. broad at the base of the pistil, perianth- 
tube 2.5-5 mm. long, 1-5 mm. thick, narrowly ovoid to globose, glabrous except at 
the minutely lobed apex, style branches 2-6 mm. long. Fruit ovoid to ellipsoid, be- 
coming 25 mm. long and globose, smooth and glabrous. 



BURGER: FLORA COSTARICENSIS 131 

Trees of the very wet evergreen forest formations between sea 
level and 1000 m. elevation on both the Caribbean and Pacific slopes 
(near Golfo Dulce) in Costa Rica; probably flowering throughout 
the year, but fruiting material has been most often collected be- 
tween September and December. The species ranges from Central 
Mexico to Bolivia and Brazil. 

Large trees recognized by the unusual male spikes with inter- 
mixed bracts and stamens and the usually paired female flowers 
with peltate bracts at the apex of their pedicels. The vegetative 
parts are often glabrous or nearly so, and the larger roots are said to 
be reddish. The foliage of this species is very similar to that of 
species of Brosimum, Sorocea, and Trophis. In Clarisia the mid- 
vein is impressed above, and multicellular gland-tipped trichomes 
(X150) are lacking on the lower surface of the leaves. These tall 
trees are poorly represented in herbaria, and there are no staminate 
collections from our area. 

COUSSAPOA Aublet 

Unisexual trees or shrubs, usually epiphytic in early stages and sometimes stran- 
gling the hose, the sap clear or colored but not milky; stipules completely united and 
apparently solitary, fully amplexicaul, enclosing the stem-apex and leaving a scar 
completely surrounding the stem, often large. Leaves simple, alternate in a spiral, 
often large and subcoriaceous, petiolate, the laminae basifixed, entire to undulate, 
tertiary veins subparallel. Inflorescences unisexual, usually paired in the axils of 
current foliage, the flowers minute and densely clustered in usually small heads 
(capitula), the heads solitary on a peduncle to many on a branched inflorescence, the 
flowers interspersed with bracts slender at the base and spatulate or somewhat 
peltate at the apex; male flowers with 3 or 4 usually separate perianth-parts (tepals 
or sepals), the stamens 2 (or apparently solitary, free with 2-thecous anthers or com- 
pletely fused and the anther apparently 4-thecous by connation ; female flowers with 
the perianth united and tubular or clavate, often thickened apically, usually with a 
minute aperture apically through which the penicillate stigma protrudes, ovary and 
style included but free, ovary superior with a single basal ovule. Fruiting inflores- 
cence occasionally becoming somewhat succulent, fruit included in the persisting 
perianth, fruit a very small glabrous achene with crustaceous endocarp, a mucilagin- 
ous mesocarp and a membranaceous exocarp. 

A genus of more than 30 species, largely South American where it 
exhibits considerable morphological diversity. With the exception 
of a few more common species, the genus is very poorly known, per- 
haps because of the difficulty in collecting large epiphytic plants. 
Many species are known from only a very few collections, and these 
seem to indicate that the genus flowers primarily from January to 
May in Costa Rica. The genus resembles Ficus in the epiphytic ger- 



132 FIELDIANA: BOTANY, VOLUME 40 

mination and strangling habit, but Coussapoa is apparently less 
aggressive than Ficus and strangled hosts are only rarely seen. This 
genus, like Cecropia and Pourouma, is a member of the subfamily 
Conocephaloideae, a subfamily that should be removed from the 
Moraceae and transferred to the Urticaceae, according to Corner 
( 1962). It is retained in the Moraceae here to facilitate reference. 

la. Largest laminae (on mature plant-parts) more than 20 cm. long and 15 cm. 
wide, whitish or pale brown beneath with short slender hairs and long thin floe- 
cose hairs, with 9 to 16 pairs of major secondary veins, and prominent tertiary 

veins; wet evergreen formations, 0-1000 m 2a. 

Ib. Largest laminae (on mature plant-parts) less than 20 cm. long and 15 cm. 

broad; plants rarely collected 3a. 

2a. Large laminae abruptly truncate at the base; female capitula solitary or 
several on peduncles 1-8 cm. long; common and widespread. . . C. panamensis. 
2b. Large laminae cordate at the base with a sinus 2-3 cm. deep; female inflores- 
cence solitary and subsessile; endemic and rare in collections. 

C. nymphaeifolia. 

3a. Laminae with 9 to 12 pairs of major secondary veins, drying chartaceous; short 
(0.2-1.5 mm.) slender hairs usually present on stipule-scars and stipules; wet 

evergreen formations of southwestern Costa Rica C. contorta. 

3b. Laminae with 2 to 6 pairs of major secondary veins, drying subcoriaceous or 

very stiffly chartaceous; glabrous or minutely (-0.2 mm.) puberulent 4a. 

4a. Laminae usually narrow (2-6 cm.), with only 2 or 3 pairs of major secondary 

veins; Caribbean lowlands, 0-500 m C. glaberrima. 

4b. Laminae usually relatively broad (8-13 cm.), with 3 to 6 pairs of major secon- 
dary veins; wet cloud forest formations, 500-1200 m C. parviceps. 



Coussapoa contorta Cuatrecasas, Caldasia 7:289. 1956. Figure 22. 

Trees 5 to 25 m. tall, beginning as epiphytes, the trunk becoming contorted, leafy 
internodes 3-26 mm. long, 2-4 mm. thick, glabrous, with minute hairs or with 
slender hairs 0.2-1.5 mm. long on the stipule scar (in ours); stipules 1-2.5 cm. long, 
2.5-6 mm. thick, very minutely (0.05-0.2 mm.) sericeous and with scattered longer 
hairs (in ours) or glabrous. Leaves relatively uniform in size, petioles (1) 2-5.5 cm. 
long, 0.7-2 mm. thick, glabrous or minutely puberulent, (especially near the apex), 
narrowly sulcate above; laminae (5) 8-16 cm. long, (2) 4-7 cm. broad, elliptic to 
elliptic-oblong or slightly obovate, abruptly acuminate or very short-acuminate (in 
ours), cuneate to obtuse at the base, entire, drying chartaceous, smooth and gla- 
brous above, glabrous or very sparsely puberulent beneath, the 9 to 12 pairs of 
major secondary veins loop-connected near the margin to form a thin submarginal 
vein, central secondaries arising at angles of 30-50 degrees, tertiary veins very 
slightly raised beneath. Male inflorescences of 8 to 20 capitula borne on a branched 
rachis ( 1) 2-8 cm. long, common peduncle 0.4-1 mm. thick, minutely puberulent, male 
capitula 2-6 mm. in diameter, globose, with about 10 to 30 flowers. Female inflores- 
cence of one or 2 capitula on a rachis about 2 cm. long, female capitula 6-12 mm. in 



BURGER: FLORA COSTARICENSIS 133 

diameter, globose, with more than 20 flowers, perianth pale brown and very 
minutely puberulent. Fruit about 2 mm. long, ellipsoid and flattened. 

This species is known from only a single male collection in Costa 
Rica: Paul Allen 5949, from above Palmar Norte de Osa, Pun- 
tarenas, at 450 m. altitude, February 1951. Otherwise, the species 
is only known from the Pacific slope of northern Colombia (Choco, 
Valle) between sea level and 100 m. elevation. 

Coussapoa contorta is an easily recognized species of the genus 
because of its relatively small thin leaves, often lustrous on both 
sides, with a relatively large number of secondary veins and the 
very small male capitula. The Costa Rican material differs from the 
South American collections in the even smaller male capitula, the 
thin petioles, and differences in pubescence. Our sampling of this 
species is still so small (four collections) that these differences may 
prove to be individual differences, and not differences in the popula- 
tions. This species was referred to as Coussapoa parviceps in the 
Rain Forests of Golfo Dulce (Allen 1956). 

Coussapoa glaberrima Burger, Phytologia 26:422. 1973. Figure 
22. 

Small trees, independent or epiphytic, with watery sap, leafy internodes 4-15 mm. 
long, 2-5 mm. thick, essentially glabrous; stipules 8-23 mm. long, 3-4 mm. thick at 
the base, glabrous and drying dark brown. Leaves rather uniform and not usually 
clustered at the ends of branches, petioles 6-15 (20) mm. long, 1-2.5 mm. thick, gla- 
brous and drying dark, flattened or sulcate above, petiolar tissue often extending 
1-4 mm. down the stem at the base; laminae 7-14 cm. long, 2.3-6 cm. broad, obovate 
to narrowly elliptic or oblanceolate, obtuse to acute at the apex, cuneate to obtuse 
at the base, entire, the laminae drying very stiffly chartaceous to subcoriaceous, 
smooth and glabrous on both surfaces, often dark above (dry), venation sub- 
palmate, the 2 or 3 pairs of major secondary veins not loop-connected, basal secon- 
daries arising from the petiole and parallel with the primary vein for 0-10 mm. 
viewed from above or apparently united when viewed from below, pockets some- 
times present at the juncture of the basal secondaries with the primary vein, central 
secondaries arising at angles of 15-30 degrees, tertiary veins slightly raised be- 
neath. Male inflorescences and flowers unknown. Female inflorescences of 2 or 3 
capitula on a common peduncle 2-4 cm. long, about 1-1.4 mm. thick, glabrous, 
peduncles of the capitula 5-15 mm. long, female capitula 6-14 mm. in diameter, glo- 
bose, each with about 14 to 40 flowers. Fruit 2-2.5 mm. long, about 1.3 mm. broad, 
abruptly rounded at both ends, slightly flattened longitudinally. 

This species is known from only two collections, both from low- 
land rain-forest formations: A. Jimenez 3016, 8 km. south of Rin- 
con, Peninsula de Osa ( Puntarenas) in Costa Rica and the type from 
near Cerro San Isidro, Rio Kama, Rio Escondido (Bluefields) in 
Nicaragua, flowering on February 28 and March 10, respectively. 



134 FIELDIANA: BOTANY, VOLUME 40 

Coussapoa glaberrima is distinguished by its relatively small nar- 
row leaves with few secondary veins and its glabrous parts. This 
species appears to be related to C. parviceps among our species but 
differs in the narrower leaves with fewer veins, more compact in- 
florescences, and lower altitude habitat. Because these plants are so 
rarely collected, the species of the genus and their inter- 
relationships are very poorly understood. 

Coussapoa nymphaeifolia Standley, Proc. Biol. Soc. Wash. 37:50. 
1924. Figure 22. 

Trees or strangling epiphytes, 5-22 m. tall, trunk becoming 1 m. thick at the base, 
leafy internodes 2-40 mm. long, 4-14 mm. thick, glabrous or very minutely puberu- 
lent, the leaf-scars becoming as wide as the internodes; stipules 17-35 mm. long, 10- 
15 mm. thick at the base, densely ascending sericeous with pale brownish hairs 0.3-1 
mm. long. Leaves in terminal clusters, petioles 8-14 cm. long, 3-5 mm. thick, longi- 
tudinally ridged, very minutely (0.01-0.05 mm.) brownish puberulent and with a few 
longer hairs, longitudinally striate, abruptly expanded at the base; laminae about 
28 cm. long and 20 cm. broad, ovate to ovate-oblong, bluntly obtuse to broadly 
rounded at the apex, shallowly cordate at the base with the basal lobes extending 
2-3 cm. below the petiole attachment, margin undulate, laminae drying stiffly 
chartaceous to subcoriaceous, smooth or slightly scabrous and glabrous or sparsely 
puberulent above, puberulent beneath with short (0.3 mm.) thin grayish hairs and 
soft spreading floccose hairs along the margins, the 9 to 12 pairs of major secondary 
veins weakly loop-connected near the margin, tertiary veins prominent beneath. 
Male inflorescence of (4) 10 to 30 capitula borne on a branching rachis 3-8 cm. long, 
common peduncle about 1.7 mm. thick, densely ferruginous puberulent, male capi- 
tula 5-8 mm. in diameter, with about 30 flowers, anthers about 0.5 mm. long. Female 
inflorescences of a single capitulum, subsessile or on a very short (1-4 mm.) ped- 
uncle, somewhat cylindrical or ellipsoid in form, about 2 cm. long and 1 cm. in dia- 
meter, with many densely crowded flowers. Fruit about 3 mm. long (immature?). 

A species based on only two collections from the wet Caribbean 
slopes in the province of Alajuela: Cook & Doyle 157 (the type, 
female) from Buena Vista, San Carlos valley, at 600 m. altitude 
and Austin Smith H1632 (male) from Villa Quesada at 825 m. alti- 
tude; the male flowers were collected in February and the young 
fruiting material in April. 

Coussapoa nymphaeifolia is a distinctive but very poorly known 
species. The above description is based on only four leaves. The sub- 
sessile female inflorescence is very unusual. The cordate leaves with 
arachnoid hairs along the edge and the very large leaf-scars help to 
distinguish this species from C. panamensis with somewhat similar 
leaves. The original description of this species included material 
(Sutton Hayes 354) from Panama, which is the type of the name 
C. chagresiana A. D. Hawkes and which was placed in synonomy 



BURGER: FLORA COSTARICENSIS 135 

under C. magnifolia Tree, by Woodson (1960). This latter species 
ranges from Central Panama to Peru and is not closely related. 



Coussapoa panamensis Pittier, Contr. U.S. Nat. Herb. 18:226. 
1917. C. donnell-smithii Mildbr., Notizbl. Bot. Gart. Berlin 10:414. 
1928. Figure 22. 

Tree, 5-30 m. tall, often epiphytic and strangling, sap yellowish, leafy internodes 
3-20 mm. long, 3.5-8 mm. thick, glabrous or very minutely puberulent or occasion- 
ally with long (0.5-2 mm) slender hairs, often longitudinally ridged (dry) and red- 
dish-brown; stipules ( 1.5) 3-14 ( 19) cm. long, about 1 cm. thick at the base, minutely 
(0.1-0.3 mm.) grayish-brown puberulent or occasionally with longer hairs. Leaves 
extremely variable in size on the same tree, petioles (2) 3-8 ( 11) cm. long, 1.5-5 mm. 
thick, glabrous, minutely puberulent or with hairs 1-3 mm. long, longitudinally 
deeply ridged, epidermis often coming off in small scales; laminae (8) 12-32 (40) cm. 
long, (4) 7-21 (28) cm. broad, narrowly ovate (rarely elliptic) to broadly ovate or 
ovate-oblong, tapering gradually to a usually obtuse apex, abruptly obtuse to 
rounded or truncate at the base (rarely subcordate), margin somewhat undulate, 
laminae drying subcoriaceous, smooth, glabrous and often slightly lustrous above, 
puberulent beneath with short straight hairs 0.1-0.4 mm. long (rarely longer) and 
thin yellowish or grayish arachnoid or floccose hairs, the (9) 11 to 14 (16) pairs of 
major secondary veins weakly loop-connected near the margin, central secondaries 
arising at 30-50 degrees, tertiary veins prominent beneath. Male inflorescences of 
(2) 4 to 12 capitula borne on a branched rachis 1.5-4 ( 10) cm. long, common peduncle 
densely and minutely (0.1-0.2 mm.) puberulent or with longer ( 1-2 mm.) hairs, male 
capitula about 4-8 mm. in diameter, globose, with more than 30 male flowers, 
anthers 0.2-0.4 mm. long. Female inflorescence of usually solitary capitula on ped- 
uncles ( 1.5) 3-8 cm. long, 1.3-3 mm. thick, glabrous or minutely puberulent, occasion- 
ally with the common peduncle branched and bearing 2 or 3 capitula (only in Costa 
Rica?), female capitula 8-18 mm. in diameter, globose, with usually more than 30 
female flowers; fruit about 4 mm. long and 1.8 mm. broad, ellipsoid and flattened 
with pits on the broad surfaces. 

Plants of very wet evergreen forest formations between sea level 
and 1000 m. elevation on both the Caribbean and Pacific slopes in 
Costa Rica; flowering throughout the year but collected most often 
between January and May. The species ranges from southern 
Mexico to Panama and probably into adjacent Colombia. 

Coussapoa panamensis is recognized by its large leaves (not 
always present) truncated at the base of the lamina and yellowish- 
gray beneath with prominent tertiary veins. Several collections 
from the General Valley and the Golfo Dulce area possess more 
elliptic leaves and long slender hairs quite different from those com- 
monly encountered elsewhere. These collections may represent a 
locally differentiated population. ( Long hairs are occasionally seen 
in other areas of the range. ) This species is by far the most common- 



136 FIELDIANA: BOTANY, VOLUME 40 

ly collected Coussapoa in Costa Rica. The name Urostigma intra- 
marginale Liebmann (Danske Vidensk. Selsk. Skrivt. ser. 5, 2:320. 
1851) was based, I believe, on the leaves of Coussapoa panamensis 
and the figs of Ficus turrialbana (Oersted 14317). Liebmann's name 
is based on discordant elements and should be excluded from con- 
siderations of priority. 

Coussapoa parviceps Standley, Proc. Biol. Soc. Wash. 37:51. 
1924. C. brenesii Stand!., Field Mus. Bot. 18:382. 1937. Figure 22. 

Trees 6-10 (17) m. tall, epiphytic or independent, with a viscous yellowish sap, 
leafy internodes 4-15 mm. long, 4-8 mm. thick, essentially glabrous and drying red- 
dish-brown; stipules 1-3 (4.2) cm. long, 3-8 mm. thick at the base, glabrous or very 
sparsely puberulent, drying dark. Leaves usually uniform in size and clustered near 
the ends of stems, petioles 15-45 mm. long, 1-2.8 mm. thick, glabrous or very 
minutely puberulent in early stages, sulcate above; laminae 7-20 cm. long, 8-14 cm. 
broad, broadly ovate to suborbicular or broadly obovate, obtuse to abruptly very 
short-acuminate at the apex or occasionally rounded, rounded to subtruncate at the 
base, margin entire, laminae drying stiffly chartaceous to subcoriaceous, smooth 
and glabrous above, usually drying lustrous and very dark, paler below, glabrous or 
very minutely (0.05-0.1 mm.) puberulent beneath, the 3 to 5 (6) pairs of major secon- 
dary veins not loop-connected near the margin, basal secondaries arising at the 
petiole and the venation subpalmate, central secondaries arising at angles of 30-50 
degrees, tertiary veins usually obscure. Male inflorescences of 10 to 20 capitula on a 
branched common peduncle 3-8 cm. long, about 1 mm. thick, glabrous or very 
minutely puberulent, male capitula 2-5 mm. in diameter, globose, with 3 to 15 
flowers each, anthers about 0.3 mm. long. Female inflorescences of 3 to 12 capitula 
borne on a branching peduncle 3-9 cm. long, about 1 mm. thick, essentially glabrous, 
female capitula 2-5 mm. in diameter, globose, with 12 to 30 flowers. Fruiting capi- 
tula about 6 mm. thick, fruit about 1.5 mm. long and 1 mm. thick, somewhat flat- 
tened and abruptly narrowed at both ends. 

An endemic species of Costa Rica's wet cloud forests between 500 
and 1200 m. altitude. Collections have been made from near San 
Ramon and above the San Carlos plain in Alajuela, near Orosi in 
Cartago, and Agua Buena (Canas Gordas) in southernmost Pun- 
tarenas; flowering and fruiting collections have been made from 
February to April. 

Coussapoa parviceps is distinguished by its very small inflores- 
cences (both male and female), relatively broad leaves often lus- 
trous and dark brown above (dry), and general lack of conspicuous 
hairs. The type of C. brenesii (Brenes 20542) has more rounded 
laminae with fewer secondary veins than the type of C. parviceps 
(Pit tier 11166), but our other collections exhibit sufficient variation 
in these characters of the leaf to encompass both. The leaves of this 
species are smaller than, but similar to, those of C. magnifolia 



BURGER: FLORA COSTARICENSIS 137 

Trecul (Panama to Peru), but the latter has very different female 
inflorescences. 



DORSTENIA Linneaus 

Herbs, perennial from rhizomes with or without leaf-bearing stems (woody shrubs 
in Africa), sap whitish; stipules paired, free, lateral. Leaves alternate and simple, 
petiolate, laminae often very variable in different plants of the same species, entire 
to pinnately deeply lobed. Inflorescences usually solitary, axillary, often with long 
peduncles, the flowers sunken into the tissue of the flattened receptacle, the re- 
ceptacle borne on and continuous with the apically expanded peduncle, variously 
shaped but often saucer-like with the flowers in the broad slightly concave distal 
surface, usually bisexual with flowers of both sexes intermixed or the male flowers 
surrounding solitary female flowers, bracts minute and inconspicuous, confined to 
the margin of the receptacle, perianth usually connate with the receptacle, male 
flowers with usually 2 (1 or 3) stamens, inflexed in bud and becoming exserted; 
female flower with the ovary included within the tubular perianth in the receptacle, 
style lateral or eccentric with 2 style branches. Fruit developing within the re- 
ceptacle, protruding only at maturity and sometimes expelled with force (the exo- 
carp remains in the receptacle), seeds small. 

A genus of about 50 species; pantropical but with the greatest 
number of species in tropical America and Africa. A very unusual 
genus of the Moraceae because of its herbaceous habit (in ours) and 
the discoid inflorescences with imbedded flowers. 

la. Leaves borne on erect or ascending herbaceous stems and distant on the stem, 
elliptic-oblong and entire to apically toothed or deeply pinnately lobed with the 
narrow lobes about the same size, venation pinnate; receptacle rounded on 
edge; plants of very wet evergreen forest formations D. choconiana. 

Ib. Leaves borne from the apex of the rhizome and arising close together on long 
petioles, usually deeply lobed or with large teeth and the basal lobes or teeth 
much larger than the distal, venation pinnate to palmate 2. 

2a. Receptacle more or less rectangular in outline and usually with conspicuous 
narrow lobes; plants of evergreen formation D. contrajerva. 

2b. Receptacle rounded on edge, orbicular to oval or ellipsoid; plants of the decidu- 
ous forest formations of Guanacaste D. drakena. 

Dorstenia choconiana Watson, Proc. Amer. Acad. Sci. 22:477. 

1887. D. choconiana var. integrifolia Donn.-Smith, Bot. Gaz. 13:76. 

1888. D. cordato-acuminata Cufod., Archive Bot. Sist. Fitogeog. & 
Genet. 10:27. 1934. Figure 17. 

Herbs to about 40 (90) cm. tall, leafy internodes 2-15 (22) mm. long, 1.2-4 (6) mm. 
thick (dry), somewhat succulent, puberulent with slender crooked hairs 0.2-1 mm. 
long; stipules 3-8 mm. long, 2 mm. broad at the base, subulate, often persisting. 
Leaves very variable on different plants (rarely lobed and unlobed on the same 



138 FIELDIANA: BOTANY, VOLUME 40 

plant), petioles 1-4.5 cm. long, 0.8-2 mm. thick, longitudinally ridged (dry), puberu- 
lent; laminae usually of two types, unlobed laminae oblong to obovate, acute to 
acuminate at the apex and attenuate to obtuse or rarely truncate at the base, oc- 
casionally with a few small (5 mm.) lobes in the distal third, the lobed laminae with 
(2) 3 to 5 (6) prominent pinnate lobes on each side, the lobes usually opposite and 
symmetrical, basal lobes often slightly smaller than the more distal, sinuses one- 
half to two-thirds the length of the associated secondary veins, truncate at the base, 
both kinds of laminae 6-25 cm. long and 3-10 cm. broad, drying thin-chartaceous, 
glabrous or very sparsely puberulent above, usually scabrous beneath and sparsely 
to densely puberulent on the veins with short (0.2-0.6 mm.) stiff hairs, the 3 to 8 
pairs of major secondary veins weakly loop-connected near the margin or with a sub- 
marginal vein along the sinuses. Inflorescence solitary from the axils of current foli- 
age, peduncles 1-3 cm. long, 1-2 mm. thick, expanding gradually to the circular or 
ellipsoid disc (as viewed from above), disc 10-25 mm. broad, slightly concave and 
often deep blue-green in color (live). 

Plants often found in deep shade on the floor of very wet ever- 
green forests between sea level and 1600 m. (rare above 1100 m.) on 
both the Caribbean and Pacific slopes in Costa Rica; flowering 
throughout the year. The species ranges from the Caribbean side of 
Guatemala to within a few kilometers of the border with Panama in 
Costa Rica. 

Dorstenia choconiana is easily recognized among our species be- 
cause of its leaves borne at intervals along the elongated stem. This 
species is unusual in having two definite kinds of leaves that are 
never found on the same plant and with very few plants having inter- 
mediate kinds of leaves. Both forms (or varieties) can be found in a 
large population, but one usually greatly outnumbers the other. The 
plants with deeply pinnately lobed leaves can be referred to as 
variety choconiana, and those with almost entire oblong leaves, 
often with long acuminate apices, can be referred to as variety in- 
tegrifolia Donn.-Smith. The plants with deeply lobed leaves are not 
as common as those with entire leaves in Costa Rica, on the basis of 
our present sampling of the species. 

Dorstenia contrajerva L., Sp. PI. 121. 1753. D. houstoni L., Sp. PI. 
ed. 2, 176. 1762. D. contrajerva var. houstoni (L.) E. Bureau in DC., 
Prodr. 17:259. 1873. D. contrajerva ssp. tenuiloba S. F. Blake, 
Contr. U.S. Nat. Herb. 24:2. 1922. D. contrajerva var. tenuiloba 
(Blake) Standl. & Steyerm., Field Mus. Bot. 23:40. 1944. Figure 17. 

Herbs, acaulescent from a tuberous base or rarely from a short (3 cm.) stem with 
several internodes, becoming about 20-40 cm. tall, slightly succulent; stipules 2-6 
mm. long, aculeate and often persisting. Leaves originating close together at the 
apex of the rhizome, petioles 8-26 cm. long, 1-2.5 mm. thick, longitudinally ribbed 
(dry), puberulent with minute (0.2-0.8 mm.) crooked whitish hairs; laminae quite 



BURGER: FLORA COSTARICENSIS 139 

variable on different plants, variously lobed, 7-26 cm. long, 9-34 cm. broad, with 1 to 
8 lobes or prominent teeth on each side, sinuses shallow to very deep, acute to 
acuminate at the apex, attenuate or obtuse to deeply cordate at the base, margins 
minutely dentate to entire, the laminae drying thin-chartaceous, smooth or scabrous 
above, sparsely puberulent with minute hairs or with a few stiff longer (0.5-2 mm.) 
hairs, sparsely to densely puberulent on the veins beneath, with minute (0.1-0.3 
mm.) hairs, venation pinnate to subpalmate with 3 to 6 pairs of major secondary 
veins, the basal pair often bordering the basal sinuses of the laminae. Inflorescences 
apparently solitary in the axils of the current leaves, peduncles 10-34 cm. long, 0.8-3 
mm. thick (dry), glabrous to densely and minutely puberulent, abruptly expanded 
below the centrally peltate receptacle, the receptacle approximately rectangular 
(viewed from above) but with a very irregular and often lobed margin, the lobes few 
to many, receptacle flat or slightly concave distally, 8-45 mm. broad, anthers about 
0.2-0.3 mm. long. 

Plants of shaded sites in evergreen forest formations from sea 
level to 1200 ( 1400) m. elevation on both the Caribbean and Pacific 
slopes in Costa Rica; probably flowering throughout the year, but 
with the greatest number of collections being made from June to 
August. The species ranges from Central Mexico through Central 
America and the West Indies to Peru and the Guianas in South 
America. 

Dorstenia contrajerva is recognized by its unusual receptacle of 
roughly rectangular outline with irregularly lobed edges. It is found 
in areas that are very wet to those that are seasonally dry but where 
shade is present throughout the year. The common name, con- 
trayerba or contrahierba, refers to its use to counteract fever. 
Several varieties have been proposed, but these seem to be no more 
than unusual leaf-forms that are usually consistent for an indivi- 
dual plant but not for a population. Variety houstoni has few-lobed 
laminae that are ovate to triangular with cordate bases and variety 
tenuiloba has very deeply lobed laminae. 

Dorstenia drakena L., Sp. PI. ed. 2, 176. 1762. D. mexicana 
Benth., PL Hartweg. 51. 1839. Figure 17. 

Herbs, acaulescent from a tuberous base, becoming 20-40 cm. tall, slightly succu- 
lent; stipules 2-4 mm. long, obtuse to acute apically, persisting on the rhizome. 
Leaves originating close together at the apex of the rhizome, petioles 1.5-20 cm. 
long, 0.8-3 mm. thick, sparsely to densely puberulent with small irregular whitish 
hairs 0.1-0.8 mm. long; laminae very variable on different plants, 4-20 cm. long, 4-23 
cm. broad, oval to triangular in outline, with 1 to 5 lobes or large teeth on each side, 
sinuses shallow to deep, acute to acuminate at the apex, truncate to deeply cordate 
at the base, margins entire to bluntly dentate, lamina drying thin-chartaceous, 
scabrous above with scattered stiff slender hairs 0.1-1 mm. long, minutely puberu- 
lent beneath but with larger hairs near the edges, venation pinnate to subpalmate 
with 2 to 5 pairs of major secondary veins. Inflorescences apparently solitary in the 



140 FIELDIANA: BOTANY, VOLUME 40 

axils of the current foliage at the apex of the rhizome, peduncles (3) 8-28 cm. long, 
0.7-3 mm. thick, very minutely puberulent or apparently glabrous, abruptly ex- 
panded below the eccentrically peltate receptacle, the receptacle broadly elliptic to 
oval or somewhat oblong (viewed from above), 1-5 cm. long, distal surface essen- 
tially flat, anthers 0.2-0.3 mm. long. 

Plants from the floor of the seasonally very dry deciduous forest 
formations of Guanacaste province between sea level and 300 m. 
elevation in Costa Rica; flowering in June, July, and August. The 
species ranges from Central Mexico to Costa Rica and occurs in 
South America. 

Dorstenia drakena is recognized by its elliptic to oval receptacle 
attached near the edge with entire margin and the deciduous forest 
habitat with restricted flowering period. This species displays a 
pattern of leaf variation that is very similar to that found in D. 
contrajerva, varying from triangular-cordate to deeply pinnately 
lobed. 

FICUS Linnaeus 

REFERENCES: P.C. Standley, The Mexican and Central 
American Species of Ficus, Contr. U.S. Nat. Herb. 20: 1-35. 1917. 
G.P. DeWolf, Jr., Ficus in Flora of Panama, R.E. Woodson, Jr., 
& R.W. Schery, Ann. Missouri Bot. Card. 47: 146-165. 1960. 

Trees or shrubs with milky or rarely clear (F. citrifolia) sap, rarely climb- 
ers (as in F. meistosyce and the cultivated F. pumila), often beginning as 
epiliths or epiphytes and the coalescing roots surrounding the host plant as a 
"strangler"; stipules 2 at a node and enclosing the shoot-apex, usually caducous 
and leaving scars that encircle the stem. Leaves alternate in a spiral and entire in 
native species, short to very long petiolate. Inflorescence a hollow usually round 
fruit-like structure called the fig (receptacle, syconium, higo) with a small apical 
opening, the ostiole, formed by overlapping scales, the base subtended (in ours) 
by a whorl of 2 or 3 bracts; the flowers borne on the inner wall of the fig, usually 
numerous and interspersed with bracts, the fig with both male and female flowers 
in native species and the plants bisexual (or the fig with flowers of one sex and the 
plants unisexual in subgenus Ficus of the Old World); the flowers are of three kinds 
and usually intermixed in American species, male flowers of American species 
generally have 2 to 6 perianth-parts and 1 or 2 stamens, female flowers with 2 to 4 
perianth-parts, pistil 1 with a single style borne from the side of the ovary, stigma 1, 
sterile flowers usually called gall-flowers but formed without the intervention of an 
insect and serving as the food source for the larvae of the pollinators; fruit small 
achenes or drupes borne within the receptacle which usually becomes succulent at 
maturity; the usually juicy fruiting fig is eaten by many animals, especially birds. 

A genus of several hundred species found throughout the 
tropics but especially diverse in southeast Asia. Ficus is a very 
distinctive genus with one of the most unusual inflorescences and 



BURGER: FLORA COSTARICENSIS 141 

pollinating mechanisms in the plant world. The flowers and fruit 
enclosed by a fleshy receptacle require that pollen enter the ostiole 
through a barrier of overlapping scales. Only the small fig-wasps, 
chalcid wasps of the family Agaonidae, can effect pollination in 
Ficus and these wasps can only develop within the fig. The wasps 
have developed unusual morphology and behavior patterns to 
carry on pollination, and the different species of Ficus are pollina- 
ted by different and specific species of wasps (see Ramirez, Evolu- 
tion, 24:680-691. 1970). The developmental phases of the fig 
(syconium) have been divided by Galil and Eiskowitch (in New 
Phytol. 67:745-758. 1968) as follows: Phase A, the prefemale, 
or the immature fig prior to opening of the ostiole. Phase B, the 
female, as the ostiolar scales loosen, female flowers ripen, wasps 
enter the fig and oviposit into the ovaries. Phase C, interfloral, 
as the wasp larvae and seed embryos develop within the fig and 
the ovaries occupied by larvae become galls. Phase D, the male, as 
male flowers mature and the wasps reach adulthood, mate, and the 
female wasps leave the fig. Phase E, post-floral, as the fig becomes 
more succulent and the seeds ripen to the point where they are 
ready for dispersal. 

The genus is quite distinctive vegetatively with its entire (in 
native species) usually stiff leaves and stipules protecting the 
shoot-tip and leaving circular rings on the stem. These circular 
stipule-scars are useful in recognizing trees without figs as species 
of Ficus, but several other genera of the Moraceae have similar 
stipules, as do the Magnoliaceae and some Polygonaceae. 



KEY TO THE SPECIES OF Ficus 

la. Plants growing wild in forests, pasture, or roadsides, not usually planted . . . 2a. 
Ib. Plants grown for ornament, shade, or fruit, usually found only in gardens, 

parks, or abandoned homesites 55a. 

2a. Figs solitary at a node (rarely 2 or more), the older leaf-scars never subtend- 
ing 2 fig-scars but often subtending a single fig-scar and an axillary bud or 
bud-scar; bracts subtending the fig 3, ostiole of the fig often with more than 
3 scales visible; laminae with unusual clear translucent clavate hairs on the 
lower surface (X150); independent trees rarely beginning as epiphytes and 

often restricted to streamsides (subgenusPharmacosycea) 3a. 

2b. Figs usually 2 at a node, older leaf-scars often subtending 2 fig-scars; bracts 
subtending the fig 2 (but often deeply split and appearing as 3 or 4), ostiole 
of the fig usually with only 2 or 3 exterior scales visible; laminae lacking 
clavate hairs (X150) but slender hairs with somewhat enlarged distal cells 
translucent reddish-brown often present; plants often beginning as 



142 FIELDIANA: BOTANY, VOLUME 40 

epiphytes and becoming independent or strangling, the trunks often deeply 

fluted or of grown-together stems ( subgenus Urostigma) lOa. 

3a. Figs sessile; laminae medium to large in size (14-40 cm.) and relatively 

broad, the width usually exceeding half the length 4a. 

3b. Figs subsessile to pedunculate; laminae small to large, the width of the 

larger laminae generally less than half the length 5a. 

4a. A definite submarginal vein present near the edge of the lamina, laminae 

glabrous beneath; wet evergreen formations 0-1000 m F. tonduzii. 

4b. A definite submarginal vein absent or the secondaries weakly loop- 
connected near the margin, lamina usually scabrous beneath; very wet 

Caribbean slopes (500) 1000-1600 m F. macbridei. 

5a. Stipule 10-25 mm. long, petioles with reddish-brown epidermis usually 
peeling off in small flakes (in ours), laminae 7-20 cm. long with 5 to 13 pairs 
of secondary veins and slightly scabrous beneath; figs 14-20 mm. in dia- 
meter; widespread, 0-1000 m F. maxima. 

5b. Stipules 20 -160 mm. long, petioles with the epidermis only rarely flaking 
off (in ours), laminae with 12 to 40 pairs of secondary veins, smooth to the 

touch beneath 6a. 

6a. Figs 25-60 mm. in diameter at maturity, with very thick walls 7a. 

6b. Figs 12-22 mm. in diameter (dry) or unknown 8a. 

7a. Laminae thin to moderately thick, acute to short acuminate at the apex; 
stipules usually drying yellowish-green, 3-8 cm. long; widespread, 0-500 
m F. insipida. 

7b. Laminae very thick, obtuse to acute at the apex; stipules usually drying 
dark, 2-5 cm. long; montane forests 1200-2000 m F. crassiuscula. 

8a. Stipules 7-17 cm. long, laminae 14-32 cm. long with 16 to 24 pairs of major 
secondary veins; figs 15-22 mm. in diameter, with a conical ostiole; 
0-800 m F. werckleana. 

8b. Stipules 2-9 cm. long, laminae 5-15 (20) cm. long, secondary veins often dif- 
ficult to distinguish from the intermediate veins, 10 to 50 pairs 9a. 

9a. Laminae drying thin, acute to short-acuminate; mature figs 12-16 mm. in 
diameter, with a narrow apex supporting the ostiole; (0) 500-1200 (1600) 
m F. yoponensis. 

9b. Laminae drying very stiff, rounded to obtuse at the apex; figs about 15 
mm. in diameter; wet Caribbean lowlands F. crassivenosa. 

lOa. Laminae glabrous beneath when viewed with a X10 hand lens lla. 

lOb. Laminae puberulent beneath, the hairs 0.1 mm. long or longer 36a. 

lla. Largest laminae rarely more than 12 cm. long (not measuring the peti- 
ole), usually less than 5 cm. broad; acute to acuminate or sharply obtuse 
at the apex 12a. 

lib. Largest laminae usually more than 13 cm. long (not including the peti- 
ole) or bluntly obtuse to rounded at the apex when shorter 18a. 

12a. Laminae with sub-palmate venation, 3 prominent primary veins usually 
arising from the apex of the petiole; figs sessile, 5-8 mm. in diameter, 
evergreen lowlands, 0-800 m F. colubrinae. 



BURGER: FLORA COSTARICENSIS 143 

12b. Laminae with pinnate venation, with 4 or more pairs of secondary veins 

13a. 

13a. Laminae with 4 to 8 pairs of major secondary veins; figs sessile .... 14a. 
13b. Laminae with 7 to 20 pairs of major secondary veins; figs usually ped- 
unculate 16a. 

14a. Mature figs 4-6 mm. in diameter, the fig attached at the base; 900- 

1600 m F. hartwegii. 

14b. Mature figs 7-10 mm. in diameter 15a. 

15a. Figs attached on the side, sessile and leaving depressions in the stem; 
laminae acute to obtuse at the apex; wet Caribbean slope 

F. laterisyce. 
15b. Figs usually borne on peduncles; laminae rounded at the apex; plants 

of the seasonally very dry deciduous formations F. ovalis. 

16a. Laminae mostly actue to obtuse; ostiole flat or slightly raised, mature 

figs 6-9 mm. in diameter; 0-1200 m F. perforata. 

16b. Laminae mostly acute to acuminate; ostiole enclosed by a crateriform 

ring or collar of elevated tissue 17a. 

17a. Mature figs 8-14 mm. in diameter, ostiole enclosed by a short (1-2 mm.) 

ring of elevated tissue; (0) 900-1600 (2000) m F. pertusa. 

17b. Mature figs 14-18 mm. in diameter, ostiole hidden within a deep (3-6 
mm.) collar of elevated tissue; seasonally dry areas, 0-1000 m. 

F. trachelosyce. 

18a. Laminae cordate to subcordate with basal lobes extending 1-7 cm. below 
the petiole attachment, petioles 5-18 cm. long, laminae 10-24 cm. broad; 
figs subsessile with a lustrous minutely velutinous surface; wet evergreen 

lowlands F. nymphaeifolia. 

18b. Laminae attenuate to subcordate, never deeply cordate, the basal lobes 

rarely more than 1 cm. long 19a. 

19a. Laminae often abruptly acuminate at the apex, usually short- to long- 
acuminate, often oblong in general outline; stipules glabrous or sparsely 

and very minutely puberulent; the figs glabrous 20a. 

19b. Laminae rounded to obtuse or acute at the apex, only rarely short-acumi- 
nate 26a. 

20a. Figs with an apical collar 3-6 mm. high surrounding the ostiole, peduncu- 
late; laminae small (7-16 cm.) and thin; seasonally dry Pacific slope, 

0-1000 m F. trachelosyce. 

20b. Figs without an apical collar, rare or absent on the seasonally dry Paci- 
fic slope 21a. 

2 la. Figs only 4-5 mm. in diameter at maturity, sessile and often in clusters; 

plants often climbers in lowland rain forest F. schippii. 

21b. Figs becoming 8-16 mm. in diameter (dry) and never in clusters; plants 

often epiphytic but not climbers 22a. 

22a. Figs borne on peduncles to 10 mm. long or occasionally subsessile; 

leaves with petioles 15-120 mm. long 23a. 

22b. Figs sessile or occasionally borne on peduncles to 3 mm. long; leaves 
with petioles 8-36 mm. long 24a. 



144 FIELDIANA: BOTANY, VOLUME 40 

23a. Figs on peduncles 5-10 mm. long; laminae oblong; twigs usually 
brownish to grayish, sap clear and thick; moist forests of the Carib- 
bean slope and eastern Meseta Central, 0-1200 m F. citrifolia. 

23b. Figs sessile or on peduncles 1-4 mm. long; laminae ovate-oblong; twigs 
usually dark reddish-brown, sap whitish; moist forest formations, 

0-1000 m F. dugandii. 

24a. Laminae with unusual hairs along the sides of the midvein beneath in 
the basal (proximal) half of the lamina, elliptic-oblong to oblong; figs 

sessile; moist montane formations 1200-1700 m F. cervantesiana. 

24b. Laminae lacking unusual flat hairs along the sides of the midvein be- 
neath; plants of moist evergreen lowlands, 0-1000 m 25a. 

25a. Laminae usually oblong and abruptly acuminate; figs subsessile and 
usually longer than thick, the ostiole usually conical, basal bracts 2-4 

mm. long F. paraensis. 

25b. Laminae usually obovate and gradually acuminate or very short-acumi- 
nate; figs sessile and shorter than thick, ostiole flat, basal bracts 1-2 
mm. long F. brevibracteata. 

26a. Stipules usually persisting with the leaves, with sericeous hairs along the 
base and midrib abaxially; figs sessile, oblate, 10-14 mm. in diameter, 
leaving shelf-like depressions in the stems ; petioles 7-40 mm. long, laminae 
usually abruptly narrowed at both base and apex; 300-1200 m. and com- 
mon in the Central Highlands F. costaricana. 

26b. Stipules rarely persisting (in ours) 27a. 

27a. Figs with the basal bracts small and inconspicuous, the figs sessile or ped- 
unculate 28a. 

27b. Figs with the basal bracts large and conspicuous, covering the basal half 
or third of the fig, the figs usually sessile 30a. 

28a. Stipules glabrous or sparsely puberulent; figs borne on peduncles 4-14 
mm. long; seasonally dry evergreen and deciduous formations of the 
Pacific slope F. goldmanii. 

28b. Stipules densely hairy; figs sessile or borne on peduncles 0-5 mm. long; 
wet evergreen formations 29a. 

29a. Figs sessile or pedunculate, basal bracts 4-7 mm. broad from a basal 
disc; stipules usually lacking hairs along the edges F. trigonata. 

29b. Figs sessile, basal bracts 1-2 mm. broad, a basal disc absent; stipules 
densely puberulent throughout F. brevibracteata. 

30a. Mature figs 16-22 mm. in diameter (dry); laminae often somewhat obovate 
and widest above the middle 31a. 

30b. Mature figs 5-16 mm. in diameter, sessile, often attached on the side . . 32a. 

31a. Surface of the fig minutely velutinous (X20), fig often on a short ped- 
uncle; laminae 11-22 cm. long by 5-10 cm. broad; widespread, 0-1000 m. 

F. obtusifolia. 

31b. Surface of the fig glabrous, fig sessile; laminae 14-32 cm. long by 9-20 
cm. broad; rare on the wet Caribbean slopes around 1000 m. 

F. cuatrecasana. 



BURGER: FLORA COSTARICENSIS 145 

32a. Major secondary veins often difficult to distinguish from the intermediate 

veins (dry), (6) 10 to 20 pairs; evergreen formations, 800-1400 m 33a. 

32b. Major secondary veins usually easy to distinguish from the smaller inter- 
mediate veins, 6-1 1 pairs 34a. 

33a. Stipules glabrous or very minutely (0.05 mm.) puberulent; laminae 

bluntly acute to obtuse; figs 6-8 ( 10) mm. in diameter . . . F. davidsoniae. 

33b. Stipules densely puberulent; laminae bluntly obtuse to rounded and 

emarginate; figs 8-10 mm. in diameter F.jimenezii. 

34a. Figs 12-15 mm. diameter at maturity, leaving deep shelf-like depressions 

in the stems; moist montane formations, 1000-1800 m. . . .E. tuerckheimii. 

34b. Figs 8-12 mm. in diameter, leaving only slight depressions in the stems; 

wet or seasonally dry lowlands, 0-1000 m 35a. 

35a. Laminae usually rounded at the apex and base, often more than 12 cm. 
long; plants of both Caribbean and Pacific slopes 0-500 (800) m. 

F. isophlebia. 

35b. Laminae acute to short-acuminate at the apex, acute to obtuse at the base, 
rarely more than 12 cm. long; known only from the wet Caribbean slopes 

around 750 m. altitude F. laterisyce. 

36a. Laminae densely puberulent beneath, usually rounded or bluntly obtuse at 
the apex; figs often puberulent and often with a ring or collar around the 

ostiole 37a. 

36b. Laminae sparsely or very minutely ( -0.5 mm. ) puberulent beneath 43a. 

37a. Trees of montane forests, 1000-2000 m. elevation; leaves with the tertiary 
venation very prominent beneath, smooth above; figs globose, 18-22 mm. 
in diameter with a short (1-2 mm.) collar around the ostiole, puberulent, 

pedunculate F. velutina. 

37b. Trees of lowland and lower montane formations, 0-1200 m. elevation; 

leaves with the tertiary veins usually only slightly raised 38a. 

38a. Pubescence very dense, lower leaf-surface and young parts often dark 
brown; laminae often scabrous above; figs puberulent, with a distinct 

collar or longer than broad; plants of wet evergreen formations 39a. 

38b. Pubescence not usually so dense, lower leaf-surface and young parts not 
dark brown, laminae smooth above; figs globose to oblate, lacking a high 
collar around the ostiole 40a. 

39a. Fig ellipsoid to cylindrical, distinctly longer than broad, 9-16 mm. in 
diameter, ostiole not surrounded by a ring of elevated tissue; pubescence 
of young parts often yellowish-brown F. popenoei. 

39b. Fig globose, 10-14 mm. in diameter, ostiole surrounded by a collar 1-3 
mm. high; pubescence of younger parts often very dark brown. 

F. bullenei. 

40a. Figs pedunculate or subsessile and the basal bracts inconspicuous; 

petioles 1.2-4 (6) cm. long 41a. 

40b. Figs sessile and with conspicuous basal bracts 7-15 mm. long; petioles 2-9 

cm. long; plants of the very wet Caribbean slopes 42a. 

4 la. Figs minutely puberulent; laminae with 9 to 14 pairs of secondary veins; 
trees commonly found on the seasonally very dry Pacific slope. 

F. morazaniana. 



146 FIELDIANA: BOTANY, VOLUME 40 

41b. Figs glabrous, laminae with 6 to 1 1 pairs of major secondary veins; trees 

of evergreen vegetation (in our area) F. trigonata. 

42a. Laminae much narrower than broad, obtuse to subtruncate at the base; 

figs 12-16 mm. in diameter, densely puberulent F. turrialbana. 

42b. Laminae almost as broad as long, rounded and subcordate at the base; figs 

about 22 mm. in diameter, sparsely puberulent F. caldasiana. 

43a. Largest laminae rarely more than 12 cm. long (except F. davidsoniae); figs 

not exceeding 10 mm. in diameter at maturity (dry) 44a. 

43b. Largest laminae usually more than 12 cm. long (on mature plant parts) ; figs 

often more than 10 mm. in diameter at maturity 48a. 

44a. Laminae with sub-palmate venation, 3 prominent primary veins usually 
arising from the apex of the petiole; figs sessile, 5-8 mm. in diameter; wet 

lowlands, 0-800 m F. colubrinae. 

44b. Laminae with pinnate venation 45a. 

45a. Laminae narrowly lanceolate or very narrowly elliptic-oblong, rarely more 
than 2.5 cm. broad; figs borne on peduncles 4-9 mm. long, the figs 7-10 
mm. in diameter (when dry) ; wet Caribbean areas below 500 m. elevation. 

F. donnell-smithii. 

45b. Laminae never lanceolate, usually more than 2.5 cm. broad; figs sessile or 
subsessile; plants of the seasonally dry Pacific slope or in evergreen areas 

above 500 m. elevation 46a. 

46a. Stipules 12-35 mm. long, glabrous; laminae very stiff, brownish beneath; 
figs 6-9 mm. in diameter; wet forest formations, (0) 800-1200 m. 

F. davidsoniae. 

46b. Stipules 5-12 mm. long, usually with conspicuous hairs 47a. 

47a. Figs 6-10 mm. in diameter; petioles 10-80 mm. long, laminae broadly ellip- 
tic to suborbicular; seasonally dry Pacific slope, 0-900 m. . . . F. cotinifolia. 
47b. Figs 4-6 mm. in diameter; petioles 8-35 mm. long, laminae broadly elliptic 
to obovate or ovate; wet evergreen forest formations on both Pacific and 

Caribbean slopes, 900-1600 m F. hartwegii. 

48a. Laminae glabrous except for unusual hairs in rows along the proximal half of 
the midvein beneath; figs sessile, about 10 mm. in diameter; very wet mon- 
tane formations, 1300-1700 m F. ceruantesiana. 

48b. Laminae puberulent over a larger area beneath 49a. 

49a. Laminae almost as broad as long, 8-20 cm. broad, rounded and often cordu- 
late at the base; figs becoming 22 mm. in diameter, sessile; wet Caribbean 
slope, 800-1300 m F. caldasiana. 

49b. Laminae usually much narrower than broad and not rounded at the base 
( except F. cotinifolia); figs usually less than 20 mm. in diameter 50a. 

50a. Stipules densely puberulent, petioles 10-80 mm. long, laminae with 4-12 pairs 

of prominent secondary veins 51a. 

50b. Stipules sparsely puberulent, petioles 5-35 mm. long, laminae with 10-20 

pairs of secondary veins; wet evergreen formations 54a. 

51a. Figs 6-10 mm. in diameter, sessile, basal bracts 2-4 mm. long; laminae 
usually very broad; seasonally dry Pacific slope, 0-900 m. . . . F. cotinifolia. 



BURGER: FLORA COSTARICENSIS 147 

51b. Figs 12-15 mm. in diameter; laminae usually about half as broad as long. 

52a. 

52a. Figs sessile with conspicuous basal bracts 5-10 mm. long, surface of the fig 
densely puberulent; wet Caribbean slope 600-800 m F. turrialbana. 

52b. Figs sessile or pedunculate, the basal bracts inconspicuous, 1-3 mm. long; 
0-1100 m 53a. 

53a. Figs glabrous (in ours), laminae with 6 to 11 pairs of major secondary 

veins; evergreen vegetation F. trigonata. 

53b. Figs minutely puberulent; laminae with 9 to 14 pairs of major secondary 

veins; commonly found in deciduous areas F. morazaniana. 

54a. Petioles 4-18 mm. long, laminae bluntly acute to obtuse and often reddish- 
brown beneath; figs 6-10 mm. in diameter, globose; wet evergreen forma- 
tions, (0) 800-1200 m F. davidsoniae. 

54b. Petioles 8-36 mm. long, laminae usually short-acuminate; figs 10-14 mm. in 

diameter, often longer than broad; 0-1000 m F. paraensis. 

55a. Introduced plants climbing on walls and flat surfaces with adventitious roots 
and small cordate leaves, fruiting branches shrub-like lacking roots, and with 

larger ovate leaves F. pumila. 

55b. Plants not climbers 56a. 

56a. Laminae with bluntly serrate margins and palmate venation; shrubs or small 

trees, rarely more than 6 m. tall 57a. 

56b. Laminae with entire margins and never deeply lobed, venation pinnate; trees 

often becoming more than 10 m. tall 58a. 

57a. Figs edible, 2-5 cm. in diameter; leaves usually 3-lobed F. carica. 

57b. Figs inedible, 1-2 cm. in diameter; leaves sometimes 3-lobed . . . . F. palmata. 
58a. Laminae very short (3-12 cm.) and narrow (1-4 cm.), usually lanceolate to ellip- 
tic; commonly planted in parks and along avenues 59a. 

58b. Laminae larger, never lanceolate 61a. 

59a. Trees with many aerial roots, planted in wet lowland areas; figs 5-8 mm. in 

diameter F. retusa. 

59b. Trees with few or no aerial roots, planted at higher elevations and in lowland 

areas with a dry season; figs 8-14 mm. in diameter 60a. 

60a. Introduced trees often grown in parks and along walkways with widely 

spreading trunks; figs sessile F. benjamina. 

60b. Native trees often used in hedgerows as living fences; figs pedunculate. 

F. pertusa. 

61a. Laminae broadly ovate and abruptly truncate at the base, with a very long 
slender apex, petioles 5-10 cm. long; often planted in parks F. religiosa. 

61b. Laminae lacking a long slender apex and borne on petioles much shorter than 
the laminae 62a. 

62a. Laminae becoming 40 cm. long, broadest above the middle and pandurate in 
shape; planted in gardens and also in pots as house plants F. lyrata. 

62b. Laminae not becoming so large, widest at or below the middle 63a. 

63a. Laminae with many (50) pairs of major secondary veins and very thick, the 
laminae often differing greatly in size on different trees; figs narrowly oblong; 



148 FIELDIANA: BOTANY, VOLUME 40 

introduced and planted in parks and gardens as well as in pots indoors. 

F. elastica. 

63b. Laminae with fewer pairs of secondary veins and stipules rarely exceeding 5 
cm.; native trees found in parks and along streets. Compare F. costaricana 
(with persisting stipules), F. jimenezii (thick glabrous leaves), F. goldmanii 
(with pedunculate figs), and others in key under native species. 

Ficus benjamina L., Mant. PL 129. 1767. 

Trees 5-20 m. tall, branching from near the ground and with a very broad crown, 
the terminal branchlets often drooping, leafy internodes 5-30 mm. long, 1.2-3 mm. 
thick, glabrous; stipules about 1 cm. long. Leaves glabrous, petioles 5-16 mm. long, 
about 1 mm. thick; laminae 4-12 cm. long, 2-4.5 cm. broad, elliptic to elliptic-oblong 
or narrowly ovate, acute or short-acuminate at the apex with a blunt tip, abruptly 
rounded at the usually obtuse base, margin entire but somewhat undulate and the 
lamina stiff-chartaceous (dry), major secondary veins difficult to distinguish from 
the intermediate veins and numerous (more than 15). Figs usually paired at a node, 
sessile, 8-11 mm. in diameter, globose or slightly ovoid, bracts not evident, ostiole 
flat or slightly conical. 

Handsome spreading trees planted in parks and along paths, 
originally from India. The small leaves with many secondary veins, 
short stipules, lack of pubescence, small sessile figs, and charac- 
teristic growth-form distinguish this species. 

Ficus brevibracteata Burger, Phytologia 26:423. 1973. Figure 17. 

Trees 8-18 m. tall, leafy internodes 0.5-2.5 cm. long, 5-12 mm. thick, sparsely 
puberulent with thin yellowish or grayish hairs about 1 mm. long, often becoming 
glabrous, smooth and gray, with few prominent angular ridges on drying; stipules 
7-12 mm. long, about 6 mm. broad at the base, densely sericeous with thin pale 
grayish ascending hairs. Leaves often confined to the ends of twigs, petioles 
1.4-8.2 cm. long, 1.5-4 mm. thick, with scattered thin hairs 0.8-1.5 mm. long or 
glabrous, periderm often peeling off in small flakes; laminae 12-28 cm. long, 5-12 
cm. broad, elliptic-oblong to obovate, usually broadest at or above the middle, 
abruptly narrowed at the short-acuminate apex, obtuse or rounded and occa- 
sionally cordulate at the petiole, margin entire or occasionally slightly rounded- 
crenate distally, the laminae drying stiff-chartaceous to subcoriaceous, smooth and 
glabrous above, glabrous or with slender ascending hairs on the midvein beneath, 
the 6 to 9 pairs of major secondary veins arising at angles of 30-60 degrees, loop- 
connected and forming a submarginal vein only near the apex, the basal second- 
aries often differing from those above and arising at a smaller angle. Figs usually 
paired at a node, sessile, the basal bracts difficult to see, 1-2 mm. long and equally 
broad, pale grayish sericeous; the fig 10-15 mm. in diameter (dry), slightly 
flattened above and below, subglobose to oblate, glabrous or with a few thin hairs 
near the base, smooth and drying dark, often with a few pale spots, the ostiole 
within a slightly elevated circle of tissue 2.5-4 mm. broad; seeds and galls about 1 
mm. long. 

Plants of the very wet evergreen forest formations of the Carib- 
bean slopes between 100 and 800 m. elevation; fertile collections 



BURGER: FLORA COSTARICENSIS 149 

have been made in December, January, and April. This species is 
known only between the area of Volcan Arenal (Alajuela) and the 
basin of the Rio Pacuare (Cartago) in Costa Rica. 

Ficus brevibracteata is recognized by the unusual fluted leafy 
stems (when dry), the short stipules broad at the base and covered 
with long pale grayish hairs, laminae often on long petioles and 
broadest above the middle, the sessile figs subtended by very 
small bracts, and the ostiole only very slightly elevated. The 
paired figs and distally brown oblongoid-capitate microscopic 
hairs (X150) on the lower leaf surface are characteristics of the 
subgenus Urostigma. This species is closely related to F. trigonata 
L. and F. morazaniana Burger, but those usually have pedunculate 
figs and the leaves are quite different. This species is known from 
below Volcan Arenal (the type), near the Rio Sarapiqui (Hartshorn 
989 and Walters 32), near the Rio Puerto Viejo (Burger & Matta 
4205 and Hartshorn 1099), and near Turrialba (GMV 640, Museo 
Nacional 40467). A number of sterile collections with somewhat 
thicker leaves with the major veins broadly impressed to give the 
laminae a corrugated appearance are probably this species and 
were collected near Taus (Lent 2536 & 2752) and Valle Escondido 
( Walter 77) in the province of Cartago. 

Ficus bullenei I. M. Johnston, Sargentia 8: 113. 1946. Figure 19. 

Trees 5-20 m. tall, leafy internodes 3-15 (40) mm. long, 3.5-6 mm. thick, densely 
velutinous with stiff erect usually dark brown hairs 0.5-1.5 mm. long, longer inter- 
nodes becoming longitudinally striate (dry); stipules 10-22 mm. long, 4-8 mm. 
thick at the base unopened, densely ascending sericeous. Leaves clustered or 
distant (? juvenile shoots), petioles 8-40 mm. long, 1.5-3 mm. thick, densely dark 
brown or orange-brown velutinous, not obviously sulcate above; laminae 7-26 cm. 
long, 4-13 cm. broad, ovate-oblong to slightly obovate or broadly elliptic, rounded 
or occasionally very short acuminate at the apex, rounded to truncate at the base 
and slightly cordulate at the petiole, drying very stiffly chartaceous and the mar- 
gins strongly revolute, scabrous and puberulent above, puberulent beneath with 
mostly straight stiff yellowish-brown hairs 0.5-1.2 mm. long (but not scabrous), 
the 5 to 10 pairs of major secondary veins slightly impressed above and very 
prominent beneath, central secondaries arising at angles of 45-70 degrees, second- 
aries weakly loop-connected near the margin, tertiary veins usually prominent 
beneath. Figs usually paired at a node, subsessile or short-pedunculate, basal 
bracts 2, entire or cleft, about 2 mm. long from a small disc-like area formed by 
the apically flared peduncle, with dark brown hairs to 1 mm. long; fig 10-14 mm. 
in diameter, globose, the surface densely tomentulose with yellowish-brown or 
grayish hairs 0.2-0.5 mm. long, the ostiole hidden within an elevated collar of 
receptacular tissue 1-3 mm. high and 3-5 mm. in diameter; seeds and galls about 
1.2 mm. long. 



150 FIELDIANA: BOTANY, VOLUME 40 

Trees of evergreen lowland wet forest formations from sea level 
to 200 m. (?) elevation and known in Costa Rica from only two 
collections (Allen 6638 & Croat 16622) made near Palmer Sur, 
Puntarenas. The known range of this species extends from southern- 
most Costa Rica to Central Panama. 

Ficus bullenei is recognized by the densely brown velutinous 
pubescence on many parts, laminae scabrous above, and the 
relatively small fig with unusually large apical collar surrounding 
the ostiole. The species is vegetatively very similar to F. popenoei 
with very different figs and is related to F. velutina of montane 
forests. 

Ficus caldasiana Dugand, Caldasia 1, no. 4:33. 1942. Figure 17. 

Trees to about 25 m. tall, becoming very large with trunks over 3 m. in diameter 
and a crown over 20 m. broad, leafy internodes 4-30 mm. long, 5-16 mm. thick, 
with thin whitish hairs 0.3-0.8 mm. long; stipules 12-34 mm. long, about 8 mm. 
thick near the base, narrowly acute, with thin whitish hairs about 0.5 mm. long 
except along the edges. Leaves clustered at the ends of stems in mature growth, 
petioles 3-9 cm. long, 2-4.5 mm. thick, densely pilose with thin white hairs; laminae 
(9) 15-27 cm. long, 8-19 (21) cm. broad, broadly elliptic or elliptic-oblong to broadly 
obovate, abruptly narrowed at the bluntly obtuse or round apex, abruptly rounded 
and usually subcordate at the base, margin entire, laminae drying stiffly 
chartaceous to subcoriaceous, smooth above and with minute hairs above the 
major veins, densely pilose or hirtellous on the veins beneath, the thin 0.3-0.8 mm. 
long hairs sparse between the veins, the 8 to 12 pairs of major secondary veins 
arising at angles of 50-70 degrees, only weakly loop-connected in the distal third of 
the lamina. Figs usually paired at a node, sessile and often producing shelf-like 
structures on old stems, the basal bracts 2 but usually deeply split and apparently 3 
or 4, becoming 15 mm. long and 15 mm. broad at the broadest point, whitish serice- 
ous, covering the fig in early stages; the fig becoming about 14 mm. long and 22 
mm. in diameter, flattened at both ends and oblate, the surface with thin whitish 
hairs 0.3-1 mm. long, ostiole flat, 2-5 mm. broad and densely sericeous; seeds and 
galls about 1.5-2 mm. long. 

Trees of the very wet Caribbean slopes and the area of the Gen- 
eral Valley between 800 and 1300 m. elevation. The species has 
been collected in Costa Rica above Turrialba (Holdridge 6809 & 
6810) near Juan Vinas (O. Jimenez s. n.. Museo Nacional 38280), 
along the Rio Grande de Orosi near Tapanti (Burger & Gentry 
9206), all in the province of Cartago, and northeast of San Isidro 
del General (Luteyn 3283) in the province of San Jose. Otherwise 
the species is only known from the province of Caldas, Colombia. 

Ficus caldasiana is recognized by its broad leaves subcordate at 
the base with long petioles, large sessile figs subtended and at 
first enclosed by large basal bracts, and the thin whitish hairs on 



BURGER: FLORA COSTARICENSIS 151 

both figs and vegetative parts. The paired figs, two bracts, and 
ostiole with only three exposed scales (in most stages) are charac- 
teristics of the subgenus Urostigma. This species resembles F. 
cuatrecasana, but the figs are larger with larger bracts and the 
plants are more puberulent in F. caldasiana. However, two recent 
collections from the road to Dominical west of San Isidro del 
General, lacking figs and tentatively placed here (Burger & Baker 
lOlOlb & 10115) may indicate that this species contains glabrous 
individuals. Placement of this Costa Rican material under the 
species originally described from Colombia is a tentative 
expedient; further study may show that the plants are not 
conspecific. Ficus garcia-barrigae Dugand and F. jaramilloi 
Dugand, both of Colombia, appear to be close relatives of F. 
caldasiana. 

Ficus carica L., Sp. PI. 1059. 1753. 

Small trees 3-10 m. tall, wood soft, leafy internodes 1-8 cm. long, 5-10 mm. thick, 
glabrous or sparsely puberulent; stipules 15-30 mm. long. Leaves usually sparsely 
puberulent, petioles 4-14 cm. long, about 2.5 mm. thick; laminae 12-24 cm. long, 
10-22 cm. broad, broadly ovate to orbicular in general outline but usually deeply 
3-lobed in the distal half with small lobes present or absent near the base, cordate 
at the base, the margin bluntly dentate, drying stiffly chartaceous and scabrous 
above, venation palmate with 3(5) main veins arising at the apex of the petiole. 
Fig solitary at a node, sessile or subsessile below the small bracts, narrowed above 
the bracts and usually pyriform to obovoid, 2-5 cm. in diameter. 

Widely cultivated for ornament as well as for the edible figs, 
which vary greatly in size and shape in different varieties. This 
species is readily recognized by the lobed leaves, small stature, 
and edible figs (higos). Ficus carica is not an economically impor- 
tant crop in Central America. 

Ficus cervantesiana Standley & L. O. Williams, Ceiba 3:194. 
1953. Figure 18. 

Trees 6-20 m. tall, leafy internodes 5-20 (32) mm. long, 2.8-4 mm. thick, glabrous, 
the periderm becoming longitudinally ridged and pale grayish on drying; stipules 
16-36 mm. long, 2-5 mm. thick at the base unopened, glabrous or very minutely 
(0.05-0.1 mm.) puberulent, drying dark brown. Leaves not usually clustered at the 
ends of twigs, petioles 10-28 mm. long, 1.6-2.8 mm. thick, glabrous and narrowly 
sulcate above; laminae (6) 9-21 cm. long, (3) 4-8.5 cm. broad, oblong to elliptic- 
oblong, tapering abruptly to the acuminate apex, tapering abruptly and somewhat 
rounded at the obtuse base, laminae drying chartaceous to very stiffly chartaceous 
or subcoriaceous, smooth and glabrous above, smooth below with a few groups of 
pale colored strigulose hairs 0.5-1 mm. long on the sides of the midvein in the 
basal half of the lamina, the 12 to 18 pairs of major secondary veins raised above 



152 FIELDIANA: BOTANY, VOLUME 40 

and prominent below, central secondaries arising at angles of 60-80 degrees, loop- 
connected near the margin but not forming a definite submarginal vein, tertiary 
veins becoming raised on both surfaces. Figs usually 2 per node, sessile or sub- 
sessile, basal bracts 2 and entire or split 3-4 mm. long and about 4 mm. broad, 
glabrous, the fig about 10 mm. in diameter, subglobose with a flattened apex, 
surface smooth and glabrous or very minutely (-0.05 mm.) puberulent, drying 
dark, ostiole flat or slightly conical, about 2 mm. broad, exterior scales 2 (3); 
seeds and galls 1-1.5 mm. long. 

Trees of the very wet montane (premontane wet) forest forma- 
tions between 1000 and 1700 m. elevation and presently known 
from only four collections: Reark 394, the type, from near Cer- 
vantes (Cartago); Standley 36149 from La Hondura; Burger & 
Liesner 7098 from the upper Rio Chirripo del Pacifico (San Jose); 
and Lent 2613 from Quebrada Azul northwest of San Ramon 
( Alajuela); mature figs have been collected at the end of August and 
the end of December. 

Ficus cervantesiana is recognized by the abruptly acuminate 
leaves with slightly raised venation on both surfaces, very unusual 
hairs along the side of the midvein beneath in the basal part of the 
lamina, the smaller sessile figs, and restricted wet montane 
habitat. This species is poorly known but appears to be related to 
F. paraensis. 

Ficus citrifolia P. Miller, Card. Diet. ed. 8, Ficus no. 10. 1768, fide 
DeWolf. Figure 18. 

Small to medium sized trees 5-12 (16) m. tall or rarely a shrub, often found origi- 
nating as epiphytes, the sap usually clear and very viscous, leafy internodes 3-20 
( 35 ) mm. long, 3-7 mm. thick, glabrous, periderm often peeling off in small ( 0.5 mm. ) 
flakes, older stems brown to pale gray; stipules 6-16 mm. long, 3-5 mm. thick at the 
base unopened, glabrous and drying brown. Leaves usually distant on the stem, 
petioles 1.4-6 (12) cm. long, 1-2.3 mm. thick, quite variable in length on the same 
tree, glabrous, slightly sulcate above; laminae 8-18 (22) cm. long, 4-8 ( 10) cm. broad, 
oblong to elliptic-oblong, gradually to abruptly narrowed to the acuminate apex, 
obtuse to rounded and subtruncate at the base, drying chartaceous to stiffly chart- 
aceous and flat, smooth and glabrous on both surfaces, the 4 to 12 pairs of major 
secondary veins flat above and slightly raised beneath, central secondaries arising 
at angles of 50-70 degrees, secondaries loop-connected near the margin and often 
forming a weak submarginal vein, tertiary veins usually flat beneath. Figs usually 
paired at a node, borne on peduncles 5-10 mm. long, about 2 mm. thick, glabrous or 
very minutely (0.05 mm.) puberulent, slightly expanded at the apex, bracts 2, 
entire or divided, about 2 mm. long and 4 mm. broad, glabrous; figs 10-14 mm. 
in diameter, globose to obovoid and slightly narrowed at the base, surface smooth 
and glabrous, usually green ostiole slightly raised or slightly conical, the usual 3 
outer scales surrounded by a slight ridge of receptacular tissue 3-5 mm. in diameter; 
seeds and galls 1-1.4 mm. long. 



BURGER: FLORA COSTARICENSIS 153 

Plants of moist and wet evergreen forest formations from sea 
level to 1200 m. in Costa Rica on the Caribbean slopes and on the 
eastern side of the Meseta Central around San Jose; probably 
flowering throughout the year. This species, as interpreted by 
DeWolf , ranges from southern Florida and Mexico to Paraguay. 

Ficus citrifolia is a striking species because of its oblong laminae 
abruptly narrowed at both ends and short-acuminate apically, long 
slender petioles, glabrous parts (in ours), and pedunculate figs often 
slightly narrowed at the base. The species is unusual because of its 
clear thick sap (fide Holdridge and Croat). This species is very 
closely related to F. dugandii (F. turbinata), which has milky sap, 
dark brown twigs, thinner leaves, and apparently grows to a larger 
size. 

Ficus colubrinae Standley, Contr. U.S. Nat. Herb. 20:16. 1917. 
Figure 20. 

Small to medium sized trees 4-12 (20) m. tall, epiphytic and strangling or occa- 
sionally independent, trunk smooth or several grown together, leafy internodes 
2-15 (22) mm. long, 1.5-4 mm. thick, sparsely puberulent with slender crooked or 
straight hairs 0.8-3 mm. long, soon becoming glabrescent and gray on drying; 
stipules 4-8 mm. long, about 2-3 mm. thick at the base unopened, densely covered 
with long thin crooked hairs. Leaves often numerous and clustered on the ends of 
branchlets, petioles 8-20 (26) mm. long, 0.8-2.4 mm. thick, densely to sparsely 
puberulent with straight and crooked hairs 0.5-3 mm. long, ridged on drying and 
sulcate above, the epidermis often peeling off in small flakes; laminae (4) 6-12 cm. 
long, (2) 3-6 cm. broad, obovate to broadly elliptic, usually abruptly narrowed at the 
short acuminate (rarely rounded) apex, obtuse to rounded at the base, lamina 
drying stiffly chartaceous and the margin flat or slightly revolute, smooth and 
glabrous above, sparsely puberulent beneath with slender hairs, the 2 to 4 pairs of 
major secondary veins flat above and prominent beneath, central secondaries 
arising at angles of 35-60 degrees, basal secondaries very prominent and the 
venation sub-palmate. Figs usually paired at the node, sessile, bracts 2, entire or 
split, about 2 mm. broad and 1-2 mm. long, with slender yellowish hairs 0.3-1 mm. 
long, often slightly (0.5 mm.) united to the receptacle basally and the peduncle 
somewhat acentric; figs 5-8 mm. in diameter, globose or flattened apically, 
surface smooth and glabrous pale pink but yellowish and wrinkled when dry, 
ostiole slightly raised of lustrous tissue drying dark, 2-3 mm. broad, the wall very 
thin; galls and seeds 0.7-1 mm. long. 

Trees of wet evergreen forest formations from sea level to about 
800 m. altitude in Costa Rica on both the Caribbean and Pacific 
slopes; flowering throughout the year. The species, as here defined, 
ranges from British Honduras and Guatemala to central Panama. 

Ficus colubrinae is easily recognized by its small leaves with 
subpalmate venation with few prominent secondary veins, small 



154 FIELDIANA: BOTANY, VOLUME 40 

stipules, small figs, and lower elevation habitat. This species is very 
closely related to F. hartwegii but differs in habitat and leaf-vena- 
tion; see the discussion under that species. 



Ficus costaricana (Liebm.) Miquel, Ann. Mus. Bot. Ludg.-Bat. 
3:298. 1867. Urostigma costaricanum Liebm., Danske. Vidensk. 
Selsk. Skrivt. 5, ser. 2:322. 1851. Figure 19. 

Small to large trees 8-20 (30) m. tall, independent or rarely seen as a strangler, 
trunk relatively smooth and usually short, leafy internodes 5-15 (50) mm. long, 3-8 
mm. thick, with stiff straight or crooked hairs 0.3-1 mm. long in early stages, be- 
coming gray and ridged, often with the persisting stipules and shelf-like formations 
above the leaf-scars where figs were attached; stipules 7-30 mm. long, 3-5 mm. broad 
at the base unopened, with slender whitish hairs 0.3-1 mm. long at the base and 
along the midrib. Leaves usually clustered at the ends of branchlets, petioles 7-30 
(50) mm. long, 1.2-3.2 mm. thick, sparsely puberulent near the base, very narrowly 
sulcate above; laminae very variable (on different trees), 5-16 cm. long, 3-6.5 (8) cm. 
broad, obovate to broadly elliptic or oblong, gradually to abruptly narrowed to the 
obtuse or rounded apex (occasionally short-acuminate), narrowed gradually or 
abruptly at the base and cuneate to rounded, drying stiffly chartaceous, glabrous 
and smooth on both surfaces, the (3) 4 to 8 (10) pairs of major secondary veins flat 
above and prominent beneath, central secondaries arising at angles of (35) 40-65 
degrees, basal secondaries strongly ascending, secondaries not usually loop-con- 
nected near the margin, tertiary veins obscure. Figs usually paired at a node, sessile 
and the stem becoming shelf-like at the point of attachment, bracts 2 and usually 
split, about 4 mm. long and 4 mm. broad, with long (1 mm.) ascending yellowish 
hairs, united with the receptacle for about 1 mm. from the slightly acentric base, 
figs becoming oblate and distinctly flattened at both ends at maturity, 10-12 (14) 
mm. in diameter, surface smooth and glabrous, becoming pink marked by red spots, 
wall of the fig very thin, ostiole conical in early stages, very slightly raised and dry- 
ing dark at maturity, 2-3 mm. broad, exterior scales 2 or 3; seeds and galls about 1.2 
mm. long. 

Trees of evergreen forest formations between sea level and 1200 
m. elevation on both the Caribbean and Pacific slopes in Costa Rica. 
The species is common on the Meseta Central but is rarely collected 
below 300 m.; mature figs have been collected in all months but 
September and October. The species ranges from Guatemala to 
Panama. 

Ficus costaricana is recognized by its relatively thick stems with 
broad brown stipules often persisting as long as the leaves and the 
sessile figs broader than long. The leaves vary greatly in the species 
but are often small to medium-sized and usually taper abruptly at 
both ends. This species is related to F. hartwegii among our species 
but is more likey to be confused with F. turrialbana. The illustration 



BURGER: FLORA COSTARICENSIS 155 

in the "Flora of Panama" (Ann. Missouri Bot. Gard. 47:164. 1960) 
is very atypical. 

Standley placed a large number of collections from northern Cen- 
tral America under this name, but these differ from ours in a 
number of ways and, I believe, are better placed under his F. keller- 
manii. The two are in turn related to a group of species that are 
often difficult to distinguish and appear to be closely related; these 
include F. cotini folia, F. hartwegii, F. hondurensis, F. inamoena, F. 
morazaniana, andF. trigonata. 

Ficus cotinifolia H.B.K., Nov. Gen. & Sp. 2:49. 1817. Figure 19. 

Small to large trees 6-20 (40) m. tall with broad spreading crown, trunks fluted 
and the branches with aerial roots, leafy internodes 2-30 mm. long, 2.5-6.5 mm. 
thick, dense soft grayish tomentulose hairs 0.1-1 mm. long, becoming prominently 
ridged and grayish on drying; stipules 5-12 mm. long, 3-4 mm. thick at the base un- 
opened, densely grayish strigulose or tomentulose or glabrous apically. Leaves not 
usually clustered, petioles (6) 12-80 mm. long, 1.2-3.5 mm. thick, densely soft 
puberulent but becoming glabrous and the epidermis flaking off, narrowly sulcate 
above; laminae (5) 7-15 cm. long, (3) 4-8 cm. broad, very broadly oblong or elliptic to 
suborbicular or somewhat ovate or obovate, rounded to bluntly obtuse at the apex, 
obtuse to rounded or subtruncate at the base, drying stiffly chartaceous, smooth 
and glabrous above, sparsely puberulent with thin whitish hairs 0.1-0.7 mm. long 
beneath, the 4 to 7 pairs of major secondary veins flat above and prominent beneath, 
central secondaries arising at angles of 35-70 degrees, secondaries weakly loop-con- 
nected near the margin, tertiary veins distinct beneath. Figs usually 2 at a node, 
sessile, bracts 2 and usually split, 2-4 mm. long, 3-5 mm. broad, densely puberulent 
on both surfaces with the inner hairs longer, united with the receptacle only near the 
base; figs 6-10 mm. in diameter, globose or slightly broader than long, surface 
smooth to the touch and very minutely (0.05 mm.) puberulent or apparently 
glabrous, ostiole slightly sunken within a ring of thickened tissue 1.5-2 mm. in dia- 
meter, entrance covered by 2 exterior scales, wall very thin; seeds and galls about 
0.8 mm. long. 

Trees of the seasonally very dry deciduous and evergreen forma- 
tions of the Pacific slope in central and northwestern Costa Rica 
from sea level to about 900 m. elevation; apparently flowering 
throughout the year. The species ranges from Mexico along the 
drier western slopes of Central America to Central Costa Rica. 

Ficus cotinifolia is recognized by the relatively broad leaves 
usually on long petioles and rounded at the apex, short stipules 
often covered with thin pale grayish hairs, small figs, and season- 
ally dry habitat. This species is related toF. hartwegii (with smaller 
leaves and figs at higher elevations), F. costaricana (with persisting 
stipules, larger figs, and wetter habitat), and perhaps most closely 



156 FIELDIANA: BOTANY, VOLUME 40 

with F. trigonata and its allies (q.v.). I am using this name as 
Standley applied it, not having seen the type. An unusual collection 
(Burger & Gentry 9149) from above the falls of the Rio Potrero west 
of Bagaces is placed here. This tree has short-pedunculate figs and 
short-petiolate leaves very similar in shape and venation to leaves 
of F. hartwegii. I believe it represents no more than a very unusual 
combination of morphological characters in the species. 

Ficus crassiuscula Warburg ex Standley, Contr. U.S. Nat. Herb. 
20:12. 1917. Figure 21. 

Medium-size to large trees 7-25 m. tall, trunks smooth or slightly buttressed, leafy 
internodes 2-25 (45) mm. long, 3-6 mm. thick, glabrous or very sparsely puberulent 
with minute (0.1 mm.) straight whitish hairs, periderm smooth or slightly striate, 
drying very dark on new shoots or pale gray; stipules 2-5 cm. long, 3-6 cm. thick at 
the base unopened, glabrous and usually drying very dark. Leaves often crowded 
near the ends of branchlets, petioles 12-22 (30) mm. long, about 2 mm. thick, gla- 
brous, deeply sulcate above, epidermis not usually flaking off; laminae (6) 8-16 cm. 
long, ( 2.5 ) 4.5-8 cm. broad, elliptic to narrowly obovate or oblong, abruptly narrowed 
to the obtuse to acute apex but rounded at the tip, obtuse to cuneate at the base, 
drying subcoriaceous and the margins usually revolute, smooth and glabrous on 
both surfaces, the 12 to 17 pairs of major secondary veins flat above and only 
slightly raised beneath, central secondaries arising at angles of 60-80 degrees, 
secondaries loop-connected near the margin and forming a slightly arcuate sub- 
marginal vein, the submarginal vein often joining a bifurcated midvein near the 
apex, tertiary veins often obscure. Fig solitary at a node, borne on a peduncle 5-15 
mm. long, 2-4 mm. thick, glabrous, basal bracts 3, usually entire, 3-4 mm. long, 
4-5 mm. broad; figs becoming 3-5 cm. in diameter with a very thick wall, globose and 
narrowed above the bracts to form a stalk-like continuation of the peduncle, surface 
smooth and glabrous, ostiole conspicuously raised in early stages and 5-10 mm. 
broad at maturity, exterior scales 3-6 mm. broad at the base, 3 with the apices of in- 
terior scales readily visible, wall very succulent, 3-6 mm. thick (dry); seeds and galls 
2-2.8 mm. long. 

Trees of wet evergreen cloud forests between 1200 and 2000 (? 
2500) m. altitude and known in Costa Rica from Volcan Rincon de la 
Vieja (Guanacaste), La Palma de San Ramon and Fraijanes (Ala- 
juela), Zurqui, Irazii, and Cerro de la Carpintera (San Jose) above 
Orosi (Cartago), and above San Vito de Java (Puntarenas). The 
species, as here understood, occurs from Guatemala southward to 
Chiriqui, Panama. 

Ficus crassiuscula is distinguished by its thick blunt glabrous 
leaves, broad stipules drying dark, thick twigs, large figs with very 
thick walls, and cloud-forest habitat. The solitary figs and unusual 
trichomes on the lower leaf-surface (X150) are characters of the sub- 
genus Pharmacosycea. This species is closely related to F. yopo- 



BURGER: FLORA COSTARICENSIS 157 

nensis and is part of a group of species that were considered conspe- 
cific with F. insipida (q.v.) in the "Flora of Panama." Unlike many 
other species of the subgenus Pharmacosycea, this species does not 
appear to grow near streams. 

Ficus crassivenosa Burger, Phytologia 26:424. 1973. Figure 21. 

Trees to over 30 m. tall or occasionally epiphytic, leafy internodes 1-35 mm. long, 
2-6 mm. thick, glabrous or sparsely and very minutely puberulent, the epidermis 
occasionally reddish-brown and flaking off in long (5 mm.) strips, the periderm be- 
coming deeply ridged and striate when dry, twigs grayish in age; stipules 2-3 cm. 
long, about 2-4 mm. thick at the base unopened, glabrous. Leaves separate or 
clustered at the ends of branchlets, petioles 8-24 mm. long, 1-3 mm. thick, usually 
glabrous, sulcate above; laminae 5.5-13 cm. long, (2) 3-7 cm. broad, obovate to ellip- 
tic or elliptic-oblong, rounded to obtuse and with a blunt tip at the apex, obtuse at 
the base, drying subcoriaceous and the margins slightly revolute, smooth and gla- 
brous (10X) above and below, often lustrous above, the 10 to 40 pairs of major 
secondary veins often difficult to distinguish from the intermediate veins, raised on 
both surfaces, appearing thickened above, the central secondaries arising at angles 
of 60-90 degrees, the secondaries connected by a submarginal vein 1-2 mm. from the 
margin, tertiary veins slightly raised on both surfaces. Figs solitary at a node, borne 
on peduncles 6-8 mm. long, 1-1.5 mm. thick, glabrous, basal bracts 1-2 mm. long and 
2-3 mm. broad, sparsely and minutely puberulent, deciduous, the fig narrowed be- 
neath to form a stalk-like portion 1-3 mm. long above the 3 bracts, expanded portion 
of the fig globose, about 15 mm. in diameter, surface smooth and glabrous or with a 
few minute (0.05 mm.) hairs, ostiole conical, wall of the fig about 1 mm. thick (dry), 
seeds and galls 1.5-2 mm. long. 

Very tall trees or (?) epiphytes in the very wet forests of the Carib- 
bean slopes and lowlands between about 60 and 600 m. elevation. 
The species is known from only three collections: the type, Hart- 
shorn 1238 from near La Selva on the Rio Puerto Viejo; Burger & 
Burger 8134 from Tirimbina near the Rio Sarapiqui, Heredia; and 
Walters 79 from Valle Escondida, Cartago. 

The characteristic microscopic oblongoid-capitate trichomes 
(X150) on the lower leaf surfaces and the solitary figs with three 
bracts are characteristics of the subgenus Pharmacosyce. The thick 
leaves with many secondary veins and a submarginal vein near the 
edge are similar to the leaves of F. crassiuscula, but the tertiary 
veins are more pronounced and the laminae more blunt in this 
species. The lowland habitat and small stipules and figs are also 
very different from those of F. crassiuscula. The figs of this species 
are very similar to those of F. yoponensis, but that species has very 
different foliage. This species was only known from two sterile 
twigs until Gary Hartshorn collected material with figs on 29 May 
1973. 



158 FIELDIANA: BOTANY, VOLUME 40 

Ficus cuatrecasana Dugand, Caldasia 1, no. 4:36. 1942. Figure 17. 

Small trees about 8 m. tall (becoming very large?), Crown open, the branches 
wide-spreading, leafy internodes 1-12 (20) mm. long, 4-8 (12) mm. thick, glabrous or 
with slender hairs about 1 mm. long near the node, periderm becoming striate or 
somewhat ridged, grayish; stipules 14-30 (60) mm. long, 6-14 mm. thick at the base 
unopened, glabrous and deciduous in ours (densely reddish brown appressed 
puberulent and persisting in Colombia). Leaves usually clustered at the ends of 
shoots, petioles 3-8 (11) cm. long, 2-4 (5) mm. thick, glabrous or sparsely puberulent 
with slender whitish hairs, terete; laminae (10) 14-32 (40) cm. long, (8) 10-20 (24) cm. 
broad, elliptic-obovate to slightly pandurate, usually broadest above the middle, 
rounded or abruptly narrowed to a very short acute or obtuse apex, abruptly trun- 
cate to subcordate at the base (in larger leaves), drying stiffly chartaceous, smooth 
and glabrous on both surfaces, the 9 to 13 pairs of major secondary veins slightly 
raised above and prominent beneath, central secondaries arising at angles of 50-80 
degrees, not strongly loop-connected near the margin, the basal pair of secondaries 
often very prominent and strongly ascending, tertiary veins flat beneath. Figs 2 at a 
node, maturing well behind the current foliage in ours (maturing both behind and 
among the leaves and persisting stipules in the type), sessile, bracts 2, variously 
split and 3-5 lobed, 3-5 mm. long, glabrous to puberulent with slender hairs about 0.5 
mm. long, united near the base and occasionally forming a small disc-like area with 
the attachment acentric; figs 16-20 mm. in diameter, 10-12 mm. long, oblate to 
obovoid with the apex usually strongly flattened, surface smooth and glabrous, 
brown, ostiole flat or slightly raised forming a circular area 3-4 mm. broad, exterior 
scales 2 or 3; seeds and galls 1-1.5 mm. long. 

Poorly known trees tentatively placed under this name and known 
from only two collections from the wet Caribbean slopes at 500 
and 1000 m. elevation in Costa Rica: Lent 3445 from the slopes of 
Volcan Arenal, Alajuela, and Burger 4162 from the Rio Claro (Rio 
La Hondura-Rio Zurqui drainage) below La Palma, San Jose; 
mature figs were collected in December and January. The species 
was originally described from Colombia (Cuatrecasas 8218). 

Ficus cuatrecasana is recognized by the large laminae usually 
broadest above the middle and borne on long petioles and the 
mature oblate figs borne well behind the leaves (in ours). I have 
seen only two fertile collections, which may not be conspecific but 
which are very closely related. The type material differs from the 
Costa Rican collections in that the stipules are densely reddish- 
brown puberulent and larger and more persistent, and the figs are 
borne among as well as behind the leaves. The two collections are 
very similar in leaf-shape, microscopic hairs (X150), venation, and 
form and size of the figs. It seems best to treat these collections as a 
single species until the populations concerned are better under- 
stood. This species is closely related to F. richteri Dugand of 
Colombia and to F. caldasiana and its allies. 



BURGER: FLORA COSTARICENSIS 159 

Ficus davidsoniae Standley, Field Mus. Bot. 22:15. 1940. Figure 
20. 

Small to large trees 10-30 m. tall, independent or epiphytic, leafy internodes 5-17 
mm. long, 3-7 mm. thick, glabrous or sparsely puberulent, periderm becoming pale 
gray and longitudinally striate; stipules 12-30 mm. long, 3-5 mm. thick at the base 
unopened, glabrous or very minutely (0.05 mm.) puberulent. Leaves usually 
clustered at the ends of branchlets, petioles 4-18 mm. long, 1.3-4 mm. thick, glabrous 
near the base but with thin whitish hairs 0.5-1.5 mm. long distally, deeply sulcate 
above, laminae 6-14 (18) cm. long, 2-6 (9) cm. broad, narrowly obovate to elliptic or 
elliptic-oblong, bluntly acute to obtuse or occasionally rounded near the apex, 
cuneate to obtuse and somewhat rounded at the base, lamina drying subcoriaceous 
and the margins revolute, smooth, glabrous, and often glaucous above, usually pale 
brown beneath, glabrous or with crooked or straight whitish hairs 0.3-1.5 mm. long 
on the proximal half of the mid vein, the 10 to 20 pairs of major secondary veins 
slightly raised on both surfaces and often difficult to distinguish from the inter- 
mediary veins, an arcuate submarginal vein present, tertiary veins forming a very 
slightly raised reticulum. Figs usually paired at a node, sessile and forming a small 
shelf-like depression on the stem, bracts 2, entire or split, 3-5 mm. long, about 8 mm. 
broad, united to the receptacle and forming a thickened basal area on one side, 
bracts conspicuous and glabrous; figs 6-8 (10) mm. in diameter, 4-6 mm. high, glo- 
bose to oblate, surface smooth and glabrous, brown, ostiole about 1.5 mm. broad, 
conspicuously umbonate and drying dark, 1-1.5 mm. high, exterior scales 2 or 3, wall 
of the fig thin ; seeds and galls about 1 mm. long. 

Trees of wet evergreen forest formations between (600) 800 and 
1200 m. elevation, known only from the Caribbean slopes between 
Turrialba and Moravia (Cartago) in Costa Rica. In Panama the 
species is known from Boquete (Chiriqui) and near El Valle de 
Anton (Cocle); figs have been collected in November, December, 
and May. The species is, I believe, endemic to this area in Central 
America. 

Ficus davidsoniae is recognized by its very thick generally nar- 
rowly obovate leaves brownish beneath, glabrous stipules, small 
sessile figs with umbonate ostiole and conspicuous bracts, and high- 
land habitat. This species is probably related to F. jimenezii among 
our species. 

Ficus donnell-smithii Standley, Contr. U.S. Nat. Herb. 20:21. 
1917. Figure 18. 

Small to medium size trees 4-16 m. tall, epiphytes or independent, leafy inter- 
nodes 2-10 ( 15) mm. long, 1.7-3.8 mm. thick, minutely puberulent with erect grayish 
hairs 0.1-0.3 mm. long, periderm becoming somewhat striate and dark gray; stipules 
(2) 3-9 mm. long, 1.5-2.5 mm. thick at the base unopened, drying dark brown with a 
uniform covering of minute (0.05 mm.) grayish hairs. Leaves clustered or distant, 
petioles 7-22 mm. long, 0.9-1.7 mm. thick, minutely (0.1 mm.) puberulent, narrowly 
sulcate above; laminae 5-15 cm. long, 1.4-3.2 cm. broad, narrowly lanceolate to very 



160 FIELDIANA: BOTANY, VOLUME 40 

narrowly elliptic, tapering gradually to the acute or obtuse apex and often rounded 
at the tip, acute to abruptly obtuse at the base, drying stiffly chartaceous and 
usually dark in color (above) with flat or slightly involute margins, smooth and very 
minutely puberulent on both surfaces with erect grayish hairs about 0. 1 mm. long, 
the 6 to 12 pairs of major secondary veins flat above and slightly raised beneath, 
central secondaries arising at angles of 40-60 degrees, tertiary veins flat and often 
obscure. Figs usually paired at a node, borne on peduncles 4-9 mm. long, 0.5-1 mm. 
thick, slightly expanded at the apex, glabrous or very minutely (0.05 mm.) puberu- 
lent, bracts 2, usually entire and rounded, 1-2 mm. long, glabrous or very minutely 
puberulent; figs 7-10 mm. in diameter, globose or somewhat flattened at the top, 
surface smooth and glabrous, drying reddish brown or yellowish and not con- 
spicuously wrinkled, ostiole flat and often surrounded by wrinkled tissue at the apex 
of the fig (dry), about 2 mm. broad, exterior scales 3, drying dark; seeds and galls 
0.7-1 mm. long, enclosed within the conspicuous perianth. 

Trees of the wet Caribbean Lowlands from sea level to about 500 
m. elevation and known in Costa Rica from only two collections: 
near the mouth of the Rio Colorado, Limon ( Walter 53), and near the 
Rio Puerto Viejo, Heredia (Hartshorn 1068). The species is other- 
wise known only from British Honduras and Guatemala, with 
mature figs having been collected in December in Costa Rica and in 
February, May, August, and November in northern Central Amer- 
ica. 

Ficus donnell-smithii is easily recognized by its small narrow 
leaves on prominent petioles, many parts drying dark in color and 
having a pubescence of very small (0.05-0.2 mm.) erect slender gray- 
ish hairs, and the small pedunculate figs. The species appears to be 
related to F. perforata. 

Ficus dugandii Standley, Trop. Woods 32:20. 1932. F. turbinata 
Pittier, Bol. Soc. Venez. Cienc. Nat. 4(30):61. 1937 (non Willd. 
1806), fide auctores in herb. Figure 18. 

Medium to large size trees 10-25 m. tall, not seen as stranglers, leafy internodes 
4-35 mm. long. 2.5-6 mm. thick, glabrous, periderm becoming irregularly ridged 
or smooth (dry) and reddish-brown; stipules 5-15 (40) mm. long, 2-5 mm. thick at 
the base unopened, glabrous or very minutely (0.05 mm.) puberulent, drying brown. 
Leaves usually distant on the twigs, petioles 2-9.5 cm. long, 1-2.4 mm. thick, 
glabrous, slightly sulcate above; laminae 11-22 cm. long, 4-8 cm. broad, ovate- 
oblong to elliptic-oblong, tapering gradually or abruptly to the short- or long- 
acuminate apex, abruptly obtuse to subtruncate at the base, drying chartaceous 
and flat, smooth and glabrous on both surfaces, the 6 to 13 pairs of major secondary 
veins flat above and slightly elevated beneath, central secondaries arising at angles 
of 45-65 degrees, weakly loop-connected near the margin and a submarginal vein 
absent, tertiary veins flat beneath. Figs paired or solitary at a node, subsessile or 
borne on peduncles 0-4 mm. long, 1-2 mm. thick, glabrous or very minutely puber- 
ulent. bracts 2. entire or split, 2-4 mm. long, 3-4 mm. broad, glabrous or very 



BURGER: FLORA COSTARICENSIS 161 

minutely (0.05 mm.) puberulent; figs 9-13 mm. in diameter, subglobose to obovoid 
or turbinate in early stages, surface smooth and glabrous, drying pale yellowish 
in color, ostiole slightly conical, 1.5-3 mm. broad, exterior scales usually 3; seeds 
and galls 1-1.5 mm. long. 

Trees of the moist evergreen forest formation from sea level to 
about 1000 m. elevation; probably flowering throughout the year. 
This species is known in Costa Rica from only two collections: 
Lankester & O. Jimenez 1316 from La Hermosa, Perez Zeledon, 
in the General Valley and Brenes 23013 from San Pedro de San 
Ramon. The species is also known from several collections in the 
Canal Zone (Croat 8293, 12694, & 15242; Muenscher 12302} , and the 
type (Dugand27) near Galapa, Colombia. 

Ficus dugandii is recognized by its thin ovate-oblong laminae 
on long slender petioles, and short-pedunculate figs often turbinate 
in form. This species has been mistaken for F. citrifolia but differs 
in the white sap, dark brown branchlets, thinner laminae of slightly 
different form, somewhat different ostiole, and apparently larger 
habit. 

Ficus elastica Roxb., Fl. Ind. ed. 2, 3:541. 1832. 

Large trees to over 20 m. tail but most often cultivated in a juvenile form (often 
as a potted plant in homes), leafy internodes 1-10 cm. long, 5-15 mm. thick; stipules 
(1.5) 5-20 cm. long. Leaves glabrous, petioles 2-7 cm. long; laminae (6) 12-30 cm. 
long, (4) 5-12 cm. broad, oblong to elliptic, sharply acute at the apex, drying sub- 
coriaceous, major secondary veins very numerous (50+), united near the margin 
by a submarginal vein. Figs usually paired at a node, sessile but with a thick 
articulated base about 4 mm. long and 4 mm. thick (dry), figs 5-8 mm. in diameter 
and 10-12 mm. long, oblong, glabrous, ostiole slightly conical and surrounded by a 
ring of tissue 2-3 mm. broad. 

Common small trees of homes and gardens occasionally growing 
to large size in gardens and parks (as in the Parque Nacional, San 
Jose). The large lustrous thick leaves, usually dark green above, 
and the very large, often pink, stipules make this a very striking 
species. However, some trees do not have these large stipules and 
large leaves. The variations in leaf-size in the trees of this species 
must be due to genetic differences in different cultivated forms. 
The large tree in the northwestern corner of Parque Nacional in 
San Jose with small (6-12 cm. long) leaves looks very different 
from the large-leaved plants of this species that one usually sees. 

Ficus goldmanii Standley, Contr. U.S. Nat. Herb. 20:32. 1917. 
Urostigma verrucosum Liebm., Danske Vidensk. Selsk. Skrivt. 
5, 2:321. 1851. Ficus verrucosa Hemsl., Biol. Centr. Amer. Bot. 



162 FIELDIANA: BOTANY, VOLUME 40 

3:148. 1883, not F. uerrucosa Miquel, 1867. F. hemsleyana Standl., 
I.e. 20:29. 1917, as to type only, not F. hemsleyana King, 1887. 
Figure 19. 

Trees 6-15 m. tall, trunks often fluted and branching near the ground, aerial roots 
often present, leafy internodes 2-25 (55) mm. long 3-8 mm. thick, glabrous, periderm 
smooth but becoming ridged and pale brown (dry); stipules 8-14 mm. long, 3-4 mm. 
thick at the base unopened, glabrous to very minutely (-0.05 mm.) puberulent or 
with a few sericeous hairs 0.2-0.5 mm. long. Leaves clustered or distant, petiole 
16-38 mm. long, 1.2-2.8 mm. thick, glabrous or very minutely (0.05 mm.) puberulent, 
slightly sulcate above; laminae 8-21 cm. long, 3-9 (11) cm. broad, oblong to elliptic- 
oblong, abruptly rounded to obtuse or with a very short acute tip at the apex, ob- 
tuse to rounded at the base, stiffly chartaceous to subcoriaceous, smooth and gla- 
brous on both surfaces, the 7 to 12 pairs of major secondary veins flat above and 
slightly raised beneath, central secondaries arising at angles of 50-75 degrees, sec- 
ondaries weakly loop-connected near the margin, tertiary veins often obscure. Figs 
usually paired at a node, borne on peduncles 4-14 mm. long, 1.2-3 mm. thick, glab- 
rous or very minutely puberulent, slightly expanded at the apex but not forming a 
definite disc-like area, bracts 2, entire or split, about 3 mm. long and 3-4 mm. broad, 
essentially glabrous; figs globose, 9-14 mm. in diameter, surface smooth and glab- 
rous or very minutely (-0.05 mm.) puberulent, ostiole raised and conical, 3-4 mm. in 
diameter, the outer scales usually 3 (4) and occasionally surrounded by a weakly de- 
veloped ring of receptacular tissue 3-4 mm. in diameter; seeds and galls 1.3-1.7 mm. 
long. 

Trees of seasonally dry deciduous and evergreen forest forma- 
tions along the Pacific Coast in Costa Rica between sea level and 
300 m. elevation (to 1000 m. in Honduras); fertile collections have 
been made in December-January and July-August. The species 
ranges from Western Mexico and British Honduras to Panama. 

Ficus goldmanii is recognized by its glabrous or very minutely 
puberulent parts with pale colored hairs less than 0.05 mm. long 
(longer hairs on the stipules), usually oblong leaves, pedunculate 
figs, and seasonally dry lowland habitat. This species is said to be 
used for living fence posts in the Golfito area. This species is closely 
related to F. morazaniana, but that species has larger figs on short- 
er peduncles and is densely pubescent in many parts. A photograph 
of the type of Urostigma verrucosum (Oersted 14339 in C) appears 
to be this species. Standley proposed a new name for this species, 
Ficus hemsleyana, but did not see the type and placed material un- 
der his F. hemsleyana that is clearly referable to F. citri folia Miller. 

Ficus hartwegii (Miq.) Miquel, Ann. Mus. Bot. Lugd.-Bat. 3:299. 
1867. Urostigma hartwegii Miq. in Hooker, London Journ. Bot. 
6:545. 1847. Ficus brenesii Standl., Field Mus. Bot. 18:385. 1937. 
Figure 18. 



BURGER: FLORA COSTARICENSIS 163 

Trees 6-15 m. tall, epiphytes and stranglers or independent, leafy internodes 3-20 
mm. long, 2-5 mm. thick, sparsely puberulent or glabrous, periderm smooth but be- 
coming longitudinally ridged on drying and pale brown; stipules (4) 6-11 mm. long, 
2.5-3.5 mm thick at the base unopened, densely strigose with ascending straight or 
crooked hairs. Leaves often clustered near the ends of branchlets, petioles (8) 10-35 
mm. long, 0.8-2.2 mm. thick, glabrous or with a few slender hairs 0.5-1.5 mm. long, 
epidermis often coming off in small (0.5 mm.) flakes, usually sulcate above; laminae 
4-11 cm. long, 2.5-6 cm. broad, broadly elliptic to obovate or occasionally ovate, 
obtuse to acuminate or occasionally rounded at the apex, rounded or obtuse at the 
base, drying stiffly chartaceous, smooth and glabrous above, smooth below and usu- 
ally with a few slender yellowish hairs along the mid vein, the 4 to 8 pairs of major 
secondary veins slightly raised above and prominent beneath, central secondaries 
arising at angles of 40-70 degrees, basal secondaries prominent and strongly ascend- 
ing, secondaries weakly loop-connected near the margin, tertiary veins slightly 
raised beneath. Figs usually paired at the nodes, sessile and leaving a slight shelf on 
the stem, basal bracts 2, entire or deeply split, about 3 mm. broad and 1.5 mm. long, 
often united to the receptacle to form a circular area 3 mm. broad with the peduncle 
attached acentrically, puberulent at the base; figs 4-6 mm. in diameter, subglobose 
and flattened at the apex, surface smooth and glabrous, ostioles slightly elevated 
and disc-like, 1.5-2 mm. broad, wall of the fig very thin; galls and seeds 0.7-1 mm. 
long. 

Trees of the wet evergreen forest formations between 900 and 
1600 m. elevation and known in Costa Rica from the areas of San 
Pedro de San Ramon (Brenes 21931), La Palma de San Ramon 
(Brenes 5193, the type of F. brenesii), and near San Carlos (A. 
Smith 1668) in Alajuela; Cedral de Montes de Oro (Lankester & O. 
Jimenez 1344) in San Jose; near Cervantes ( Walters 48), Santa Cruz 
de Turrialba ( Valeria 1296), and near Tapanti (Lent 838) in Cartago; 
collected with mature figs from December to April. The species, as 
here defined, ranges from Costa Rica to Colombia. 

Ficus hartwegii is recognized by its small pinnately veined leaves 
with a few slender hairs along the midrib, small stipules and figs, 
and lower montane habitat. This species has been interpreted (De- 
Wolf 1960) to include the closely related F. colubrinae, which has, 
however, very different leaf-venation and lowland habitat. The lack 
of intermediates, both in morphology and altitudinal range, con- 
vinces me that these are distinct species. This species is more dis- 
tantly related to F. costaricana. 

Ficus insipida Willd., Sp. PI. ed. 4, 4:1143. 1806. F. glabrata 
H.B.K., Nov. Gen. & Spec. 2:47. 1818. Figure 21. 

Small to very large buttressed trees 8-40 m. tall, leafy internodes 4-35 mm. long, 
2-6 (8) mm. thick, glabrous, periderm smooth or slightly striate, often with the epi- 
dermis breaking off in small (0.5 mm.) flakes, grayish; stipules (2.5) 4-8 cm. long, 



164 FIELDIANA: BOTANY, VOLUME 40 

2-5 mm. thick at the base unopened, glabrous, drying yellowish-green. Leaves some- 
what clustered or distant near the ends of branchlets, petioles 16-50 mm. long, 1-2.2 
mm. thick, glabrous and narrowly sulcate above; laminae 8-22 cm. long, 3-8 cm. 
broad, oblong to elliptic or narrowly ovate, acute or short-acuminate at the apex, 
rounded to obtuse at the base, drying stiffly chartaceous and usually flat along the 
edge, glabrous and relatively smooth on both surfaces, the 12 to 24 pairs of major 
secondary veins slightly raised on both surfaces, central secondaries arising at 
angles of 60-90 degrees, secondaries weakly loop-connected near the margin and a 
submarginal vein present or absent, tertiary veins often obscure. Fig solitary at a 
node, borne (in ours) on a peduncle 5-10 mm. long, 2-4 mm. thick, glabrous, basal 
bracts 3, usually entire, about 3 mm. long and 3 mm. broad; figs 25-50 mm. in dia- 
meter at maturity (dry), globose to obovoid and distinctly narrowed above the basal 
bracts, sometimes stalked above the bracts, surface smooth and glabrous, green 
with paler colored spots but these drying darker, ostiole conical and 1-2 mm. high in 
early stages, remaining slightly raised in later stages, 2.5-5 mm. broad, exterior 
scales 3-5, the apices of the interior scales visible in later stages, wall of the figs. 3-6 
mm. thick (dry), seeds and galls 1.5-3 mm. long. 

Trees of the lowland areas of both the Caribbean and Pacific sides 
between sea level and 500 m. elevation in both wet evergreen forest 
formations and seasonally dry deciduous formations in Costa Rica; 
mature figs have been collected in December, March, and April. 
The species ranges from southern Mexico to southern Brazil (fide 
DeWolf). 

Ficus insipida is recognized by its often long narrow leaves gradu- 
ally tapering to the apex and with many secondary veins, glabrous 
parts, very large figs, and lowland habitat. The solitary figs, 
unusual trichomes on the lower leaf-surface, and frequent stream- 
side growth-site are characters of the subgenus Pharmacosycea. 
This species is more narrowly defined here than it was by DeWolf in 
the "Flora of Panama." Of the species recognized here and con- 
sidered conspecific with F. insipida by DeWolf, F. crassiuscula is 
most easily separated by both its morphology and ecology. Ficus 
werckleana differs only slightly in its larger, more blunt leaves and 
larger stipules, but the mature fruit appear to be much smaller. 
Ficus yoponensis is also closely related but seems to be more com- 
mon in wetter regions and at higher altitudes and the smaller leaves 
have more secondary veins. While the above are all closely related, 
it is interesting that no definite intermediates are known to me, but 
we do have several collections (Burger & Ramirez 4119, Guana- 
caste, and Croat 12695, Canal Zone) that appear to represent hy- 
brids with F. maxima. Ficus insipida appears to be better isolated 
from its close allies than from the more distantly related F. maxima. 
The latex is said to be used to remove intestinal parasites. 



BURGER: FLORA COSTARICENSIS 165 

Ficus isophlebia Standley, Contr. U.S. Nat. Herb. 20:14. 1917. 
Figure 20. 

Small to large trees 5-20 (30) m. tall, often with broad crowns and fluted banyan- 
like trunks, leafy internodes 5-15 (25) mm. long, 4-7 mm. thick, glabrous, becoming 
somewhat striate and grayish, figs forming slight indentations on the stems; 
stipules 12-35 (70) mm. long, 3-6 mm. thick at the base unopened, essentially gla- 
brous. Leaves often clustered near the ends of branchlets, petioles 1.5-4.5 (12) cm. 
long, 1.3-2.8 mm. thick, glabrous, narrowly sulcate above; laminae 5-12 (21) cm. 
long, 3-9 (16) cm. broad, oblong-orbicular to ovate or slightly obovate, usually 
rounded or more rarely bluntly obtuse at the apex, rounded at the base (rarely 
obtuse) and often cordulate at the petiole, lamina drying stiff-chartaceous to sub- 
coriaceous and the margin flat, smooth and glabrous above and below, the 6 to 9 
pairs of major secondary veins flat or slightly raised above and below, central 
secondaries arising at angles of 45-70 degrees, weakly loop-connected near the mar- 
gin and sometimes forming an arcuate submarginal vein distally, tertiary veins 
flat beneath. Figs usually 2 at a node, sessile and forming depressions on the stem, 
basal bracts 2, borne on the edge of a disc-like area on the lower half or third of the 
fig and marked by a peripheral ring of tissue or the bracts apparently united to the 
receptacle to form the disc-like area (in dried material), bracts about 6 mm. long and 
8 mm. broad (free portion), glabrous or minutely (0.05-0.1 mm.) puberulent, 
peduncle attached acentrically on the disc; figs 8-12 mm. in diameter, globose or be- 
coming flattened apically and in the plane of attachment, covered about 50 per cent 
by the bracts, surface glabrous and smooth with dark spots, ostiole about 2 mm. 
broad, raised and conical, about 1.5 mm. high and drying dark, seeds and galls 1.2 
mm. long. 

Trees known only from near sea level (0-80 m. ) in Costa Rica and 
Panama on both the Caribbean and the Pacific coasts. This species 
is also found in Nicaragua on the Pacific slopes to as high as 900 m. 
altitude on the Sierra de Managua and ranges to Tabasco, Mexico, 
along the Caribbean slope. Figs have been collected in May, July, 
and September. 

Ficus isophlebia is recognized by the usually small rounded gla- 
brous leaves, glabrous stipules, and very unusual figs. In living 
material the lower half or third of the fig appears quite different 
from the top and is not simply the area where the bracts are adnate 
to the receptacle. Rather, the bracts arise from the edge of this basal 
"disc." These differences are very difficult to see in dried material. 
This unusual base, with acentrically attached peduncle rimmed by 
a periphery of thickened tissue from which the bracts arise, is 
similar to that seen in F. jimenezii. The depressions formed by the 
figs on the stems are not as deep and shelf-like as those seen on F. 
tuerckheimii. Ficus aurea Nutt. of the West Indies is more dis- 
tantly related toF. isophlebia and its Costa Rican allies. 



166 FIELDIANA: BOTANY, VOLUME 40 

Ficus jimenezii Standley, Contr. U.S. Nat. Herb. 20:13. 1917. 
Figure 20. 

Trees 10-25 m. tall, often with large spreading crowns, epiphytic stranglers or in- 
dependent, trunks becoming 2 m. in diameter and fluted, grayish, leafy internodes 
3-14 (20) mm. long, 3-6 mm. thick, glabrous, periderm striate and dark to pale gray, 
stems often with shelf-like depressions formed at the fig attachments; stipules (5) 
16-42 mm. long, 3-5 mm. thick at the base unopened, densely puberulent (except 
along the margins) abaxially with grayish white ascending hairs 0.05-0.4 mm. long. 
Leaves usually clustered at the ends of twigs, petioles 12-25 (45) mm. long, 1.2-3 
mm. thick, glabrous, narrowly sulcate adaxially; laminae 5-12 (15) cm. long, 3-79) 
cm. broad, broadly elliptic to oblong, obovate, or suborbicular, rounded or bluntly 
obtuse at the apex and occasionally emarginate, rounded to subtruncate or abruptly 
obtuse at the base, drying subcoriaceous and the margin flat or slightly revolute, 
glabrous and smooth on both surfaces, the 6 to 18 pairs of major secondary veins 
usually flat on both surfaces and difficult to distinguish from intermediate veins, 
central secondaries arising at angles of 50-80 (90) degrees, a slightly arcuate sub- 
marginal vein present but often difficult to see, tertiary veins flat but readily visible 
beneath. Figs usually 2 at a node, often crowded behind the leaves near the ends of 
branchlets, sessile and attached on its side (relative to the ostiole), bracts 2, arising 
from the edge of a basal disc-like area on the fig, entire or split, about 4 mm. long 
and 7 mm. broad, encircling half the fig, glabrous; figs 8-10 mm. in diameter, flat- 
tened longitudinally and oblate, round or slightly 3-cornered, surface glabrous and 
smooth, pale reddish to whitish, ostiole drying darker, slightly raised and conical, 
exterior scales usually 2; seeds and galls 0.7-1.2 mm. long. 

Common large trees of the seasonally dry evergreen forest forma- 
tions between about 800 and 1400 m. elevation in Costa Rica; 
probably flowering throughout the year. The species is known from 
near Tilaran (Guanacaste) in the west to the eastern edge of the 
Meseta Central near Santa Ana (San Jose) and Cartago (Cartago) 
in Costa Rica; it ranges northward to Guatemala. 

Ficus jimenezii is recognized by the thick glabrous rounded leaves 
with venation somewhat obscure (dry), stipules with minute 
whitish hairs, small figs with conspicuous bracts borne from a large 
(3-6 mm. broad) basal "disc" and attached to the stem near the edge 
of this disc, and the very restricted distributions. This species is 
commonly planted in hedgerows and in parks. Ficus isophlebia, F. 
jimenezii, and F. tuerckheimii are a closely related trio and were 
considered conspecific in the "Flora of Panama"; see the discussion 
under F. tuerckheimii. 

Ficus laterisyce Burger, Phytologia 26:426. 1973. Figure 20. 

Medium sized ( 10 m.) trees, often stranglers, leafy internodes 4-12 ( 16) mm. long, 
2-6 mm. thick, essentially glabrous, becoming grayish and longitudinally striate 
with shelves formed beneath the sessile figs; stipules (5) 8-18 mm. long, about 4 mm. 



BURGER: FLORA COSTARICENSIS 167 

broad at the base, glabrous or very minutely (0.05-0.1 mm.) puberulent throughout. 
Leaves often clustered near the ends of branches, petioles 1.2-3.6 cm. long, about 2 
mm. thick, glabrous or very minutely puberulent, longitudinally striate when dry 
and sulcate above; laminae 4.5-11 cm. long, 2.5-6 cm. broad, elliptic to elliptic-oblong 
or slightly obovate, acute or very short acuminate at the apex, acute to obtuse 
(rarely rounded) at the base, entire, the laminae drying stiffly chartaceous, smooth 
and glabrous on both surfaces, the 5 to 9 pairs of major secondary veins arising at 
angles of 30-60 degrees, weakly loop-connected near the margin, flat on both sur- 
faces and often somewhat obscure beneath. Figs usually paired at a node, sessile 
and leaving shelves on the branchlets, usually attached on the side with respect to 
the ostiole, basal bracts arising from the edge of a broad disc-like area about 5 mm. 
broad beneath, attachment of the fig at the edge of this often pusticulate disc-like 
area, bracts about 3-4 mm. long (measured from the edge of the disc) and 5 mm. 
broad, glabrous or very minutely (0.05-0.1 mm.) puberulent; the fig 6-8 mm. in dia- 
meter (larger at maturity?), flattened above and below and occasionally on one side 
but usually oblate, the surface smooth and glabrous, ostioles 2-2.5 mm. broad, very 
slightly conical, lustrous brown, with usually only 2 exterior scales; seeds and galls 
about 0.7-1.3 mm. long. 

The species is only known from the wet Caribbean slopes between 
Cariblanco and San Miguel de Sarapiqui, Alajuela, and near Taus, 
Cartago. All of these collections were made near an altitude of 750 
m. with figs in pre-fruiting stages in October, April, and May. 

Ficus laterisyce is distinguished by the glabrous or very minutely 
puberulent parts, small laminae on prominent petioles, sessile figs 
attached at the side and leaving prominent shelves in the branch- 
lets, and the relatively large bracts arising from the edge of a disc- 
like area beneath the fig. The paired figs, strangling habit, and few 
exterior scales on the ostiole are characteristics of the subgenus 
Urostigma. The figs of this species are very similar to those of F. 
isophlebia in the development of the disc-like base and lateral 
attachment, but the leaves are quite different. This species also re- 
sembles F. davidsoniae, which has much more coriaceous leaves 
with many more secondary veins and the figs not usually laterally 
attached. 

Dr. Leslie Holdridge has recently suggested that F. laterisyce is 
conspecific with F. jimenezii. The type of F. laterisyce (Lent 2972) 
differs from material of F. jimenezii in the leaves more acute at the 
base and apex, the venation more prominent above, the petioles 
shorter, the stipules only minutely puberulent, and somewhat 
smaller figs (see fig. 20). These differences, however, may be only 
extremes of variation centering around the more typical characters 
of F. jimenezii. More extensive sampling of these populations will 
be required to resolve these problems. 



168 FIELDIANA: BOTANY, VOLUME 40 

Ficus lyrata Warburg, Bot. Jahrb. 20:172. 1894. F. pandurata 
auctores in hort. 

Trees to 20 m. tall, leafy internodes 1-5 cm. long, 6-12 mm. thick, glabrous or 
sparsely puberulent. Leaves usually glabrous, petioles 5-30 mm. long, 2-6 mm. thick, 
often shorter than the lamina-lobes; laminae 11-40 cm. long, 7-20 cm. broad, usually 
pandurate in shape with the distal half broader than the proximal half, abruptly 
rounded at the apex with a blunt rounded tip, narrowed below the middle and nar- 
rowly cordate at the base, margin entire but often somewhat undulate, drying sub- 
coriaceous, the 4 to 6 pairs of major secondary veins prominent beneath, a sub- 
marginal vein absent. Figs usually paired at a node, sessile or subsessile, globose, 
becoming 3-5 cm. in diameter. 

Grown in parks and gardens as trees and also in pots within 
homes. The large dull green leaves of unusual shape are very distinc- 
tive. 

Ficus macbridei Standley, Field Mus. Bot. 13:305. 1937. F. tor- 
resiana Standl., I.e. 18:387. 1937. Figure 21. 

Small or medium-size trees 6-15 m. tall with spreading branches and a broad 
crown, trunk relatively smooth, leafy internodes 2-30 (40) mm. long, 6-15 (20) mm. 
thick, glabrous or sparsely puberulent, periderm with small dark lenticels, often pale 
and peeling off in small flakes; stipules 4-6 (7) cm. long, 5-10 mm. thick at the base 
unopened, glabrous to very densely and minutely sericeous. Leaves borne near the 
ends of thick branchlets, petioles (2) 4-16 cm. long, 3.5-6 mm. thick, sparsely and 
minutely (0.3-0.6 mm.) puberulent, epidermis often breaking off in small (0.5 mm.) 
flakes, longitudinally striate or deeply ridged, terete; laminae 20-36 (42) cm. long, 
10-23 (28) cm. broad, broadly elliptic or ovate, broadest at or just below the middle, 
tapering abruptly to the obtuse to short-acuminate apex, abruptly narrowed or 
rounded to the truncate or sub-cordate base, margins usually cordulate at the 
petiole, drying stiff-chartaceous and often pale grayish green, usually glabrous and 
smooth above, puberulent beneath with thin straight whitish hairs 0.1-0.5 mm. 
long and very sparse to moderately dense on the midvein, the 9 to 13 pairs of major 
secondary veins flat above and prominent beneath, central secondaries arising at 
angles of 60-90 degrees, weakly loop-connected near the margins but not forming a 
submarginal vein, tertiary veins slightly raised beneath. Figs solitary at a node, 
sessile or subsessile on peduncles 0-4 mm. long and 2-3 mm. thick, bracts 3, usually 
entire, 4-8 mm. long and equally broad, glabrous; figs becoming 3 cm. in diameter 
and 2.5 cm. long, obovoid to slightly oblate, surface dark green with paler green 
spots but these drying dark on a paler background, minutely hispidulous between 
the spots and the surface somewhat scabrous, ostiole about 2 mm. broad, conical, 
with several exterior scales and the apices of interior scales evident, fig-wall 2.5-4.5 
mm. thick (dry); seeds and galls 2-2.8 mm. long. 

Plants of the very wet Caribbean slopes between (400) 1000 and 
1600 m. elevation; known in Costa Rica only from the areas of 
Volcan Arenal, La Calera de San Ramon, and Zarcero in Alajuela, 
from the La Hondura area in San Jose, and from the upper Rio 



BURGER: FLORA COSTARICENSIS 169 

Reventazon drainage in Cartago. Mature figs have been collected in 
May and immature figs in April and September. The species ranges 
to Venezuela and Peru. 

Ficus macbridei is distinguished by the large and relatively broad 
leaves scabrous beneath and lacking a definite submarginal vein. The 
figs solitary at a node and the unusual multicellular trichomes on 
the lower leaf-surface (150X) are characteristic of the subgenus 
Pharmacosycea. This species is very closely related to F. tonduzii 
but is of smaller stature, with rather different leaves, and usually 
found at higher elevations. An unusual collection from the lower 
slopes of Volcan Arenal (Lent 3326} has one, two, or three figs at a 
node. 

The name Ficus lapathifolia (Liebm.) Miq. has been used in- 
correctly in Central America and Mexico, according to Gomez- 
Pompa (Estudios Botanicos en la region de Misantla, Vera Cruz. 
Mexico, D.F., 1966). It is, in fact, a species of Pharmacosycea simi- 
lar to F. macbridei, but differs in the less puberulent laminae with a 
greater number of secondary veins. That species, like F. macbridei, 
differs from F. tonduzii in the laminae scabrous beneath and lacking 
a definite submarginal vein. The three species are closely related but 
appear to be unrepresented in the area between Veracruz and Hon- 
duras. 

Ficus maxima P. Miller, Card. Diet, ed 8, Ficus no. 6. 1768. F. 
radula H. & B. ex Willd., Sp. PL ed. 4, 4: 1144. 1806. Figure 21. 

Small to large trees 7-25 m. tall, trunk usually smooth, often developing but- 
tresses, leafy internodes 5-30 (45) mm. long, 2-5 mm. thick, glabrous, periderm dark 
brown or reddish brown, smooth or somewhat stria te, epidermis often peeling off in 
small strips; stipules 10-25 (35) mm. long, 2-4 mm. thick at the base unopened, gla- 
brous or puberulent near the base. Leaves usually distant near the ends of branch- 
lets, petioles 8-30 (40) mm. long, 1.5-3 mm. thick, glabrous, epidermis usually crack- 
ing and peeling off in small (0.5 mm.) flakes and reddish-brown; laminae (7) 10-19 
(23) cm. long, (3) 5-8 (12) cm. broad, elliptic to oblong or obovate, abruptly acute, 
or short-acuminate, obtuse at the apex but the tip usually rounded, obtuse to acute 
or occasionally cuneate at the base, drying stiff -chartaceous and the margins often 
revolute, usually smooth above and scabrous beneath, glabrous on both surfaces, 
the (5) 8 to 11 ( 13) pairs of major secondary veins usually flat above and prominent 
beneath, loop-connected near the margin but with a definite submarginal vein only 
in the proximal third of the lamina (or rarely throughout), central secondaries 
arising at angles of 60-80 degrees, basal secondaries strongly ascending and forming 
the submarginal vein, tertiary slightly raised beneath. Fig solitary at a node, 
usually borne on peduncles (2) 5-18 (25) mm. long, 1-2 mm. thick, glabrous or 
minutely puberulent, bracts 3, usually entire, about 1 mm. long and 2 mm. broad; 



170 FIELDIANA: BOTANY, VOLUME 40 

figs 14-20 (28) mm. in diameter, globose or slightly narrowed at the base and sub- 
globose-obovoid, surface scabrous, glabrous (X10) or very minutely (0.05 mm.) 
puberulent in ours, ostiole 1-2 mm. broad, flat, external scales several with the 
apices of interior scales evident, wall of the fig 0.5-2.5 mm. thick (dry); seeds and 
galls 1.5-2 mm. long. 

A tree of lower (0-1000 m.) elevations on both the Caribbean and 
Pacific sides of Costa Rica, frequently growing along streams and 
more commonly collected in the seasonally dry areas; mature figs 
have been collected from January to August. The species ranges 
from southern Mexico into the Amazonian basin. 

Ficus maxima is recognized by the brownish stems, exfoliating 
epidermis on the petioles, medium-size leaves scabrous beneath, and 
pedunculate figs with scabrous surface. The solitary figs and 
unusual trichomes on the lower leaf-surface (X 150) are characters of 
the subgenus Pharmacosycea. The species is related to F. insipida 
and there are collections (A. Jimenez 93 and Burger & Ramirez 
4119) that appear to represent hybrids between the two species. Col- 
lections from the Caribbean lowland are distinguished in our area by 
leaves with a rather prominent submarginal vein throughout the 
length of the lamina. 

Ficus morazaniana W. Burger, Phytologia 26:427. 1973. F. 
lapathifolia auctores notF. lapathifolia (Liebm.) Miquel. Figure 19. 

Trees 5-25 m. tall, trunk often fluted of grown-together stems, usually seen as 
independent trees but often beginning as epiphytes or stranglers, leafy internodes 
8-65 mm. long, 4-12 mm. thick, sparsely to densely puberulent with erect slender 
hairs about 0.5 mm. long, periderm becoming glabrous, smooth and longitudinally 
deeply ridged (dry); stipules 12-30 mm. long, 5-9 mm. thick at the base unopened, 
with minute (0.05 mm.) or larger (0.5 mm.) ascending hairs. Leaves clustered or dis- 
tant, petioles 12-40 mm. long, 2-4 mm. thick, densely hirsute with brownish hairs 
0.3-1 mm. long, terete to narrowly sulcate above and longitudinally striate on dry- 
ing; laminae 10-29 (33) cm. long, 5-13 ( 16.5) cm. broad, obovate to oblong or broadly 
elliptic, abruptly rounded or occasionally obtuse at the apex, obtuse to rounded at 
the base and often slightly cordulate at the petiole, drying very stiffly chartaceous 
and the margins slightly revolute, smooth but minutely hirsute above, densely 
hirsute beneath with slender pale brownish hairs 0.3-1 mm. long, the 9 to 14 pairs of 
major secondary veins flat above and prominent beneath, central secondaries 
arising at angles of 50-80 degrees, secondaries weakly loop-connected near the mar- 
gin and a submarginal vein usually absent, tertiary veins readily evident beneath. 
Figs usually paired at a node, borne on peduncles 4-8 mm. long, 1.5-3 mm. thick, 
hirsute with ascending yellowish hairs about 0.7 mm. long, bracts 2, usually entire, 
about 2-4 mm. long and 5 mm. broad, minutely puberulent, a disc-like thickening at 
the base of the bracts usually absent or poorly developed (sometimes present); figs 
12-19 mm. in diameter, 16-20 mm. long, globose to somewhat obovoid, the surface 
densely pale tomentulous with hairs 0.05-0.5 mm. long, ostiole conical in early stages 



BURGER: FLORA COSTARICENSIS 171 

but becoming surrounded by a ring of thickened tissue 2-3 mm. broad, often 
elevated above the surface of the fig; seeds and galls 1-1.5 mm. long. 

Trees of the seasonally dry deciduous and evergreen forest forma- 
tions from sea level to about 1100 m. elevation on the Pacific slopes 
of Costa Rica and more rarely on the wet Caribbean slopes ; mature 
figs have been collected between November and March. This species 
ranges from southern Mexico to Central Costa Rica, mostly along 
the Pacific slopes. 

Ficus morazaniana is recognized by its puberulent leaves and 
stems, pedicellate figs with densely puberulent surface and rather 
small bracts, and its apparent preference for seasonally dry habi- 
tats. This species is very closely related to F. trigonata L. but dif- 
fers in the slightly larger and more puberulent figs, more puberulent 
laminae with a greater number of secondary veins, and different 
habitat and range. This species is a member of the subgenus 
Urostigma but the plants have been incorrectly placed under 
the name F. lapathifolia (Liebm.) Miq., which is a Mexican species 
belonging to the subgenus Pharmacosyce. 

There are collections from the Yucatan peninsula and from a few 
areas of Central America that lack the dense pubescence typical of 
F. morazaniana, and these resemble F. trigonata. There are insuf- 
ficient collections at present to determine whether these are local 
variants or whether they represent intermediates between what are 
here considered to be two different species. Ficus morazaniana can 
also be mistaken for F. velutina andF. goldmanii. 

Dr. Leslie Holdridge has recently made a collection (6804) from 
Nosara on the Pacific coast of the Nicoya peninsula, which differs 
from typical material of this species by having figs 3.5 cm. in dia- 
meter that become about 2.8 cm. in diameter when dry with seeds 
and galls 1.5-2 mm. long. A rather similar collection (Lundell 1242) 
has been made from Monterey, Campeche, Mexico. These collec- 
tions may be unusual representatives of this species or they may in- 
dicate that more than one species is represented by the material 
placed under this name. A study of these plants will have to include 
the closely related F. perez-arbelaezii Dugand and F. sanguinosa 
Dugand of Central Colombia. 

Ficus nymphaeifolia P. Miller, Card. Diet. ed. 8, Ficus no. 9. 1768. 
F. duquei Dugand, Caldasia 1:42. 1942. Figure 20. 

Small to very large trees 7-35 m. tall, epiphytes or independent, occasionally with 
buttress-like aerial roots, leafy internodes 2-25 (50) mm. long, 4-10 mm. thick, gla- 



172 FIELDIANA: BOTANY, VOLUME 40 

brous, periderm striate on drying, figs often forming shelf -like depressions in the 
stem; stipules 16-30 (40) mm. long, 4-9 mm. thick at the base unopened, glabrous 
and drying dark brown. Leaves usually clustered at the ends of branchlets, petioles 
5-18 cm. long, 1.7-3 mm. thick, terete but longitudinally striate on drying; laminae 
(10) 14-35 cm. long, (9) 11-24 cm. broad, broadly ovate or ovate-elliptic, narrowed 
abruptly to the obtuse, acute, or short-acuminate apex, cordate at the base with the 
rounded lobes extending 1-7 cm. below the petiole attachment and slightly overlap- 
ping in larger leaves, drying chartaceous and flat, smooth and glabrous on both sur- 
faces, the 4 to 8 pairs of major secondary veins flat or slightly raised above and 
below, central secondaries arising at angles of 40-80 degrees, tertiary veins forming 
a fine flat reticulum beneath. Figs usually paired at a node, sessile or subsessile on 
a peduncle 1-4 mm. long and about 3 mm. thick, basal bracts 2, usually entire and 
quite variable, 6-20 mm. long, about 6 mm. broad at the base, united with the 
receptacle near the base, glabrous or minutely (0.03-0.1 mm.) puberulent; figs 17-20 
(25) mm. in diameter, globose or oblate, surface smooth to the touch with very 
minutely (0.01 mm.) velutinous hairs, drying pale in color, ostiole usually raised on 
a ring of tissue 5-7 mm. in diameter, exterior scales usually 3, wall of the fig very 
thin (dry); seeds and galls 1.6-2 mm. long. 

Trees of the lowland wet evergreen forest formations along the 
Caribbean coast and in the Golfo Dulce areas of Costa Rica between 
sea level and. 500 m. elevation; probably flowering throughout the 
year. The species ranges from Costa Rica southward to Colombia 
and northern Brazil. 

Ficus nymphaei folia is one of our most easily recognized species 
with its long-petiolate broadly cordate leaves, subsessile figs with 
satin-like surface, and wet lowland habitat. The species is apparent- 
ly common but, perhaps because of its size, only rarely collected. 



Ficus obtusifolia H.B.K., Nov. Gen. & Sp. 2:49. 1817. Urostigma 
involutum Liebm., Danske Vidensk. Selsk. Skrivt. 5, ser. 2:320. 
1851. Ficus involuta (Liebm.) Miq., Ann. Mus. Bot. Lugd. Bat. 
3:298. 1867. F. proctor-cooperi Standl., Field Mus. Bot. 4:201. 1929. 
Figure 20. 

Small to very large trees 8-25 (45) m. tall, stranglers or independent, the trunks of- 
ten fluted and with narrow buttresses, leafy internodes 2-25 mm. long, 5-10 ( 14) mm. 
thick, glabrous, periderm becoming deeply ridged longitudinally and often grayish, 
figs producing shelf-like depressions in the branchlets; stipules 10-40 mm. long, 7-11 
mm. thick at the base unopened, glabrous, occasionally persisting with the leaves. 
Leaves usually clustered at the ends of twigs, petioles 8-25 (45) mm. long, 1.5-5 mm. 
thick, glabrous, deeply sulcate above; laminae 11-22 cm. long, 5-10 cm. broad, obo- 
vate, abruptly rounded at the apex or occasionally bluntly obtuse, attenuate at the 
base, drying stiffly chartaceous to subcoriaceous and the margin slightly revolute, 
smooth and glabrous on both surfaces, the 5 to 10 pairs of major secondary veins 
flat above and prominent beneath, central secondaries arising at angles of 45-70 de- 



BURGER: FLORA COSTARICENSIS 173 

grees, secondaries usually loop-connected only near the apex of the lamina, tertiary 
veins slightly raised or flat beneath. Figs usually paired at a node, often clustered at 
the ends of stems, borne on short (2-5 mm.) thick (3-6 mm.) peduncles, peduncles 
slightly expanded apically, glabrous, bracts 2, entire or split, 6-14 mm. long, about 
12 mm. broad, united basally with the receptacle over an area about 10 mm broad, 
glabrous or very minutely (0.05 mm.) puberulent; figs 16-20 mm. in diameter, glob- 
ose or becoming flattened at both ends, 12-16 mm. long, surface very minutely (0.05 
mm.) velutinous and soft to the touch, often lustrous, ostioles 3-5 mm. broad, flat or 
slightly raised to form an elevated disc, exterior scales usually 2(3); seeds and galls 
1.5-2.5 mm. long. 

Trees of the lowland forest formation between sea level and 1000 
m. elevation on both the very wet Caribbean slopes and in the sea- 
sonally very dry areas of Guanacaste in Costa Rica; mature figs 
have been collected in February, March, and September. The spe- 
cies ranges from southern Mexico to northern Peru. 

Ficus obtusifolia is readily recognized by the obovate leaves 
rounded at the apex attenuate at the base and crowded at the ends 
of branchlets, essentially glabrous parts, and large subsessile figs 
with very conspicuous basal bracts. This species does not appear to 
be closely related to other Costa Rican species but compare F. 
nymphaei folia. This species possesses a wider ecological amplitude 
as regards rainfall than most of our species of Ficus, but its altitudi- 
nal range is not unusual. 



Ficus ovalis (Liebm.) Miq., Ann. Mus. Bot. Lugd. Bat. 3:299. 
1867. Urostigma ovale Liebm., Danske Vidensk. Selsk. Skrivt. 5, 
2:324. 1851. Figure 19. 

Shrubs or small trees 4-10 m. tall or occasionally becoming large with spreading 
branches, leafy internodes 1-10 (25) mm. long, 2-5 mm. thick, glabrous or puberulent 
with slender hairs 0.2-0.5 mm. long, becoming grayish and smooth or ridged; 
stipules 6-14 (18) mm. long, 2-4 mm. thick at the base unopened, glabrous or 
sparsely and very minutely puberulent near the base. Leaves clustered or occasion- 
ally distant, petioles 6-20 (40) mm. long, glabrous or puberulent, narrowly sulcate 
above; laminae (4) 5-11 cm. long, (2) 3-7 cm. broad, broadly oblong to obovate or 
rarely ovate, rounded to bluntly obtuse at the apex, narrowed to truncate or 
rounded at the base and often emarginate at the petiole, drying very stiffly 
chartaceous, smooth and glabrous above, glabrous to densely puberulent beneath 
with slender erect hairs 0.2-0.7 mm. long, the 3 to 5 (6) pairs of major secondary 
veins raised above and prominent beneath, central secondaries arising at angles of 
30-60 degrees, tertiary venation slightly raised beneath. Figs usually paired at a 
node, borne on peduncles 2-12 (17) mm. long, 0.8-1.5 mm. thick, expanded at the 
base of the bracts, glabrous or very minutely puberulent, bracts 2, about 3 mm. 
long and 4 mm. broad, glabrous; mature figs 8-10 mm. in diameter, globose or 
slightly obovoid, surface smooth and glabrous, often yellowish, ostiole 2-3 mm. 



174 FIELDIANA: BOTANY, VOLUME 40 

broad and usually conspicuously umbonate, 1-2 mm. high, only 2 exterior scales 
usually visible; seeds and galls 0.7-1 mm. long. 

A species of the seasonally very dry deciduous formations of the 
Pacific slope in southern Central America and ranging from sea 
level to 1200 m. elevation; mature fruit have been collected from 
November to July but the majority of collections are from June. 
The species ranges from southern Mexico and British Honduras 
southward to Nicaragua and northwestern Costa Rica. The type 
(Oersted 14326) from Sta. Rosa, Guanacaste, is the only collection 
reported from Costa Rica. 

Ficus ovalis is distinguished by its small pedunculate figs with 
prominent ostiole, small rounded leaves, and seasonally very dry 
habitat. Nicaraguan and Costa Rican material is glabrous but col- 
lections from Honduras vary from glabrous to densely puberulent 
on the leaves beneath; the figs are always glabrous. This species is 
apparently related to F. perforata, F. hartwegii, and F. goldmanii 
among our species. 

Ficus palmata Forsk., Fl. Aegypt. Arab. 179. 1775. 

Shrubs or small trees 2-6 m. tall, leafy internodes 5-30 mm. long, 4-7 mm. thick, 
densely puberulent; stipules 5-10 mm. long. Leaves quite variable and sometimes 
3-lobed, petioles 2-7 cm. long, 1.5-3 mm. thick, densely hispidulous; laminae 8-18 cm. 
long, 6-16 cm. broad, usually ovate, obtuse at the apex or occasionally 3-lobed, 
rounded at the truncate to subcordate base (occasionally with 2 side lobes at the 
base), the margin bluntly dentate, drying stiffly chartaceous and very scabrous 
above, venation somewhat palmate with 3 main veins from the base, midvein with 3 
to 5 pairs of secondaries, densely puberulent beneath. Fig solitary at a node, borne 
on a peduncle about 1 cm. long, 1.5 mm. thick and densely hispidulous, bracts 3; fig 
stalked above the bracts, obovoid to pyriform, 12-18 mm. in diameter, ostiole 
slightly elevated and conical. 

Occasionally planted in the gardens of San Jose and called 
higueron de Kabul. This species can be mistaken for F. carica and is 
unusual in that the male flowers have three to six stamens; it is 
native to northern Africa and Arabia. 

Ficus paraensis (Miq.) Miquel, Ann. Mus. Bot. Lugd. Bat. 3:298 
1867. Urostigma paraensis Miq., Hook. London Journ. Bot. 6:534. 
1847. F. panamensis Standl., Contr. U.S. Nat. Herb. 20:15. 1917. 
Figure 18. 

Shrubs or small to large trees 5-20 m. tall, often seen as epiphytes and associated 
with the aerial carton nests of ants, leafy internodes 6-18 (30) mm. long, 2.3-6 mm. 
thick, glabrous (in ours), periderm weakly ridged or striate and gray or pale brown, 
the figs often leaving shallow shelf-like depressions in the stems; stipules 12-28 mm. 



BURGER: FLORA COSTARICENSIS 175 

long, 3-5 mm. thick at the base unopened, glabrous or very minutely (0.05 mm.) pub- 
erulent, drying dark brown. Leaves usually distant along the stem, petioles 8-36 
mm. long, 1.3-2.3 mm. thick, glabrous or very minutely (0.05 mm.) puberulent, 
deeply sulcate above; laminae 8-20 (25) cm. long, 3.5-7 cm. broad, narrowly oblong 
to elliptic-oblong or narrowly obovate, tapering abruptly to the short-or long-acu- 
minate apex, the narrowed tip 5-15 mm. long, gradually narrowed below the middle 
but abruptly narrowed and rounded or subtruncate to cordulate at the petiole, dry- 
ing stiffly to very stiffly chartaceous, smooth and glabrous on both surfaces or very 
minutely (0.05 mm.) puberulent on the midvein beneath, the (6) 10-17 (20) pairs of 
major secondary veins usually flat above and prominulous beneath, central second- 
aries arising at angles of 60-75 (80) degrees, secondaries weakly loop-connected near 
the margin and sometimes forming a weak submarginal vein. Figs usually paired at 
a node, sessile, subsessile or borne on a peduncle to 3 mm. long, 2-3 mm. thick, bracts 
2, usually entire, 2-4 mm. long, 3-4 mm. broad, glabrous or very minutely puberu- 
lent, occasionally with the apex of the peduncle forming a disc-like ring 3 mm. in dia- 
meter at the base of the bracts; figs 10-14 mm. in diameter, globose to slightly ellip- 
soid or sub-pyriform,surface smooth, glabrous and often pale in color with darker 
longitudinal streaks, ostiole prominently raised and cone-like or umbonate, 1-3 mm. 
high and 2-4 mm. broad, usually with 2 large outer scales and a third smaller scale 
apparent, usually drying dark; seeds and galls 1-1.5 mm. long. 

Trees of wet evergreen forest formations between sea level and 
1000 (1600) m. elevation and known in Costa Rica from only the 
General Valley, San Jose (Skutch 5423), and Pejivalle, Cartago, 
(Skutch 4623). The species ranges from southern Mexico and Bri- 
tish Honduras to Peru and Northern Brazil. 

Ficus paraensis is recognized by its usually abruptly acuminate 
oblong-obovate leaves, essentially glabrous parts, and sessile or 
short-pedunculate figs often longer than thick and with a very 
prominently umbonate ostiole. The species is often associated with 
the aerial nests of ants, either as an epiphyte growing on or with the 
nest and as independent trees. This species appears to be closely 
related toF. citrifolia andF. cervantesiana among our species. 



Ficus perforata L., PI. Surinam. 17. 1775. Urostigma eugeniae- 
folium Liebm., Danske Vidensk. Selsk. Skrivt. 5, ser. 2:329. 1851. 
U. oerstedianum Miq. in Seem., Bot. Voy. Herald 196, t. 36. 1854. 
Ficus oerstediana (Miq.) Miq., Ann. Mus. Bot. Lugd. Bat. 3:299. 
1867. F. eugeniaefolia (Liebm.) Hemsl., Biol. Centr. Amer. Bot. 
3:144. 1883. F. georgii Standl. & L.O. Williams, Ceiba, 1:236. 1951. 
Figure 18. 

Small to large trees (4-20 (30) m. tall, often branching near the ground, only occa- 
sionally seen as epiphytes, leafy internodes 1-12 (25) mm. long, 1.4-3.5 (5) mm. thick, 
glabrous, periderm becoming striate and often peeling in small (0.5 mm.) flakes, 
grayish brown; stipules 4-16 mm. long, 2-4 mm. thick at the base unopened, mi- 



176 FIELDIANA: BOTANY, VOLUME 40 

nutely (0.05-0.1 mm. ) puberulent or glabrous. Leaves distant or clustered, petioles 4- 
18 mm. long, 1-1.5 mm. thick, glabrous or very minutely (0.05 mm.) puberulent, sul- 
cate above; laminae (2.5) 4-12 cm. long, (1.5) 2-5.5 cm. broad, elliptic to obovate or 
oblanceolate, obtuse to acute or short -acuminate (rarely rounded) at the apex but 
often blunt at the tip, cuneate to obtuse at the base, drying very stiffly chartaceous 
to subcoriaceous, smooth and glabrous above and below, the 7 to 14 pairs of major 
secondary veins slightly raised on both surfaces and often difficult to distinguish 
from the intermediate veins, central secondaries arising at angles of 60-80 degrees, 
secondaries loop-connected near the margins and an arcuate submarginal vein usu- 
ally present, tertiary veins slightly raised on both surfaces. Figs usually paired at a 
node, borne on peduncles 4-12 mm. long, 0.5-1 mm. thick, flared at the apex, glab- 
rous, bracts 2, usually entire, 1-2 mm. long, about 2 mm. broad, glabrous or very mi- 
nutely (-0.05 mm.) puberulent; figs (4) 6-9 mm. in diameter, globose to somewhat 
obovoid or turbinate, with narrowed base and flattened apex, surface glabrous and 
smooth, pale in color with darker spots, ostiole 2-3 mm. broad, flat or slightly raised, 
drying dark, sometimes with a thickened ring of tissue around the periphery, exter- 
ior scales 2 or 3; seeds and galls 0.7-1 mm. long. 

Plants of the very wet evergreen forest formations between sea 
level and 1200 m. elevation and probably flowering throughout the 
year. Most commonly collected between 400 and 1000 m. on the 
Caribbean slope in Costa Rica and planted on the Meseta Central. 
The species ranges from Guatemala and British Honduras south- 
ward to Colombia and is found in the Bahamas and Greater 
Antilles. 

Ficus perforata is recognized by the usually very small, stiff glab- 
rous leaves and small pedunculate figs with flat or slightly raised 
ostiole. This species is similar to F. pertusa in leaf-size and shape 
but differs in the fig. 



Ficus pertusa L.F., Suppl. Plant. 442. 1781. F. padifolia H.B.K., 
Nov. Gen. & Sp. 2:47. 1817. Figure 18. 

Usually small trees 5-12 (30) m. tall, often seen as epiphytes or stranglers, leafy 
internodes 3-20 (30) mm. long, 1.2-3.5 mm. thick, glabrous or less often puberulent 
with small whitish hairs 0. 1-0.3 mm. long, periderm becoming irregularly striate and 
grayish; stipules (3) 5-10 mm. long, 1.2-3 mm. thick at the base unopened, glabrous 
or very minutely (0.05 mm.) puberulent. Leaves distant or congested, petioles 6-25 
(32) mm. long, 0.6-1.6 mm. thick, glabrous, deeply sulcate; laminae 5-11 cm. long, 
1.8-4 cm. broad, narrowly elliptic to elliptic-oblong, acute or acuminate at the apex, 
obtuse to acute at the base, lamina drying chartaceous to very stiffly chartaceous 
and the margin flat or slightly revolute, smooth and glabrous on both surfaces, the 
(4) 7 to 12 (20) pairs of major secondary veins very slightly raised above and below, 
often difficult to distinguish from the intermediate veins, central secondaries aris- 
ing at angles of 60-80 degrees, secondaries loop-connected near the margin and a 
weak arcuate submarginal vein usually present, tertiary veins slightly raised above 
and below, upper surface usually distinctly punctate. Figs usually paired at a node. 



BURGER: FLORA COSTARICENSIS 177 

borne on peduncles 2-6 mm. long, about 1 mm. thick, slightly expanded at the apex, 
usually glabrous, bracts 2, usually entire, about 2 mm. long, 2-3 mm. broad, glab- 
rous or very minutely (0.05 mm.) puberulent; figs 8-14 mm. in diameter, globose, 
surface smooth and glabrous but often drying prominently wrinkled, pale colored 
with darker spots, ostiole surrounded by a flat or slightly raised collar of receptacu- 
lar tissue 0-2 mm. high and 1-3 mm. in diameter, external scales usually 3, below the 
level of the collar; seeds and galls 0.7-1 mm. long. 

Trees of wet evergreen forest formations from sea level to 2000 m. 
elevation, but usually found between 900 and 1600 m. in Costa Rica, 
and common in the wetter parts of the Meseta Central; flowering 
throughout the year. The species ranges from southern Mexico and 
Jamaica to Paraguay (fide DeWolf). 

Ficus pertusa is recognized by its small, often acuminate leaves, 
glabrous parts, and small pedunculate figs with a crateriform apex 
formed by a collar of tissue around and above the ostiole. Lowland 
collections from our area are rare and often puberulent, while the 
highland collections are usually glabrous. This species is very simi- 
lar vegetatively to F. perforata with somewhat smaller figs lacking 
the crateriform apex. 

Ficus popenoei Standley, Field Mus. Bot. 4:301. 1929. F. toli- 
mensis Standl., I.e. 17: 177. 1937. Figure 19. 

Trees 10-25 m. tall, often found as stranglers, leafy internodes 3-12 (40) mm. long, 
4-8 mm. thick, densely hirsute with stiff yellowish-brown or dark brown hairs 0.3-0.8 
mm. long, periderm becoming dark gray and not strongly ridged; stipules 6-10 
(14) mm. long, 3-5 mm. thick at the base unopened, ascending sericeous with 
golden-brown hairs about 1 mm. long. Leaves clustered or distant, petioles 2-15 
(23) mm. long, 1.3-4 mm. thick, obscurely sulcate above, densely hirsutulous with 
yellowish-brown hairs 0.3-1 mm. long; laminae (6) 7-18 cm. long, (3) 4-8 cm. broad, 
oblong to broadly obovate, abruptly rounded at the apex or occasionally obtuse, 
narrowed to the base and abruptly truncate to cordulate at the petiole, laminae dry- 
ing very stiffly chartaceous to subcoriaceous with the margins often strongly 
revolute, usually scabrous and minutely hispid above, hirsutulous beneath with 
yellowish-brown hairs 0.2-0.7 mm. long, the 6 to 9 pairs of major secondary veins 
slightly raised above and prominent beneath, central secondaries arising at angles 
of 45-65 degrees, the secondaries loop-connected near the margin but a definite 
submarginal vein absent, tertiary veins raised beneath. Figs usually paired at a 
node, subsessile or borne on peduncles to 3 mm. long, 1-2 mm. thick, not expanded 
at the apex, densely yellowish hirsute, basal bracts 2, usually entire, about 2-4 mm. 
long and 3-4 mm. broad, appressed hirsute basally and along the midrib abaxially; 
figs distinctly longer than thick 15-24 mm. long, 9-16 mm. in diameter, surface of the 
fig densely yellowish hirsutulous, ostiole often obscure, flat or slightly conical, 
1.5-3 mm. broad; seeds and galls 1.3-1.7 mm. long. 

Trees of wet evergreen forest formations between sea level and ( ? ) 
1000 m. elevation; fertile collections have been made in August, 



178 FIELDIANA: BOTANY, VOLUME 40 

October, and November. The species ranges from British Honduras 
to Colombia but is known in Costa Rica from only a single collec- 
tion: Holm & Iltis 806 near the Rio Frio, Alajuela. 

Ficus popenoei is recognized by the unusual shape of its figs, 
densely hirsute pubescence on many parts, and the usually obovate 
laminae rounded at the apex. This species is vegetatively similar 
to F. bullenei with very different figs. 

Ficus pumila L., Sp. PL 1060. 1753. 

Plants climbing on surfaces or becoming small shrubs 1-2.5 m. tall, stems with 
slender adventitious roots and with small (2-3 cm.) leaves, fruiting stems thicker 
(2-5 mm.) and with larger leaves, puberulent; stipules 8-16 mm. long, densely 
sericeous. Leaves on fruiting stems with petioles 4-18 mm. long, about 1.5 mm. 
thick; laminae on fruiting stems 3-9 cm. long, 2-4 cm. broad, oblong to narrowly 
ovate, obtuse and often rounded at the apex, rounded to shallowly cordate at the 
base, drying subcoriaceous, the 3 to 5 pairs of major secondary veins strongly 
ascending, tertiary veins prominent beneath and forming a reticulum, puberulent 
beneath, laminae of the rooting stems 12-25 mm. long and sessile. Fig solitary at a 
node, borne on a short (3-7 mm.) puberulent peduncle, narrowed above the bracts 
and pyriform or obovoid, 2-4 cm. in diameter and 5-7 cm. long, abruptly narrowed 
distally but with the ostiole borne on a conical apex. 

Widely planted in gardens to cover walls and other surfaces and 
requiring relatively little care. The stiff distichous leaves, large figs 
of unusual shape, and unusual habit distinguish this species. Native 
of Japan and China, the plants are referred to as hiedra in Costa 
Rica. 

Ficus religiose L., Sp. PL 1059. 1753. 

Trees 8-20 m. tall, often planted for shade, leafy internodes 5-25 mm. long, 2-5 mm. 
thick, glabrous; stipules 4-30 mm. long. Leaves glabrous, petioles 5-10 cm. long, 
0.8-2 mm. thick; laminae 7-15 cm. long, 3-9 cm. broad, ovate but with a very long 
(15-40 mm.) narrow (1-3 mm.) acuminate tip, abruptly truncate at the base, drying 
stiffly chartaceous, the 6 to 11 pairs of major secondary veins slightly raised on both 
surfaces. Figs usually paired at a node or occasionally several, sessile, 5-8 mm. in 
diameter, globose, subtended by conspicuous puberulent bracts, surface of the fig 
glabrous, ostiole slightly conical. 

Trees planted in parks and large gardens and along streets. The 
unusual laminae broadly ovate, but with a very long tip and borne 
on long slender petioles, distinguish this species. 

Ficus retusa L., Mant. PL 129. 1767. F. nitida Thunb., Diss. Fie. 
10. 

Becoming large trees more than 20 m. tall, producing many aerial roots, leafy 
internodes 3-15 mm. long, about 4 mm. thick, glabrous; stipules 5-10 mm. long. 



BURGER: FLORA COSTARICENSIS 179 

Leaves glabrous, petioles 5-10 mm. long, about 1 mm. thick; laminae 3-8 cm. long, 
1-3 cm. broad, elliptic, acute to acuminate at the apex, cuneate at the base, drying 
stiffly chartaceous, major secondary veins difficult to distinguish, 6-12 pairs. Figs 
usually paired at a node, sessile, about 5-8 mm. in diameter, globose, subtended by 
3 very small (1.5 mm. ) bracts, ostiole flat. 

Trees from the wet tropical lowlands of southeastern Asia; called 
the "malayan banyan" or referred to as laurel de la India in Costa 
Rica. These are the trees that dominate the parks of Limon. The 
aerial roots, small leaves, very small figs, and glabrous parts are 
distinguishing characteristics. 

Ficus schippii Standley, Field Mus. Bot. 8:7. 1930. Ficus meisto- 
syce Standl. & L. O. Wms., Ceiba 3: 195. 1953. Figure 18. 

Woody climbers or trees 6-20 m. tall, leafy internodes 3-24 mm. long, 2.5-5 mm. 
thick, glabrous, periderm often becoming strongly ridged and pale gray or brown; 
stipules 12-22 mm. long, 2-4 mm. broad at the base unopened, glabrous, drying pale 
brown to dark brown. Leaves clustered or distant on the stems, petioles 14-44 (58) 
mm. long, 1.2-2.6 mm. thick, essentially glabrous with the epidermis often flaking 
off in small (0.5 mm.) flakes, narrowly sulcate above; laminae 7-18 (20) cm. long, 
3-7.5 (9) cm. broad, oblong to elliptic-oblong or occasionally slightly ovate or 
obovate, abruptly short-acuminate to caudate-acuminate at the apex, rounded to 
the obtuse base, lamina drying stiffly chartaceous, smooth and glabrous on both 
surfaces, (rarely with hairs along the sides of the midvein beneath), the 6 to 12 pairs 
of major secondary veins slightly raised above and prominent beneath, central 
secondaries arising at angles of 60-80 degrees, joined near the edge by a distinct 
and arcuate submarginal vein, tertiary veins slightly raised beneath. Figs usually 
paired at a node but also found in clusters of 3 to 9 on very short (?) short-shoots, 
subsessile or borne on very short (0-2 mm.) peduncles, basal bracts 2, usually entire, 
about 2 mm. broad and 1.5 mm. long, glabrous; figs 4-5 mm. in diameter, subglobose 
and slightly flattened at the apex, surface smooth and glabrous, often drying 
orange-brown, ostiole flat or slightly raised, 1.4-1.8 mm. broad, galls and seeds 
about 0.5 mm. long. 

Plants of the lowland Caribbean wet forest formations between 
sea level and about 500 m. elevation; probably flowering through- 
out the year. The species ranges from British Honduras southward 
along the Caribbean to Central Panama and perhaps south-central 
Colombia. 

Ficus schippii is one of our most unusual species of Ficus because 
of the climbing habit seen in many individuals and the very small 
figs often found in clusters of three to nine at a node. Some plants 
have the figs often borne in these clusters while other plants exhibit 
this clustering only rarely. The species is known in Costa Rica from 
only two fertile collections: Hartshorn 1055 from near the Rio 
Puerto Viejo (Heredia) and Shank & Molina 4208, type of F, 



180 FIELDIANA: BOTANY, VOLUME 40 

meistosyce, from the drainage of the Rio Parismina and Rio Reven- 
tazon (Limon). Ficus microclada Dugand of south-central Colombia 
is a liana with very small clustered figs probably conspecific with 
Central American material placed here. 

Ficus tonduzii Standley, Contr. U.S. Nat. Herb. 20:8. 1917. 
Figure 21. 

Small or medium-size trees (5) 10-20 m. tall, trunks simple and usually smooth, 
leafy internodes 5-20 (40) mm. long, 5-11 mm. thick, essentially glabrous, periderm 
becoming deeply striate and pale gray (dry) often with the epidermis flaking off; 
stipules 2-4 (6) cm. long, 5-10 mm. thick at the base unopened, glabrous. Leaves 
usually distant but near the ends of branchlets, petioles (2) 3-8.5 cm. long, 3-6 mm. 
thick, glabrous, epidermis often cracking and coming off in small (0.5 mm.) flakes, 
longitudinally striate and terete or slightly sulcate above; laminae (12) 16-32 cm. 
long, 7-15 cm. broad, broadly elliptic or slightly obovate to elliptic-oblong, abruptly 
narrowed or rounded at the bluntly acute or obtuse apex, narrowed or slightly 
rounded at the obtuse base (never cordulate at the petiole), lamina drying stiffly 
chartaceous and the margin slightly revolute, glabrous and relatively smooth on 
both surfaces, the 7 to 11 (14) pairs of major secondary veins slightly raised above 
and prominent beneath, central secondaries arising at angles of 55-90 degrees, 
secondaries loop-connected near the margin and forming a definite submarginal 
vein, tertiary veins slightly raised beneath. Fig solitary at a node, sessile (in ours), 
or on a peduncle 1-10 mm. long and 3-4 mm. thick, bracts 3, entire or more often 
variously split, 2-3 mm. long 3-4 mm. broad, glabrous, united with the receptacle 
near the base; figs becoming 20-35 mm. in diameter, globose or somewhat obovoid 
and narrowed above the basal bracts, green with pale round markings, glabrous or 
very minutely (0.1 mm.) hispidulous and slightly rough to the touch, wall of the fig 
2-3 mm. thick (dry), ostiole flat or slightly raised, about 2 mm. broad, exterior scales 
several and the apices of the interior scales evident; seeds and galls 1.5-3 mm. long. 

Trees of the very wet evergreen forest formations between sea 
level and 1000 (? 1400) m. elevation on the Caribbean side of the 
Central Highlands, on the Caribbean slope and lowlands, and in the 
General Valley and Golfo Dulce region in Costa Rica; probably 
flowering throughout the year. The species ranges from Honduras 
to Ecuador. 

Ficus tonduzii is distinguished by its relatively broad leaves 
glabrous and smooth on both surfaces with a prominent submar- 
ginal vein. The figs solitary at a node, unusual trichomes on the 
lower leaf-surface (X150), and frequent streamside habitat are char- 
acters of the subgenus Pharmacosycea. This species is very closely 
related to F. macbridei but differs in possessing a distinct submar- 
ginal vein, smaller figs, and growing at lower elevations. 

Ficus trachelosyce Dugand, Caldasia 4:69, fig. 14. 1942. Figure 
18. 



BURGER: FLORA COSTARICENSIS 181 

Medium to large trees 10-25 m. tall, stranglers or independent, trunk to over 1 m. 
diameter and often of intertwined parts, leafy internodes (4) 8-30 mm. long, 1.5-3 
mm. thick, glabrous, periderm becoming striate and often pale grayish brown; 
stipules (3) 5-16 mm. long, 1.3-2.7 mm. thick at the base unopened. Leaves usually 
distant, petioles 8-20 mm. long, 0-8.2 mm. thick, glabrous and deeply sulcate above; 
laminae 7-16 cm. long, 2.5-6 cm. broad, elliptic to elliptic-oblong, usually tapering 
gradually to the acuminate apex, acute to obtuse at the base, drying stiff -chartace- 
ous and the margin often involute, smooth and glabrous on both surfaces with small 
raised dots above, the 6 to 15 pairs of major secondary veins very slightly raised 
above and below, often difficult to distinguish from the intermediate veins, central 
secondaries arising at angles of 60-75 degrees, loop-connected near the margin to 
form an arcuate submarginal vein, tertiary veins often obscure. Figs usually paired 
at a node, borne on a peduncle 2-6 mm. long, 1-1.5 mm. thick, glabrous, slightly ex- 
panded at the apex and occasionally forming a disc-like area at the base of the 
bracts, bracts 2, usually entire, 1-2 mm. long, 1-2 mm. broad, glabrous; figs 14-18 
mm. in diameter, globose but with a conspicuous apical collar, surface smooth and 
glabrous, often wrinkled and yellowish on drying, ostiole deeply hidden within the 
3-6 mm. high and 2-4 mm. broad urceolate collar; seeds and galls 1.2-1.5 mm. long. 

Trees of the seasonally dry Pacific Slope in Costa Rica between 
sea level and 1000 m. elevation and known only from San Miguel de 
San Ramon, Alajuela, (Brenes 14953 & 21909) and near Sta. Cruz, 
Nicoya Peninsula, (Burger & Ramirez 4104). The only other collec- 
tion seen from our area is from Puerto Armuelles, Chiriqui (Allen 
6295). Mature figs have been collected in January, August, and 
December. The species ranges to Colombia. 

Ficus trachelosyce is distinguished by its small glabrous thin 
leaves and its very unusual figs with apically developed collar. This 
species is very closely related to F. pertusa but differs in the devel- 
opment of the collar, larger fig size, and the very different habitat. 
Collections lose their leaves within 24 hr. if not quickly killed. The 
species is called tinajita near San Ramon. 

Ficus trigonata L., PI. Surinam. 17. 1775. Figure 19. 

Trees 10-25 m. tall, often large, leafy internodes 5-30 mm. long, 2.5-6 (8) mm. 
thick, glabrous or puberulent at the nodes with yellowish hairs 0.5-1 mm. long, peri- 
derm smooth and drying with prominent longitudinal ridges and pale brown; 
stipules 8-20 (27) mm. long, 2.4-4 mm. thick at the base unopened, with ascending 
whitish strigose hairs basally and along the midrib. Leaves clustered or distant, 
petioles (7) 12-40 (60) mm. long, 1.2-3.5 mm. thick, glabrous or very sparsely puberu- 
lent, very narrowly sulcate above; laminae (5) 8-25 cm. long, 3-13 cm. wide, obovate 
to elliptic or oblong, usually rounded at the apex but occasionally acute to short- 
acuminate, obtuse to rounded at the base and often slightly cordulate at the petiole, 
drying very stiffly chartaceous, smooth and glabrous above, glabrous or puberulent 
beneath with hairs 0.05-0.7 mm. long, often slightly rough to the touch beneath, the 
6 to 11 pairs of major secondary veins flat above and prominent beneath, central 
secondaries arising at angles of 45-80 degrees, basal pair of secondaries usually 



182 FIELDIANA: BOTANY, VOLUME 40 

prominent and strongly ascending, secondaries usually loop-connected near the 
margin but a definite submarginal vein absent, tertiary veins usually evident be- 
neath. Figs usually paired at a node, sessile or short pedunculate, peduncles 0-5 mm. 
long, 1-2.4 mm. thick, very minutely puberulent, a basal disc usually present about 
3-5 mm. broad with thickened edges from which the bracts arise, peduncle acentric 
near the edge of the disc, bracts 2 and entire or split, often semicircular, 1-3 mm. 
long and 4-7 mm. broad, strigose or occasionally glabrous; figs becoming red at 
maturity, 10-15 mm. in diameter, globose or broader than long, the surface smooth 
and glabrous, ostiole conical in early stages but becoming surrounded by a ring of 
thickened tissue 2-4 mm. in diameter; seeds and galls 1-1.5 mm. long. 

Plants of the moist or wet evergreen forest formations from sea 
level to 700 m. elevation on both the Caribbean and Pacific slopes of 
Costa Rica; probably flowering throughout the year. The species 
ranges from the Yucatan peninsula through Central America 
mostly along the Caribbean coast to Colombia and the West Indies. 

Ficus trigonata is recognized by the subsessile or short-peduncu- 
late figs with a small basal "disc" from which the short bracts arise 
and by the ostiole within a ring of tissue. This species is very closely 
related to F. morazaniana and the two may be conspecific. They are 
maintained separately here to focus attention on their differences 
and because they appear to live in somewhat different habitats. 
Also closely related is F. brevibracteata with stipules densely seri- 
ceous throughout, similar stems, and sessile figs with very small 
basal bracts. 



Ficus tuerckheimii Standley, Contr. U.S. Nat. Herb. 20:13. 1917. 
Figure 20. 

Small to very large and massive trees, 5-25 (35) m. tall, epiphytic or independent, 
trunk often banyan-like and fluted, leafy internodes 3-15 mm. long, 3.5-8 mm. thick, 
glabrous, becoming irregularly ridged or wrinkled and grayish, stems with shelf- 
like depressions where figs were borne; stipules (6) 14-24 (32) mm. long, 4-8 mm. 
thick at the base unopened, glabrous or very minutely (0.05 mm.) puberulent at the 
base. Leaves usually clustered at the ends of twigs, petioles 15-40 (65) mm. long, 
1.6-3 mm. thick, glabrous, slightly sulcate above; laminae quite variable in size and 
shape, 7-18 cm. long, 5-12 cm. broad, broadly ovate to oblong or suborbicular, obtuse 
to rounded or very short and bluntly acuminate at the apex, obtuse to rounded, 
truncate, or occasionally shallowly cordate at the base, lamina drying stiff-char- 
taceous to subcoriaceous and the margins flat, glabrous and smooth on both sur- 
faces, often somewhat glaucous above (dry), the 6 to 11 pairs of major secondary 
veins usually flat on both surfaces, central secondaries arising at angles of 45-70 
degrees, the basal pair of secondaries often prominent and strongly ascending, 
secondaries weakly loop-connected near the margin, tertiary veins often obscure. 
Figs usually 2 at a node, often clustered near the ends of branchlets, sessile and 
leaving a prominent shelf on the stem, attachment of the fig somewhat lateral (in 
respect to the ostiole) near the edge of a disc-like basal area from which the 2 entire 



BURGER: FLORA COSTARICENSIS 183 

or split bracts arise, bracts almost half the circumference ( 12 mm.) of the fig, broad 
at the base. 4-8 mm. long and covering the sides of the fig, glabrous; figs 12-15 mm. 
thick, globose or somewhat flattened in the plane of attachment, surface smooth 
and glabrous, ostiole about 2-3 mm. broad, slightly conical, or elevated and ringed, 
hidden by the bracts in early stages, exterior scales 2 or 3; seeds and galls about 1.2 
mm. long. 

Trees of wet evergreen forest formations between (1000) 1200 
and 1800 m. elevation known only from the area of the Montes de 
Aquacate and Zarcero (Alajuela), eastward to La Palma (San Jose), 
Irazu and Cartago (Cartago); probably flowering throughout the 
year. This species, as here interpreted, is endemic to Costa Rica and 
adjacent Panama. 

Ficus tuerckheimii is recognized by the stems with "shelves" 
formed by the figs, glabrous broad leaves often rounded at the base, 
figs laterally attached on the edge of a disc-like area from which the 
bracts arise, bracts glabrous and covering much of the upper sur- 
face of the fig, and the restricted highland distribution. This species 
is closely related to F. jimenezii, but that species has smaller figs, 
thicker leaves, densely puberulent stipules, and stems in which the 
depressions left by the figs are not as prominent. Ficus tuerck- 
heimii is even more closely related to F. isophlebia, but that species 
differs in the smaller figs with more prominent ostiole, figs forming 
only slight depressions in the stems, smaller bracts, and lowland 
habitat. All three species were considered as one in the "Flora of 
Panama"; however, I prefer to consider them distinct, as there is 
virtually no evidence of intergradation, though sterile collections 
are difficult to place. The unusual basal disc-like area (see under 
F. isophlebia) is a significant character in distinguishing this group 
and is comparable to a similar structure in F. trigonata. 



Ficus turrialbana Burger, Phytologia 26:429. 1973. Figure 19. 

Medium-size trees 15-20 m. tall, leafy internodes 2-28 mm. long, 4-12 mm. thick, 
sparsely puberulent with slender white or brown hairs 0.3-1 mm. long, periderm be- 
coming pale gray and striate; stipules 8-12 mm. long, 4-7 mm. broad at the base un- 
opened, densely ascending sericeous with brownish or whitish hairs but the hairs 
usually absent along the margins abaxially. Leaves not closely crowded, petioles 2-7 
cm. long, 1.8-4 mm. thick, minutely puberulent, deeply striate on drying but not 
usually sulcate above; laminae 12-24 cm. long, 6-12 cm. broad, elliptic-oblong to 
somewhat obovate, tapering abruptly to the bluntly obtuse apex or sometimes with 
a very short acute tip, obtuse to sub-truncate at the base but often rounded at the 
petiole, margin entire or very shallowly indented distally, drying stiffly chartaceous 
to subcoriaceous with the margin slightly revolute, smooth and glabrous or very 
minutely (0.05 mm.) puberulent above, densely to sparsely puberulent on the veins 



184 FIELDIANA: BOTANY, VOLUME 40 

and veinlets beneath with slender straight hairs 0.1-0.9 mm. long, the 9 to 12 pairs of 
major secondary veins usually flat above and prominent below, central secondaries 
arising at angles of 35-55 degrees, secondaries weakly loop-connected near the mar- 
gin and a submarginal vein absent, tertiary veins often prominent beneath. Figs 
usually 2 at a node, sessile and often leaving shelf-like impressions on the stems, 
basal bracts 2 but often deeply split and 2- to 5-lobed, 6-8 mm. long (measured from 
the area of attachment), densely puberulent with brownish hairs to 1 mm. long near 
the base, united with the receptacle for 1 or 2 mm. around the base; figs 12-16 mm. 
in diameter, (globose) oblate and about 1 cm. high (dry), surface densely puberulent 
and often longitudinally 3- to 5-ribbed, ostiole conical and surrounded by a small 
ring of tissue 3-4 mm. in diameter, external scales 2 or 3; seeds and galls 0.9-1.2 mm. 
long. 

Plants of the very wet Caribbean slopes and lowlands (premon- 
tane wet forest formations) around 700 m. elevation in Costa Rica: 
Burger 4004, Ramirez s.n. (Museo Nacional 41515), and Leon 2463, 
all from near Turrialba, Cartago; fruiting collections have only been 
made in December. 

Ficus turrialbana is distinguished by its blunt or shortly acute 
leaves puberulent beneath, prominent petioles, densely pubescent 
stipules with glabrous edges, thick stems with depressions formed 
by the sessile puberulent figs with large bracts and conspicuously 
umbonate ostiole surrounded by a thickened ring of tissue. This 
species can be mistaken for F. costaricana (persistent stipules and 
glabrous leaves and figs), F. morazaniana (pedunculate figs and 
small bracts), and F. velutina (larger pedunculate figs and montane 
habitat). I have seen figs similar to the type only in F. tequendamae 
Dugand, a high-altitude species of Colombia. The species mentioned 
above are part of a complex of species that include F. trigonata L. 
and are well represented in northern South America and Central 
America. 

Ficus turrialbana appears to be a wide ranging species of the 
Caribbean slopes of Central America and Mexico but fertile collec- 
tions are rare. A collection from Veracruz, Mexico (Llewelyn Wil- 
liams 8766) is conspecific and very similar to the type, both in its 
leaves and its figs. The figs of this species were described under 
Urostigma intramarginale by Liebmann (1851); however, the figs 
were associated with the leaves of Coussapoa panamensis. These 
discordant elements are a sufficient basis for rejecting Liebmann's 
name. 

Ficus velutina H.& B. ex Willd., Sp. PI. 4: 1141. 1806. Figure 19. 

Small to medium sized trees 7-15 (20) m. tall, trunks often fluted or several grown 
together, leafy internodes 8-50 mm. long, 4-12 mm. thick, densely to sparsely tomen- 



BURGER: FLORA COSTARICENSIS 185 

tulose with brownish hairs 0.5-1 mm. long, periderm becoming prominently ridged 
on drying; stipules 12-20 mm. long, 4-10 mm. thick at the base unopened, densely 
brownish tomentulose to sericeous. Leaves distant or clustered and often relatively 
few per twig, petioles 14-34 mm. long, 2-5 mm. thick, densely brownish tomentulose, 
sulcate above; laminae 10-26 cm. long, 6-17 cm. broad, ovate to broadly elliptic, 
tapering to an obtuse apex or abruptly rounded, usually tapering slightly to a 
rounded obtuse to truncate base (occasionally cordulate), laminae drying very stiff- 
ly chartaceous to subcoriaceous with the margins revolute, smooth and sparsely 
puberulent above, densely brownish tomentulose beneath with soft crooked hairs 
0.3-1.5 mm. long, the 6 to 12 pairs of major secondary veins slightly impressed 
above and very prominent beneath, central secondaries arising at angles of 30-70 de- 
grees, weakly loop-connected near the margin, tertiary veins prominent beneath and 
forming a conspicuous reticulum. Figs usually paired at a node, borne on very short 
(2-6 mm.) thick (2 mm.) puberulent peduncles, apex of the peduncle sometimes ex- 
panded and forming a disc-like area, bracts 2 but often deeply split, 2-4 mm. long, 
about 4 mm. broad, usually with smaller hairs than the peduncle; figs 18-22 mm. in 
diameter (dry), narrowed at the base and obovoid or globose, surface densely 
puberulent with hairs 0.1-0.6 mm. long, ostiole within an elevated ring of tissue 3-5 
mm. broad forming a short ( 1-2 mm.) collar; seeds and galls 1.4-1.8 mm. long. 

Trees of moist and wet evergreen forest formations between 1000 
and 2000 m. elevation and known only from the northeastern side of 
the Meseta Central and along the Cordillera de Talamanca as far 
east as the Rio Chirripo del Pacifico in Costa Rica; mature figs have 
been collected in July and from November to February. The species 
ranges from Guatemala southward to Colombia and Venezuela. 

Ficus velutina is readily recognized by the presence of usually 
orange-brown hairs on younger parts, stiff leaves with the tertiary 
veins forming a prominent reticulation beneath, short-pedunculate 
figs with the ostiole within a short collar, and the montane habitat. 
This species is easily distinguished by these attributes from all our 
other figs but is closely related to F. trigonata and the lowland F. 
bullenei. 

Ficus werckleana Rossberg, Repert. Sp. Nov. 42:60. 1937. Figure 

21. 

Trees to 35 m. tall, trunks usually straight and pale colored, leafy internodes 6-20 
(30) mm. long, 4-9 mm. thick, glabrous or puberulent with slender whitish hairs 0.3- 
1 mm. long, periderm smooth or slightly striate, occasionally with the epidermis 
flaking off; stipules (6) 9-16.5 cm. long, 4-11 mm. thick at the base unopened, glab- 
rous. Leaves at the ends of branchlets but not crowded, petioles ( 18) 25-80 mm. long, 
2-5 mm. thick, glabrous, slightly sulcate adaxially, often striate (dry); laminae ( 11 ) 
14-32 cm. long, (5) 6-16 cm. broad, oblong to elliptic or less often slightly ovate or 
obovate, tapering abruptly to the obtuse or rarely short-acute apex, often rounded 
at the tip, rounded to obtuse at the base, laminae drying stiff-chartaceous to sub- 
coriaceous, glabrous and smooth on both surfaces, the 16 to 24 pairs of major sec- 



186 FIELDIANA: BOTANY, VOLUME 40 

ondary veins slightly raised above and below, central secondaries arising at angles 
of 60-80 degrees, secondaries usually loop-connected near the margin and a submar- 
ginal vein often present, 1-3 mm. from the edge, tertiary veins often obscure. Fig 
solitary at a node, borne on peduncles 5-12 mm. long and about 2 mm. thick, glab- 
rous, bracts 3, entire or slightly split, about 2 mm. long and 3 mm. broad, glabrous; 
figs (14) 18-22 mm. in diameter, globose or obovoid and narrowed above the basal 
bracts, surface glabrous and smooth, ostiole about 2.5 mm. broad, conical, exter- 
ior bracts several with apices of the interior bracts visible, wall of the fig 1-3 mm. 
thick ( dry ) ; seeds and galls 1.5-2.2 mm. long. 

Plants of river edges and bottomlands (or areas with a high water 
table) in wet evergreen forest formations on both the Pacific and 
Caribbean slopes below 800 m. altitude in Costa Rica; mature figs 
have been collected in January and March. The species probably 
ranges from British Honduras southward to northern South 
America. 

Ficus werckleana is recognized by the often larger leaves bluntly 
obtuse or rounded at the apex, very large stipules, and figs about 2 
cm. in diameter (dry) at maturity and with a prominent (2 mm.) 
ostiole. The figs solitary at a node, unusual trichomes on the lower 
leaf-surface (X150), and frequent streamside habitat are characters 
of the subgenus Pharmacosycea. This species has usually been con- 
sidered conspecific with F. insipida but Dr. Leslie Holdridge, who 
knows these plants in the field, states that they are very different. 
Our collections with mature figs are very few (A Jimenez 94, Coop- 
er 444, and Tonduz 17435), but these appear to be much smaller 
than those of F. insipida. 



Ficus yoponensis Desv., Ann. Sci. Nat. Ser. 2, 18:310. 1842, fide 
DeWolf. Ficus multinervis Pittier, in herb. (? nom. nud). Figure 21. 

Medium-size to large trees 8-50 m. tall, trunk usually straight and smooth, leafy 
internodes 5-30 mm. long, 2-5 mm. thick, glabrous, periderm smooth to somewhat 
striate (dry) and light brown, the epidermis not usually flaking off; stipules (2) 3-6 
(9) cm. long, 1.5-6 mm. thick at the base unopened, usually drying yellowish green or 
yellowish brown, glabrous. Leaves usually distant near the ends of branchlets, 
petioles 10-28 (40) mm. long, 1.2-2 (3) mm. thick, glabrous, shallow or deeply sulcate 
above; laminae (5) 6-14 (26) cm. long, 2-5 (6.5) cm. broad, elliptic to narrowly oblong 
or narrowly obovate, acute to short-acuminate at the apex, obtuse to acute at the 
base, drying stiff-chartaceous and the margins slightly revolute, smooth and glab- 
rous on both surfaces, the 16-28 (52) pairs of major secondary veins slightly raised 
on both surfaces and often difficult to distinguish from the intermediate veins, cen- 
tral secondaries arising at angles of 60-80 degrees, secondaries joined 0.5-1 mm. 
from the margin by a slightly arcuate submarginal vein, tertiary veins usually 
obscure. Fig solitary at a node, usually borne on a peduncle 6-16 mm. long and 1-1.5 



BURGER: FLORA COSTARICENSIS 187 

mm. thick, glabrous, bracts 3, usually entire, about 1 mm. long and 2 mm. broad, 
glabrous; figs 12-16 mm. in diameter, globose but narrowed abruptly at the base and 
borne on a stalk above the bracts 1-6 mm. long and as thick as the peduncle, surface 
smooth and glabrous, ostiole borne on a narrowed column at the apex of the recep- 
tacle 1-4 mm. long and about 2 mm. thick, ostiole about 1.5 mm. broad at the apex 
of the column, exterior scales several, wall of the fig 0.5-1 mm. thick (dry); seeds and 
galls 1-1.5 mm. long. 

Trees of moist ravines, river edges, and wet forests from sea level 
to 1600 m. elevation, but most commonly collected between 500 and 
1200 m. in our area on both the Caribbean and Pacific slopes. The 
species is known in Costa Rica from near Tilaran (Guanacaste), near 
San Ramon (Alajuela), near San Francisco de Guadalupe (San 
Jose), and along the Rio Pacuare near Tuis (Cartago). The species is 
known from Barro Colorado Island (Canal Zone) and the Boquete 
area (Chiriqui) in Panama. The species ranges from Chiapas, 
Mexico, and British Honduras to Colombia and Venezuela. 

Ficus yoponensis is recognized by its relatively narrow glabrous 
leaves with many secondary veins and definite submarginal vein, 
long stipules drying pale in color, and small figs stalked above the 
bracts and with a distinct apical "column." The solitary figs and 
unusual trichomes on the lower leaf-surface (X150) are characters of 
the subgenus Pharmacosycea. The species is closely related to F. 
crassiuscula and F. insipida and has often been mistaken for the 
latter, and they are difficult to distinguish in the absence of mature 
figs. 

HELICOSTYLIS Trecul 

REFERENCE: C.C. Berg, Olmedieae. Fl. Neotrop. Monog. 7:75- 
92. 1972. 

Unisexual or bisexual trees, without spines; stipules not completely encircling the 
stem, free, small and caducous. Leaves distichous, petiolate, margin entire to denti- 
culate apically, chartaceous to coriaceous, usually brownish when dry and dull 
above, usually puberulent, the microscopic multicellular hairs globose-capitate 
or oblongoid-capitate. Male inflorescences solitary, paired or more numerous on 
short shoots, often together with female inflorescences, receptacle discoid and 
pedunculate, covered with imbricate bracts usually incurved in early stages, flowers 
mostly free and numerous; male flower with (2-) 4-lobed or (2-) 4-parted perianth, 
the 2 whorls of perianth-parts and the 2 whorls of (2-) 4 stamens usually different in 
form, filaments straight in bud, anthers basifixed or dorsifixed, connective narrow 
or broad. Female inflorescences solitary or with 1 or more male inflorescences (or 
the female inflorescences paired and uniflorous in H. tovarensis), sessile or pedun- 
culate, the receptacle covered with imbricate bracts, each inflorescence with about 
5 ( 1 in H. tovarensis, many in H. pedunculata) flowers; female flowers with 4 free or 



188 FIELDIANA: BOTANY, VOLUME 40 

united perianth-parts, the tepals of the 2 whorls are often different in form, the inner 
cohering by thin hairs, ovary almost free, stigmas slender, straight or twisted. 
Fruit with succulent perianth becoming yellow, free or somewhat adnate to the per- 
ianth, cotyledons thick and equal. 

A genus of seven species best represented in the Western Amazon 
Basin and ranging from Costa Rica to Peru and Brazil. Our species 
differs from others in the genus and resembles Olmedia aspera in 
general aspect. 

A recent collection of Helicostylis (W. H. Lewis et al 2188) from 
about 300 m. altitude in Bocas del Toro province, Panama, is proba- 
bly H. tomentosa (Poeppig & Endlicher) Rusby (C.C. Berg, pers. 
comm.). That species differs from H. tovarensis in the leaves usu- 
ally being scabrous above. Both species may occur in Costa Rica. 

Helicostylis tovarensis (Klotz. & Karst. ) C.C. Berg, Acta Bot. 
Neerl. 18:464. 1969. Olmedia tovarensis Klotzsch & Karsten, Lin- 
naea 20:526. 1847. Helicostylis urophylla Standley, Field Mus. Bot. 
18:389. 1937. Figure 16. 

Trees to 25 m. tall, unisexual, sap yellowish, leafy internodes 1-3 cm. long, 1.3-4 
mm. thick, with thin yellowish brown hairs 0.3-0.9 mm. long; stipules 2-10 mm. long, 
densely velutinous to sericeous, narrow. Leaves often very slightly inequilateral, 
petioles 3-10 mm. long, 0.7-2 mm. thick, densely puberulent; laminae (3) 5-15 (17) 
cm. long, 1.5-4.5 cm. broad, narrowly oblong to narrowly obovate, acuminate to 
caudate-acuminate at the apex, the narrow tip 5-25 mm. long, margin entire or 
serrulate near the apex, thin to stiffly chartaceous, upper surface smooth and glab- 
rous but minutely puberulent above the major veins, sparsely to densely puberulent 
on the veins beneath with thin ascending straight or curved hairs 0.3-0.8 mm. long, 
the major veins slightly prominent to impressed above and prominent beneath, with 
6 to 12 pairs of major secondary veins, the lower surface with numerous microscopic 
oblongoid-capitate hairs, the narrow distal part orange on a short transparent base 
(X150). Male inflorescences 1 or 2 in the axils of leaves or fallen leaves, hemispheri- 
cal in form and 9-12 mm. in diameter, borne on peduncles 2-8 (25) mm. long, the 
receptacle with 3 or 4 series of bracts forming an involucre at the base of the more 
than 20 flowers; male flowers free or united at the base, perianth 1.5-2.7 mm. high, 4- 
lobed or 4-parted, minutely puberulent, filaments 2.5-4 mm. long, anthers 0.8-1.4 
mm. long, apiculate or not, a pistillode occasionally present. Female inflorescences 1 
or 2 in the axils of leaves or fallen leaves, borne on peduncules 1-8 (25) mm. long, 
receptacle with 3 or 4 series of broadly triangular, acute to obtuse, puberulous 
bracts forming an involucre 2-6 mm. thick, ovoid and enclosing the solitary female 
flower; perianth about 3 mm. high, style subterminal and 1-2.5 mm. long, stigmas 5- 
10 mm. long. Fruit 7-10 mm. long, 5-8 mm. thick. 

In wet forest formations of the Caribbean slope and adjacent 
areas between 700 and 1500 m. elevation in Costa Rica: probably 
flowering throughout the year but collected at anthesis only in Feb- 



BURGER: FLORA COSTARICENSIS 189 

ruary and March in our area. The species is known from Costa Rica 
and ranges from the coastal ranges of Venezuela through Colombia 
along the Andes to Peru. The species is known from the Caribbean 
slopes above the San Carlos River (Holdridge 6780 & A. Smith 1695) 
and near San Ramon (Brenes 5536 & 13578) in the province of Ala- 
juela and from Cerro Doan, east of Cachi (Lent 2340) in the province 
of Cartago. 

Helicostylis tovarensis is recognized by the puberulent leaves 
with narrow tip and often serrulate near the apex, the hemispheric 
little male inflorescences with puberulent bracts covering the recep- 
tacle, or the small ovoid female inflorescences with broadly over- 
lapping puberulent bracts including a single flower with two slender 
stigmas. The upper leaf-surfaces, glabrous except above the major 
veins, help to distinguish this species from plants with similar 
leaves such as Olmedia aspera, Sorocea trophoides, and others. 



MAQUIRA Aublet 

REFERENCE: C. C. Berg, Olmedieae. Fl. Neotrop. Monog. 7:62- 
75. 1972. 

Trees, usually unisexual, without spines, periderm of the twigs peeling off easily; 
stipules small and free, not completely encircling the stem, caducous. Leaves dis- 
tichous, petiolate, subcoriaceous to coriaceous, the margins entire, glabrous or 
sparsely puberulent, usually greenish when dry and lustrous above, the microscopic 
multicellular hairs oblongoid-capitate. Male inflorescences pedunculate, on short 
shoots, discoid to globose, the flowers numerous and free or basally connate; male 
flowers with 4-lobed or 4-parted perianth, stamens 4 (rarely 3 or 2), filaments 
straight or slightly curved in bud, anthers basifixed, connective broad or narrow. 
Female inflorescence mostly solitary, subsessile or pedunculate, with imbricate 
bracts covering the receptacle, with many free flowers, a few connate flowers, or one 
flower; female flower with the perianth (2-) 4-lobed or (2-) 4-parted, ovary almost 
entirely united with the perianth or free above, stigmas short and disciform to long 
and filiform. Fruit with perianth becoming succulent, the seed large with a large 
terminal hilium, cotyledons thick and equal. 

A genus of five species ranging from the Caribbean side of Nicar- 
agua southwards to Peru and Brazil. The genus is rather similar in 
its flowering parts to Perebea but differs in the stipules, the more 
glabrous leaves with entire margins, and the periderm of the twigs. 

Maquira costaricana (Standl.) C.C. Berg, Acta Bot. Neerl. 18:463. 
1969. Perebea costaricana Standley, Field Mus. Bot. 18:390. 1937. 
P. trophophylla Standl. & L.O. Williams, Ceiba 3:196. 1953. Fig- 
ure 16. 



190 FIELDIANA: BOTANY, VOLUME 40 

Shrubs or trees 2-10 (20) m. tall, unisexual, leafy internodes 1-4 cm. long, 1-5 mm. 
thick, glabrous or very minutely puberulent, brownish and often becoming ridged on 
drying; stipules 3-8 mm. long, minutely puberulent. Leaves often inequilateral at 
the base, petioles 6-13 mm. long, ridged on drying and the cuticle often peeling off in 
small reddish-brown flakes; laminae 9-22 (30) cm. long, 3.5-8 (9.5) cm. broad, oblong 
to elliptic-oblong or slightly obovate, abruptly acuminate at the apex with the nar- 
rowed tip 5-20 mm. long, obtuse to acute or occasionally rounded at the often obli- 
que base, margin entire or slightly undulate, the lamina drying stiffly chartaceous 
to subcoriaceous, glabrous and lustrous above, essentially glabrous beneath, 
smooth on both surfaces, major veins prominent on both surfaces, the 7 to 15 pairs 
of major secondary veins loop-connected near the margin, microscopic aculeate 
hairs with a perimeter of small cells around the base present on the lower surface, 
epidermal cells and stomates readily visible (dry). Male inflorescences 1 to 3 in the 
axils of leaves, borne on peduncles 2-8 mm. long, discoid in form and 5-10 mm. in 
diameter, receptacle with about 5 series of deltoid to ovoid puberulent bracts 1-2 
mm. broad basally, the flat disc with more than 20 flowers; male flowers free, per- 
ianth 4-parted, 0.6-1 mm. high, stamens 4, filaments 0.8-1.2 mm. long, straight or 
slightly incurved before anthesis, anthers 0.4-0.5 mm. long. Female inflorescence 
solitary in the leaf axils, subsessile or with a peduncle to 6 mm. long, discoid and 6- 
10 mm. in diameter, receptacle with 3 to 6 series of often broad ( 1-3 mm. ) puberulent 
acute or obtuse bracts, with usually 15 to 35 flowers; female perianth 2-2.5 mm. 
high, 4-lobed, minutely brownish puberulent, ovary basally adnate to the perianth, 
style 0.5-1 mm. long, stigmas very broad and 0.5-1.5 mm. long, recurved. Fruit 
united with the succulent perianth (except near the top), drupaceous and ellipsoid, 
about 1.5 cm. long, glabrescent, reddish, the infructescence with few ellipsoid 
drupes separate or with more numerous fruit clustered and 3-4 cm. in diameter, seed 
9-10 mm. long. 

Plants of the wet evergreen forest formations on both the Carib- 
bean and Pacific sides of Costa Rica; flowering from February to 
June. The species ranges from the Caribbean lowlands of Nicaragua 
to Peru at altitudes to 850 m. It has been collected near Ciudad 
Quesada (Burger & Stolze 4951 and A. Smith (H) 1733), Alajuela, 
near Guapiles (Standley 37027, the type), Limon, and near Golfito 
(Allen 6348), Puntarenas. 

Maquira costaricana is usually found as a shrub or small tree but 
occasionally reaches 20 m. in height (Allen 6348). The essentially 
glabrous, entire, oblong leaves with abruptly acuminate apices and 
loop-connected venation, and flat discoid inflorescences with over- 
lapping brownish and minutely puberulent bracts covering the 
lower part distinguish this species. The cuticle of the petioles and 
peduncles often cracks and flakes off in small ( 1 mm. ) pieces. 

MORUS Linnaeus 

Trees or shrubs, bisexual or unisexual, sap white, without spines; stipules paired 
and free, lateral, caducous. Leaves alternate and distichous, petiolate, usually den- 



BURGER: FLORA COSTARICENSIS 191 

tate or serrate, with or without prominent lobes, pinnately veined or palmately 3- 
veined, microscopic (X150) globose-capitate hairs usually present, hooked (unci- 
nate) hairs occasionally present, transparent aculeate hairs or epidermal cells with 
sharp conic tips often present. Male inflorescences axillary and solitary, pedun- 
culate, elongate narrow spikes (catkins); male flowers sessile or subsessile, with 
usually 4 imbricate perianth-parts, usually puberulent and ovate, stamens 4, fila- 
ments bent inward in bud, springing back suddenly and elastically at anthesis, 
the anther becoming exserted, basifixed or dorsifixed. Female inflorescences axil- 
lary and solitary, pedunculate, short or long spikes with sessile closely crowded 
flowers; female perianth with 4 free ovate decussate-imbricate perianth-parts, ovary 
superior but included within the perianth, globose to ovoid, style apical and short, 
stigmas 2, equal. Fruit included within the accrescent succulent perianth, the outer 
part of the ovary (fruit) also succulent, seed with membranous testa and equal 
cotyledons. 

A genus of about a dozen species in the temperate and tropical 
regions of both hemispheres. The genus is recognized by the small 
lateral stipules, serrate leaves, male spikes with sessile four-parted 
flowers with stamens incurved in bud, and the female spikes with 
crowded flowers with four perianth-parts that become succulent in 
fruit. The genus may also be represented in Costa Rica by the wide- 
ly cultivated Morus alba L., native of China, with long petiolate 
leaves often cordate at the base. Morus celtidifolia H.B.K. with 
much smaller leaves and spikes has an unusual disjunct distribu- 
tion: Mexico and Guatemala, Colombia to Bolivia. 



Morus insignis Bureau in DC., Prodr. 17:247. 1873. Figure 14. 

Shrubs or medium sized trees to about 15 m. tall, the trunk and branches often 
thick, sap whitish, leafy internodes 0.5-5 cm. long, 1.5-4.5 mm. thick, sparsely to 
densely puberulent with thin ascending hairs 0.1-0.3 mm. long; stipules 7-12 mm. 
long, sparsely to densely minutely puberulent, scars about 3 mm. long, encircling 
about half the stem. Leaves often slightly asymmetric, petioles 8-22 mm. long, 1.3- 
2.7 mm. thick, with thin whitish ascending hairs 0.1-0.4 mm. long, narrowly sulcate 
apically; laminae (6) 9-25 cm. long, (3) 5-13 cm. broad, ovate to elliptic-ovate, nar- 
rowed to the acuminate apex, obtuse to rounded and truncate or subcordate at the 
base, the margin conspicuously serrate with 2 to 6 teeth per cm. the teeth usually 
with a small (0.5 mm.) tip terminating a tertiary vein, the laminae drying thinly to 
stiffly chartaceous, smooth to scabrous above but essentially glabrous, sparsely 
puberulent beneath with very thin whitish hairs to 0.5 mm. long, the midvein im- 
pressed above, the 7 to 9 pairs of major secondary veins weakly loop-connected near 
the margin, microscopic globose-capitate hairs with orange coloring present beneath 
and with broad-based transparent aculeate hairs on the veins (X100). Male inflores- 
cences 3-11 cm. long, short-pedunculate, with flat round or irregularly shaped peltate 
bracts covering the flowers in early stages; male perianth about 1.5 mm. long, with 
thin whitish hairs abaxially, filaments 2-3 mm. long, anthers about 1.2 mm. long, 
broader than long. Female inflorescence borne on peduncles 5-10 mm. long, puber- 
ulent and with a few flat peltate bracts 1-2 mm. broad, spikes becoming 12 cm. long, 



192 FIELDIANA: BOTANY, VOLUME 40 

with numerous peltate bracts among the closely contiguous flowers; female per- 
ianth and bracts dark centrally with pale brownish edges, perianth-parts about 1.5 
mm. long, sparsely puberulent, stigmas 1-2 mm. long, minutely puberulent. Fruit 
drying angular, often separate on the rachis, loosely enclosed within the slightly 
succulent perianth, 2-3 mm. high, the reddish stigmas persisting, seed lenticular- 
ovoid, about 2 mm. long. 

Trees of the evergreen montane forest formations between 1500 
and 2200 m. elevation on the Caribbean and Eastern sides of the 
Meseta Central and near Copey in the Cordillera de Talamanca in 
Costa Rica; collected in fruit in March and May. The species is 
found in Guatemala, Costa Rica, Venezuela, and from Colombia 
southward to Peru. 

Morus insignis is recognized by its rather broad serrate leaves 
usually rough to the touch, paired stipules leaving conspicuous 
scars, sessile male flowers congested on narrow spikes sessile fe- 
male flowers with distinct perianth parts, and the presence of broad 
flat-topped peltate bracts on both male and female inflorescences. 
The trees can have trunks to 2 m. in diameter and are said to have a 
low spreading crown with very thick branches (probably in highland 
pastures). The species is known from only a few collections and may 
have been common in the moister forests in the eastern half of the 
Meseta Central (on the Pacific watershed) that have now been 
largely destroyed. This species appears to be quite different from 
other species in the genus; the long inflorescences and peltate 
bracts are uncommon in this genus. 

NAUCLEOPSIS Miquel 

REFERENCE: C. C. Berg, Olmedieae. Fl. Neotrop. Monog. 
7:104-144.1972 

Trees, unisexual or rarely bisexual, without spines; stipules free, completely en- 
circling the stem, caducuous or tardily deciduous. Leaves distichous, petiolate, 
often coriaceous to subcoriaceous, margins always entire, mostly glabrous, micro- 
scopic multicellular hairs not frequent, oblongoid-capitate. Male inflorescence 1 to 
4 per axil, mostly pedunculate, disc-like to cup-shaped, receptacle covered with im- 
bricate bracts, the inner bracts often perianth-like and covering the flowers before 
anthesis, male flowers free or basally connate, perianth with usually 4 (0-8) parts, 
free or basally connate, often cucullate to subpeltate, stamens 1-4, filaments 
straight in bud, connectives mostly broad. Female inflorescences solitary, sessile or 
short-pedunculate, discoid to hemispherical, with many to few (rarely 1) flowers; 
female flowers with usually 4 to 6 (3-10) perianth-parts, the perianth parts free to 
completely united, often similar to the pseudobracts, ovary completely immersed 
within the receptacle, stigmas filiform to short-linguiform ; pseudobracts present or 
absent, very variable in form. Fruit borne within hemispheric to subglobose infruc- 



BURGER: FLORA COSTARICENSIS 193 

tescences, perianth-parts and pseudobracts becoming enlarged, hard and often 
angular, seeds imbedded in the pulpy receptacle, cotyledons thick and equal. 

A genus of 18 species ranging from the Caribbean side of Hon- 
duras southward to Peru and to the state of Rio de Janeiro in Brazil. 

Naucleopsis naga Pittier, Contr. U.S. Nat. Herb. 13:440. 1912. 
Ogcodeia naga (Pittier) Mildb., Notizbl. Bot. Gart. Berlin 11:420. 
1932. Figure 16. 

Trees to 15 m. tall, unisexual, the sap brownish, leafy internodes 5-40 mm. long, 
3-7 mm. thick, essentially glabrous, dark brown to pale gray, longitudinally striate 
when dry; stipules 10-19 mm. long, very narrow in the distal half, dark brown, minu- 
tely (0.2 mm.) puberulent along the midrib and basally (abaxially). Leaves usually 
slightly asymmetric, petioles 7-22 mm. long, 2-4 mm. thick, narrowly sulcate distal- 
ly ; laminae 14-30 (40) cm. long, 5-1 1 cm. broad, oblanceolate to narrowly obovate or 
elliptic-oblong, gradually to abruptly short-acuminate at the apex, obtuse or slight- 
ly rounded at the base, the margins usually forming a slit in the distal part of the 
petiole above, margins entire or slightly undulate, the lamina drying very stiffly 
chartaceous or subcoriaceous, smooth and lustrous above, glabrous on both sur- 
faces, the midvein prominent above, the 15 to 26 pairs of major secondary veins flat 
or slightly raised above, very weakly loop-connected near the margin, microscopic 
capitate hairs absent or few on the lower surface. Male inflorescence and flowers 
unknown. Female inflorescences solitary in the axils of leaves or fallen leaves, hemi- 
spherical with a flat or curved sessile base, receptacle subtended by 3 to 5 series of 
thick woody deltoid to lanceolate bracts with minute (0.1 mm.) appressed hairs, 
bracts numbering about 24-32, dark brown, the larger 5 mm. broad at the base, the 
flowers more than 40 per inflorescence; female perianth-parts free, similar to the 
pseudobracts, subulate to clavate, acute, minutely brownish puberulent, ovary 
immersed in the receptacle, style about 4 mm. long, stigmas about 3 mm. long. Fruit 
borne within the receptacle of the infructescence, the infructescence becoming 
woody, 3-5 mm. in diameter, the perianth-parts and pseudobracts becoming spine- 
like and woody, 7-22 mm. long. 

Small trees of the wet evergreen forest formations below 600 m. 
elevation on the Caribbean slopes and lowlands; collections with 
developing fruit have been made in June and August. The species 
ranges along the Caribbean from northern Honduras to Central 
Costa Rica. Only a single fertile (fruiting) collection has been made 
in Costa Rica: Pittier 13444 from the Llanura de Santa Clara. 

Naucleopsis naga is distinguished by the unusually long and nar- 
row glabrous and lustrous leaves that are usually widest above the 
middle, the stipules encircling the stem, the petiole narrowly sulcate 
apically, and the very unusual infructescence with short spinelike 
structures covering much of the surface. The species is apparently 
rare and the male flowers probably have a very short flowering 
period. The names majao de indio and concha de indio have been 
used for this species in Honduras. 



194 FIELDIANA: BOTANY, VOLUME 40 

OLMEDIA Ruiz & Pavon 

REFERENCE: C.C. Berg, Olmedieae. Fl. Neotrop. Monog. 7:13- 
17. 1972. 

Trees or shrubs, unisexual, spines absent; stipules free, partly encircling the 
stems, caducous. Leaves distichous, petiolate, chartaceous to subcoriaceous, sca- 
brous or slightly scabrous, usually dentate or denticulate. Male inflorescences axil- 
lary, usually solitary or paired, subsessile to pedunculate, discoid in form, with 3 to 
4 series of imbricate bracts covering the outer surface of the receptacle, many- to 
several-flowered; male flowers free or basally connate, perianth-parts coherent and 
2-, 3-, or 4-parted on opening, valvate; stamens 4, bent inward in bud and snapping 
open elastically at anthesis, anthers basifixed or dorsifixed, latrorse to introrse. 
Female inflorescences, axillary, subsessile to pedunculate, usually solitary or paired, 
surface of the receptacle with a few series of imbricate bracts, nearly always with a 
single flower; female flower with a tubular 4-dentate perianth, ovary free, stigmas 
filiform. Fruit enclosed in the fleshy perianth, cotyledons thick and equal, radicle 
short and apical. 

The genus is composed of a single species ranging from Costa 
Rica southward along the Andes to Bolivia. 

Olmedia aspera Ruiz & Pavon, Fl. Peruv. & Chil. 1:257. 1798. 
O. falcifolia Pittier, Contr. U.S. Nat. Herb. 13:435. 1912. Figure 16. 

Shrubs or trees to 15 (20) m. tall, unisexual, leafy internodes 5-45 mm. long, 1-4 
mm. thick, glabrous to hispidulous, the sap white or yellow; stipules 5-12 mm. long, 
very minutely puberulent and slightly scabrous. Leaves often asymmetric and 
somewhat curved, petioles 3-8 (15) mm. long, 0.7-1.5 mm. thick, usually minutely 
hispidulous and with tranverse cracks in the cuticle; laminae 6-26 (40) cm. long, 1.5- 
7 ( 12) cm. broad, oblanceolate to narrowly obovate, oblong or elliptic, usually some- 
what asymmetric and subfalciform, narrowly acuminate to caudate-acuminate, the 
narrow tip 1-3 cm. long, gradually narrowed to the acute base, margin bluntly serru- 
late in the distal half of the lamina (rarely entire), the lamina drying thin- to thick- 
chartaceous and often grayish above, glabrous and scabrous to very slightly sca- 
brous above, usually scabrous beneath with hispid hairs 0.1-0.5 mm. long, the major 
veins prominent beneath but flat above, with 6 to 18 pairs of prominent secondary 
veins, the lower surface with microscopic (X150) narrowly aculeate transparent 
hairs. Male inflorescences 1 or 2 (rarely to 6) in the axils of current leaves, subsessile 
or borne on peduncles to 6 mm. long, receptacle with 3 or 4 series of ovate to lanceo- 
late bracts forming an involucre around the edge of the disc, the larger bracts 2 mm. 
broad near the base, minutely strigose, the flat top of the inflorescence 4-10 mm. in 
diameter with 10 to 30 flowers; male perianth 2-3 mm. high, 2- to 4-parted at anthe- 
sis, minutely strigulose apically, filaments 3.5-5 mm. long, anthers 1.3-1.8 mm. long 
and 0.5-0.9 mm. broad. Female inflorescences 1 or 2 (rarely to 5) in the axils of cur- 
rent or fallen leaves, subsessile or borne on peduncles to 6 mm. long, receptacle cov- 
ered with 5 to 7 series of ovate to deltoid bracts about 2-4 mm. broad, with minute 
(0.1-0.2 mm.) stiff appressed hairs, inflorescence ovate in form, 3-6 mm. thick, with 1 
(very rarely 2) flowers, female perianth 3-3.5 mm. high, minutely strigulose, ovary 
free, often with minute stiff appressed hairs apically, style 1.2-4 mm. long, the stig- 



BURGER: FLORA COSTARICENSIS 195 

mas 5-11 mm. long, very slender. Fruit borne within the orange to red fleshy peri- 
anth, about 4-5 mm. thick, subglobose. 

Small trees of moist and wet evergreen forest formations between 
sea level and 66 m. elevation on both the Caribbean and Pacific 
slopes in Costa Rica; flowering throughout the year but collected 
most often between October and March. The species has not been 
collected north of the General Valley on the Pacific slope and is rare- 
ly encountered north of the Rio Reventazon on the Caribbean side of 
Costa Rica; it ranges southward through the Andes to Bolivia. 

Olmedia aspera is recognized by the narrow, often curved and 
slightly scabrous leaves that are bluntly serrulate distally and have 
a long narrow tip, the bracteate ovoid little female inflorescence 
with single flower and two long stigmas, and the male flowers on 
small flat-topped receptacles. Often the trees arch over brooks and 
small streams. The bent anthers can be released by touch; this 
quick motion may be an adaptation for pollen dispersal by small 
insects. However, the stream-side habitat may be one in which 
wind-pollination is possible and anthers may be released by desic- 
cation. 

PEREBEA Aublet 

REFERENCE: C.C. Berg, Olmedieae. Fl. Neotrop. Monog. no. 
7:38-61. 1972. 

Trees or shrubs, unisexual or bisexual, without spines; stipules free, encircling the 
stem completely, caducous. Leaves distichous, petiolate, chartaceous to coriaceous, 
often dentate to denticulate, usually drying brownish and often gray above, the mic- 
roscopic multicellular hairs either globose-capitate or oblongoid-capitate and mostly 
abundant. Male inflorescences borne on well developed short-shoots or axillary and 
pedunculate, 1 to several per axil or many on the short-shoots, mostly discoid in 
form, with many to few (1) flowers; male flowers with (2-3) 4 free or connate peri- 
anth-parts, each with usually 4 (2-6) stamens, filaments straight or slightly incurved 
before anthesis, free or united near the base, anthers small, basifixed or dorsifixed, 
connective broad. Female inflorescences axillary and solitary or accompanied by 
males, sessile or pedunculate, receptacle covered with imbricate bracts forming an 
involucre, with 1 to many flowers; female flowers mostly free, perianth 3-4 lobed or 
parted or completely united and forming a tube with entire margin, ovary free or 
partly united with the perianth, stigmas filiform to short and thick. Fruiting peri- 
anth fleshy, the fruit free or variously united to the perianth; seed with a large or- 
bicular to reniform hilum, cotyledons thick and equal. 

A genus of eight species, all represented in the western part of the 
Amazon Basin, with three species reaching their northwestern lim- 
its in our area. The involucre of thin imbricate bracts covering the 



196 FIELDIANA: BOTANY, VOLUME 40 

receptacle of the rather small inflorescences, the fruit usually borne 
about the surface of the receptacle, and the distally narrowly sul- 
cate petioles are useful in recognizing the genus. 

la. Stipules 30-60 mm. long; laminae 20-50 cm. long, 8-18 cm. broad, slightly 
rounded to cordate at the base, with 16 to 26 pairs of major secondary veins, 
densely hirsute beneath; Western Panama P. guianensis. 

Ib. Stipules 4-25 mm. long; laminae usually narrowed and acute to obtuse at the 
base, sparsely puberulent or glabrescent beneath 2a. 

2a. Laminae 12-34 (48) cm. long, 4-12 (20) cm. broad, with 12 to 18 pairs of major 
secondary veins; male inflorescence with more than 20 flowers; Caribbean and 
Pacific slopes P. xanthochyma. 

2b. Laminae 5-17 (22) cm. long, 1-7 cm. broad with 8-12 pairs of major secondary 
veins; male inflorescence usually with fewer than 20 flowers; Caribbean low- 
lands P. angustifolia. 

Perebea angustifolia (Poep. & Endl.) C.C. Berg, Acta Bot. Neerl. 
18:463. 1969. Olmedia angustifolia Poeppig & Endlicher, Nov. Gen. 
2:30 1. 143. 1838. Figure 16. 

Shrubs or slender trees 3-10 (20) m. tall, unisexual, latex white, leafy internodes 
5-50 mm. long, 1-3 mm. thick, with thin appressed white or yellowish hairs; stipules 
4-10 mm. long, with slender ascending pale yellowish or whitish hairs on the base 
and midrib. Leaves usually symmetrical, petioles 2-10 mm. long, 0.5-1.1 mm. thick, 
appressed sericeous with straight thin hairs 0.2-0.5 mm. long; laminae 5-17 (22) cm. 
long, (1) 2-7 cm. broad, narrowly oblong to elliptic-oblong or narrowly obovate, 
abruptly acuminate or caudate-acuminate at the apex, the slender tip 1-2 cm. long, 
obtuse to acute at the base and slightly rounded at the petiole, margin entire to 
bluntly serrulate distally, lamina drying chartaceous, smooth on both surfaces, 
essentially glabrous and the midvein prominent above, sparsely and minutely stri- 
gose on the veins beneath, the 8 to 12 pairs of major secondary veins weakly loop- 
connected near the margin, microscopic oblongoid-capitate hairs usually present be- 
neath. Male inflorescences usually 1 or 2 in axils of leaves or fallen leaves, goblet- 
shaped at anthesis (abruptly narrowed beneath), 3-5 mm. in diameter, borne on 
bracteate peduncles 1-3 mm. long, the receptacle covered by 4 to 5 series of 15 to 25 
thin ovate bracts obtuse at the apex and sparsely puberulent abaxially, flowers 5 to 
20; male perianth 1-2 mm. high, 4-lobed or 4-parted, not thickened distally, fila- 
ments free, anthers 0.2-0.5 mm. long. Female inflorescences solitary, 1-5 mm. in 
diameter, borne on peduncles 1-3.5 mm. long and bracteate distally, receptacle cov- 
ered with 3 to 5 series of 6 to 23 thin suborbicular to ovate bracts, minutely puberu- 
lent, flowers 1 to 12; female perianth urceolate, 2-2.5 mm. high, 4-lobed, minutely 
appressed puberulent, ovary almost free or partly united with the perianth, nearly 
glabrous, stigmas 0.6-1 mm. long, slender. Fruit enclosed within the fleshy sparsely 
appressed puberulent perianth. 

Small trees and slender treelets in the understory of wet ever- 
green forest sormations between sea level and 200 m. on the Carib- 
bean side of Costa Rica (to 600 m. elsewhere); probably flowering 



BURGER: FLORA COSTARICENSIS 197 

throughout the year. The species ranges from Central Costa Rica 
southward to the upper Amazon Basin of Brazil and Peru. 

Perebea angustifolia is usually found as a slender treelet with thin 
(1-3 cm.) stems on the dark forest floor. The thin, narrow almost 
glabrous leaves, often abruptly acuminate and with a few blunt 
teeth distally, stipules surrounding the stem, white sap, and minute 
inflorescences with thin imbricate bracts distinguish this species. 
The plants resemble juvenile specimens of Sorocea. The small few- 
flowered inflorescences are very difficult to see and may account for 
the very few collections in herbaria. This species is known in Costa 
Rica from near Puerto Viejo de Sarapiqui (Burger et al. 4325, 9281, 
& 9286 and Hartshorn 821 ) Heredia, and from near El Carmen (Lent 
2473} in the province of Limon. 

Perebea guianensis Aublet, PI. Guian. 2:953, t. 361. 1775. P. cas- 
tilloides Pittier, Contr. U.S. Nat. Herb. 13:438. 1912. Figure 16. 

Usually small trees, 3-20 m. tall, unisexual, latex white to yellowish, leafy inter- 
nodes 3-7 (13) mm. thick, subsericeous to substrigose or hirsute with slender yellow- 
ish hairs; stipules 3-6 cm. long, occasionally persisting, yellowish subsericeous to 
hirsute. Leaves usually slightly asymmetric, petioles 3-16 mm. long, 2-6 mm. thick, 
with thin ascending yellowish hairs 0.8-2 mm. long; laminae 20-50 cm. long, 8-18 cm. 
broad, oblong to ovate-oblong or obovate-oblong, widest in the distal or proximal 
part, abruptly acuminate or caudate at the apex with the narrowed tip 1-2 cm. long, 
truncate and rounded to cordulate at the base with the small basal lobes sometimes 
over-lapping, margin entire to repand, the laminae drying stiffly chartaceous to sub- 
coriaceous, smooth and puberulent on the major veins above, hirsute on the veins 
beneath with yellowish hairs 1-1.5 mm. long, the 16 to 26 pairs of major secondary 
veins usually weakly loop-connected near the margin, narrowly oblongoid-capitate 
microscopic hairs present on the veins beneath. Male inflorescences often in groups 
on short-shoots in the leaf axils, discoid, 10-15 mm. in diameter, on peduncles as 
much as 30 mm. long, receptacle covered with 5 or 6 series of about 50 to 90 thin 
bracts narrowed apically, flowers more than 15; male perianth 1-1.5 mm. high, fila- 
ments 1-1.6 mm. long, anthers 0.4-0.5 mm. long, apiculate. Female inflorescences' 
solitary or rarely together with the males, discoid, 10-15 mm. in diameter, receptacle 
covered with 3 to 5 (9) series of 30 or more thin bracts narrowed apically and sub- 
sericeous to hirtellous, flowers 8 to 27; female perianth 4-6 mm. high, the perianth- 
tube 4-lobed with the free lobes 0.5-2 mm. long, style 2-5 mm. long, stigmas 1.2-1.7 
mm. long, plane and 0.6-2 mm. broad or revolute to 4 mm. broad. Fruit borne within 
the succulent ellipsoid perianth 10-22 mm. high on the discoid infructescence 2-5 cm. 
broad. 

Plants of wet evergreen forest formations between sea level and 
about 1000 m. altitude in our area. This species has not been col- 
lected in Costa Rica but is known from Bocas del Toro and Chiriqui 
Provinces in Panama and ranges southward to the Amazon Basin 
and the Guianas. 



198 FIELDIANA: BOTANY, VOLUME 40 

Perebea guianensis is represented in our area by subspecies cas- 
tillodes (Pittier) Berg. The plants are distinctive because of the 
large, usually oblong leaves slightly cordate at the base, short peti- 
oles, slender silky yellowish hairs on many parts, and discoid pedun- 
culate inflorescences with an involucre of thin imbricate puberulent 
bracts. The plants are very similar to Castilla elastica, but that 
species has the two stipules at each node fused and the leaves are 
minutely denticulate whereas our material of Perebea guianensis 
has separate stipules and entire leaf-margins. 

Perebea xanthochyma Karsten, Fl. Colomb. 2:23. t. 112, 1862. P. 
hispidula Standl., Ann. Missouri Bot. Card. 29:350. 1942. P. mol- 
li flora Standl. & Wms., Ceiba 3:41. 1952. Figure 16. 

Shrubs or trees to 35 m. tall, unisexual or bisexual, latex yellowish but turning 
brown or reddish, leafy internodes 5-50 mm. long, 1.6-6 (8) mm. thick, variable in 
pubescence with minute (0.1-0.3 mm.) appressed ascending hairs or longer (0.5-1.5 
mm.) spreading straight hairs or both, often becoming glabrescent; stipules 5-15 
(25) mm. long, yellowish to pale grayish sericeous with lustrous thin ascending 
hairs. Leaves often slightly asymmetric, petioles 2-10 (20) mm. long, about 1.8 mm. 
thick, narrowly sulcate distally, often hirsute; laminae 12-34 (48) cm. long, 4-12 (20) 
cm. broad, abruptly acuminate at the apex, the narrow tip 1-3 cm. long, acute to ob- 
tuse and slightly rounded at the usually unequal base, margin entire to repand or 
distinctly serrate, laminae drying thinly to stiffly chartaceous, smooth on both sur- 
faces, glabrescent and the midvein prominent above, almost glabrous to conspicu- 
ously puberulent on the veins beneath with slender stiff hairs to 1 mm. long, the 
12 to 18 pairs of major secondary veins weakly loop-connected near the margin or 
not, microscopic narrowly oblongoid-capitate hairs present on the lower surface. 
Male inflorescences 3-6 (10) mm. in diameter, borne on peduncles 1-3 (6) mm. long, 
receptacle covered with 4 to 8 series of about 25 to 60 broad thin subsericeous 
bracts, flowers 10 or more; male perianth 0.8-1.1 mm. high, perianth-parts free and 
yellowish puberulent, filaments 0.6-1.1 mm. long, free, anthers 0.3-0.5 mm. long. 
Female inflorescences solitary or with male inflorescences in the axils of leaves, 
discoid to subglobose, 4-15 mm. in diameter, subsessile or borne on a bracteate 
peduncle to 3 mm. long, receptacle covered by 4 to 10 series of 20 to 90 thin sub- 
sericeous bracts, flowers (5) 10 or more; female perianth about 2 (rarely, 3.5) mm. 
high, perianth-tube entire or minutely 4-lobed, yellowish to whitish puberulent, 
ovary partly united to the perianth, style 0.5-2 mm. long, stigmas 0.5-1.5 mm. long, 
0.2-0.7 mm. broad. Fruit borne within the succulent perianth on infructescences 
1-2 cm. in diameter, fruiting perianth ellipsoid, 10-13 mm. long amd 8-10 mm. thick 
(dry), sparsely to densely hirsute with long ( 1 mm.) yellowish hairs, becoming red. 

Plants of the lowland wet evergreen forest formations from sea 
level to 850 m. elevation; on both the Caribbean and Pacific slopes 
of Costa Rica; probably flowering throughout the year. The species 
ranges from Costa Rica to Peru. 

Perebea xanthochyma is recognized by the yellowish sap, stipules 



BURGER: FLORA COSTARICENSIS 199 

encircling the stem, thin and occasionally long leaves abruptly acu- 
minate and sparsely puberulent beneath, small inflorescences with 
thin overlapping bracts forming an involucre, and the usually hir- 
sute ellipsoid drupe-like fruit borne on the infructescence. The mar- 
gins of the lamina form a narrow slit at the apex of the petiole, and 
this is useful in placing material with immature flowering parts, but 
compare Naucleopsis. 

POULSENIA Eggers 

Trees, bisexual, the younger branches usually with short broad-based spines; 
stipules paired and free at a node, completely enclosing the shoot-apex, caducous 
and leaving a scar encircling the stems. Leaves distichous, petiolate, laminae often 
large, epidermal cells often with sinuate outlines, very narrow oblongoid-capitate 
hairs present on the lower surface ( 150X ), the lower surface with microscopic trans- 
parent cells round in outline and apparently flat. Male inflorescences usually soli- 
tary in the axils of leaves, pedunculate, globose or subglobose heads with many 
flowers; male flower with 4 perianth-parts and 4 stamens, compressed and angular 
in early stages, with the perianth united basally and 4-lobed, stamens 4, apparently 
straight in bud, anthers basifixed. Female inflorescences a capitate sessile cluster 
of flowers, solitary in the leaf-axil, the (3) 5 to 15 flowers united in the lower half; fe- 
male flower with the free upper portion of the perianth tubular and conic, shortly 4- 
dentate, ovary free of the perianth but within the united part of the flower and 
becoming immersed in fruit, style exserted, stigmas 2. Fruit formed within the 
fleshy head (syncarp). 

A genus with a single species ranging from Veracruz, Mexico, to 
Ecuador. There is great variation in leaf-size, venation, and sym- 
metry in different collections but the small spines, often found on 
petioles and stipules as well as stems, distinguish these plants from 
other Moraceae in our flora. 

Poulsenia armata (Miq.) Standley, Trop. Woods 33:4. 1933. 
Olmedia armata Miquel in Seem., Bot. Voy. Herald 196, 1854. 
Figure 15. 

Trees, 5-25 m. tall, bisexual, sap white, leafy internodes (0.8) 1.5-6 (10) cm. long, 
3-8 mm. thick, glabrous or with very minute (0.5 mm.) appressed brownish hairs, 
usually with scattered spines 2-4 mm. long, broad ( 1.3 mm.) at the base with a thick- 
ened brownish central portion and abruptly narrower translucent sharp tip; stipules 
1-6 cm. long, 5-10 mm. thick near the base, glabrous or with brown multicellular 
hairs, often with short spines. Leaves symmetric or often very asymmetric near the 
base on flowering branchlets; petioles 1-4.5 cm. long, 2.5-4.5 mm. thick, glabrous or 
with very minute (0.05-0.1 mm.) appressed hairs, a few spines usually present, nar- 
rowly sulcate above; laminae (8) 12-45 cm. long, (4) 8-22 cm. broad, ovate to ovate- 
oblong, acute to acuminate or occasionally obtuse at the apex, obtuse to rounded 
and truncate or cordate at the equal to very unequal base, margin entire or slightly 



200 FIELDIANA: BOTANY, VOLUME 40 

sinuate, the laminae drying very stiffly chartaceous to subcoriaceous, smooth and 
the major veins prominent above, essentially glabrous on both surfaces, the 4 to 12 
pairs of major secondary veins weakly loop-connected near the margin (an arcuate 
submarginal vein absent), microscopic hairs very narrowly oblongoid beneath. Male 
inflorescences borne on peduncles 1-2 cm. long, the globose head about 1-1.5 cm. in 
diameter (dry), lacking an obvious involucre of bracts, the young flowers variously 
angled by compression, about 0.8 mm. in diameter; perianth-lobes about 0.5 mm. 
wide, minutely puberulent, stamens slightly exserted above the perianth, anthers 
about 0.5 mm. long and 0.8 mm. broad, with a broad connective. Female inflores- 
cence a loose head of apically separate flowers sessile in the leaf axil, subglobose to 
obovoid or ovoid in general form, 1.5-2 cm. in diameter; free portion of the female 
flowers 3-5 mm. high, perianth-lobes 1-2 mm. long, sparsely and very minutely pub- 
erulent. Fruit borne within the fleshy syncarp about 2-3 cm. in diameter, apices of 
the individual fruiting perianths about 3 mm. high with the larger part of the seed 
beneath the surface of the syncarp, seed about 8 mm. long and 4 mm. thick. 

Plants of evergreen wet forest formations between sea level and 
about 400 (?) m. elevation; flowering material has been collected 
in April and September (in Panama). The species ranges from Cen- 
tral Mexico to Bolivia. 

Poulsenia armata is recognized by the aculeate spines, milky sap, 
stipules encircling the stem, large leaves, and capitate inflores- 
cences that are globose and pedunculate in the male and a sessile 
cluster united basally in the female. The inflorescences of both sexes 
lack an involucre and have no peltate bracts but the peduncle is 
often dilated at the apex and may resemble an involucre. The whorl- 
ed arrangement of bracts may give the impression of an involucre 
in the female inflorescence. The species is very poorly represented in 
collections. The larger trees appear to have smaller leaves that are 
often very asymmetric. 

POUROUMA Aublet 

Unisexual trees, often tall with relatively slender smooth trunks, independent or 
(?) rarely epiphytic; the sap clear but quickly becoming dark in color, not milky; 
stipules connate and (consequently) solitary, enclosing the stem-apex and leaving 
a scar encircling the stem, usually large. Leaves simple and alternate in a spiral, 
petiolate and basifixed, the lamina entire to deeply lobed (entire and narrowly ellip- 
tic in juvenile stages), pinnately or palmately veined, tertiary veins subparallel, 
often pale-grayish tomentose beneath. Inflorescences unisexual, usually paired in 
the axils of the current leaves, peduncle usually branched with the flowers in cymose 
clusters or rarely unbranched and the flowers umbellate. Male flowers usually in 
congested clusters or capitate, sessile on the branches of the inflorescence; perianth 
of 3 or 4 parts or lobes, stamens 3 or 4, filaments erect, free or connate at the base. 
Female flowers sessile or more often pedicellate, perianth tubular with a small open- 
ing at the apex, enclosing ovary and style and persisting in fruit, stigma simple, 
papilla te-puberulent, peltate-discoid, ovule borne on the wall of the locule near the 



BURGER: FLORA COSTARICENSIS 201 

base by adnation of the funicle. Fruit moderately large (1-3 cm.), tightly enclosed 
within the persisting slightly succulent perianth. 

A poorly understood genus of probably fewer than 30 species, 
represented in Central America by only the following two species. 
Unlike its close relative, Coussapoa, the epiphytic-strangling habit 
is apparently never encountered in Pourouma. Like Coussapoa and 
Cecropia, also members of the subfamily Conocephaloideae, these 
plants are probably more closely related to the Urticaceae than to 
the other genera of the Moraceae (Corner, 1962). 

Laminae of mature trees usually deeply lobed and scabrous above; female inflores- 
cences distally much-branched with the flowers in cymose groups; common and 
widespread in wet evergreen formations, 0-1000 m P. aspera. 

Laminae of mature trees entire and elliptic, smooth above; female inflorescence 
umbellate with 5 to 9 flowers on each peduncle; rare (?) and known only from the low 
hills (200 m.) at the edge of the Caribbean escarpment in Costa Rica P. minor. 

Pourouma aspera Trecul, Ann. Sci. Nat. ser. 3, 8: 102. 1847. sensu 
lato. P. scobina Benoist, Bull. Mus. Hist. Nat. Paris 28:320. 1922. 
P. johnstonii Woodson, Ann. Missouri Bot. Gard. 47: 166-167. 1960. 
Figure 22. 

Trees (5) 10-30 m. tall, trunk smooth and mottled with shades of gray and brown, 
the cut trunk producing clear sap but the branchlets producing a sap that quickly 
becomes dark brown or black, leafy internodes 8-20 mm. thick, sparsely to densely 
puberulent with minute or long (3 mm.) hairs; brown circular lenticels often pres- 
ent; stipules 5-12 cm. long, 5-20 mm. thick, densely pale yellowish gray sericeous 
with hairs 0.5-3 mm. long, caducous. Leaves very variable (on different trees and oc- 
casionally on the same tree) in mature plants, petioles 12-30 cm. long, 3-7 mm. thick, 
minutely (0.1-0.5 mm.) appressed sericeous, smooth or weakly striate; laminae on 
mature plants 12-50 cm. long, 10-40 cm. broad, with 3 to 5 (7) usually deep or occa- 
sionally shallow lobes, distal lobes acute to acuminate at the apex or less often ob- 
tuse, cordate to truncated at the base, margins usually undulate, the laminae drying 
stiffly chartaceous to subcoriaceous, scabrous and sparsely puberulent above, 
puberulent beneath with slender ascending hairs about 1 mm. long and thin 
minutely floccose or arachnoid hairs giving the under-surface a pale grayish color, 
venation palmate with 3 to 5 (7) primary veins, the central primary with 16 to 24 
pairs of major secondary veins, central secondaries arising at angles of 30-60 
degrees, tertiary veins slightly raised beneath. Male inflorescences 10-28 cm. long, 
common peduncle 3-12 cm. long, 1-3 mm. thick, densely ascending sericeous, distally 
much branched and the flowers in dense clusters; anthers about 0.4 mm. long. 
Female inflorescences 10-22 cm. long, common peduncle 5-11 cm. long, 2-4 mm. 
thick, distally much branched and the flowers in cymose groups, female flowers 
borne on short (1-10 mm.) thick (1-2 mm.), densely reddish puberulent pedicels 
expanded apically and somewhat cupulate, the female flowers 3-7 mm. long, (above 
the cupule), 1.5-3 mm. thick, narrowly ovoid, densely reddish-brown puberulent, 
stigma 1-2 mm. broad, minutely puberulent. Fruit becoming 15 mm. long and 10 



202 FIELDIANA: BOTANY, VOLUME 40 

mm. thick, ovoid, abruptly truncate or rounded at the base narrowed to the 
persisting stigma, the surface puberulent and scabrous. 

Large trees of rain forest formations from sea level to 900 m. 
altitude on both the Caribbean and Pacific slopes but not collected 
below 150 m. in Costa Rica; flowering and fruiting collections have 
been made between January and August. The species ranges from 
British Honduras southward to Venezuela and the Guianas. 

Pourouma aspera is recognized by the usually deeply lobed leaves 
scabrous above, complex inflorescences much branched distally, 
and the female flowers covered with minute reddish-brown hairs. 
This is the only species of the genus ranging into northern Central 
America. I believe that most of the material referred to under 
Pourouma in the "Flora of Panama" (Woodson, 1960) is synony- 
mous with P. aspera as interpreted here. This species is called 
Yahal, Pacica, guarumo de montafia, andguarumo macho in Nicara- 
gua and Costa Rica. The leaves are used for scouring, and the fruits 
were said to be eaten. 

Pourouma minor Benoist, Bull. Mus. Hist. Nat. Paris 30:103. 
1924, sensu lato fide C.C. Berg in litt. P. umbellifera Burger, Phy- 
tologia26: 430. 1973. Figure 22. 

Trees 10-25 m. tall, leafy internodes 2-10 (30) cm. long, 2.5-7 ( 15) mm. thick, dense- 
ly to sparsely puberulent with slender ascending hairs 0.5-2 mm. long, periderm 
becoming wrinkled (dry); stipules 5-15 cm. long, 4-14 mm. thick, densely sericeous 
with lustrous pale silvery hairs about 1 mm. long. Leaves often clustered near the 
ends of branchlets, quite variable in size (on the same tree), petioles 2-6 cm. long, 
1.5-4 (5) mm. thick, longitudinally ridged, puberulent with mostly ascending ap- 
pressed hairs about 1 mm. long; laminae (6) 10-28 (34) cm. long, (3) 4-12 (16) cm. 
broad, narrowly elliptic to elliptic-oblong, abruptly acute at the apex, obtuse or 
slightly rounded at the base, paired gland-like thickenings often present at the base 
of the blade above the petiole ( adaxially ), margin slightly rounded-undulate distally, 
laminae drying stiffly chartaceous to subcoriaceous, smooth above and puberulent 
only on the midvein, densely pale yellowish or whitish sericeous on the veins be- 
neath, minutely whitish flocose between the veins, venation pinnate, the (8) 15 to 22 
pairs of major secondary veins weakly loop -connected near the margin, central 
secondaries arising at angles of 30-50 degrees, tertiary veins slightly raised beneath. 
Male inflorescences about 6 cm. long, paniculate, peduncles about 3-4 cm. long and 1 
mm. thick, appressed sericeous, secondary and tertiary branches with the lustrous 
hairs not closely appressed; male flowers pedicellate or sessile, usually in clusters 
about 4 mm. broad, perianth about 1.5 mm. long, brownish with pale hairs along the 
midrib abaxially, anthers about 0.4 mm. broad. Female inflorescences umbellate, 
peduncle (2) 4-8 cm. long, about 2 mm. thick, sparsely or densely puberulent, with 5 
to 9 flowers per umbel, pedicels (2) 5-15 mm. long (lengthening in fruit), very slight- 
ly expanded at the apex; female flowers 4-8 mm. long, 1.5-3 mm. thick, narrowly 
ellipsoid or ovoid, densely yellowish or grayish velutinous, stigma peltate, thick and 



BURGER: FLORA COSTARICENSIS 203 

undulate, densely and minutely reddish velutinous. Fruiting inflorescence with fruit 
borne on pedicels 1-3 cm. long, about 1.5 mm. thick, sparsely puberulent, the peri- 
anth-tube becoming 15-22 mm. long, 10-15 mm. thick, ovoid, abruptly narrowed at 
the base, gradually narrowed at the apex, sparsely puberulent with slender ascend- 
ing hairs about 0.3 mm. long, fruit only slightly smaller than the enclosing perianth, 
ovoid and somewhat flattened with suture-like lines on the flattened surfaces, glab- 
rous and lustrous. 

A species of the Caribbean coastal plain and adjacent slopes be- 
tween 50 and 300 m. elevation in Costa Rica; flowering collections 
have been made in October, January, and May. Fertile collections 
have been made near Tirimbina (Lent 2327} and Las Horquetas 
(Hartshorn 1224} in Heredia and above Siquerres (Holdridge 6818} 
in Limon. The species ranges southward to the Amazon basin. 

Pourouma minor is distinguished by the long-petiolate elliptic 
leaves with many parallel secondary and tertiary veins, whitish 
undersurfaces, and umbellate female inflorescence. Vegetatively 
these plants resemble some species of Coussapoa, but those usually 
begin as epiphytes. I am following Dr. C.C. Berg's interpretation 
(pers. comm. ) that P. minor is a variable species of wide range. 

PSEUDOLMEDIA Trecul 

REFERENCE: C.C. Berg, Olmedieae. Fl. Neotropica. Monog. 
7:17-38.1972. 

Unisexual trees, branches without spines; stipules free, encircling the stem com- 
pletely, caducous. Leaves distichous, petiolate, mostly entire, microscopic multi- 
cellular oblongoid-capitate or globose-capitate hairs often abundant. Male inflores- 
cences 1 to 4 (rarely more) in each axil, sessile, discoid in form, receptacle covered 
with imbricate bracts, forming an involucre that covers the stamens until anthesis; 
male flowers not recognizable, the many free stamens intermixed with concentri- 
cally arranged interstaminal bracts, the interstaminal bracts variable in size and 
shape, filaments straight in bud, anthers basifixed, often apiculate and with or with- 
out apical hairs, the thecae opening laterally. Female inflorescences 1 or 2 (rarely 
more) in the leaf-axils, sessile, receptacle covered with imbricate bracts forming an 
involucre, flower solitary in each inflorescence; female flower with a tubular 4-den- 
tate perianth, ovary completely united with the perianth-tube, stigmas filiform. 
Fruit relatively large within the reddish and fleshy perianth, cotyledons thick and 
equal. 

A genus of nine species ranging from southern Mexico and the 
West Indies to Brazil and Bolivia. 

Fruit pale yellowish sericeous to velutinous, subglobose to ellipsoid; laminae usually 
6-17 cm. long and 2-7 cm. broad; between 500 and 1000 m. elevation in our area 

P. oxyphyllaria. 



204 FIELDIANA: BOTANY, VOLUME 40 

Fruit sparesly puberulent near the tip and glabrous over most of its surface, oblong- 
oid to obovoid or ellipsoid; laminae usually 4-14 cm. long and 1.5-4.5 cm. broad; 
rarely found above 500 m. elevation in Costa Rica P. spuria. 

Pseudolmedia oxyphyllaria Donnell-Smith, Bot. Gaz. 20:294. 
1895. P. mollis Standl., Journ. Wash. Acad. Sci. 13:30. 1923. Bro- 
simum ramonense Standl., Field Mus. Bot. 18:379. 1937. Pseudol- 
media simiarum Standl. & Steyer., loc. cit. 23:154. 1944. P. mala- 
cocarpa Standl. & Wms., Ceiba 3:42. 1952. Figure 16. 

Trees to 20 (30) m. tall, latex whitish, leafy internodes 5-40 mm. long, 0.7-3.5 mm. 
thick, essentially glabrous or sparsely puberulent with thin yellowish hairs 0.2-0.8 
mm. long, bark of the twigs usually smooth (dry); stipules 4-10 mm. long, minutely 
puberulent abaxially (rarely sericeous or hirsute). Leaves generally symmetrical, 
petioles 2-9 mm. long, 1-2.5 mm. thick, glabrous to sparsely puberulent; laminae 6- 
17 (28) cm. long, 2-7 ( 10) cm. broad, lanceolate to narrowly oblong or elliptic-oblong, 
abruptly and narrowly acuminate, obtuse to acute at the base, margin entire, the 
lamina drying stiffly chartaceous to subcoriaceous, smooth on both surfaces, essen- 
tially glabrous and the midvein prominent above, glabrous to sparsely puberulent 
beneath, the 8 to 18 pairs of major secondary veins prominent beneath and usually 
loop-connected near the margin, microscopic globose-capitate or oblongoid-capitate 
hairs usually present on the lower surface, clear or orange distally. Male inflores- 
cences 1 to 4 in the axils of leaves or fallen leaves, sessile, 5-10 mm. in diameter, 
bracts 14 to 22 in 3 to 7 series, 1.5-4 mm. broad and acute to broadly obtuse, minu- 
tely sericeous, stamens more than 20 per inflorescence; interstaminal bracts 2-4.5 
mm. long, spathulate to oblanceolate, filaments 0.3-1.5 mm. long, anthers about 2 
mm. long, narrow. Female inflorescence 1 or 2 in the axils of leaves or fallen leaves, 
ovoid, 2-4 mm. in diameter, the 10 to 18 broad bracts in 3 to 6 series, acute to obtuse 
and minutely sericeous, with slender pale yellowish hairs, flower solitary; female 
perianth 2-2.5 mm. high, densely velutinous with ascending straight yellowish 
hairs about 0.5 mm. long, style 0.8-1 mm. long, stigmas 5-7 mm. long, slender. Fruit 
formed within the subglobose to ovoid or ellipsoid perianth, 20-23 mm. long, 17-20 
mm. thick, pale yellowish sericeous to velutinous. 

Rare plants of moist evergreen forest formations between 500 and 
1000 m. elevation in Costa Rica (0-1800 m. elsewhere); flowering 
from February to May, fruiting from March to June. This species 
ranges from the State of Veracruz, Mexico, to central Costa Rica. 

Pseudolmedia oxphyllaria is recognized by the stipules encircling 
the stem, the medium sized leaves with entire margins, glabrous or 
very sparsely puberulent beneath, and the small sessile inflores- 
cences enclosed in an involucre of thin broad sericeous bracts. This 
species is very similar to Pseudolmedia spuria with essentially glab- 
rous fruit and less puberulent floral bracts. Fruiting collections 
from Costa Rica have larger, more puberulent leaves that dry much 
darker in color than the leaves of the male collections. It may be 
that the former represent a distinct entity to which the type of Bros- 



BURGER: FLORA COSTARICENSIS 205 

imum ramonense would belong. This species is very poorly repre- 
sented in collections, and decisions at this time must be considered 
no more than tentative. 

Pseudolmedia spuria (Sw.) Grisebach, Fl. Brit. W. Ind. 152. 1859. 
Brosimum spurium Swartz, Prodr. Veg. Ind. Occ. 12. 1788. Figure 
16. 

Trees 5-30 m. tall, sap white, leafy internodes 0.5-5 cm. long, 1.5-2.5 mm. thick, 
glabrous or sparsely and very minutely puberulent, usually smooth and brown; 
stipules 2-12 mm. long, about 1 mm. broad at the base, very slender apically, minute- 
ly puberulent along the midrib and ba sally (abaxially) or glabrous, dark brown. 
Leaves usually symmetrical, petioles 3-8 mm. long, 0.5-1.5 mm. thick, smooth, dark 
bnown and essentially glabrous; laminae 4-14 (17) cm. long, 1.5-4.5 (6) cm. broad, 
narrowly elliptic to narrowly oblong or ovate-lanceolate, usually short-acuminate at 
the apex, acute to obtuse and usually equal at the base, margins entire, the lamina 
drying stiffly chartaceous, smooth and essentially glabrous on both surfaces, mid- 
vein prominent and the smaller veins usually slightly raised above, the 10 to 18 pairs 
of major secondary veins loop-connected near the margin, lower surface with very 
few narrow (oblongoid-capitate) microscopic hairs and the sto mates usually readily 
apparent. Male inflorescences 1 to 4 in the axils of leaves or fallen leaves, subsessile 
or sessile, ovoid before anthesis, receptacle covered by an involucre of 2 to 4 series of 
15 to 25 mostly ovate to lanceolate bracts, brown and minutely puberulent along the 
midrib, interstaminal bracts 2-4 mm. long, narrow and often broadened apically, 
stamens about 15 per inflorescence; filaments 0.5-1 mm. long, anthers 1.2-2 mm. 
long, apiculate. Female inflorescences usually 1 or 2 in the axils of leaves or fallen 
leaves, ovoid, 1.5-2 mm. in diameter, receptacle hidden within an involucre of 3 to 6 
series of deltoid to ovate bracts 1-3 mm. broad, minutely puberulent centrally ( abax- 
ially) and brown, thin, the flower solitary; female perianth-tube 2-2.5 mm. high, 
minutely puberulent, style 1-1.5 mm. long, stigmas 2-6 mm. long. Fruit enclosed 
within the fleshy perianth-tube and drupaceous, 9-15 mm. long and 5-9 mm. thick, 
oblongoid to obovoid or ellipsoid, sparsely puberulent near the tip, the involucre 
of bracts remaining small but persisting at the base. 

Apparently rare plants of the wet evergreen forest formations 
with a short but definite dry season between sea level and about 400 
(900) m. elevation; flowering from February to June (September). 
The species ranges from Chiapas, Mexico, to Panama and in the 
Greater Antilles but has only been collected from along the Rio 
Grand de Tarcoles, near Capulin (Standley 40109 & 40145), Alajue- 
la, and from Palmar Norte (Allen 5961 ), Puntarenas, in Costa Rica. 

Pseudolmedia spuria is recognized by the relatively small, essen- 
tially glabrous leaves on slender branchlets with stipule encircling 
the stem, and the small sessile inflorescences enclosed in an invo- 
lucre of thin broad bracts, the drupe-like fruit subtended by the 
small imbricate bracts, and lack of organized male flowers. The 
smaller leaves, more sparse pubescence, and lowland habitat (in 



206 FIELDIANA: BOTANY, VOLUME 40 

ours?) distinguish this species from the rather similar Pseudolmedia 
oxyphyllaria. 



SOROCEA St. Hilaire 

REFERENCE: W. Burger, J. Lanjouw, and J. G. Wessels Boer, 
The genus Sorocea, Acta Bot. Neerl. 11:428-477. 1962. 

Shrubs or trees, unisexual, without spines, sap whitish; stipules paired and later- 
al, caducous or rarely persistent, their scars encircling less than half the stem. 
Leaves simple, alternate and distichous, petioles sulcate above, venation pinnate, 
margins entire to sharply serrate. Inflorescences paired or solitary in the axils of 
present or fallen leaves, racemose or spicate (capitate in South America), with 
numerous suborbicular, usually peltate bracts along the rachis; flowers often lack- 
ing along one side of the rachis. Male flowers sessile or pedicellate, perianth 4-parted 
with equal or unequal tepals, decussate-imbricate in bud, stamens 4 and opposite 
the tepals, filaments straight in bud, glabrous, anthers usually dorsifixed and open- 
ing outwards (extrorse), a pistillode usually absent. Female flowers sessile or pedi- 
cellate, perianth tubular or rarely 4-parted and accrescent in fruit, irregularly or 
minutely 4-lobed at the apex, ovary inferior to superior by adnation of the perianth- 
tube, style bifid with the style branches usually short and thick. Fruit drupaceous, 
perianth accrescent and succulent, the stone globose or ellipsoid, lacking endo- 
sperm, the cotyledons thick, the pedicels often elongating and thickening in fruit. 

A genus of about 22 species ranging from Guatemala to Para- 
guay, southern Brazil, and northernmost Argentina, but with centers 
of diversity in Costa Rica and Panama, the upper Amazon Basin, 
and in eastern Brazil near Rio de Janeiro. This genus is very similar 
to Trophis and Clarisia as regards the female flowers, but the male 
flowers are very different. Sterile material is also difficult to sepa- 
rate from Brosimum and other small genera of the Moraceae. The 
plants resemble some Euphorbiaceae and some Flacourtiaceae 
such as Lozania. 

The species of Sorocea are quite variable and often difficult to sep- 
arate from each other. There are a few collections that may be inter- 
mediate between what are here described as species. This is especi- 
ally the case with collections between 300 and 1000 m. elevation, 
many of which are sterile. These may represent hybrids between S. 
trophoides and S. affinis or S. pubivena, or they may only be unusu- 
al individuals on the periphery of one of these populations. These 
same kinds of problems are found in the Amazon Basin where the 
greatest number of species of Sorocea are found. 

la. Plants rarely found below 800 m. elevation; male flowers with filaments 1.8- 
2.6 mm. long and anthers 0.7-1.1 mm. long; female flowers with an urceolate 
perianth-tube S. trophoides. 



BURGER: FLORA COSTARICENSIS 207 

Ib. Plants rarely found above 500 m. elevation; filaments 1.1-2 mm. long, anthers 
0.4-0.8 mm. long; female flowers with an urceolate to ovoid or globose perianth- 
tube 2a. 

2a. Male flowers pedicellate or rarely subsessile; fruiting pedicels 0.7-1.7 mm. thick 
(dry); leaves glabrous and usually entire, rarely more than 16 cm. long and 6 
cm. broad S. affinis. 

2b. Male flowers broadly sessile on the rachis; fruiting pedicels 1.5-3 mm. thick; 
leaves often more than 16 cm. long and 6 cm. broad 3a. 

3a. Plants of the Caribbean slopes and lowlands; leaves usually bluntly serrate 
distally and usually puberulent beneath; fruit usually ellipsoid, about 8 mm. 
thick, and borne on an elongated rachis 4-14 cm. long S. pubivena. 

3b. Plants of Golfo Dulce and adjacent areas in the Pacific lowlands; leaves entire 
and usually glabrous; fruit globose, about 1 cm. in diameter and borne on a 
short (2-3 cm.) rachis S. cufodontisii. 



Sorocea affinis Hemsley, Biol. Centr. Amer. 3:150.1883. Figure 
14. 

Shrubs or trees, 3 to 15 m. tall, leafy internodes 3-25 mm. long, 0.9-2.8 mm. thick, 
puberulent but often becoming glabrous, lenticels often conspicuous; stipules 2-5 
mm. long, narrowly cuneate, puberulent, caducous, the scars inconspicuous. Leaves 
in 2 ranks, petiole 3-11 mm. long, 0.6-1.8 mm. thick, sparsely puberulent and soon 
glabrescent; laminae 8-18 (23) cm. long, 2.5-7.2 cm. broad, narrowly elliptic to ellip- 
tic-oblong or narrowly obovate, acuminate to abruptly caudate-acuminate at the 
apex, acute or occasionally obtuse at the base, margin entire or occasionally bluntly 
serrate, the laminae drying thin chartaceous, smooth and glabrous on both surfaces, 
midvein slightly impressed above, the 5 to 10 pairs of major secondary veins loop- 
connected near the margin and forming an arcuate submarginal vein. Male inflores- 
cences paired or solitary, racemose or occasionally spicate, peduncles 1.2-4.8 mm. 
long, minutely puberulent, bracts 0.6-1.9 mm. broad on stipes 0.5 mm. long, flowers 
numerous and distant; male flowers usually pedicellate, pedicels (0) 0.3-1.7 mm. 
long, perianth-parts subequal, about 2 mm. long and 1.5 mm. wide, sparsely and mi- 
nutely puberulent, filaments about 1.5 mm. long, anthers 0.5-0.8 mm. long, connec- 
tive forming a gland-like projection. Female inflorescences paired or solitary, race- 
mose, 1.3-5.8 cm. long, peduncles 1.2-3.8 mm. long, minutely puberulent, bracts 0.5- 
1.4 mm. broad on prominent stipes, flowers 10 to many and usually distant; female 
flowers on pedicels 0.4-2 mm. long, perianth-tube ovoid to globose and later becom- 
ing thickened above, about 2 mm. in diameter, sparsely and very minutely (-0.05 
mm.) papillate-puberulent on the basal half, ovary adnate to the perianth-tube, 
style-branches 0.6-1.2 mm. long and recurved. Fruit about 8 mm. in diameter, glo- 
bose, becoming red, glabrous or very minutely puberulent, fruiting pedicels 2-10 
mm. long and 0.7-2 mm. thick. 

Plants of the lowland wet evergreen forest formations of both the 
Caribbean coastal plain and the Golfo Dulce region between sea 
level and 300 m. elevation in Costa Rica; probably flowering 
throughout the year but collected mostly between November and 



208 FIELDIANA: BOTANY, VOLUME 40 

April. The species ranges from the Caribbean coast of Guatemala to 
the Darien region of Panama. 

Sorocea affinis is recognized by its generally glabrous parts, thin 
abruptly acuminate leaves, usually pedicellate male flowers, short 
female inflorescences with very minutely puberulent fruit, and low- 
land habitat. Very few fertile collections are known from Costa Rica 
(Allen 5492 & Lent 2243), but the species is common in Central 
Panama. These trees are usually found on well-drained sites. 

Sorocea cufodontisii W. Burger, Acta Bot. Neerl. 11:447. 1962, 
as cufodonti. Figure 14. 

Trees, leafy internodes 5-40 mm. long, about 1.5-3.5 mm. thick, glabrescent, lenti- 
cels becoming conspicuous; stipules about 5 mm. long, cuneate. Leaves in 2 ranks, 
petioles 9-20 mm. long, 1.4-3 mm. thick, glabrous; laminae 13-30 cm. long, 8-11 cm. 
broad, narrowly elliptic to narrowly obovate or elliptic-oblong, abruptly acuminate 
at the apex, the narrow tip 8-30 mm. long, acute to obtuse at the usually oblique 
base, margin entire, drying stiffly chartaceous, smooth and glabrous above, glab- 
rous or very minutely (0.01 mm.) puberulent below, midvein slightly impressed 
above, the 8 to 14 pairs of major secondary veins loop-connected near the margin 
and forming a marginal vein in the distal half of the lamina. Male inflorescences 
usually paired, spicate, 2-10 cm. long, peduncles about 4 mm. long, sparsely minute- 
ly puberulent, bracts 0.9-1.5 mm. broad, flowers numerous and usually not closely 
crowded; male flowers sessile, 1.8-3.5 mm. wide, perianth-parts broadly oval, about 
2 mm. long, obtuse at the apex, minutely puberulent, filaments 0.7-2 mm. long, 
anthers 0.7-1 mm. long, the connective slightly prolonged beyond the thecae, a prom- 
inent pistillode broad at the base and with a slender twisted style very rarely pres- 
ent in the center of the flower. Female inflorescences about 2 cm. long, female flow- 
ers about 3 mm. high on pedicels 0-1.5 mm. high, perianth-tube broadly urceolate, 
about 2.5 mm. in diameter. Fruit borne on a short (2 cm.) unexpanded rachis, the 
pedicels becoming 3-9 mm. long and 1.5-3.5 mm. thick, drupes globose or slightly 
ellipsoid about 1 cm. in diameter, the surface apparently glabrous with trichomes 
less than 0.03 mm.mm. long. 

Plants of the lowland evergreen rain (tropical wet) forests around 
the area of Golfo Dulce between sea level and perhaps 200 m. eleva- 
tion in Costa Rica and adjacent Panama; male flowers have been 
collected between March and June and fruit in August. The species 
as presently known is endemic to the area between Palmar Sur, 
Costa Rica, and Progreso, Panama. 

Sorocea cufodontisii is very closely related to S. pubivena but 
geographically isolated and poorly known. This species differs from 
S. pubivena in the entire, more glabrous leaves tapering more grad- 
ually to a usually longer acuminate tip, the less arcuate submar- 
ginal vein, the female inflorescences remaining short in fruit, and 



BURGER: FLORA COSTARICENSIS 209 

the larger more globose fruit on short thick pedicels. The male flow- 
ers appear to be very similar to those of S. pubivena; the pistillode 
that was used to separate this species in the original description is 
apparently very rare. This redefinition of S. cufodontisii includes 
the following collections: Brenes 12207, Burger & Stolze 5500 (d), 
Cooper & Slater 174(9), Cufodontis 200 (d) the type, Raven 21558 
( 9 ), and Tonduz 6751 ( d). The tree is called lechosa in Panama. 

Sorocea pubivena Hemsley, Biol. Centr. Amer. 3:150. 1883. 
Trophis macrostachya Donn.-Sm., Bot. Gaz. 40:10 1905. Clarisia 
mollis Standl., Ann. Missouri Bot. Gard. 30:85. 1943. Figure 14. 

Shrubs or trees to 20 m. tall, leafy internodes 1-6 cm. long, 1.5-5 mm. thick, dense- 
ly to sparsely hirtellous with hairs 0.1-0.5 mm. long, becoming glabrous, lenticels 
usually conspicuous; stipule 4-8 mm. long, cuneate, puberulent, caducous, scars 
often conspicuous. Leaves in 2 ranks, petioles 7-23 mm. long, 1.2-4.5 mm. thick, 
minutely puberulent in early stages; laminae 10-28 cm. long, 4.2-11 (14) cm. broad, 
narrowly to broadly elliptic to oblong or obovate, abruptly acuminate or caudate- 
acuminate at the apex, acute to obtuse at the base, margin bluntly serrate distally, 
the lamina drying chartaceous, smooth and glabrous above, puberulent with slender 
straight hairs 0.2-0.5 mm. long or glabrescent beneath, midvein slightly impressed 
above, the 7 to 12 pairs of major secondary veins loop-connected near the margin 
and forming a submarginal vein in the distal half of the lamina. Male inflorescences 
paired or solitary, spicate, 4-11 cm. long, peduncle 2-5.5 mm. long, densely hirtel- 
lous, bracts 0.7-1.4 mm. broad, flowers numerous but not congested, male flowers 
broadly sessile, 1.8-3.5 mm. broad, perianth-parts about 1.8 mm. long, obtuse at the 
apex, minutely puberulent, filaments 1.1-1.6 mm. long, anthers 0.6-0.8 mm. long, 
connective often forming a gland-like projection at the apex. Female inflorescences 
solitary or paired, spicate, 1.3-6.5 cm. long, elongating in fruit, peduncle 1.2-4.3 mm. 
long, densely hirtellous, bracts 0.7-1.5 mm. broad, flowers numerous but becoming 
distant in fruit; female flowers at first subsessile or on very short (0.5 mm.) pedi- 
cels, the pedicels elongating in fruit, perianth-tube about 2 mm. in diameter, ovoid 
or cylindrical, very minutely (0.05 mm.) papillate-puberulent, ovary partly adnate 
to the perianth or free, style-branches 0.6-1 mm. long. Fruit usually ellipsoid, about 
8 mm. in diameter, glabrescent or very minutely puberulent, occasionally subsessile 
but usually borne on stout pedicels to 13 mm. long, and 3 mm. thick, the fruiting 
raceme becoming as much as 14 cm. long. 

Plants of the very wet evergreen forest formations between sea 
level and 800 m. on the Caribbean side of Costa Rica; flowering 
throughout the year. The species is known only from Costa Rica and 
western Panama. 

Sorocea pubivena is recognized by the broadly sessile male flow- 
ers, the female inflorescences elongating in fruit, and the usually 
puberulent leaves slightly rough to the touch beneath and often 
caudate-acuminate at the apex. The trees usually exude abundant 
sap when cut. These plants are often found near streams or on poor- 



210 FIELDIANA: BOTANY, VOLUME 40 

ly drained soils but not in swampy locations. Occasional specimens 
are encountered that can be interpreted as intermediate with the 
other species; see the discussion under the genus and under the very 
closely related S. cufodontisii. 



Sorocea trophoides W. Burger, Acta Bot. Neerl. 11:450. 1962. 
Figure 14. 

Trees to 15 m. tall, trunk becoming 1 m. thick, leafy internodes 8-40 mm. long, 
0.8-2.5 mm. thick, sparsely and very minutely (0.1 mm.) appressed puberulent in 
early stages but soon glabrous; stipules 3-7 mm. long, narrowly cuneate, essentially 
glabrous, caducous, the scars inconspicuous. Leaves in 2 ranks, petioles 5-14 (22) 
mm. long, about 1.4 mm. thick, laminae 7-17 (28) cm. long, 2-6 (9) cm. broad, elliptic 
to elliptic-oblong, long-acuminate at the apex with the acumen 1-3 (4) cm. long, 
acute to obtuse at the base, the margin bluntly serrate, drying chartaceous, smooth 
and glabrous above, glabrous or minutely puberulent beneath, the 6 to 10 pairs of 
major secondary veins weakly loop-connected near the margin, central secondaries 
arising at angles of 50-80 degrees. Male inflorescences paired or solitary, spicate, 
2.5-6.5 cm. long, peduncles about 2-3 mm. long, bracts 0.7-1.8 mm. broad, flowers 
numerous and crowded; male flowers sessile, perianth-parts about 2 mm. long, 
glabrous, obtuse at the apex, filaments 1.8-2.6 mm. long, anthers 0.7-1.1 mm. long, 
connective forming a small projection. Female inflorescences solitary or paired, 
racemose, 2-4 cm. long but elongating to 10 cm. in fruit, peduncle 3-8 mm. long, 
puberulent, with 12 to many flowers; female flowers pedicellate, pedicels enlarging 
in fruit, the urceolate perianth-tube about 2 mm. in diameter, glabrous, ovary free 
within the tube, style-branches 0.5-1.2 mm. long. Fruit borne on pedicels 4-20 mm. 
long, 1-1.8 mm. thick, globose or ellipsoid, 4-8 mm. in diameter, the surface sparsely 
and very minutely (0.02 mm.) puberulent, becoming reddish and turning black. 

Plants of wet evergreen (premontane and lower montane rain) 
forest formations between 750 and 2000 m. elevations on both the 
Caribbean and Pacific slopes in Costa Rica; flowering from May to 
July and collected with fruit from July to October. The species has 
been collected from near San Ramon (Alajuela) in the west to near 
San Vito ( Puntarenas) near the border with Panama, but it is appar- 
ently now very rare around the Meseta Central. 

Sorocea trophoides is recognized by the thin leaves with abruptly 
long-acuminate tips, short spikes of male flowers, female inflores- 
cence with the fruit becoming raised on elongated pedicels, and the 
wet montane forest habitat. Specimens from lower altitudes may 
be difficult to distinguish from S. affinis or S. pubivena and may 
represent some intergradation with those species, but there is very 
little material presently available from these altitudes (300-800 m.). 



BURGER: FLORA COSTARICENSIS 211 

TROPHIS P. Browne 
Nomen conservandum 

Unisexual shrubs and trees, without spines, sap whitish; stipules paired, lateral, 
stipule-scars encircling less than half the stem. Leaves alternate and distichous, 
simple, entire or serrate, pinnately veined. Inflorescences paired or solitary in the 
axils of leaves or of fallen leaves, racemose or spicate, with triangular or suborbicu- 
lar peltate or basally attached bracts along the rachis, flowers usually lacking along 
one side of the inflorescence; male flowers sessile or pedicellate, perianth 4-parted or 
4-lobed, valvate in bud, stamens 4 and arising at the base of the perianth parts 
(opposite the tepals) and incurved in bud, erect at anthesis, anthers subcentrally 
dorsifixed, dehiscing laterally and introrse, 2-thecous; female flowers sessile or pedi- 
cellate, perianth tubular and irregularly or obscurely 4-lobed at the apex, ovary 
superior to inferior by adnation of the perianth-tube, style deeply bifid with the 
style-branches slender and minutely papillate-puberulent on the inner surface. Fruit 
drupaceous, the perianth-tube accrescent and succulent, stone globose. 

A genus of four neotropical species with perhaps a few additional 
species in the western Pacific. Vegetatively these plants are very 
similar to several other genera of the Moraceae (Brosimum, Clari- 
sia, Sorocea, etc.) as well as some Euphorbiaceae and Flacour- 
tiaceae. The female flowers of this genus are very similar to those 
of Clarisia and Sorocea, but the male flowers are quite different. 
The recently discovered Trophis involucrata has very unusual fe- 
male flowers, but the male flowers are very similar to those of T. 
mexicana. 

la. Leaves usually rough to the touch on one or both surfaces, with a short or 
broad acuminate apex; female flowers broadly sessile on short spikes, lack- 
ing a basal involucre of bracts; male flowers sessile; trees rarely found above 
800 m. elevation T. racemosa. 

Ib. Leaves smooth to the touch on both surfaces, usually with a long slender 
acuminate apex; male flowers sessile or pedicellate 2a. 

2a. Female flowers sessile and subtended by a basal involucre of bracts; inflor- 
escences 1-4 cm. long; small treelets of the wet Caribbean forest floor 
0-200 m T. involucrata. 

2b. Female flowers pedicellate; inflorescences 4-10 cm. long; trees usually found in 
montane forests, 600 to 1800 m T. mexicana. 

Trophis involucrata Burger, Phytologia 26:432. 1973. Figure 14. 

Small treelets 3-5 m. tall, unisexual, leafy internodes 5-35 mm. long, 0.7-1.6 mm. 
thick, densely puberulent on new growth with minute (0.1-0.2 mm.) stiff erect 
hairs; stipules paired, about 2 mm. long and 1 mm. broad at the base, minutely 
puberulent, occasionally persisting, scars encircling less than half the stem. 
Leaves usually symmetrical, often few at the ends of slender twigs, petioles 2-5 
mm. long, about 1 mm. thick, minutely puberulent; laminae 6-15 cm. long, 2-6 



212 FIELDIANA: BOTANY, VOLUME 40 

cm. broad, broadly elliptic-oblong to slightly obovate, abruptly narrowed at the 
long-acuminate apex, obtuse or slightly rounded at the base, margin bluntly 
serrulate with 2 to 4 teeth per cm., laminae drying chartaceous, smooth and glab- 
rous above, minutely (0.1-0.2 mm.) puberulent near the base or glabrous beneath, 
the midvein flat above, the 6 to 10 pairs of major secondary veins weakly loop- 
connected near the margin, microscopic globose-capitate hairs present on the 
lower surface and with clear round apically acute cells in the epidermis and 
epidermal cells with sinuate outlines (X100). Male inflorescences usually paired 
at a node, 1-3 (4) cm. long, racemose, peduncle and rachis densely puberulent 
with minute (0.1 mm.) erect hairs, rachis with triangular bracts about 0.5 mm. 
long, and basally attached; male flowers borne on pedicels 1-2.3 mm. long and 
0.2-0.4 mm. thick, perianth-parts about 2 mm. long, acute at the apex, sparsely 
and minutely puberulent, united near the base, filaments 2-3 mm. long, anthers 
about 1 mm. long (dry), a minute puberulent pistillode present. Female inflores- 
cences usually paired in leaf axils but small (5-10 mm.) and branched near the 
base (or on short-shoots?), the rachis densely puberulent with minute (0.1 mm.) 
erect hairs, with spine-tipped bracts about 1.5 mm. long subtending the inflores- 
cence-branches, the rachis and bases of the flowers with smaller triangular bas- 
ally-attached bracts 0.5-1 mm. long; female flower about 3-4 mm. high, the lower 
half or two-thirds enclosed within an involucre of small puberulent bracts in 2 or 3 
series; perianth bract-like, 4-lobed, about 1 mm. high, ovary 1.5-2 mm. high (to the 
stigmas or style-branches) about 1 mm. thick, minutely puberulent, stigmas about 3 
mm. long, arising from the apex of the ovary. Fruit not known. 

Small trees in the dark understory of the tropical wet forest for- 
mation in the Caribbean lowlands of Costa Rica; collected in flow- 
er in mid-January, 1973. The species is known only from the La 
Selva field station of the Organization for Tropical Studies along 
the Rio Puerto Viejo above the confluence with the Rio Sarapiqui 
(Hartshorn 1091 & 1094 and Oplerl657). 

Trophis involucrata is recognized by the relatively short leaves 
with abruptly acuminate apex and serrulate edges, small lateral 
stipules, short male racemes with pedicellate 4-parted flowers and 
stamens incurved in bud, and the very small axillary female in- 
florescences with few flowers subtended by an inconspicuous 
perianth and several series of imbricate bracts. The slender min- 
utely puberulent stigmas arising from the apex of the narrowed 
ovary are also distinctive. The male flowers and inflorescences 
are very similar to those of T. mexicana and T. chiapensis Bran- 
deg. The female flowers and inflorescences, however, are very 
different from other neotropical representatives of Trophis. 

Trophis mexicana (Liebm.) Bureau in DC., Prodr. 17:253. 1873. 
Sorocea mexicana Liebm., Danske. Vidensk. Selsk. Skrivt. ser. 5, 
2:335. 1851. Skutchia caudata Pax & Hoffm., Journ. Wash. Acad. 
Sci. 27:307. 1937. Figure 14. 



BURGER: FLORA COSTARICENSIS 213 

Shrubs or trees to 20 m. tall, leafy internodes 4-25 mm. long, 1.5-3.2 mm. thick, 
minutely puberulent or more often glabrous; stipules 2-3.6 mm. long, occasionally 
persistent, lanceolate, minutely puberulent, stipule scars very small. Leaves in 2 
ranks, petioles 3-15 mm. long, 0.7-1.5 mm. thick, glabrescent; laminae 6-16 (20) 
cm. long, 2-6.5 cm. broad, narrowly elliptic to oblong or occasionally obovate, 
usually long-acuminate at the apex, acute to obtuse at the base, entire or bluntly 
serrulate distally, the laminae drying chartaceous and smooth on both surfaces, 
glabrous above and below or rarely sparsely and very minutely (0.05 mm.) puber- 
ulent beneath, midvein plane above, the 4 to 9 pairs of major secondary veins 
usually loop-connected and forming a submarginal vein in the distal half of the 
lamina, microscopic globose-capitate hairs usually absent on the lower surface but 
with round transparent apically acute cells in the epidermis. Male inflorescences 
solitary or less often paired, spicate, 4-11 cm. long, peduncle 3-12 mm. long, mi- 
nutely puberulent, bracts 0.4-0.8 mm. broad, the 13 to many flowers loosely crowd- 
ed, male flowers sessile or rarely subsessile, perianth-parts 1.5-2.6 mm. long, 0.5- 
1.3 mm. broad, acute at the apex and connate at the base, very minutely puber- 
ulent, filaments 2-3.2 mm. long, anthers 0.6-1.2 mm. long, pistillode about 0.6 
mm. long. Female inflorescences solitary or occasionally paired, racemose, (2) 
4-10 cm. long, peduncles (to the first flowers) 4-25 mm. long, densely puberulent, 
bracts 0.5-1.1 mm. broad, rarely peltate; female flowers distant, 6-22 mm. long, 
pedicels (0) 0.5-2.3 mm. long and often elongating in fruit, perianth-tube 1.8-5 
mm. long, 1.2-2.8 mm. thick, ovoid, sparsely puberulent, ovary half-inferior, style- 
branches 2.8-4.5 mm. long. Fruit globose, about 5-7 mm. in diameter, sparsely 
puberulent to glabrescent, becoming red, fruiting pedicels 2-6 (13) mm. long, or 
occasionally subsessile. 

Uncommon trees of the seasonally dry cloud forests on the 
Pacific slopes between 600 and 1800 m. elevation or occasionally 
found at low elevations (Golfo Dulce) or in very wet montane 
(premontane rain) forests (near Zarcero, Alajuela) in Costa Rica; 
flowering collections have been made from January to March. The 
species ranges from Central Mexico to within a few kilometers 
of the border with Panama in Costa Rica. 

Trophis mexicana is recognized by its long spikes, sessile male 
flowers with stamens incurved in the bud, pedicellate female flow- 
ers with two slender style-branches, and thin leaves often long- 
acuminate. The species is quite common in the cloud forests of 
the Cordillera Central de Nicaragua and it is probably common on 
the Cordillera de Guanacaste and Cordillera de Tilaran in Costa 
Rica, but it appears to be rare in other parts of Costa Rica. This 
species was mistaken to be a plant of the Euphorbiaceae by Pax and 
Hoffmann and was described as a new genus, Skutchia, honoring 
Dr. Alexander Skutch. Female inflorescences look like those of 
Alchornea costaricensis (Euphorbiaceae). 



214 FIELDIANA: BOTANY, VOLUME 40 

Trophis racemose (L.) Urban, Symb. Ant. 4:195. 1905. Buce- 
phalon racemosum L., Syst. Nat. ed. 10, 1289. 1759. Trophis ra- 
mon Schlecht. & Cham., Linnaea 6:357. 1831. Sahagunia urophyl- 
la Donn.-Sm., Bot. Gaz. 40:11. 1905. Clarisia urophylla (Donn.- 
Sm.) Lanj., Rec. Trav. Bot. Veerl. 33:263. 1936. Figure 14. 

Shrubs or trees to 18 m. tall, trunk becoming 50 cm. thick, leafy internodes 1-5 
cm. long, 2-5 mm. thick, sparsely and minutely puberulent, glabrescent, becoming 
lenticellate; stipules 2-4 mm. long, caducous or persisting, scars small. Leaves in 
2 ranks, petioles 4-16 mm. long, 0.7-2 mm. thick, minutely (0.05-0.1 mm.) puber- 
ulent and becoming glabrous, sulcate above; laminae 5-23 cm. long, 2.4-10 cm. 
broad, obovate to oblong or elliptic, acuminate to subcaudate-acuminate at the 
apex, acute to obtuse and often slightly oblique at the base, entire or bluntly 
serrate distally, drying chartaceous to subcoriaceous, usually scabrous above and 
below, glabrous above, glabrous or very minutely (0.05 mm.) puberulent beneath, 
mid vein plane or impressed above (dry), the 3 to 8 pairs of major secondary veins 
loop-connected in the distal half and a submarginal vein sometimes present, 
microscopic globose-capitate hairs sometimes present on the lower surface and 
with clear round apically acute cells in the epidermis (100X). Male inflorescences 
paired or solitary, 1.5-7.5 cm. long, peduncles 2-11 mm. long, minutely velutinous, 
bracts 0.5-1.1 mm. broad, with 15 to many densely crowded flowers; male flowers 
sessile or rarely subsessile, perianth-parts 1.6-2.2 mm. long, 1-1.5 mm. broad, free 
or basally connate, minutely (0.1 mm.) puberulent, filaments 2-2.6 mm. long, 
anthers 0.8-1.2 mm. long, pistillode 0.3-0.6 mm. long. Female inflorescences paired 
or solitary, 1-3 cm. long, (in ours), peduncles 2-14 mm. long, bracts 0.5-1.2 mm. 
broad, with 4 to 15 crowded flowers rarely more than 1 mm. distant; female 
flowers broadly sessile, ovoid or conic, perianth-tube 2-4.5 mm. long, 1.4-2.5 mm. 
in diameter, densely velutinous with hairs about 0.1 mm. long, ovary inferior 
or half -inferior, style-branches 2-5.5 mm. long, slender. Fruit globose or ovoid, 
often with a narrow collar at the apex, smooth or ridged, becoming rose-red. 

Shrubs and meduim-sized trees of both wet and seasonally dry 
evergreen and semideciduous forest formations between sea level 
and 1000 m. elevation on the Caribbean and, less commonly, on 
the Pacific watersheds in Costa Rica; apparently flowering 
throughout the year but with the fruit collected most often be- 
tween January and June. The species, comprising three subspe- 
cies, ranges from northern Mexico through Central America and 
the West Indies to Venezuela and Peru. 

Trophis racemosa is recognized by the short female inflorescen- 
ces with minutely velutinous flowers and fruit, male spikes with 
the anthers inflexed in bud, and the leaves usually abruptly a- 
cuminate and often scabrous on both surfaces. The species is 
apparently less common in Costa Rica than in other parts of Cen- 
tral America and Panama, where it is sometimes used for animal 
fodder. Common names used in our area are ramon, ramoon, ojo- 



BURGER: FLORA COSTARICENSIS 215 

chillo Colorado, and breadnut. Our plants belong to subspecies 
ramon (Schlecht. & Cham.) W. Burger, which ranges from Mexico 
to Panama. 



CANNABACEAE 

( Cannabinaceae) 
WILLIAM BURGER 

Herbs, annual or perennial from a rhizome, unisexual or rarely bisexual, stems 
erect or scandent, usually ridged and scabrous; stipules paired, free or united, 
persisting. Leaves simple or palmately compound, alternate or opposite, petiolate, 
lamina margin lobed or serrate (rarely entire), lower surface puberulent and punc- 
tate, upper surfaces usually with cystoliths and short scabrous hairs. Male inflor- 
escences axillary, bracteate, erect or pendant, cymose paniculate; the male flow- 
ers pedicellate, perianth of 5 tepals, regular, soft-puberulent, stamens 5 and oppo- 
site the tepals, erect in bud, filaments short, anthers dehiscing longitudinally, 
a pistillode absent. Female inflorescences axillary, basically cymose but forming 
spikes, glandular hairs usually present, subsessile, often two and subtended or 
covered by a bract or bracteole, perianth united to form a tube almost completely 
enclosing the ovary, staminodes absent, ovary free from the perianth, 1-locular 
with a solitary ovule pendulous from near the apex of the locule, style short but 
with 2 long stigmatic branches (style-branches), the latter caducous. Fruit an 
achene within the persisting perianth-tube, seed with little endosperm and a 
curved or coiled embryo. 

A family of only two genera and perhaps three or four species, two 
of which are of great economic importance. Cannabis sativa L. (in a 
wide sense) is the source of hemp fibers and of the narcotic 
extracts marijuana and hashish. The stipular bracts of the fruit- 
ing inflorescence of Humulus lupulus L. produce lupulin, which is 
used to impart flavor and aroma to beer and also aids in the fer- 
mentation of beer. Both are now widely distributed over the 
world, but Humulus originated in temperate eastern Asia and 
Cannabis probably originated near the Caspian sea in western 
Asia. These plants have not been reported as naturalized in Cen- 
tral America, but they may be expected in horticultural areas. 

The following key to the genera and the previous information 
have been adapted from Norton G. Miller. The genera of the Can- 
nabaceae in the southeastern United States, in the Journal of the 
Arnold Arboretum, vol. 51: 185-203, 1970 (q.v.). These plants 
have also been placed in the Moraceae family. 



216 



BURGER: FLORA COSTARICENSIS 217 



Plants erect herbs; leaves palmately divided into long lanceolate serrate leaflets; 
2-parted hairs absent on stems and petioles; female inflorescences erect 

Cannabis. 

Plants scandent herbs; leaves simple, palmately lobed or without lobes, 2-parted 
hairs present on stems and petioles ; female inflorescences pendant . . . . Humulus. 



URTICACEAE 

WILLIAM BURGER 

REFERENCE: N.G. Miller, The Genera of the Urticaceae in the 
Southeastern United States, Journ. Arnold Arbor. 52:40-68. 1971. 

Herbs, shrubs, or small weak-stemmed trees, bisexual or unisexual, sap usually 
transparent, stems usually puberulent and often provided with stinging hairs (con- 
taining irritating liquid); stipules usually present, paired and free or variously uni- 
ted, caducous or persisting. Leaves alternate or opposite, the leaves at the same or 
adjacent nodes similar in size and shape or very different (as in some spp. oiBoeh- 
meria), petiolate; laminae mostly ovate to lanceolate with serrate or dentate mar- 
gins, venation often palmate, punctate to linear or curved cystoliths often visible on 
the upper and/or lower surfaces. Flowers small and unisexual (in ours), often borne 
in dense fascicles or clusters, or on open cymose panicles, racemes, and spikes, ses- 
sile or pedicellate; male flowers greenish or whitish, the perianth-parts (tepals) in a 
single whorl of 3, 4, or 5, equal and valvate in bud, free or united, often with appen- 
dages, stamens as many as the perianth-parts and opposite them, filaments thin and 
inflexed in bud, anthers 2-thecous, dehiscing laterally, a pistillode often present; 
female flowers usually very small, perianth 3- or 4-parted or united to form a tube or 
the perianth absent (as inPhenax), staminodia rarely present, pistil 1, ovary super- 
ior with a single locule and single basal ovule (but see the species of uncertain pos- 
ition included here), stigma long and linear or short-sessile, minutely glandular- 
puberulent or penicellate. Fruit a hard achene, usually flattened laterally and lenti- 
cular, ovoid to ellipsoid, usually enclosed in the persisting dry or succulent perianth 
parts or bracts. 

A very natural family closely related to the Ulmaceae, Moraceae, 
and Cannabaceae, together forming the order Urticales. Like other 
members of the order, this family has only a single perianth-whorl 
with the stamens opposite the perianth-parts and a unilocular pistil 
with solitary ovule. The family is further characterized by the her- 
baceous or woody but weak-stemmed habit, the unisexual flowers, 
pistils with solitary stigma, and the usually serrate leaves with 
cystoliths. Many species are found along stream and brook edges 
and in protected wet sites. The palmately veined serrate leaves of- 
ten resemble those of the Malvales, but the Urticaceae lack stellate 
hairs and the flowers are very different. 

An unusual species that appears to be related to Boehmeria and 
having opposite leaves is placed at the end of the family without 



218 



BURGER: FLORA COSTARICENSIS 219 

generic designation because of its unique female flowers. These pis- 
tillate flowers have 2- or 3-locular ovaries, a condition otherwise 
unknown in the family. However, the female flowers are very few in 
the lower leaf-axils and the difficulty of finding stages in anthesis 
suggests that the flowers may be abnormal in their development. 

Gyrotaenia microcarpa (Wedd.) Fawcett & Rendle has been col- 
lected once in the Changuinola Valley, Bocas del Toro, Panama 
(Dunlap 174). This record is probably of an isolated introduced 
plant, as this species is endemic to Jamaica and the genus in ende- 
mic to the West Indies. They are unisexual trees or shrubs with 
serrate pinnately veined alternate leaves, small spicate or panicu- 
late inflorescences with sessile flowers, the female flowers with 2- 
lobed perianth and capitate stigma, and the male perianth 4-lobed. 

Two genera with discontinuous distributions are found in Central 
America and in northern South America but have not been collected 
from Costa Rica or Panama. These areHemistylis, shrubs and small 
trees, and Rousselia, puberulent herbs; both have alternate entire 
leaves and female flowers subtended by conspicuous greenish 
bracts. Discocnide is an endemic genus ranging from Mexico to 
Nicaragua that resembles Urera but has thin disc-like achenes with 
a hyaline pericarp. 

Species of Boehmeria and Phenax with densely crowded flowers 
may be difficult to separate on the basis of the female flowers pos- 
sessing or lacking a perianth-tube. The simplest way to determine 
this difference is by gently crushing an inflorescence between the 
fingers and allowing the parts to fall on a flat surface. If small naked 
pistils are found, the perianth-tube is probably lacking (Phenax). 
The perianth-tube of Boehmeria is quite strong and will not separ- 
ate from the pistil unless considerable pressure is applied. 

la. Leaves opposite or whorled, two or more at each node (the leaves occasionally 
very unequal in size and apparently alternate) 2a. 

Ib. Leaves alternate, always solitary at a node, never with even a very small sessile 
stipule-like opposing leaf 5a. 

2a. Plants with stinging hairs Urtica. 

2b. Plants without stinging hairs; leaves often unequal 3a. 

3a. Female perianth parts separate, not enclosing the fruit; stigma tufted, 
short; herbs or subshrubs Pilea. 

3b. Female perianth tubular and tightly enclosing the fruit; mostly small 
shrubs. . 4a. 



220 FIELDIANA: BOTANY, VOLUME 40 

4a. Stigma filiform, easily seen, female flowers several to numerous, usually 
in sessile clusters at leafless nodes or on a branched inflorescence; ovary 
with a single locule Boehmeria. 

4b. Stigmas short, inconspicuous, female flowers very few among male flow- 
ers at lower leafy nodes; ovary with 2 or 3 locules, fruit often 3-angled. 
Species of uncertain position, placed at the end of the family. 

5a. Some stinging hairs usually present, thin, translucent, straight and narrow, 
0.5-3 mm. long; inflorescence complex and branched 6a. 

5b. Stinging hairs absent 7a. 

6a. Shrubs or trees, perennial, usually unisexual; stigma terminal and erect 

Urera. 

6b. Herbs or subshrubs with succulent stems, annuals, usually bisexual; stigma 
becoming curved or subterminal Laportea. 

7a. Female flower and fruit borne within a persisting perianth tube, this tightly 
enclosing the fruit and open only at the apex (often difficult to see), perianth 
tube thin and dry in fruit (never fleshy), stigma or style linear- filiform 

8a. 

7b. Female flower and fruit not enclosed by a tubular perianth; the perianth parts 
sometimes fleshy and accrescent in Urera 9a. 

8a. Female perianth tube without definite longitudinal ribs or prominent veins, 
surface of the achene dull, stigma persisting; leaves always dentate or ser- 
rate Boehmeria. 

8b. Female perianth tube with definite longitudinal ribs, surface of the achene 
lustrous, stigma deciduous; leaves usually entire Pouzolzia. 

9a. Flowers in small axillary glomerules or fasciculate; herbs or shrubs lOa. 

9b. Flowers on open paniculate or spicate inflorescences; stigma short penicellate; 
shrubs or trees 1 la. 

lOa. Shrubby plants; leaves crenate to serrate; stigma filiform; female perianth 
absent, many brownish, acute bracts subtending the flowers Phenax. 

10b. Herbs or small subshrubs; leaves entire (in ours); stigma short penicellate; 
female perianth present but difficult to see; bracts present, few, greenish, 
and exceeding the flowers in length Parietaria. 

lla. Female flowers without perianth but subtended by bractlets and the pistil 
with a puberulent surface; flowers on panicles with long pendulous spicate 
branches (in ours) Myriocarpa. 

lib. Female flowers with perianth segments often becoming fleshy orange and 
enclosing the fruit; flowers on short-branched panicles Urera. 



URTICACEAE, 

male and female flowers: 




FlG. 24. Urticaceae with opposite leaves: species of Boehmeria, Urtica, and a 
species of uncertain position. 



221 




PILEA 



ligulate 
stipule 

petiole 





imparifolia 




tilarana 





diversissima 





FIG. 25. Urticaceae with opposite leaves: species of Pi lea with very unequal leaves 
at each node. 



222 



pallida 



PILEA 

angustifolia , \ i 




FIG. 26. Urticaceae with opposite leaves: species of Pi lea with equal or subequal 
larger leaves at each node. 



223 



PILEA 

herniarioides 





fruit 



hyalina 




cornuto-cucullata Nv/X 





gracilipes 





FIG. 27. Urticaceae with opposite leaves: species of Pi lea with equal or subequal 
smaller leaves at each node. 



224 





FIG. 28. Urticaceae with alternate leaves and the pistil and fruit enclosed in a 
perianth-tube: species ofBoehmeria and Pouzolzia. 



225 



PHENAX 

sonneratii 





angustifolius 




hirtus 




mexicanus 



rugosus 




| perianth-appendages 




bracts 



(perianth 
absent) 
male flower female flower 
(unopened) and bracts 

PHENAX 



PARIETARIA 

debilis 




FIG. 29. Urticaceae with alternate leaves and the perianth-parts free or absent: 
Laportea, Parietaria, andPhenax. 



226 




FIG. 30. Urticaceae with alternate leaves and long or much-branched inflores- 
cences: species ofMyriocarpa and Urera. 



227 



228 FIELDIANA: BOTANY, VOLUME 40 

BOEHMERIA Jacquin 

Shrubs, small trees, or perennial herbs, unisexual or bisexual, lacking stinging 
hairs; stipules paired and lanceolate (in ours), puberulent along the midrib abaxially 
and drying brown. Leaves alternate or opposite, those of adjacent nodes often very 
unequal in size in alternate-leaved species, petiolate; laminae usually palmately 3- 
veined, margins serrate to dentate, minutely punctate cystoliths usually present on 
the upper epidermis. Inflorescences cymose-paniculate, racemose, or fasciculate 
glomerules, solitary and axillary or in the axils of undeveloped leaves, bisexual or 
unisexual, the flowers in fasciculate globose clusters (glomerules) separate or con- 
gested on the inflorescence-rachis ; male flowers sessile or short-pedicellate, per- 
ianth-parts 4 or rarely 3, valvate in bud, stamens 4 (3), a pistillode usually present; 
female flowers sessile, perianth united to form a tube completely enclosing the 
ovary and minutely toothed at the apex, minute straight and uncinate (hooked) 
hairs usually present on the perianth-tube, style and stigma linear. Fruit enclosed 
within the strongly persistent perianth-tube, the perianth-tube becoming inflated in 
a few species, the fruit a hard-walled achene, often slightly compressed laterally. 

A genus of about 80 species best represented in the American and 
Asian tropics, but extending into the temperate zone in eastern 
Asia and eastern North America. Our species fall into two groups; 
those with opposite leaves and complex inflorescences and those 
with alternate leaves and sessile flower-clusters on leafy stems. The 
latter plants are very easy to confuse with species of Phenax and 
Pouzolzia. Some of these Boehmeria species are easy to recognize, 
however, because leaves at adjacent nodes differ so greatly in size. 
Those with isomorphic leaves must be carefully examined to dis- 
tinguish them from Phenax and Pouzolzia. 

la. Leaves all or mostly opposite along the main stems; inflorescences complex or 
of sessile clusters along a leafless rachis; plants rarely found above 1200 m. 

2a. 

Ib. Leaves alternate; flowers in small sessile globose clusters, usually in the axils 
of leaves or fallen leaves 4a. 

2a. Leaves whitish beneath and with long petioles, plants cultivated for fiber, 
forage, or ornament; inflorescence complex and much branched. . . . B. nivea. 

2b. Leaves not whitish beneath; plants not cultivated; inflorescences usually 
spicate and unbranched 3a. 

3a. Stipules 2-6 mm. long; inflorescences erect and often terminated by small 
leaves; margins of the fruiting perianth-tube slightly inflated. . B. cylindrica. 

3b. Stipules 8-18 mm. long; inflorescences long-pendulous and not terminating 
with small leaves, often densely flowered; margins of the fruiting perianth- 
tube thin and wing-like B. caudata. 

4a. Leaves becoming deeply rugose in age with major veins deeply impressed 
above and glabrous or very sparsely puberulent above; male flowers 4-parted, 
perianth-tube not becoming conspicuously flattened in fruit 5a. 



BURGER: FLORA COSTARICENSIS 229 

4b. Leaves rarely becoming deeply rugose, only the major veins becoming impres- 
sed above, puberulent above 6a. 

5a. Shrubs or small trees, leaves of adjacent nodes differing greatly in size and 
shape, the larger leaves lanceolate; perianth-tube pubescent near the apex; 
wet evergreen areas 0-1500 m B. aspera. 

5b. Herbs or subshrubs, leaves of adjacent nodes differing only slightly in size, 
larger leaves ovate to narrowly elliptic-ovate; perianth tube with very few 
hairs; very wet forests, 1400-1900 m B. coriacea. 

6a. Leaves differing greatly in size and shape at adjacent nodes but occasionally 
with the alternate leaf undeveloped and the leaves then apparently isomorphic 
(leafless nodes can be identified by the presence of flower clusters), petioles 
usually less than 10 mm. long, thin hairs or thicker strongly appressed hairs 
(resembling cystoliths) on the upper lamina-surface; male flowers 4-parted; 
fruiting perianth-tube slender ellipsoid and minutely puberulent; very wet 
evergreen formations 1000-2000 (2800) m B. ulmifolia. 

6b. Leaves differing by about 50 per cent or less in size at adjacent nodes and 
usually similar in shape, petioles thin, 3-90 mm. long; seasonally dry evergreen 
formations on the Pacific watershed (in Costa Rica) 7a. 

7a. Male flowers 4-parted; fruiting perianth-tube narrowly ellipsoid and densely 
brownish hirsutulous; hairs of the upper leaf-surface thick appressed and 

often radiating from the centers of aereoles (resembling cystoliths) 

B. radiata. 

7b. Male flowers 3-parted; fruiting perianth-tube strongly flattened with thin 
wing-like margins; hairs on the upper leaf-surface thin and not strongly ap- 
pressed B. rami flora. 

Boehmeria aspera Weddell, Arch. Mus. Paris 9: 349. 1856. Figure 

28. 

Shrubs or rarely small trees to 6 m. tall, leafy internodes 3-20 (40) mm. long, 0.8-4 
mm. thick, densely sericeous with appressed ascending whitish hairs 0.2-0.2-0.7 mm. 
long; stipules 4-10 mm. long, 1-2 mm. broad at the base, sparsely puberulent, often 
persisting at the base of the inflorescences. Leaves alternate and usually very dif- 
ferent in size and shape at adjacent nodes, petioles 1-23 mm. long, 0.5-1.5 mm. thick, 
minutely (0.1-0.5 mm.) hirsutulous; laminae usually of 2 different sizes at adjacent 
nodes, the smaller 1-3 cm. long and ovate in outline, the larger 4-18 cm. long, 1-3.5 
cm. broad, lanceolate to very narrowly elliptic in form, tapering gradually to a long- 
acuminate apex, obtuse to rounded at the slightly unequal base, margin coarsely 
dentate-serrate with 4 to 7 teeth per cm., lamina drying stiffly chartaceous, slightly 
scabrous and strongly rugose with the veins deeply impressed above, lower surface 
densely puberulent with stiff slender whitish hairs 0.2-0.8 mm. long, venation palm- 
ate with 3 primary veins, midvein with many small secondaries or with 1 or 2 pairs 
of more prominent secondary veins in the distal half. Inflorescences usually unisex- 
ual, the flowers numerous and clustered in dense glomerules 4-10 mm. in diameter 
in the axils of leaves or at leafless nodes; male flowers more than 20 per glomerule 
and densely crowded, sessile or pedicellate, perianth 4-parted, stamens 4, anthers 
about 0.5 mm. long (dry); female flowers densely crowded and more than 20 per in- 



230 FIELDIANA: BOTANY, VOLUME 40 

florescence, bracts not usually visible between the flowers, pistil about 2 mm. long, 
style often with a slender glabrous portion below the long puberulent stigmatic 
part. Fruit enclosed within the persisting perianth-tube, perianth-tube about 1 mm. 
long and with erect hairs distally. 

Plants of wet evergreen forest formations and locally common in 
open secondary vegetation between sea level and 1500 m. elevation 
on the Caribbean slopes and the moister sites above 500 m. on the 
Pacific slope in Costa Rica; flowering throughout the year. The 
species ranges from Costa Rica to Peru. 

Boehmeria aspera is a very distinctive species with the leaves 
usually of very different size at adjacent nodes, the larger leaves 
usually lanceolate, and all the laminae becoming deeply rugose. 
The flowers are found in small clusters on the leaf -bearing stems. 
Our specimens give the impression of being dioecious; all the mater- 
ial of each collection is of the same sex. 



Boehmeria caudata Swartz, Nov. Gen. & Sp. PL 34. 1788. B. flag- 
elliformis Liebm., Danske Vidensk. Selsk. Skrivt. ser. 5, 2:310. 
1851. Figure 24. 

Unisexual shrubs or small trees ( 1 ) 2-6 (9) m. tall, leafy internodes 3-50 mm. long, 
1.5-5 mm. thick, densely strigulose with ascending or appressed hairs 0.2-1 mm. 
long; stipules 8-18 mm. long, 1.5 mm. broad at the base, puberulent along the mid- 
rib, stipule scars almost united to form interpetiolar lines. Leaves opposite and 
usually similar in size and shape at adjacent nodes, petioles (3) 15-30 mm. long, 0.7- 
1.5 mm. thick, puberulent; laminae 4-22 cm. long, 2-11 cm. broad, ovate to elliptic 
in outline, acuminate at the apex, obtuse to rounded at the equal or subequal base, 
margin serrulate with 3 to 6 teeth per cm. laminae drying thin- to stiffly -char taceous 
and often dark above, slightly scabrous with short (0.5 mm.) stiff hairs above and 
usually becoming rugose with both major and minor veins impressed, sparsely to 
densely puberulent beneath with slender hairs 0.1-0.5 mm. long, venation palmate 
or subpalmate with 3 primary veins, the midvein with 1 to 3 pairs of major second- 
ary veins arising from the distal half, the minutely punctate cystoliths often obscure 
above. Inflorescences spicate and axillary (rarely branched near the base), the 
spikes pendulous and 5-25 (40) cm. long, flowers closely crowded in globose glome- 
rules and these separate or adjacent on the slender (0.3-0.8 mm.) rachis; male flow- 
ers in small (4-8 mm.) glomerules, with about 10 to 20 flowers, buds 1-1.5 mm. in 
diameter, perianth-parts and stamens 4; female flowers in glomerules 4-10 mm. in 
diameter, with usually 10 to 20 flowers, female flowers 2-3 mm. long, sessile and 
congested at the base, style usually glabrous beneath the puberulent stigmatic tip. 
Fruit enclosed within the persisting perianth-tube, perianth-tube 1.5-2 mm. long, 
narrowed at the base and abruptly narrowed below the style, strongly flattened 
and with thin wing-like margins, sparsely puberulent. 

Plants of stream sides and moist ravines from (0) 500 to 1500 m. 
altitude in areas of evergreen and partly deciduous formations on 



BURGER: FLORA COSTARICENSIS 231 

both the Caribbean and Pacific slopes in Costa Rica; probably flow- 
ering throughout the year. The species ranges from Mexico to Ar- 
gentina and the West Indies. 

Boehmeria caudata is recognized by its opposite leaves, long pen- 
dulous spikes with flowers borne along the rachis in round clusters, 
unusual fruit, and stipule-scars often forming interpetiolar lines. 
The species is called rabo de goto in Honduras. 

Boehmeria coriacea Killip, Journ. Wash. Acad. Sci. 13:359. 1923. 
Figure 28. 

Herbs or subshrubs to 1 m. tall, leafy internodes 2-38 mm. long, 1-2.3 mm. thick, 
strigulose with whitish ascending hairs 0.2-0.8 mm. long, becoming glabrate; stipu- 
les about 4 mm. long, 1 mm. broad at the base, glabrous except along the midrib. 
Leaves alternate and usually differing in size at adjacent nodes, very variable in 
size on the same plant or on different plants, often very different in size at adjacent 
nodes, petioles 2-40 mm. long, 0.8-1.3 mm. thick, ascending strigulose, laminae 1.2- 
12 cm. long, 0.8-4 cm. broad, ovate to elliptic-ovate, acute to acuminate at the apex, 
obtuse or slightly rounded at the base, margin coarsely serrate with 4 to 6 teeth per 
cm., drying stiffly chartaceous, smooth to the touch above with the veins usually 
becoming deeply impressed and the surface rugose-bullate, glabrous or very spar- 
sely puberulent above, with stiff appressed hairs 0.2-0.4 mm. long, on the veins 
beneath, venation palmate with 3 primary veins, the midvein with numerous minor 
secondary veins, the secondary and tertiary veins often prominent beneath. Flowers 
in dense sessile glomerules in the axils of leaves or fallen leaves, unisexual or occa- 
sionally bisexual, the plants probably unisexual or bisexual; male flowers with usu- 
ally 4 perianth-parts with whitish hairs distally and with a small projection just 
below the apex, stamens 4, anthers about 0.6 mm. long; female flowers numerous 
and densely crowded with small bracts between the flowers, perianth-tube smooth 
and glabrous or sparsely puberulent, style about 1.5 mm. long, and minutely puber- 
ulent. Fruit enclosed within the persistent perianth-tube, perianth-tube 1-1.4 mm. 
long and to 1 mm. broad, only slightly flattened, ovoid, glabrescent. 

Plants of the very wet (premontane rain) forest formations of the 
Caribbean slopes between 1400 and 1900 m. elevation and usually 
found growing along or above shaded brooks and streams in Costa 
Rica; probably flowering throughout the year. The species is only 
known from Costa Rica and Colombia. 

Boehmeria coriaceae is recognized by the herbaceous habit, re- 
stricted habitat, laminae that tend to become deeply bullate and are 
often glabrous above, and female perianth-tube with inconspicuous 
hairs. The leaves vary greatly in different plants; some have the 
largest leaves only 3 or 4 cm. long while others have laminae to 12 
cm. Texture varies greatly also, occasionally on the same plant. 
The leaves possess translucent dots. Collections placed here are: 



232 FIELDIANA: BOTANY, VOLUME 40 

Burger et al. 5718, 6824, 6861, Lent 2251 (all of these are from the 
Rio Grande de Orosi above Tapanti), and Standley & Torres 47721 
(Viento Fresco, Alajuela). There is some question whether these 
collections should be placed in Killip's poorly known Colombian 
species, but I am sure that the two are very closely related if not, 
in fact, conspecific. It is not unusual for Costa Rican plants to be 
found at lower elevations than plants of the same species in Colom- 
bia. This is probably a result of the cooler maritime climate in Costa 
Rica. 

Boehmeria cylindrica (L.) Swartz, Nov. Gen. & Sp. PL 34. 1788. 
Urtica cylindrica L., Sp. PL 984. 1753. Figure 24. 

Herbs or woody stemmed subshrubs 0.5-1 m. tall, leafy internodes 1-5 (9) cm. 
long, 1.2-6 mm. thick, puberulent with slender hairs 0.1-0.5 mm. long but becoming 
glabrescent; stipules 2-6 mm. long, about 1 mm. broad at the base, deciduous. 
Leaves opposite or subopposite, very variable in form on different plants but simi- 
lar at adjacent nodes, petioles 2-70 mm. long, 0.7-1.5 mm. thick, appressed puberu- 
lent; laminae 4-18 cm. long, 2.5-8 cm. broad, lanceolate to broadly ovate, acuminate 
at the apex, obtuse to truncate at the base, margin coarsely dentate with 1 to 4 
teeth per cm., laminae drying membranaceous to thin-chartaceous, smooth or slight- 
ly scabrous above with scattered short (0.2-0.5 mm.) hairs, very sparsely to moder- 
ately puberulent beneath, venation palmate or subpalmate with 3 primary veins, 
the midvein with 2 to 4 pairs of major secondary veins, minutely punctate cystoliths 
usually visible above. Infloresecences axillary, solitary and 3-7 ( 14 ) cm. long, spicate 
with the flowers in separate globose glomerules along the length of the unbranched 
rachis, the rachis often terminated by small leaves, the flower clusters or glomerules 
2-6 mm. in diameter; male flowers in groups of 5 to 10, perianth-parts 4; female 
flowers about 1 mm. long in early stages, styles about 0.5 mm. long and puberulent 
at the apex. Fruit enclosed within the persisting perianth-tube, perianth-tube be- 
coming about 1.5 mm. long and equally broad, somewhat flattened longitudinally, 
central area around the seed delineated by a groove from the peripheral and slightly 
inflated margins, puberulent apically. 

Plants of alluvial sandy or gravelly soils in wet evergreen forma- 
tions and growing along water courses and in wet situations in sea- 
sonally dry areas between sea level and 500 m. on both the Carib- 
bean and Pacific slopes in Central America; probably flowering 
throughout the year in wet regions. A species of very wide range, 
from eastern Canada and the eastern and southern United States 
through Central America and the West Indies to southeastern 
Brazil. 

Boehmeria cylindrica is distinguished by its opposite or suboppo- 
site leaves, small stipules, unusual spicate inflorescences often 
terminated by small leaves, small flowers, and unusual fruit. This 
species is apparently quite rare in Costa Rica and represented in 



BURGER: FLORA COSTARICENSIS 233 

herbaria by a single collection from Zent, Limon ( United Fruit Co. 
391). 

Boehmeria nivea (L.) Gaud, in Freyc., Voy. Bot. 499. 1826. Urtica 
nivea L., Sp. PL 985. 1753. Figure 24. 

Herbs or subshrubs 0.5-2 m. tall, leafy internodes 5-50 mm. long, 2-5 mm. thick, 
with stiff whitish hairs 0.5-1.5 mm. long; stipules 5-15 mm. long. Leaves alternate 
and usually of similar size at adjacent nodes, petioles 3-14 cm. long, hirsute; laminae 
7-20 cm. long, 5-16 cm. broad, broadly ovate to elliptic-ovate, abruptly narrowed at 
the acuminate apex, obtuse to subcordate at the base, margin coarsely serrate with 
1 to 3 teeth per cm., lamina drying thin chartaceous and usually very dark above, 
scabrous above, pale grayish-white beneath with a dense arachnoid tomentum 
between the veins, venation pinnate or subpalmate with the basal secondaries very 
prominent, the midvein with 2 or 3 pairs of major secondary veins above the basal 
pair, minutely punctate cystoliths usually visible above. Inflorescence axillary, 
complex in structure with small glomerules of flowers borne on a branched or un- 
branched rachis; male flowers usually 5 to 10 per glomerule, perianth-parts 4; fe- 
male flowers in glomerules about 5 mm. in diameter, bracts inconspicuous, perianth- 
tube about 1 mm. long, puberulent, style and stigma about 1 mm. long and puberu- 
lent throughout. 

A cultivated species planted from sea level to 1500 m. elevation 
in both the wet and seasonally dry areas of Central America. This 
species probably originated in China but is now widely planted. 

Boehmeria nivea is recognized by its long petiolate opposite leav- 
es whitish beneath and its complex unisexual inflorescences. The 
plants are occasionally grown for ornament as well as fiber and 
forage. They are the source of ramie fiber and are called ramio and 
ramie in Central America. 

Boehmeria radiata W. Burger, Phytologia 31: 267. 1975. Figure 
28. 

Shrubs 1-3 m. tall, bisexual or unisexual, leafy internodes 3-50 mm. long, 1-4.5 
mm. thick, with appressed or curved thin whitish hairs 0.2-1 mm. long; stipules 3-5 
mm. long, deciduous. Leaves differing in size at adjacent nodes but similar in shape, 
petioles 3-60 (90) mm. long, 0.3-1.8 mm. thick, puberulent with thin whitish hairs; 
laminae 2-13 ( 18) cm. long, 1-7 ( 10) cm. broad, ovate to elliptic-ovate, acute to acum- 
inate at the apex, obtuse to abruptly rounded at the somewhat unequal base, margin 
crenate-serrate with 2 to 5 teeth per cm., laminae drying thin- to stiff -chartaceous, 
slightly rough to the touch above with whitish strongly appressed hairs 0.2-0.8 ( 1 ) 
mm. long, the lower surface with thin whitish hairs along the veins, venation pal- 
mate or subpalmate with 3 primary veins, midvein with 1 to 3 pairs of major second- 
ary veins or often with the major secondaries on only one side or not readily disting- 
uished from the smaller secondaries, minutely punctate cystoliths visible on the 
upper surface. Inflorescences small (4-10 mm.) globose sessile clusters in the axils 
of leaves or at leafless nodes, sometimes with 2 to 6 glomerules in a row at leafless 



234 FIELDIANA: BOTANY, VOLUME 40 

nodes 3-10 mm. distant along the stem; male flowers about 1.5 mm. broad, usually 
sessile, perianth-parts 4, apex of the perianth with a slender projection abaxially; 
female flowers very numerous and closely congested, styles and stigmas about 
3 mm. long, minutely puberulent. Fruit small and enclosed within the persisting 
slender perianth-tube 1-1.5 mm. long, narrowly ellipsoid (narrowed at both base 
and apex), densely hirsutulous with minute brownish hairs. 

Plants of the seasonally dry evergreen forest formations of the 
Pacific slope and Meseta Central between 500 and 1200 m. elevation 
in Costa Rica; collected with flower and fruit from October to 
March. The species ranges from Guatemala to Central Costa Rica. 

Boehmeria radiata possesses unusual appressed hairs on the up- 
per leaf-surfaces resembling linear cystoliths, and these are often 
arranged in circular patterns within the aereoles demarked by larger 
tertiary veins. The seasonally dry habitat, shrubby habit, long and 
thin petioles, male perianth-parts with unusual apices, and very 
small fruit within a slender brown-hirsutulous perianth-tube further 
distinguish this species. Despite these features Boehmeria radiata 
is often difficult to separate from B. ulmifolia, with its shorter peti- 
oles, wetter habitat, and adjacent leaves differing more in shape, or 
from B. ramiflora, with the male flowers 3-parted, fruit inflated and 
winged, and upper leaf-surfaces without cystolith-like appressed 
hairs. This species has often been mistaken iorPhenax mexicanus. 

Boehmeria ramiflora Jacq., Enum. Syst. PI. Carib. 31. 1760. B. 
cuspidata Weddell, Arch. Mus. Paris 9:345. 1856. B. ramiflora var. 
cuspidata Wedd. in DC., Prodr. 16, pt. 1: 197. 1869. Figure 28. 

Shrubs 1-3 (4) m. tall, bisexual or unisexual, leafy internodes 5-45 mm. long, 1-4 
mm. thick, puberulent with usually thin appressed whitish hairs 0.1-0.4 mm. long; 
stipules 5-15 mm. long, puberulent along the midrib, deciduous, and not commonly 
subtending the flower clusters. Leaves of adjacent nodes usually differing in size 
but usually similar in shape, alternate, petiole 4-70 mm. long, about 1 mm. thick, 
appressed puberulent (in ours), laminae (2) 4-17 cm. long, 1-7 cm. broad, elliptic to 
elliptic-ovate or rhomboid-ovate, tapering gradually in larger leaves to the usually 
long-acuminate apex, narrowed or rounded on one side at the oblique base, coarsely 
serrate with 3 or 4 teeth per cm., lamina drying membranaceous to thin chartaceous 
and dark above, slightly rough to the touch with thin whitish appressed hairs about 
0.5 mm. long above, more densely puberulent beneath, venation palmate with 3 pri- 
mary veins, the midvein with 2 or 3 major secondary veins on only one side and the 
lamina asymmetric in area, minute punctate cystoliths present above. Inflores- 
cences of small (4-8 mm. ) glomerules of congested sessile or subsessile flowers in the 
axils of leaves or fallen leaves, flower clusters unisexual or bisexual; male flowers 
with 3-parted perianth, puberulent distally with some minute uncinate hairs, sta- 
mens 3; female flowers tightly clustered and narrowed at the base, laterally flat- 
tened, perianth tube puberulent, about 1.5 mm. long. Fruit borne within the per- 
sisting perianth-tube, the perianth-tube becoming 2 mm. long and 1 mm. broad, 



BURGER: FLORA COSTARICENSIS 235 

very much flattened beyond the seed to produce wing-like margins, abruptly nar- 
rowed at the apex. 

Apparently rare plants of the seasonally dry evergreen forest 
formations of the Pacific slope between 800 and 1300 m. elevation in 
Costa Rica; flowering from November to February. The sper - 
ranges from Veracruz, Mexico to Colombia, Venezuela and the West 
Indies. 

Boehmeria ramiflora is distinguished by its 3-parted male flowers, 
fruit borne within a persisting perianth-tube with thin wing-like 
margins, and long petiolate asymmetric laminae with secondary 
veins often on only one side of the midvein. Superficially these 
plants look very much like Boehmeria radiata and Phenax mexican- 
us, and resemblance to these common plants may explain why this 
species is so rarely collected. Our Costa Rican collections come from 
San Pedro de Poas and San Miguel de San Ramon in Alajuela (Bren- 
es 17358 and 20299) and above San Isidro del General in San Jose 
province (Skutch2562). 

Boehmeria ulmifolia Weddell, Ann. Sci. Nat. ser. 4, 1:202. 1854, 
(sensu Killip in Ann. Missouri Bot. Card. 47: 188. 1960). Figure 28. 

Shrubs or small trees 1-3 (5) m. tall, bisexual or unisexual, stems often brittle, 
leafy internodes 3-50 mm. long, 0.3-4 mm. thick, strigulose with stiff appressed hairs 
0.2-0.7 mm. long; stipules (3) 4-7 mm. long, 1-1.5 mm. broad at the base, deciduous. 
Leaves alternate and usually very different in size at adjacent nodes or the alter- 
nate leaf failing to develop and adjacent leaves apparently of similar size, petioles 
2-8 (16) mm. long, 0.8-1.4 mm. thick, puberulent; smaller laminae often reniform or 
orbicular and 2-5 mm. long, larger laminae 4-17 (22) cm. long, 1.5-7 cm. broad, ellip- 
tic to narrowly ovate or lanceolate and often asymmetric or curved, short- to long- 
acuminate at the apex, obtuse or slightly rounded at the asymmetric base, crenate- 
serrate with 1 to 6 teeth per cm., lamina drying membranaceous to thin-charta- 
ceous and usually dark above with the veins often becoming impressed, slightly 
scabrous above with thin or stiff appressed hairs about 0.5-1 mm. long, sparsely to 
densely puberulent above, venation palmate with 3 major primary veins, the mid- 
vein with 2 to 4 major secondary veins often on only one side, punctate cystoliths 
usually visible above. Inflorescences usually unisexual, small (3-8 mm.) globose 
clusters in the axils of leaves or at leafless nodes, often 2 inflorescences close to- 
gether with 1 in the axil of a leaf and the other in the axil of a minute or undeveloped 
leaf, persisting on leafless stems; male flowers with perianth about 1 mm. long, 
obtuse at the apex, anthers about 0.5 mm. long; female flowers about 2 mm. long, 
sessile, style and stigma puberulent. Fruit enclosed within a perianth-tube about 
1.5 mm. long and 0.5 mm. thick, narrowed at both apex and base, very minutely 
puberulent, a few of the hairs uncinate, ellipsoid, and not noticeably flattened or 
winged. 

Plants of very wet montane (premontane and lower montane rain) 
forest formations mostly along or near the Caribbean slope between 



236 FIELDIANA: BOTANY, VOLUME 40 

1000 and 2000 (2800) m. elevation in Costa Rica; flowering through- 
out the year but collected primarily between November and April. 
The species ranges from Guatemala to Western Panama. 

Boehmeria ulmifolia is recognized by alternating leaves being 
very small or undeveloped ( as evidenced by an inflorescence lacking 
the subtending leaf), asymmetric laminae, small sessile inflores- 
cences, small slender fruit, and very wet montane habitat. Plants 
with unusual strongly appressed hairs (resembling linear cysto- 
liths ) are placed here with plants having much thinner hairs on the 
upper lamina-surface. There are other kinds of variation among the 
plants placed under this name but these do not seem to be correlated 
with characters of flower or fruit. The species is very difficult to 
distinguish from B. radiata or B. ramiflora in the absence of flowers 
or fruit. 

LAPORTEA Gaudichaud 

Nomen conservandum 

REFERENCE: W.-L. Chew, A Monograph of Laportea. Card. 
Bull. Singapore 25: 111-177. 1969. 

Bisexual or rarely unisexual herbs or shrubs with stinging or irritating hairs; 
stipules paired, partly connate across the petiole and usually deeply bifid at the 
apex. Leaves alternate and simple, petiolate, drying thin, usually with a toothed 
margin. Inflorescences axillary, pedunculate and generally paniculate with the uni- 
sexual flowers in loose glomerules; male flowers with 4 or 5 perianth parts and the 
same number of stamens, a small pistillode present; female flowers with 4 very 
unequal perianth-parts, staminodes absent, pistil ovoid. Fruit a small achene, ovoid 
to semi-circular and usually compressed laterally, sessile or stipitate, usually be- 
coming reflexed on winged pedicels. 

A genus of 22 species best represented in Africa and Madagascar 
but with several very widely distributed species and ranging into 
the north temperate zone. Our species was formerly placed in the 
genus Fleurya, which has been changed to the status of a subgenus 
within Laportea. 

Laportea aestuans (L.) Chew, Card. Bull. Singapore 21:200. 1965. 
Urtica aestuans L., Sp. PI. ed. 2, 1397. 1763. Fleurya aestuans (L.) 
Miq. in Martius, Fl. Braz. 4, pt. 1: 196. 1853. Figure 29. 

Bisexual annual herbs, 0.3-1.5 (2) m. tall, slightly woody at the base, leafy inter- 
nodes 5-60 mm. long, 0.6-5 mm. thick (dry), glabrescent to densely covered with 
slender gland-tipped hairs 0.3-3 mm. long, and simple sharp irritating hairs; stip- 
ules 4-10 mm. long, united in the lower half with linear-lanceolate apices. Leaves 
alternate in a spiral, petioles (1) 2-12 (20) cm. long, 0.3-1 mm. thick (dry), usually 



BURGER: FLORA COSTARICENSIS 237 

glandular puberulent; laminae (2) 3-15 (30) cm. long, (1) 2-10 (22) cm. broad, ovate 
to very broadly ovate or triangular, acute to short-acuminate at the apex, obtuse 
or slightly rounded and truncate to subcordate at the base, margin coarsely serrate- 
dentate with about 2 to 5 teeth per cm. and 2-4 mm. high, the lamina drying mem- 
branaceous to very thin-chartaceous, upper surface with slender sharp hairs 0.3- 
1.5 mm. long, lower surface with somewhat shorter hairs and cystoliths occasionally 
visible (X10), the 3 to 6 pairs of major secondary veins arising at angles of 20-60 
degrees, the basal pair of secondaries prominent and the venation often subpalmate. 
Inflorescences bisexual or unisexual, 3-20 cm. long, usually solitary at a node, the 
lower often entirely male, paniculate with the flowers in distal clusters, the male 
flowers often distal within a cluster of male and female flowers; male flowers sessile 
or short pedicellate, about 1-1.5 mm. broad before anthesis, perianth-parts 4 or 5, 
puberulent only near the apex, 0.7-1.5 mm. long, anthers with very thin whitish 
walls; female flowers sessile or becoming pedicellate, perianth parts free and of 2 
lateral tepals about 0.5 mm. long, a dorsal tepal about 0.3 mm. long with 3 to 5 
glandular hairs, and a very minute ventral tepal, pistil about 0.5 mm. long. Fruit 
1-2 mm. long, becoming reflexed on the pedicel, asymmetrically ovoid and glabrous, 
narrowed at the base, the edges somewhat ribbed and forming an enclosed warty 
area on the flattened sides of the achene, pedicel and perianth usually persisting and 
falling away together with the fruit. 

Herbaceous weeds of semi-shaded areas in wet evergreen forma- 
tions on both the Caribbean and Pacific slopes of Costa Rica be- 
tween sea level and 700 ( 1200) m. elevation in Costa Rica; flowering 
throughout the year but collected most often between October and 
March. This species occurs on Cocos and the Galapagos Islands and 
ranges from Mexico and the West Indies to Peru and Brazil in this 
hemisphere, across tropical Africa, Arabia, Madagascar, and India 
to Java and the lesser Sunda Islands. 

Laportea aestuans is recognized by the presence (usually) of 
stinging hairs and glandular hairs, the conspicuously toothed al- 
ternate leaves, long erect inflorescences with many clusters of 
flowers on racemose branches and the preference for lowland hab- 
itats. 

MYRIOCARPA Bentham 

Shrubs or small to medium-size trees, unisexual or rarely bisexual, lacking sting- 
ing hairs; stipules apparently solitary, completely united across the base of the 
petiole and ligulate, usually enclosing the shoot-apex. Leaves alternate and simple, 
laminae and petioles very variable in size, margins serrate, dentate, or entire, pin- 
nately or subpalmately veined, cystoliths usually visible on the upper leaf-surface 
(X10). Inflorescences paniculate or of very long spikes from a branched base (in 
ours); male flowers clustered or separate, usually sessile, perianth 4-parted, sta- 
mens 4, pistillode usually absent; female flowers sessile, subsessile, or pedicellate, 
lacking a perianth but subtended by 2 small bracteoles, style and stigma 1 or the 
stigma rarely 2-lobed. Fruit flattened, the bracteoles and style usually persisting, 
dry and indehiscent (an achene). 



238 FIELDIANA: BOTANY, VOLUME 40 

A genus of five to ten species ranging from northern Mexico to 
Brazil and Bolivia. Several other species are known from Central 
America and Mexico. One of these differs from ours in the panicul- 
ate female inflorescences and in smaller entire leaves with relatively 
few secondary veins (M. obouata Donn.-Smith). 

Pistil and fruit glabrous to puberulent but lacking definite cilia along the edges, 
bracteoles usually appressed to the base of the pistil or fruit; plants rarely found 
above 1 100 m. altitude M. longipes. 

Pistil and fruit puberulent with definite small cilia along the edges, bracteoles usu- 
ally divergent; plants rarely found below 1100 m. elevation (in Costa Rica) 

M. cordifolia. 

Myriocarpa cordifolia Liebmann, Danske Vidensk. Selsk. Skrivt. 
ser 5, 2:306. 1851. M. longipes sensu auctores non Liebmann. Figure 
30. 

Shrubs or small trees 2.5-8 m. tall, leafy internodes 1-5 cm. long, 4-10 mm. thick, 
sparsely to densely grayish hirsutulous with slender ascending or retrorse hairs 0.3- 
1 mm. long; stipules united and ligulate, 10-26 mm. long, densely sericeous. Leaves 
alternate in a spiral, petioles 1.4-18 cm. long, 1.5-3.5 mm. thick, usually densely pu- 
berulent with soft grayish hairs about 0.5 mm. long; laminae 8-22 (30) cm. long, 4-8 
(15) cm. broad, ovate to broadly elliptic-ovate or elliptic, acute or short-acuminate 
at the apex, obtuse to rounded and subtruncate or subcordate at the base, margin 
with 4 to 7 teeth per cm., lamina drying thin-chartaceous, upper surface slightly 
scabrous and sparsely puberulent with slender hairs about 1 mm. long borne on 
raised areas from which small (0.3 mm.) narrow cystoliths radiate (but these not 
always visible), lower surfaces usually grayish puberulent with soft hairs 0.3-1 mm. 
long, the 4 to 7 pairs of major secondary veins arising at angles of 30-45 degrees, 
the basal pair of secondary veins often very prominent and the venation subpal- 
mate. Male inflorescences 10-22 cm. long with 2 or 3 branches near (1-3 cm.) the 
base, rachis 0.3-0.7 mm. thick (dry) with slender whitish hairs 0.2-0.5 mm. long; 
male flowers sessile, 1.2-1.8 mm. broad, perianth-parts about 1 mm. long, minutely 
puberulent, filaments 0.2 mm. thick, anthers about 0.9 mm. long. Female inflores- 
cences 20-40 cm. long, with several branches arising 1-3 cm. from the base, rachis 
about 0.7 mm. thick with whitish hairs 0.3-0.7 mm. long, pistil about 1 mm. long, 
subsessile or pedicellate, subtended by 2 minute (0.5 mm.) bracteoles. Fruit minute 
achenes about 2 mm. long with persisting divergent bracteoles and style, minutely 
puberulent and with the 2 edges distinctly ciliolate, flattened laterally and narrowed 
at the base. 

Plants of the wet and very wet evergreen forest formations be- 
tween 1100 and 1800 m. elevation on the Caribbean slopes and the 
adjacent areas of the Central Highlands in Costa Rica; flowering 
and fruiting collections have been made between November and 
May. The species, as presently understood, ranges from Central 
Costa Rica (near San Ramon, Alajuela, to near Capellades, Cartago) 
northward to Veracruz, Mexico. 



BURGER: FLORA COSTARICENSIS 239 

Myriocarpa cordifolia is recognized by the long pendulous inflor- 
escences with minute unisexual flowers, laminae somewhat bullate 
above with the cystoliths usually apparent (X10), and the pistil and 
fruit with ciliolate edges. Material of this species has been refer- 
red to as M. longipes, but a close examination of Oersted material 
from Aguacate shows that this name is properly applied to the more 
common species of Myriocarpa in Costa Rica, which usually grows 
at lower elevations. Costa Rican material of M. cordifolia differs 
from Mexican collections in the narrower rarely cordate leaves and 
the restricted highland habitat. 

Myriocarpa longipes Liebmann, Danske Vidensk. Selsk. Skrivt. 
ser. 5, 2:306. 1851. M. inaequilateris Liebm., loc. cit. 307. M. long- 
ipes var. yzabalensis Donn.-Sm., Bot. Gaz. 16:13. 1891. M yzaba- 
lensis (Donn.-Sm.) Killip, Proc. Biol. Soc. Wash. 40:29. 1927. Fig- 
ure 30. 

Unisexual or bisexual shrubs or small trees with slender trunks 2-6 (10) m. tall, 
leafy internodes 1-8 cm. long, 3-10 mm. thick, sparsely to densely puberulent with 
slender straight or crooked grayish hairs 0.5-1.5 mm. long, the longer hairs often 
reflexed; stipules connate and ligulate, (10) 15-25 mm. long, densely sericeous. 
Leaves variable in size and petiole-length, petioles 2-18 (35) cm. long, 2-4 mm. thick 
(dry), puberulent, ridged on drying; laminae 12-30 (46) cm. long, 8-14 (26) cm. broad, 
ovate to broadly elliptic or rarely narrowly elliptic, obtuse to acute or short-acumin- 
ate at the apex, obtuse to truncate or rounded at the base, margin serrate with 
about 3 teeth per cm., lamina drying chartaceous, upper surface smooth or slightly 
scabrous, usually glabrous with the linear or slightly arcuate cystoliths visible and 
radiating from central aereoles above, cystoliths 0.2-0.5 mm. long, lower surface 
glabrescent or with slender grayish hairs, the (5) 6 to 11 pairs of major secondary 
veins arising at angles of 30-50 degrees. Male inflorescences whitish, pendant, to 
about 12 cm. long, branched in the basal fourth, the rachis 0.2-0.5 mm. thick and 
minutely puberulent, anthers about 0.7 mm. long (dry). Female inflorescence 
branched only near the base with long (20-60 cm.) pendulous spikes, bracts 
lanceolate, 1-4 mm. long near the base of the spikes, rachis 0.2-0.5 mm. thick and 
very sparsely puberulent; female flowers crowded or distant, short-pedicellate or 
subsessile, about 1.5 mm. long, bractlets subtending the flowers about 0.5 mm. long 
and appressed, pistil glabrous or very sparsely puberulent. Fruit with the basal 
bracteoles and style persisting, about 1.5 mm. long and 1 mm. broad, flattened, 
glabrous or sparsely puberulent but without definite cilia along the edge. 

Plants of evergreen forest formations on both the Caribbean and 
Pacific slopes in Costa Rica between sea level and 1100 (1500) m. 
elevation; flowering and fruiting collections have been made from 
December to March. The species ranges from Veracruz, Mexico, 
southward to Central Panama. 



240 FIELDIANA: BOTANY, VOLUME 40 

Myriocarpa longipes is recognized by the long pendulous spikes of 
unisexual flowers, minute fruit lacking ciliolate edges, leaves with 
serrate-crenate edges, obvious cystoliths, and variable size and 
petiole-length, and usual lowland habitat. Members of this species 
may be difficult to separate from M. cordifolia (M. longipes of pre- 
vious authors, not of Liebmann) in the absence of female flowers 
or fruit though the two appear to be ecologically isolated in Costa 
Rica. Our material of M. cordifolia is more often bullate and more 
densely puberulent than our material of M. longipes. Oersted collec- 
tions that appear to be isotypes of M. longipes are conspecific with 
collections placed under the name M. yzabalensis by Killip. The 
plants are commonly called ortiga but they do not sting. 

The name Myriocarpa longipes has been misapplied for some 
time; it is not the taxon of higher altitudes (in Costa Rica), which, 
I believe, is conspecific with M. cordifolia. 



PARIETARIA Linnaeus 

Annual or perennial herbs, bisexual, usually much branched, puberulent and often 
with minutely hooked (uncinate) hairs; stipules not developed. Leaves alternate and 
simple, petiolate, the laminae entire, usually small and palmately 3-veined. Inflores- 
cences usually bisexual, of sessile or subsessile flowers axillary in small dense cy- 
mules or fascicles (glomerules or clusters), subtended by bracts connate near the 
base or free; bisexual flowers and male flowers with 4-parted perianth and 4 sta- 
mens; female flowers free with the perianth equally 4-parted and persisting in fruit, 
pistil with a linear stigma or with a narrow style below the stigma, ovary sessile or 
r^hort-stipitate. Fruit an achene, usually ovoid and laterally compressed to become 
somewhat lenticular, stigma terminal, pericarp smooth, perianth loosely enclosing 
the maturing fruit. 

A genus of about eight species in the temperate and tropical 
regions of both hemispheres. Only one species is occasionally found 
in our area, though it is quite common in parts of Guatemala. 

Parietaria debilis Forst., Fl. Ins. Austr. Prodr. 73. 1786. Figure 
29. 

Herbs, erect stems 10-60 cm. tall, older stems occasionally becoming woody, bi- 
sexual, leafy internodes 2-20 (30) mm. long, 0.5-1.5 mm. thick, sparsely to densely 
puberulent with very small (0.2 mm.) thin hairs; stipules absent but with stipule- 
like bracts subtending the inflorescences. Leaves alternate, petioles 3-35 mm. long, 
0.2-0.5 mm. thick (dry), puberulent; laminae 3-45 mm. long, 3-20 mm. broad, ovate 
to ovate-lanceolate, tapering to the acuminate apex, abruptly obtuse to rounded at 
the base, margin entire, laminae drying membranaceous, sparsely puberulent on 



BURGER: FLORA COSTARICENSIS 241 

both surfaces with thin whitish hairs about 0.5 mm. long, venation subpalmate but 
obscure, punctate cystoliths visible above. Inflorescences axillary, the flowers in 
short subsessile clusters with interspersed green linear bracts about 3 mm. long, 
flowers usually fewer than 8 and the inflorescence less than 5 mm. long. Fruit about 
1 mm. long, ovoid and slightly flattened, the surface smooth and very lustrous. 

Weedy plants introduced in Costa Rica and occasionally in culti- 
vated land above 1000 m. elevation. The paucity of herbarium ma- 
terial may indicate that populations do not persist. This species is 
widely distributed in the tropics and temperate zones of both hemi- 
spheres. 

PHENAX Weddell 

Shrubs, herbs, or occasionally small trees, bisexual or unisexual, lacking stinging 
hairs; stipules paired and free, lanceolate. Leaves alternate, petiolate, the lamina 
crenate or serrate (in ours), venation usually palmate, the cystoliths usually mi- 
nutely punctate in the upper epidermis. Inflorescences of dense fasciculate clusters 
(glomerules) of sessile or short-pedicellate flowers in the axils of leaves or fallen 
leaves, bisexual or unisexual, floral bracts thin and brownish, often broad and per- 
ianth-like; male flowers with 4-lobed perianth united below the middle, the lobes 
valvate or subimbricate in bud and rounded or acuminate at the apex of the bud, 
stamens usually 4; female flowers without perianth, enclosed within thin bracts, 
ovary sessile or short-stipitate, laterally compressed; style and stigma linear and 
persistent. Fruit protected within the perianth-like bracts, a minute achene with 
glabrous surface, surface smooth to pusticulate. 

A genus of about 12 species of tropical America with some 
having become naturalized in the Asian tropics (see discussion 
under P. sonneratii). Members of this genus are often confused with 
species oiBoehmeria andPouzolzia but differ in lacking a perianth- 
tube enclosing the pistil and fruit. The male flowers of Phenax are 
often narrowed to a minutely lobed apex or have projections on the 
back of the perianth-lobes that make these unopened or partly 
opened flowers resemble the female flowers oiBoehmeria andPouz- 
olzia. The flower-clusters must be dissected to separate the floral 
bracts and expose the naked female flower to distinguish Phenax 
with certainty. Additionally, Phenax has usually many floral bracts 
and flowers in each inflorescence, and the leaves are never conspicu- 
ously alternating in size at adjacent nodes. 

la. Laminae very narrowly elliptic to lanceolate 2a. 

Ib. Laminae narrowly to broadly ovate; plants usually bisexual 4a. 

2a. Plants unisexual; laminae usually narrowly lanceolate, inconspicuously ser- 
rulate (sub-entire), stipules 4-9 mm. long; fruit about 0.5 mm. long; uncom- 
mon shrubs, 0-1000 m P. angustifolius. 



242 FIELDIANA: BOTANY, VOLUME 40 

2b. Plants usually bisexual; laminae narrowly elliptic to lanceolate, obviously 
serrulate 3a. 

3a. Shrubs or small trees, stipules becoming 4-7 mm. long; fruit about 0.7 mm. 
long; common, 1000-2500 m P. mexicanus. 

3b. Herbs or subshrubs to 1 m. tall, stipules 1-3 mm. long; fruit about 1 mm. 
long; weeds of very wet evergreen lowlands P. sonneratii. 

4a. Fruit about 0.6 mm. long; laminae often becoming rugose with both major and 
minor veins deeply impressed above, stipules about 4 mm. long; common 
shrubs, 500-2500 m P. rugosus. 

4b. Fruit about 1 mm. long; laminae drying thin chartaceous, only the larger veins 
becoming impressed 5a. 

5a. Herbs or subshrubs with spreading branches to 2 m. tall, laminae abruptly 
narrowed at the base, stipules usually 3-8 mm. long; 1200-2000 m. elevation 

P. hirtus. 

5b. Herbs or subshrubs to 1 m. tall, laminae usually gradually narrowed to the 

base, stipules 1-3 mm. long; 0-300 (800) m. in areas of high rainfall 

P. sonneratii. 

Phenax angustifolius (H.B.K.) Weddell, Ann. Sci. Nat. ser. 4, 
pt. 1:193. 1854. Boehmeria angustifolia H.B.K. Nov. Gen. & Sp. 
2:34. 1817. Figure 29. 

Shrubs 1-2(3) m. tall, unisexual, leafy internodes 1.5-15 (30) mm. long, 0.7-3 mm. 
thick, sparsely to densely puberulent with minute (0.1-0.4 mm.) ascending whitish 
hairs; stipules 4-9 mm. long, about 1 mm. broad at the base, persisting as long as the 
leaves. Leaves clustered at the ends of branches and resembling Salix, petioles 3-20 
mm. long, 0.3-0.8 mm. thick, appressed puberulent; laminae 4-14 cm. long, 1-3 cm. 
broad, lanceolate, gradually tapering to an acute or acuminate apex, obtuse to 
slightly rounded at the base, margin minutely serrulate with 3 to 5 teeth per cm., 
laminae drying membranaceous to thin-chartaceous, and dark above, smooth and 
often glabrous above with the primary veins impressed above, appressed puberulent 
with thin whitish hairs about 0.3 mm. long on the veins beneath, venation palmate 
with 3 primary veins, midvein with many small secondary veins, minutely punctate 
cystoliths visible above. Inflorescences and the plants unisexual, globose glomer- 
ules in the axils of leaves and persisting on leafless nodes; male flowers not seen; fe- 
male flowers usually more than 20 per inflorescence and the inflorescence about 1 
cm. in diameter, bracts 1-1.5 mm. long, styles glabrous or very minutely puberulent, 
3-5 mm. long. Fruit 0.4-0.6 mm. long, about 0.3 mm. broad, only slightly flattened 
laterally, ellipsoid, very minutely pusticulate. 

A poorly known species of wet evergreen formations or in wet 
sites in seasonally dry evergreen formations between sea level and 
1000 m. elevation in Costa Rica; collected with flowers or fruit from 
December to February. The species ranges from Costa Rica to Peru 
and Bolivia. 

Phenax angustifolius is characterized by the lanceolate leaves 



BURGER: FLORA COSTARICENSIS 243 

often at the ends of long slender branchlets, sessile unisexual inflor- 
escences, and very small fruit. 

Phenax hirtus (Sw.) Weddell in DC., Prodr. 16, pt. 1:235(38). 
1869. Urtica hirta Swartz, Fl. Ind. Occ. 1:285. 1797. Figure 29. 

Herbs woody at the base or small shrubs to 1.5 m. tall, but often with creeping or 
clambering lateral stems to 2 m. long, bisexual, leafy internodes 6-50 mm. long, 0.7-4 
mm. thick, densely to sparsely puberulent with minute (0.3 mm.) curved yellowish 
hairs, the older stems glabrescent, brown or reddish-brown; stipules (1) 3-8 mm. 
long, 2 mm. broad at the base, persisting and often subtending the inflorescences. 
Leaves generally uniform in size and shape on a plant, petioles (4) 8-25 (50) mm. 
long, 0.3-0.7 mm. thick, minutely puberulent; laminae (2) 3-7 (12) cm. long, 1.5-4 (6) 
cm. broad, ovate, acuminate at the apex, rounded and truncate to subcordate at the 
base, margin coarsely crenate to serrate with 3 to 5 teeth per cm,, laminae drying 
thin chartaceous and dark above, smooth above with few scattered hairs about 0.7 
mm. long and the major veins occasionally becoming deeply impressed, minutely 
(0.1-0.5 mm.) puberulent on the veins beneath, venation palmate with 3 primary 
veins, the midvein with weak secondaries arising throughout the length of the blade, 
minutely black-punctate cystoliths usually visible above. Inflorescences bisexual, 
usually only in the axils of new and persisting leaves, each flower cluster with many 
thin brownish bracts; male flowers with an abruptly narrowed apex in bud, peri- 
anth-parts with an acuminate and thickened apex, anthers about 1 mm. long; female 
flowers enclosed in numerous thin bracts, style and stigma 3-5 mm. long. Fruit 
loosely enclosed in the broad bracts, about 1 mm. long and 0.7 mm. broad, slightly 
flattened laterally, drying dark, the surface minutely pusticulate. 

Plants of the very wet montane (premontane and lower montane 
rain) forest formations on the Caribbean slopes between 1200 and 
2000 m. elevation in Costa Rica; probably flowering throughout the 
year but collected primarily from January through March. The 
species ranges from Mexico to Bolivia and to Jamaica and Hispani- 
ola in the West Indies. 

Phenax hirtus is recognized by the short or sprawling habit, iso- 
morphic coarsely dentate leaves thin in texture and abruptly nar- 
rowed at the base, male perianth-parts with unusual apices, and 
relatively large fruit. This species resembles Pouzolzia phenacoides 
and species oiBoehmeria. 

Phenax mexicanus Weddell, Ann. Sci. Nat. ser. 4, pt. 1:193. 1854. 
Figure 29. 

Shrubs or small trees 2-6 ( 10) m. tall, bisexual, leafy internodes 3-25 mm. long, 0.8- 
3.5 mm. thick, sparsely to densely puberulent with slender hairs 0.1-0.5 mm. long, 
drying reddish-brown and longitudinally ridged; stipules 4-7 mm. long, 1 mm. broad 
at the base, lanceolate, deciduous or persistent. Leaves quite variable in size and 
petiole-length on the same or different plants, petioles 3-18 (50) mm. long, 0.3-0.8 



244 FIELDIANA: BOTANY, VOLUME 40 

(1.1) mm. thick, minutely appressed puberulent; laminae 1.5-13 (19) cm. long, 0.6-3 
(4) cm. broad, very narrowly elliptic to lanceolate, broadest at or below the middle, 
tapering gradually to the short- or long-acuminate apex, acute to obtuse at the equal 
or subequal base, margin crenate to serrate with 3 to 6 teeth per cm., lamina drying 
thin- to stiff -chartaceous, smooth above and glabrous or with minute (0.2 mm.) 
scattered hairs, very rarely rugose in age, sparsely puberulent on the veins beneath, 
venation palmate or subpalmate with 3 primary veins, the outer primary veins 
united above the petiole to the midvein and occasionally forming small pockets, 
midvein usually with 2 pairs of secondary veins in the distal half, minutely punctate 
cystoliths usually visible above. Inflorescence small (4-10 mm.) globose axillary 
clusters or glomerules often persisting at leafless nodes; male flowers 2 mm. broad 
before anthesis, perianth parts acute or obtuse at the apex, anther about 1 mm. 
long; female flowers enclosed in perianth-like bracts 2 mm. long, ovary about 0.5 
mm. long, style 3-4 mm. long, minutely puberulent. Fruit about 0.7 mm. long and 0.6 
mm. broad, slightly flattened, ovoid, smooth. 

Plants of very wet montane (premontane and lower montane rain) 
forest formations between (800) 1000 and 2500 m. elevation primar- 
ily on the Caribbean slope in Costa Rica; collected with flowers and 
fruit throughout the year excepting October and November. The 
species ranges from southern Mexico to western Panama. 

Phenax mexicanus is recognized by its globose bisexual inflor- 
escences, small smooth- surfaced fruit, closely spaced narrow leaves 
with very variable petioles, and restricted montane habitat. 

Phenax rugosus ( Poir. ) Weddell in DC., Prodr. 16, pt. 1:235. 1869. 
Procris rugosa Poiret in Lam., Encycl. 5:628. 1804. Figure 29. 

Shrubs 1-3 m. tall, bisexual, leafy internodes 3-30 (50) mm. long, 0.7-3.5 mm. thick, 
densely hirsutulous with ascending or appressed hairs 0.2-1 mm. long; stipules 
about 4 mm. long, lanceolate, deciduous or occasionally persisting. Leaves and 
petioles differing greatly in size on different plants, petioles (2) 5-35 (60) mm. long, 
0.6-1 mm. thick, densely hirsutulous; laminae 2-13 cm. long, 1-7 cm. broad, usually 
narrowly to broadly ovate in outline, acute to acuminate at the apex, obtuse to 
rounded at the base, margin dentate to serrate with 3 to 7 teeth per cm., laminae 
drying stiffly chartaceous, smooth or slightly rough to the touch and usually be- 
coming rugose with all the veins deeply impressed above, hirsutulous or tomentu- 
lose with slender whitish hairs 0.2-1 mm. long on the veins beneath, venation palm- 
ate or subpalmate with 3 primary veins or 1 primary vein and 2 strongly ascending 
secondaries, midvein with 1 or 2 pairs of major secondary veins above the basal 
veins, minute punctate cystoliths usually visible above. Inflorescences small (5-12 
mm.) globose glomerules in leaf-axils and persisting at leafless nodes; male flowers 
with the perianth parts acuminate at the apex, flower buds about 2 mm. broad; an- 
thers about 1 mm. long; female flowers enclosed by thin brown perianth-like bracts 
1-2 mm. long, styles 1-3 mm. long, very minutely puberulent. Fruit about 0.6 mm. 
long and 0.4 mm. broad, ellipsoid, very slightly flattened, smooth, and drying pale 
brownish. 



BURGER: FLORA COSTARICENSIS 245 

Plants of moist and wet evergreen (premontane wet and rain, 
and lower montane wet and rain) forest formations between (500) 
1000 and 2000 (2500) m. elevation on both the Caribbean and Pacific 
slopes in Costa Rica; probably flowering throughout the year but 
collected with flower and fruit primarily between November and 
April. The species ranges from Mexico to Venezuela and Bolivia. 

Phenax rugosus is recognized by the shrubby habit, globose bi- 
sexual inflorescences, minute fruit, and usually rugose leaves more 
or less ovate in outline. The unopened male flowers are narrowed, 
acuminate, and often bilobed at the apex, resembling quite closely 
the female perianth-tube in the genus Boehmeria. This may explain 
why collections are so often placed in the wrong genus. 

Phenax sonneratii (Poir.) Weddell in DC., Prodr. 16, pt. 1:235. 
1869. Parietaria sonneratii Poiret in Lam., Encyc. 5:15. 1804. Phe- 
nax vulgaris Wedd., Ann. Sci. Nat. ser. 4, pt. 1: 192. 1854. Figure 29. 

Herbs or diffusely branched subshrubs 0.3-1 m. tall, bisexual, leafy internodes 2- 
50 mm. long, 0.3-1.5 mm. thick, very sparsely puberulent with minute (0.1-0.4 mm.) 
whitish hairs, becoming pale in color and longitudinally ridged when dry; stipules 
1-3 mm. long, usually persisting beneath the flower-clusters. Leaves relatively uni- 
form in size and shape, petioles 4-16 (35) mm. long, 0.3-0.8 mm. thick, sparsely and 
minutely puberulent; laminae 1.5-6 cm. long, 0.8-2.5 cm. broad, ovate to elliptic or 
lanceolate, acute to acuminate at the apex, obtuse, acute or attenuate at the base, 
serrate along the margin with 3 to 9 teeth per cm., laminae drying membranaceous 
to thin-chartaceous, smooth or slightly scabrous above with appressed hairs about 
0.7 mm. long, with thin whitish hairs about 0.4 mm. long on the veins beneath, vena- 
tion palmate to subpalmate with 3 primary veins, midvein usually with a pair of 
major secondary veins arising near the center, minute black-punctate cystoliths 
often visible above. Inflorescences dense small axillary glomerules occasionally 
persisting at leafless nodes, with about 10 to 20 flowers each, outer bracts relatively 
broad, drying dark, and with a conspicuously ciliolate apical edge; male flowers 
about 1 mm. long before anthesis; female flowers with slender very minutely puber- 
ulent styles 1-2 mm. long. Fruit about 1 mm. long and 0.7 mm. broad, ovoid, acute 
apically, minutely pusticulate. 

Weedy plants of open and shaded sites in areas of very wet ever- 
green forest formations between sea level and 800 (1200) m. eleva- 
tion along the Caribbean slopes and coastal plain in Costa Rica; 
flowering throughout the year. This species appears to have been 
introduced and is now widely naturalized in the Caribbean area (see 
below). 

Phenax sonneratii is recognized by its short-lived habit, prefer- 
ence for disturbed and early secondary habitats, small stipules, 
unusual floral bracts, and relatively large fruit. It is often seen as a 



246 FIELDIANA: BOTANY, VOLUME 40 

weed on banana plantations and road sides. The type, which I have 
not seen, is said to have been collected by Sonnerat in India. How- 
ever, later floras of India do not list the species and suggest that it 
was introduced to India; it is not listed as occurring in other Asian 
countries. Thus, the origin of this species is likely to be in the New 
World, where all the other species of the genus are found. 

PILEA Lindley 

Herbs or rarely subshrubs, annual or perennial, erect to repent or climbing, occa- 
sionally epiphytic, unisexual or bisexual, stems lacking stinging hairs, often succu- 
lent, rooting from the nodes in some spp.; stipules connate across the base of the 
petiole to form a ligule-like structure, caducous or persistent. Leaves opposite and 
petiolate, similar in size and shape at a node or differing greatly; laminae entire or 
more often with serrate margins, mostly palmately 3-veined, glabrous or puberu- 
lent, linear to curved (less often punctiform) cystoliths usually visible. Inflorescen- 
ces axillary or from older leafless nodes, bracteate, basically cymose but varying 
from open paniculate to capitate or spicate, flowers of different sexes born on differ- 
ent branches of the same inflorescences, on different inflorescences of the same 
plant, or on different plants; male flowers usually pedicellate, with 3 or 4 perianth- 
parts united near the base and often bearing prolonged vertical appendages on their 
abaxial surface just below the apex, stamens 3 or 4, pistillode very small and coni- 
cal; female flowers sessile or pedicellate, perianth-parts usually 3 and equal or more 
often with 1 perianth-part much larger and somewhat hooded distally, staminodes 
3 or not apparent (said to eject the fruit at maturity), pistil ovoid to ellipsoid with a 
short sessile penicellate stigma. Fruit laterally compressed and somewhat lenticu- 
lar, ovate to orbicular or elliptic in outline, surface smooth to muricate, the apex 
sometimes becoming curved and subapical, the stigma usually deciduous, perianth 
persisting and tightly surrounding the fruit at its base. 

Pilea is the largest genus of the Urticaceae with more than 600 
species. These are mostly tropical with a few temperate representa- 
tives but the genus is absent in Europe, Australia, and New Zea- 
land. The neotropics are rich in species and some areas especially 
so; the island of Jamaica has 49 species with about 35 endemic to 
the island. Our own species of Pilea are concentrated mostly in the 
wet evergreen montane forests between 1000 and 2500 m. elevation; 
they are uncommon above and below this range. While a few species 
are common as weeds or found in the cracks of city pavement (P. 
microphylla), most species are confined to the shaded floor of moist 
forests or to the proximity of streams and brooks. 

The genus is usually easy to recognize because of its opposite 
leaves with unusual ligulate stipules. Some species have leaves very 
similar to those of the Melastomaceae family with the three or five 
primary veins subparallel and reaching the upper part of the lamina. 



BURGER: FLORA COSTARICENSIS 247 

Some of the smaller species ofPilea lend themselves to cultivation 
under glass and in terraria. The "aluminum plant," Pilea cadierei 
Gagnep. & Guill., is often grown in gardens and parks in Central 
America. 

la. Laminae with entire margins 2a. 

Ib. Laminae with crenate, serrate, or dentate margins, the teeth sometimes very 
small and confined to the distal part of the lamina 5a. 

2a. Laminae 1-6 cm. long, on long or short petioles; plants 10-100 cm. tall. . . . 3a. 

2b. Laminae 0.1-1 cm. long, petioles usually very short; plants 2-25 cm. tall 

4a. 

3a. Laminae broadest below the middle, ovate to ovate-lanceolate, obtuse to 
acuminate, with short slender hairs; above 1000 m P. parietaria. 

3b. Laminae broadest near the middle, very narrowly elliptic to elliptic-lanceo- 
late, long acuminate, glabrous P. quichensis. 

4a. Flowers in small axillary groups along the stems; leaves of a node usually 
different in size, usually longer than broad, glabrous P. microphylla. 

4b. Flowers in dense terminal clusters subtended by a "whorl" of closely spaced 
leaves; laminae usually similar in size at the same node, usually broader than 
long, glabrous or with thin hairs P. herniariodes. 

5a. Laminae of the same node differing greatly in size, the smaller lamina half the 
size of the larger or less than half as large, always glabrous; stipules 0.2-2 mm. 
long; inflorescences usually less than 2.5 cm. long; fruit 0.7-3 mm. long .... 6a. 

5b. Laminae of the same node of similar size but the petioles often very different in 
length, sometimes one lamina of a pair 20-40 per cent smaller than the other, 
glabrous or puberulent; stipules 0.3-20 mm. long; fruit 0.3-2 mm. long .... 12a. 

6a. Plants usually found as epiphytes, growing on tree-trunks, or growing on 
moss-covered rocks 7a. 

6b. Plants usually found growing on the soil 8a. 

7a. Larger laminae 2-7 cm. long, narrowly elliptic to elliptic-ovate, oblique at 
the base, venation pinnate or subpalmate, smaller laminae broad; inflor- 
escences 2-5 mm. long, fruit about 1 mm. long; 0-1600 m. . . . P. imparifolia. 

7b. Larger laminae 2-12 cm. long, lanceolate to very narrowly elliptic, subequal 
at the base, venation palmate, smaller laminae very narrow; inflorescences 
5-23 mm. long, fruit about 0.8 mm. long; (0) 500-1600 m. . . P. diuersissima. 

8a. Plants of the Cordillera de Tilaran and adjacent areas between 600 and 900 
m., becoming 40 cm. tall; larger laminae 2-8 (12) cm. long and with small 
rounded teeth; inflorescences 1-2 cm. long, fruit very large (3 mm.) and 
drying dark brown P. tilarana. 

8b. Plants found along the Caribbean slopes and Central Highlands to western 
Panama, becoming 1 m. tall; fruit 0.8-2 mm. long 9a. 

9a. Stipules short or reduced to a ligulate ridge, 0.3-1 mm. high; larger laminae 
2-10 (13) cm. long 10a. 



248 FIELDIANA: BOTANY, VOLUME 40 

9b. Stipules 1-2 mm. high; larger laminae 4-18 cm. long, often long-acuminate 

lla. 

lOa. Inflorescence capitate on short peduncles, fruit about 1.7 mm. long; 
laminae acute to short acuminate; 1400-2300 m. in the highlands of Chi- 
riqui, Panama P. chiriquina. 

lOb. Inflorescence of open or compact cymes; fruit about 0.8 mm. long; lami- 
nae often long-acuminate; 0-1600 m., from eastern Nicaragua to central 
Costa Rica P. diversissima. 

lla. Laminae with small inconspicuous teeth, the secondary veins not very 
prominent, 10 to 20 pairs; male inflorescences forming globose clusters 
around the stem 1-4 cm. in diameter; fruit 1-1.5 mm. long . . P. costaricensis. 

lib. Laminae with large conspicuous teeth and the 7 to 30 pairs of secondary 
veins prominent below; inflorescences pedunculate and few-branched, never 
encircling the stem; fruit becoming 2 mm. long P. donnell-smithiana. 

12a. Stipules more than 4 mm. long (ligule-like above the petiole-base, present only 
on the younger leaves when deciduous) 13a. 

12b. Stipules less than 4 mm. long 19a. 

13a. Plants of Cocos Island; fruit less than 1 mm. long P. gomeziana. 

13b. Plants of mainland central America 14a. 

14a. Leaves with pinnate venation and very rugose; known only from western 
Panama P. rugosissima. 

14b. Leaves palmately 3-veined or with fewer than 3 pairs of prominent secon- 
dary veins 15a. 

15a. Leaves attenuate at the base with the petiole often winged, 5-20 cm. long; 
0-1800 m. elevation P. ptericlada. 

15b. Leaves lacking a winged petiole, the lamina ending abruptly at the apex of 
the petiole where the major veins arise 16a. 

16a. Fruit 1.2 mm. long or less; laminae 4-19 cm. long, with prominent serra- 
tions; 500-2300 m 17a. 

16b. Fruit about 2 mm. long; laminae rarely more than 6 cm. long, bluntly ser- 
rate or less than 4 cm. long if prominently serrate; to 3000 m 18a. 

17a. Fruit 0.6-1 mm. long; stipules (4) 7-18 mm. long; laminae often bullate 

P. acuminata. 

17b. Fruit about 1.2 mm. long; stipules 4-8 mm. long; leaves rarely bullate 

P. pit fieri. 

18a. Laminae drying thick, 1.5-6 (8) cm. long, with a few appressed hairs be- 
neath, narrowly ovate to lanceolate; plants usually found above 2500 m. 
elevation P. cornuto-cucullata. 

18b. Laminae drying thin, 0.6-4 cm. long, glabrous beneath, ovate and promi- 
nently serrate; plants rarely found above 2500 m. elevation . . P. auriculata. 

19a. Laminae usually becoming 10 cm. long, lanceolate to very narrowly elliptic 
or elliptic 20a. 



BURGER: FLORA COSTARICENSIS 249 

19b. Laminae rarely becoming more than 7 cm. long, narrowly to broadly ovate, 
usually broadest near the base 23a. 

20a. Laminae lanceolate to linear-lanceolate, male flowers in globose heads on 
long (2-7 cm.) pendant filiform peduncles; 1000-2300 m P. angustifolia. 

20b. Laminae narrowly ovate-lanceolate to very narrowly elliptic; peduncles 
never filiform 21a. 

2 la. Leaves minutely and inconspicuously serrate, glabrous; wet Caribbean 
slopes 500-1000 m P. quichensis. 

21b. Leaves prominently serrate, glabrous or sparsely puberulent 22a. 

22a. Petioles generally short but occasionally 50 mm. long; male inflorescences 
axillary clusters, female to 15 mm. long; common on the Osa peninsula, 
rarely to 1700 m P. pallida. 

22b. Petioles to 8 cm. long; male flowers in open paniculate inflorescences 2-4 
cm. long; only known from Volcan Irazu, 1500-2500 m P. beguinotii. 

23a. Small creeping plants with roots at most nodes, stems repent; laminae 3-15 
mm. long, very broadly ovate to suborbicular P. nummularifolia. 

23b. Erect plants or having creeping stems with erect flowering shoots; laminae 7- 
80 mm. long, ovate to lanceolate 24a. 

24a. Fruit about 2 mm. long; male perianth-parts with prominent appendages 
0.5-2 mm. long 25a. 

24b. Fruit 0.5-1.5 mm. long; male perianth-parts with appendages less than 0.5 mm. 
long or none 26a. 

25a. Laminae drying thick, 1.5-6 (8) cm. long, with a few appressed hairs be- 
neath, narrowly ovate to lanceolate and serrulate; plants usually found 
above 2500 m. elevation P. cornuto-cucullata. 

25b. Laminae drying thin, 0.6-4 cm. long, usually ovate with prominent serra- 
tions; glabrous beneath; plants rarely found above 2500 m. elevation 

P. auriculata. 

26a. Fruit more than 1 mm. long; plants glabrous; inflorescences usually few 
branched on prominent peduncles, unisexual; 1500-3000 m 27a. 

26b. Fruit less than 1 mm. long; plants usually puberulent or with a few hairs; 
inflorescences much branched and bisexual (male flowers often deciduous); 
0-1600 m 28a. 

27a. Laminae 7-80 mm. long, usually narrowly ovate P. gracilipes. 

27b. Laminae 4-15 (30) mm. long, broadly ovate P. dauciodora. 

28a. Laminae with thin long (0.5-4 mm.) hairs on the upper surface, the margin 
conspicuously serrate, the upper leaves clustered close together; inflores- 
cences 3-8 cm. long; 600-1600 m P. pubescens. 

28b. Laminae glabrous above or with a few scattered hairs about 0.5 mm. long, 
the margins bluntly or minutely serrate; inflorescences to 3 cm. long 29a. 

29a. Leaves not usually clustered at the ends of stems, laminae ovate to rhombic, to 
4 cm. long; common native plants P. hyalina. 



250 FIELDIANA: BOTANY, VOLUME 40 

29b. Leaves usually clustered at the ends of stems, obovate to oblong, to 6 cm. 
long; escaped from cultivation but native in Panama P. involucrata. 

Pilea acuminata Liebmann, Danske Vidensk. Selsk. Skrivt. ser. 
5, 2:302. 1851. Figure 26. 

Herbs, stems often repent at the base, 0.2-1 m. tall, usually unisexual, the erect 
stems with few or no lateral branches, leafy internodes (1) 2-10 (12) cm. long, 1-4 
mm. thick, glabrous or with curved or crooked hairs 0.4-1 mm. long but soon becom- 
ing glabrous, often drying deep green; stipules (4) 7-18 mm. long, rounded apically, 
with a few slender hairs along the edge, often with many linear cystoliths arranged 
longitudinally near the base, usually persisting. Leaves of the same node of similar 
size or occasionally with 1 twice the size of the opposing leaf or the petioles very 
different in length, petioles 0.6-6 (8) cm. long, 0.6-1.6 mm. thick, glabrous or sparse- 
ly puberulent; laminae (2) 4-19 cm. long, 1.5-6 cm. broad, narrowly ovate to lan- 
ceolate or ovate, long-acuminate and serrate along the tip, obtuse or slightly round- 
ed at the base, prominently serrate with 1 to 3 (5) sharply acute teeth per cm., the 
laminae drying membranaceous to thin chartaceous and dark above, smooth above 
and glabrous or with a few long (0.5-2 mm.) transparent hairs in groups between 
the veins, sparsely puberulent with short (0.3-1 mm.) hairs on the veins beneath, 
venation palmate with 3 primary veins, midvein with 7 to 15 pairs of secondary 
veins, the veins often impressed above and the surface bullate, cystoliths often long 
(0.5-1 mm.) and prominent above. Inflorescences unisexual, borne in the axils of 
leaves near the ends of stems, pedunculate, male inflorescences 1-5 cm. long with 
the flowers in 3 to many dense clusters on a simple or few-branched rachis ( rarely 
many-branched), female inflorescence (1) 3-7 cm. long, usually with 3 or more 
branches and the flowers separate; male flowers 1.2-2 mm. long before anthesis, 
perianth-parts with subapical dorsal appendages 0.2-0.5 mm. long, apically dark 
green and whitish near the base of the flower; female flowers 0.7-1 mm. long. Fruit 
0.6-1 mm. long and 0.3-0.7 mm. broad, lenticular, ovoid to ellipsoid in outline with 
the central areas convex and the margin distinctly narrowed, drying brown. 

Plants of the very wet evergreen forests of the Caribbean slopes 
between 500 and 1700 m. elevation in Costa Rica; flowering from 
January to June. The species ranges from Mexico to Colombia. 

Pilea acuminata is recognized by the large stipules, relatively 
large and conspicuously serrate leaves often on petioles of different 
lengths and with the laminae of a node differing or similar in size 
and form and with long serrate tips, the peduncled relatively open 
inflorescences, appendaged male perianth-parts, and the small fruit. 
This species can be found on the moist forest floor but occurs more 
often on rocks near running water. The leaves are usually somewhat 
bullate with impressed secondary and tertiary veins, but this char- 
acteristic may be lost in pressed specimens. 

Material of this species is extremely variable, both in collections 
from diverse areas and within populations. Individual plants grow- 



BURGER: FLORA COSTARICENSIS 251 

ing together may differ in color, and those growing in sites of differ- 
ing exposure may differ greatly in size and the texture of leaves. 
In addition, Costa Rican material is much more robust than Mexi- 
can collections of this species. Specimens of P. acuminata may be 
difficult to distinguish from P. pittieri (q.v.). 

Pilea angustifolia Killip, Journ. Wash. Acad. Sci. 15:295. 1925. 
Figure 26. 

Herbs, bisexual or unisexual, 0.5-1.5 m. tall, stems erect and usually few-branch- 
ed, leafy internodes 0.5-6 cm. long, 0.7-3 mm. thick, glabrous, usually striate on 
drying, minutely punctate cystoliths present or absent; stipules 0.1-1.3 mm. long, 

1 mm. broad at the base, acute, deciduous. Leaves equal or subequal at a node, the 
smaller usually more than half as long as the larger, the petiole usually differing in 
size at a node, 2-11 mm. long, 0.3-0.7 mm. thick (dry); laminae (2) 3-14 cm. long, 0.5- 

2 cm. broad, linear-lanceolate to narrowly lanceolate or narrowly elliptic, acute to 
very long-acuminate, acute to slightly rounded at the base, minutely serrulate along 
the margin with 3 to 5 teeth per cm., the teeth more prominent distally, the laminae 
smooth and glabrous on both surfaces, drying thin chartaceous and green, vena- 
tion palmate with the 3 primary veins separate or united near the base, secondary 
veins numerous, cystoliths minutely punctate or very short-linear. Male inflores- 
cences globose heads on long (2-7 cm.) filiform peduncles, the heads about 1 cm. 
in diameter; male flowers pedicellate, buds about 2 mm. long, perianth without 
appendages, the free tips about 0.4 mm. long. Female inflorescences of dense cy- 
mose clusters on very slender peduncles 4-10 mm. long, the clusters 3-8 mm. thick; 
female flowers with the larger perianth-part 1-1.2 mm. long, linear-oblong. Fruit 
0.8-1.2 mm. long, ovate in outline, lenticular, smooth and brown, with a definite 
darker edge. 

Uncommon plants of open situations and also in shaded sites of 
wet montane forest formations between 1000 and 2300 m. elevation; 
probably flowering throughout the year. This species ranges from 
the Cordillera de Tilaran southward to Cerro Chirripo in the Cor- 
dillera de Talamanca in Costa Rica. 

Pilea angustifolia is recognized by the long narrow leaves similar 
in shape and usually subequal in size at a node, their bright green 
color, the globose male heads on long thin peduncles, and the small 
clusters of female flowers on shorter peduncles that are also very 
thin. 

Pilea auriculata Liebmann, Danske Vidensk. Selsk. Skrivt. ser. 
5, 2:299. 1851. Pilea cormanae Killip, Journ. Wash. Acad. Sci. 15: 
292. 1925. Figure 27. 

Herbs, erect or with stems procumbent near the base, 5-40 cm. tall, erect stems 
with few lateral branches or occasionally with many and shrub-like in form, usually 
unisexual, leafy internodes (0) 2-20 mm. long, 0.7-1.5 mm. thick, glabrous or with 



252 FIELDIANA: BOTANY, VOLUME 40 

minute (0.1-0.5 mm.) appressed hairs, often reddish; stipules 1.5-5 mm. long, about 
2 mm. broad, slightly auriculate at the base, rounded at the apex, conspicuous and 
persisting, pale brownish translucent. Leaves of the same node of similar size or 
rarely one leaf about half the size of the other, petioles 2-30 (40) mm. long, 0.2-0.5 
mm. thick (dry), glabrous or rarely sparsely puberulent; laminae 6-40 mm. long, 4- 
35 mm. broad, ovate to rhombic or triangular, apex formed by the terminal tooth of 
the coarsely crenate-serrate margin, abruptly narrowed at the base but slightly 
cuneate at the petiole, margin with 3 to 6 teeth per cm., the laminae drying mem- 
branaceous and often translucent, darker and with scattered transparent hairs 0.5-1 
mm. long above, essentially glabrous beneath, venation subpalmate with 3 primary 
veins, the midvein with 1 to 3 pairs of major secondary veins above the prominent 
basal lateral veins, linear cystoliths very prominent on both surfaces (dry). Inflor- 
escences usually solitary in the leaf-axils with peduncles (2) 5-30 mm. long, with 5 to 
20 flowers in short-branched or subcapitate clusters; male flowers pedicellate, peri- 
anth-parts about 3 (4) mm. long with subapical appendages 0.5-1 (1.5) mm. long, 
glabrous; female flowers 1-2 mm. long, the perianth-parts of 2 sizes. Fruit about 2 
mm. long and 1.5 mm. broad, very flat (lenticular), and ovate in outline, thickened 
along the edge, smooth and yellowish. 

Plants of the wet evergreen formations of the Caribbean slopes 
and Central Highlands between 1200 and 2700 m. in Costa Rica; 
flowering throughout the year. The species ranges from Southern 
Mexico to Western Panama. 

Pilea auriculata is recognized by the thin coarsely serrate and 
almost glabrous isomorphic leaves, conspicuous blunt intrapetiolar 
stipules auriculate at the base, small inflorescences on conspicuous 
peduncles, male perianth with appendages, and relatively large 
flattened fruit. The leaves are often dark green with the areas above 
the veins silvery-white or very pale green in life. A few plants have 
rather small ( 1-2 cm.) leaves with very prominent teeth (Lent 1852), 
but these are probably no more than an unusual form. Pilea corn- 
manae was distinguished on the basis of the leaves being rather 
different in size at each node and the staminate perianth with longer 
caudate appendages, but I believe that these represent a combina- 
tion of unusual extremes within the range of variation of P. auricu- 
lata. Two collections that exemplify this form of variation (Burger 
& Gomez 8356 and Gorman [Killip] 3543, the type) are from the 
western part of the species range and are intermediate with P. cor- 
nuto-cucullata in some respects. 

Pilea beguinotti Cufodontis, Archivio Bot. Fitogeog. & Genet. 
10:29. 1934, photo. Figure 26. 

Herbs, bisexual, 0.3-1 m. tall, stems erect and few-branched, leafy internodes 1-7 
cm. long, 2-5 mm. thick (dry), glabrous; stipules about 2 mm. long, acute, persist- 
ing. Leaves of the same node equal or subequal and similar in form but the petioles 



BURGER: FLORA COSTARICENSIS 253 

often differing in size, petioles 1.5-8 cm. long, 0.7-1.7 mm. thick (dry), glabrous, 
sulcate above; laminae 6-18 cm. long, 2-6 cm. broad, narrowly elliptic and widest at 
the center, short- to long-acuminate at the apex, acute and often unequal at the 
base, the margin bluntly serrate with 1 or 2 teeth per cm., the lamina drying very 
thin chartaceous and dark, glabrous, venation palmate with the 3 primary veins usu- 
ally united above the lamina-base and separating from the midvein at different 
points, secondary veins ascending and often somewhat S-shaped, the cystoliths 
short linear and variously arranged, sometimes absent on the upper surface. Inflor- 
escences bisexual or unisexual, 2-4 cm. long, those in lower leaf-axils mostly female, 
the distal mostly male, the clusters of 3 to 10 flowers separate along the thin glab- 
rous branches of the inflorescence; male flowers borne on pedicels becoming 1 mm. 
long, flower buds about 1 mm. long, perianth parts with very short subapical mucro- 
nate appendages; female flowers sessile or short-pedicellate, about 1 mm. long, peri- 
anth-parts about 0.6 mm. long, Fruit about 1 mm. long, with an oblique apex (not 

Rarely collected plants of the wet montane forests along the west- 
ern and south-western slopes of Volcan Irazii between 1500 and 
2500 m. elevation. This species is known from only two collections: 
Cufodontis 351 (the type) from near Guayabillos and Standley 
38819 from near Las Nubes, flowering in March and May. 

Pilea beguinotii is recognized by the large subequal leaves at each 
node, often on long slender petioles, the small stipules, glabrous 
parts, and flowers in small distant clusters on relatively short but 
open inflorescences. This species resembles Pilea myriantha Killip 
of northern South America, but that species has much larger inflor- 
escences. Vegetatively this species resembles P. quichensis with 
smaller less distinctly serrulate laminae and P. pittieri with more 
distinctly serrate leaves that are usually broadest near the base. 

Pilea centradenioides Seem, has been reported from Costa Rica 
(Standley, Field Mus. Bot. 18:394. 1937), but I have not seen mater- 
ial referable to this species collected in Costa Rica. I believe this 
record was based on the misidentification of a collection of P. pteric- 
lada. 

Pilea chiriquina Killip, Journ. Wash. Acad. Sci. 15:291. 1925. 
Figure 25. 

Herbs to 1 m. tall, unisexual, stems becoming woody near the base, unbranched or 
rarely with a few lateral branches, leafy internodes 3-30 mm. long, 0.8-4 mm. thick, 
glabrous, longitudinally grooved and reddish brown when dry, semisucculent in life; 
stipules reduced to a ligulate ridge about 0.3 mm. high. Leaves of the same node 
very different in size, smaller leaves sessile, petioles of the larger leaves 1-4 mm. 
long; smaller laminae 1-2 (3) cm. long, ovate to ovate-lanceolate and usually very 
asymmetric, subauriculate on one side basally, larger laminae 2.5-9 cm. long, 0.7-2 
(2.8) cm. broad, very narrowly elliptic to lanceolate or oblanceolate, tapering gradu- 



254 FIELDIANA: BOTANY, VOLUME 40 

ally to an acute or acuminate apex, narrowed gradually to the base but abruptly 
rounded and unequal at the petiole, margin crenate-serrate with 3 to 5 shallow teeth 
per cm., lamina drying very thin chartaceous and dark above, smooth and glabrous 
on both surfaces, venation palmately 3-veined or subpalmate with a pair of lateral 
veins arising from near the base, the 3 to 8 pairs of major secondary veins often ob- 
scure, linear cystoliths very conspicuous above. Inflorescences 1 or 2 in the axils 
of leaves, unisexual, male flowers in densely clustered cymes of 10-30 flowers on 
simple peduncles about 1 cm. long; male flowers not seen at maturity, probably 1.5 
mm. long before anthesis and the perianth with minute (-0.5 mm.) subapical appen- 
dages; female flowers in dense capitate cymes on simple peduncles about 1 cm. long, 
the 8 to 20 flowers very short pedicellate; female flowers often diseased (?) with 
black knob-like structures at the apex of the pistil. Fruit 1.5-1.8 mm. long, about 1.5 
mm. broad, thin and lenticular with the edges somewhat thickened, broadly ovate 
or suborbicular in outline, drying dark brown. 

A species known only from the moist montane evergreen forest 
formations of the Chiriqui Highlands between 1400 and 2300 m. 
altitude in Western Panama; probably flowering throughout the 
year. Endemic to Western Panama but to be expected from the 
poorly known areas above 1400 m. in adjacent Costa Rica. 

Pilea chiriquina is recognized by the relatively small leaves very 
unequal at each node with shallow teeth along the margin, glabrous 
parts, small (5-10 mm.) capitate inflorescences on short slender 
peduncles, and restricted range at higher altitudes. This species is 
closely related to P. donnell-smithiana, which seems to have the 
same kind of disease (?) afflicting its female flowers. 



Pilea cornuto-cucullata Cufodontis, Archivio Bot. Sist. Fitogeog. 
10:29. 1934, photo. Figure 27. 

Herbs with erect or procumbent stems, 10-50 cm. tall, usually bisexual, leafy 
internodes (0.5) 1-5 cm. long, 1-3 mm. thick, glabrous or with crooked ascending 
hairs about 0.5 mm. long; stipules 2-6 mm. long, 1-6 mm. broad, obtuse or rounded 
at the apex, brown, persisting. Leaves similar in size or with the smaller half the size 
of the larger at the same node, often differing in petiole-length, petioles 4-35 (40) 
mm. long, glabrous or with ascending crooked hairs; lamina 1.5-6 (8) cm. long, 1-3.5 
cm. broad, ovate to ovate-lanceolate or elliptic, obtuse to acute at the apex, obtuse 
or slightly rounded at the base, margin crenate-serrate with 3 to 5 shallow teeth 
per cm., the lamina drying thin to stiff chartaceous and dark above, glabrous above 
and with a few appressed hairs on the veins beneath, venation palmate or occasion- 
ally almost pinnate (with the basal secondaries quite prominent), the 3 to 5 pairs of 
major secondary veins (above the lateral veins or basal secondaries) usually promi- 
nent beneath, linear cystoliths prominent above and below. Inflorescences solitary 
or paired in the upper leaf-axils, the 10 to 40 flowers in capitate or globose clusters 
1 to 2 cm. in diameter or the female branched, peduncles 1-4 cm. long, 0.2-0.8 mm. 
thick (dry); male flowers pedicellate, buds about 4 mm. long before anthesis, the 
perianth usually 3-parted and with subapical appendages 1-2 mm. long, glabrous, 



BURGER: FLORA COSTARICENSIS 255 

darker apically; female flowers with perianth of 2 lengths ( 1 hooded). Fruit about 2 
mm. long, and 1.5 mm. broad, much flattened and thin-lenticular, broadly ellipsoid 
in outline, smooth, thickened along the edge and longitudinally in the center, drying 
pale greenish. 

Plants often found in the deep shade of the forest floor and along 
brooks in montane forest formations between 2500 and 3200 m. 
elevation; flowering material has been collected in August and No- 
vember. This species is endemic to the Cordillera de Talamanca 
and Volcan Irazu in Costa Rica. 

Pilea cornuto-cucullata is recognized by the usually long-peduncu- 
late inflorescences, male perianth-parts with long appendages, large 
flat fruit, blunt often broad stipules, and the very high altitude hab- 
itat. This species is closely related to P. fallax Weddell of Western 
Venezuela, Colombia, and Ecuador, which grows at similarly high 
elevations. Among Costa Rican species, P. auriculata is most close- 
ly related, and the material ascribed to P. cornmanae Killip (here 
placed into synonomy under P. auriculata) is in some ways inter- 
mediate between P. auriculata and. P. cornuto-cucullata. 

The proper delimitation of this species will require more intensive 
study. The type photograph appears quite atypical of the larger and 
thicker leaved specimens of higher altitudes that the present des- 
cription is, in large part, based upon. Plants that in some ways ap- 
pear to be intermediate between P. cornuto-cucullata (as here de- 
fined), P. auriculata (including P. cornmanae), and P. gracilipes 
have been collected both in Costa Rica and in western Panama. It 
may be that there is occasional hybridization between these three 
species or that they are not reproductively isolated and interme- 
diate populations have not been sufficiently sampled. 

Two collections from rocks bordering small streams at lower ele- 
vations of the wet Caribbean slope are tentatively placed here, 
though they may represent a new and closely related species: God- 
frey 66371 from near the Rio Toro Amarillo ( Limon ) at about 200 m. 
and Lent 3250 above Laguna Ule ( Alajuela) at about 900 m.. These 
specimens have thinner and narrower leaves, shorter stipules, and 
male flowers with somewhat shorter appendages. 

Pilea costaricensis Donn.-Smith, Bot. Gaz. 20:294. 1896. Figure 
25. 

Erect herbs to 1 m. tall, apparently unisexual, stems becoming somewhat woody, 
leafy internodes 5-40 mm. long, 1-4 mm. thick, glabrous, the cystoliths usually 
apparent; stipules 1-2 (4) mm. high, persisting. Leaves of the same node differing 



256 FIELDIANA: BOTANY, VOLUME 40 

greatly in size, smaller leaves about % the size of the larger and short-petiolate, 
petioles of the larger leaves 5-40 mm. long, about 2 mm. thick, slightly decurrent on 
the stem; smaller laminae 2-4 cm. long, very narrowly elliptic or elliptic-oblong, 
larger laminae 4-18 (21) cm. long, 1-6.5 cm. broad, narrowly elliptic-ovate to very 
narrowly elliptic or lanceolate, gradually tapering to the long-acuminate apex, grad- 
ually narrowed to the acute or attenuate and equal or subequal base, margin ob- 
scurely crenate-serrate with 2 to 4 very shallow teeth per cm., the laminae drying 
chartaceous and not usually conspicuously darker above than below, glabrous on 
both surfaces, venation palmate with 3 primary veins, the midvein with more than 
10 pairs of major secondary veins joining the lateral veins, cystoliths linear, various- 
ly oriented and visible on both surfaces. Inflorescences axillary, much-branched cy- 
mose and globose, 0.5-4 cm. in diameter and often surrounding the stem at each 
flowering node, very short pedunculate or subsessile; male flower buds about 2 mm. 
long before anthesis, perianth-parts with subapical projections 0.2-0.5 mm. long, 
perianth dark green above and pale green beneath; female flowers about 1 mm. long, 
perianth-parts unequal. Fruit 1-1.5 mm. long and equally broad, broadly elliptic to 
suborbicular, the stigma subapical, flattened and lenticular with smooth pale brown 
surface. 

Plants of the very wet forest formations of the Caribbean slopes 
and adjacent areas between 1200 and 1800 m. elevation in Costa 
Rica; flowering material has been collected between February and 
August. This species is known only from Central Costa Rica (see 
below). 

Pilea costaricensis is recognized by the erect habit, long narrow 
leaves very different in size at a node, thick stems and petioles, 
glabrous parts, large round male inflorescences that often encircle 
the stem, and round smoothly lenticular fruit. While this species 
is very distinctive in full flower, vegetative material is very similar 
to a group of species (all with long narrow leaves very different in 
size at a node) that include P. donnell-smithiana and P. ecbolophylla 
Donn. -Smith of Guatemala. A series of collections by Davidson 
(56, 267, & 717) from Bajo Chorro, Chiriqui Province, Panama, are 
very similar to material placed here but differ in the smaller more 
congested inflorescences and greater development of the small leaf 
of each node. These collections also appear to have smaller flowers 
but they are probably immature. This Bajo Chorro material may 
represent a southern population of P. costaricensis or a closely re- 
lated and undescribed species. 

Pilea dauciodora (R. & P.) Weddell, Ann. Sci. Nat. ser. 3, Hot. 18: 
223. 1852. Urtica dauciodora Ruiz & Pavon, name cited as synonym 
in Weddell, loc. cit. Figure 27. 

Herbs, bisexual or unisexual, leafy stems erect, 10-30 cm. tall, leafy internodes 
1-50 mm. long, 0.4-1.5 mm. thick, glabrous; stipules 0.5-1 (2) mm. long, persisting. 



BURGER: FLORA COSTARICENSIS 257 

Leaves of the same node of similar size and shape or differing occasionally by about 
25 per cent, petioles 1-20 mm. long, 0.1-1 mm. thick, sulcate above; laminae 4-15 
(30) mm. long, 3-18 (25) mm. broad, broadly ovate to elliptic-ovate, obtuse or occa- 
sionally acute at the apex, rounded and truncate to obtuse at the base, margin ser- 
rate with 5 to 10 strongly ascending and slightly rounded teeth per cm. (often ap- 
pearing to be rounded crenate), laminae drying chartaceous, glabrous on both sur- 
faces, venation palmate with 3 primary veins, midvein with 2 to 4 pairs of prominent 
secondary veins, linear cystoliths apparent or obscure above. Male inflorescences 2- 
6 cm. long with peduncles 1-5.5 cm. long, with 1 to 3 separate clusters of flowers; 
male flower buds about 1.5 mm. in diameter, perianth parts with subapical appen- 
dages 0.1-0.3 mm. long. Female inflorescences 1-3 cm. long, with peduncles 8-25 mm. 
long, flower clusters separate on the simple rachis or on 1 to 3 short branches. Fruit 
0.8-1.4 mm. long, 0.6-0.8 mm. broad, narrowly ovate in outline, the center rounded 
and thickened (lenticular) with a broadly or a narrowly flattened edge, surface 
smooth and pale brown. 

Small plants of the shaded forest floor (or, rarely, epiphytes) in 
evergreen montane forest formations between 1500 and 3000 m. ele- 
vation. The species ranges from southern Mexico to Venezuela and 
Bolivia but is very rare in Costa Rica ( see below). 

Pilea dauciodora is recognized by the small broad leaves usually 
similar at a node (in our area), very small stipules, glabrous parts, 
long-pedunculate male inflorescences, shortly appendaged male 
perianth, and medium sized fruit with well defined margins. The 
proper circumscription of this species is not clear. Plants from 
Guatemala and Colombia are very similar but differ in details, while 
the plants commonly placed in this species from the cloud forests of 
Honduras are somewhat smaller in all respects. This species is un- 
recorded for Panama and Nicaragua and the few Costa Rican collec- 
tions placed here (Burger & Stolze 6077, A. Jimenez 1975 & 3246, 
and Williams et al. 24400) may be no more than very small speci- 
mens of material otherwise placed under the name P. gracilipes. 
These two species, P. dauciodora and P. gracilipes, are very closely 
related and differ primarily in habit and the fact that P. gracilipes 
appears to be confined to Costa Rica and westernmost Panama. The 
disjunct range of P. dauciodora, the morphological variation in dif- 
ferent parts of its wide range, and the relationships with closely 
allied (and perhaps conspecific) species, such as P. gracilipes, are 
worthy of more intensive study than a floristic review of the Costa 
Rican material can provide. 

Pilea diversissima Killip, Field Mus. Bot. 18:394. 1937. Figure 25. 

Herbs or climbers growing on tree trunks, also epiphytes and epiliths, apparently 
unisexual, 0.3-1 m. tall or creeping, leafy internodes 3-30 mm. long, 0.7-4 mm. thick, 



258 FIELDIANA: BOTANY, VOLUME 40 

becoming woody basally, glabrous, with prominent linear cystoliths; stipules form- 
ing a minute intrapetiolar (ligulate) ridge to 1 mm. high. Leaves of the same node 
very different in size and shape, small leaves often sessile, petioles of the larger 
leaves 2-8 (15) mm. long, 0.3-1.5 mm. thick, sulcate above and decurrent on the 
stem; small laminae 4-12 mm. long, narrowly elliptic to oblanceolate, often with 
inrolled margins, larger laminae 2-10 (13) cm. long, 5-20 (35) mm. broad, oblong- 
lanceolate to very narrowly elliptic or linear-lanceolate, tapering gradually to the 
long-acuminate apex, narrowed to the acute or obtuse and slightly unequal base, 
margin crenate-serrate with 2 to 4 blunt teeth per cm., the lamina drying thin char- 
taceous and usually dark above, smooth and glabrous on both surfaces, venation 
palmate with a single pair of lateral veins, secondary veins numerous, interconnect- 
ing the primary veins, cystoliths punctiform above and below but linear and fusi- 
form near the edge above. Inflorescences 0.3-2.3 cm. long, axillary, male open and 
much branched, the female of compact cymes on short peduncles; male flowers 
borne on pedicels 1-4 mm. long, buds about 1.5 mm. long, before anthesis, perianth- 
parts minutely (0.1 mm.) mucronate; female flowers with perianth 0.5-0.7 mm. long. 
Fruit 0.7-0.9 (1) mm. long, 0.6-0.8 (1) mm. broad, broadly ellipsoid in outline, flat- 
tened but with the central axis raised, drying pale grayish-brown. 

Plants of evergreen forests subject to the very wet Caribbean 
winds between (0) 500 and 1600 m. elevation in Costa Rica; appar- 
ently flowering throughout the year. This species ranges from East- 
ern Nicaragua to Central Costa Rica. 

Pilea diversissima is recognized by the leaves differing greatly 
in size at the same node, the larger leaves narrow and trinerved, 
glabrous parts, small inflorescences, fruit with centrally thickened 
longitudinal ridge, and the plants often growing on tree trunks or 
rocks. This is a very distinctive species closely related to P. pansam- 
alana Bonn. -Smith of Guatemala with the smaller leaves of a node 
larger and petiolate and the larger laminae more prominently ser- 
rate. The plants vary greatly and it is with the larger erect plants 
that difficulties of delimitation arise. It may not be possible to dis- 
tinguish these larger plants from P. ecbolophylla Donn. -Smith (Bot. 
Gaz. 46: 115, the type not seen). The plants included here range from 
slender-stemmed creeping epiphytes with very narrow thin leaves 
in which the secondary veins dry dark in color on the lower surface 
(as in the type, Brenes 4851 ) to thicker-stemmed erect plants reach- 
ing almost 1 m. in height in wet sites and having thicker leaves that 
dry paler in color with obscure secondary venation. As these popu- 
lations are better sampled, however, it may become apparent that 
the larger plants do represent a distinct species, perhaps closely 
related to P. riparia Donn. -Smith of Guatemala. 

Pilea donnell-smithiana Killip, Journ. Wash. Acad. Sci. 15:292. 
1925. Figure 25. 



BURGER: FLORA COSTARICENSIS 259 

Erect herbs to 1 m. tall, apparently unisexual, sterns often unbranched, leafy in- 
ternodes 8-40 mm. long, 1-4.5 mm. thick, glabrous; stipules 1-2 mm. high, persisting 
or tearing off to leave a ligulate ridge. Leaves of the same node very different in size, 
smaller leaves subsessile and less than Vi the length of the larger, petioles of the 
larger leaves (0.5) 1-3 cm. long, 1-2 mm. thick, glabrous, slightly decurrent and 
forming an inter-petiolar line; smaller laminae 1-3 cm. long, ovate to elliptic, very 
asymmetric and slightly auriculate on one side basally, the larger laminae 7-18 cm. 
long, 3-9 cm. broad, elliptic to ovate-lanceolate, gradually tapering to the acuminate 
apex, obtuse to rounded at the asymmetric or oblique base, margins distinctly 
serrate with 2 to 4 teeth per cm., lamina drying very thin chartaceous, smooth and 
glabrous above and below, serration palmate with 3 primary veins, secondary veins 
variable in number (7-30 pairs) and spacing but usually at right angles to the pri- 
mary veins and interconnecting them, linear cystoliths visible above and below. 
Inflorescences solitary or 2 in the leaf-axils, unisexual, the flowers in dense clusters 
on a single unbranched peduncle or in clusters on a few-branched axis, peduncles 2- 
20 (50) mm. long; male flowers 1-1.5 mm. long in bud, perianth apparently without 
subapical appendages; female flowers usually in clusters of 5-15 flowers, borne on 
short (0.5-2 mm.) pedicels, perianth of 2 sizes, the larger 2 mm. long. Fruit becoming 
2 mm. long and 1.5 mm. broad, lenticular and broadly ovate in outline, smooth with 
thin edges, drying dull brown. 

Plants of the very wet evergreen forests of the Caribbean slope 
and adjacent areas between 1200 and 1800 m. in Costa Rica; probab- 
ly flowering throughout the year with fertile collections having been 
made from January through September. The species is known only 
from Central Costa Rica and the Boquete area of Chiriqui, Panama. 

Pilea donnell-smithiana is recognized by the distinctly serrulate 
leaves very different in size at each node, with many secondary 
veins and asymmetric lamina-base, glabrous parts, small often sub- 
capitate inflorescences, and very wet forest habitat. This species 
is very closely related to P. purulensis Donn.-Smith of Guatemala, 
but that species has the male flowers in more globose long-peduncu- 
late heads and the fruit is smaller (1.5 mm. ). 

Pilea gomeziana W. Burger, Phytologia 31:269. 1975. Figure 26. 

Herbs, bisexual (unisexual in early stages) leafy stems erect and unbranched, 
20-50 cm. tall, leafy internodes (2) 7-50 mm. long, 1-4 mm. thick, puberulent with 
thin curved or crooked whitish hairs 0.3-1 mm. long; stipules 4-8 mm. long, broad 
and rounded at the apex, persisting with the leaves. Leaves usually subequal and 
similar in form at each node, usually differing by about one-fourth in size but occa- 
sionally with the smaller leaf one-half the size of the larger (at the same node), 
petioles 1-5 cm. long, 0.4-2 mm. thick, sparsely puberulent, usually sulcate above; 
laminae 3-15 cm. long, 2.5-7 cm. broad, broadly ovate to elliptic-ovate or elliptic, 
usually broadest below the middle, short-acuminate at the apex, obtuse to truncate 
at the base, margins serrate with 2 to 4 prominent teeth per cm., laminae drying 
very thin chartaceous or membranaceous, upper surface with evenly spaced slender 



260 FIELDIANA: BOTANY, VOLUME 40 

and transparent hairs about 1 mm. long, lower surface with smaller hairs along the 
veins, venation palmate with 3 (5) primary veins, the 5 to 10 pairs of secondary 
veins ascending, very short linear cystoliths scattered or in groups above. Male 
inflorescences usually in the uppermost leaf-axils, 1-2 cm. long, usually of several 
small clusters of flowers on an unbranched rachis; male flowers subsessile, the buds 
about 1 mm. in diameter with clavate subapical appendages 1 mm. long, perianth 
usually with a few thin hairs. Female inflorescence in lower leaf-axils or at lower 
leafless nodes, 2-5 cm. long, the primary rachis with 1 to 4 branches, flower -clusters 
very small and distant along the rachis; female flowers pedicellate, less than 0.5 
mm. long. Fruit about 0.6 mm. long, oblong in outline with convex surfaces, pale 
brown, margins outlined by a submarginal ridge or dark-punctate lines. 

Plants of stream sides and shaded forest on Cocos Island; collec- 
ted with female flowers in August and with fruit and unopened male 
flowers in March. I have seen only three collections of this species: 
Dressier 4469, Gomez 3304 the type, and Pittier 16238. 

Pilea gomeziana is distinguished by its very small flowers and 
fruit, subequal leaves at each node, large stipules, pubescence of 
slender hairs, and isolated habitat. This species appears to be rela- 
ted to P. pittieri and P. pubescens among Costa Rican species. Clo- 
ser relationships are to be expected with South American species, 
but I have not been able to find any thus far. 

Pilea gracilipes Killip, Journ. Wash. Acad. Sci. 15:294. 1925. 
P. standleyi Killip, loc. cit. 298. Figure 27. 

Herbs, stems often repent or climbing but the leafy flowering parts erect and 
usually few-branched, 10-40 cm. tall, bisexual or unisexual, leafy internodes 1-5 cm. 
long, 0.8-3 mm. thick, glabrous and succulent in life; stipules 0.8-4 mm. long, 1-2 
mm. broad at the base, obtuse at the apex, persisting. Leaves of the same node 
similar in size and shape or the smaller occasionally one-half the length of the larger, 
petioles 3-30 (40) mm. long, 0.2-1.3 mm. thick, glabrous or rarely with a few hairs 
near the apex; laminae 0.7-8 cm. long, 7-30 mm. broad, elliptic-ovate to narrowly 
ovate or ovate-lanceolate, acute to acuminate at the apex or with the smaller leaves 
obtuse, obtuse to rounded at the base, bluntly to sharply serrate with 3 to 6 teeth 
per cm., lamina drying membranaceous to chartaceous, smooth and essentially glab- 
rous on both surfaces or with a few hairs at the base, venation palmate with 3 pri- 
mary veins, the lateral veins often united with the midvein 1-3 mm. above the mid- 
vein, midvein with 4 to many pairs of obscure secondary veins, linear cystoliths 
conspicuous above. Inflorescences 1 or 2 in the axils of upper leaves, unisexual but 
occasionally with both sexes from a single axil, often with a long ( 2-5 cm. ) peduncle 
and to 5 major branches, the flowers in sessile or short-stalked clusters with the 
male often in capitate groups 5-10 mm. in diameter and the female usually separate 
along the branches of the inflorescence; male flowers 1.5-2 mm. long before anthesis, 
perianth-parts 4 with subapical appendages 0.1-1.5 mm. long; female flowers often 
diseased (?) with black rounded structures at the apex of the pistil. Fruit 1.2-1.6 
mm. long, 0.8-1 mm. broad, narrowly ovate in outline, lenticular but thickened in the 
middle and the margin narrowed and distinct, drying pale brown or yellow-brown, 
smooth. 



BURGER: FLORA COSTARICENSIS 261 

Plants of wet evergreen montane forest formations between 
(1300) 1800 and 2800 (3300) m. elevation; probably flowering 
throughout the year. The species ranges from central Costa Rica 
to western Panama. 

Pilea gracilipes is recognized by the medium-sized narrow leaves 
on thin petioles often differing slightly (25 per cent) in size at each 
node, the small stipules, the usual lack of pubescence, male flowers 
usually on long-stalked capitulae, male perianth-parts with very 
short (0.2 mm.) subapical appendages, female flowers in separate 
clusters along a simple or few-branched rachis, and the fruit a little 
more than 1 mm. long with definitely outlined margin. Plants of the 
Cordillera de Talamanaca often have leaves that dry thicker and 
darker than those from the Central Volcanic Highlands while plants 
of the very moist slopes along the upper Rio Grande de Orosi tend 
to have larger (1.5 mm.) fruit. In addition, there are plants from 
high altitudes that may represent intermediates with P. cornuto- 
cucullata and possess much more conspicuous appendages on the 
male perianth. The smaller plants of this species with more ovate 
leaves may be indistinguishable from plants placed in P. daucio- 
dora: see the discussion under that species. 

Pilea herniarioides (Sw.) Weddell, Ann. Sci. Nat. ser. 3, 18:207. 
1852. Urtica herniarioides Swartz, Vet. Akad. Handl. Stockh. 8:64. 
1787. P. deltoidea Liebm., Danske Vidensk. Selsk. Skrivt. ser. 5, 
2:298. 1851. Figure 27. 

Very small herbs, erect or prostrate, 2-10 cm. tall, much branched, leafy inter- 
nodes 0-10 ( 15) mm. long, about 0.3 mm. thick (dry), glabrous or with slender whit- 
ish hairs at the nodes; stipules about 0.3 mm. long, glabrous. Leaves of the same 
node similar in size, opposite along the stems but the upper with very short inter- 
nodes and forming terminal rosettes, petioles (0) 0.2-6 mm. long, 0.2 mm. thick 
(dry), glabrous or with a few thin whitish hairs; laminae 1-8 mm. long, 2-8 mm. 
broad, deltoid to rhombic-orbicular or very broadly ovate, rounded to bluntly obtuse 
at the apex, abruptly narrowed and attenuate at the base, margins entire, the lami- 
nae drying membranaceous to thin chartaceous, glabrous or with very slender 
whitish hairs 0.1-0.7 mm. long on the upper surface and along the edge, venation pal- 
mate but obscure, linear cystoliths visible on the upper surface, variously oriented 
but the majority transverse (at right angles to the midvein). Inflorescences clus- 
tered within the axils of the terminal leaf -rosettes, about 3-4 mm. long, the flowers 
minute. Fruit about 0.5 mm. long and 0.2-0.3 mm. broad, ellipsoid and slightly 
lenticular, surfaces smooth and pale brown. 

Small plants of wet evergreen areas or of wet sites in seasonally 
dry areas from 0-1200 m. elevation in Costa Rica; collected with 
flowers and fruit from July through December. This species ranges 



262 FIELDIANA: BOTANY, VOLUME 40 

from Southern Mexico to Western Panama, and from Florida in the 
United States through the West Indies. 

Pilea herniarioides is recognized by the very small plant-size, 
small isomorphic leaves with entire margins, and rosette-like ter- 
minal leaves with the flowers restricted to the axils of these ro- 
settes. This species appears to be uncommon in Costa Rica. 

Pilea hyalina Fenzl, Denkschr. Akad. Wiss. Math. Naturw. 
(Wien) 1:256. 1850. Figure 27. 

Small erect herbs 10-30 cm. tall, bisexual, unbranched or more often with several 
lateral branches and bush-like form, leafy internodes 4-40 mm. long, 0.4-2.5 mm. 
thick, glabrous, succulent but drying yellowish and often translucent; stipules 
rudimentary and less than 1 mm. long, usually obscure. Leaves of the same node of 
similar size and shape, petioles 4-40 mm. long, 0.2-0.8 mm. thick (dry), glabrous; 
laminae 0.7-4 (6) cm. long, 0.6-3 (4) cm. broad, ovate to elliptic-ovate or rhombic, 
acute at the apex, obtuse to abruptly rounded at the base, crenate-serrate or serrate 
(except near the base) with 3 to 6 teeth per cm., laminae drying membranaceous, 
upper surface with a few scattered transparent hairs about 0.5 mm. long, the lower 
surface essentially glabrous, venation palmate with 3 primary veins, midvein with 
3 to 7 pairs of obscure secondary veins, short-linear cystoliths usually visible above. 
Inflorescences in the axils of many nodes and solitary or paired, 3-20 (30) mm. long, 
short-peduncled but usually much-branched and cymose-paniculate, bisexual but 
the male flowers soon lost, flowers in congested clusters 1-3 mm. long; male and 
female flowers about 0.5 mm. long. Fruit 0.3-0.5 mm. long, ovoid to broadly ellipsoid 
in outline, thick-lenticular with narrowed margins, drying yellowish brown or pale 
brown. 

Plants of seasonally dry or wet evergreen forest formations be- 
tween (0) 500 and 1800 m. and collected most often around the Me- 
seta Central and the General Valley in Costa Rica ( apparently rare 
on the Caribbean slope and not recorded from the deciduous areas of 
Guanacaste), collected in flower and fruit from June to March. The 
species ranges from Mexico and the Lesser Antilles to Chile and 
Argentina. 

Pilea hyalina is recognized by the small short-lived habit, thin 
isomorphic leaves at a node, few hairs on the upper lamina-surface, 
minute fruit, and lack of developed stipules. A succulent-stemmed 
plant of moist sites and along water courses; completing its life 
cycle in the wet season. This species resembles P. dauciodora with 
larger flowers and fruit. 

Pilea impari folia Weddell, Ann. Sci. Nat. ser. 3, 18:212. 1852. 
Figure 25. 

Herbs, scandent or rarely terrestrial and erect, usually rooting in the ground and 



BURGER: FLORA COSTARICENSIS 263 

climbing up tree trunks with adventitous roots, occasionally epiphytic, apparently 
unisexual, leafy internodes 5-20 mm. long, 0.5-3 mm. thick, glabrous; stipules 0.2-1 
mm. high, broad and rounded at the apex, usually persisting as an obscure ligulate 
ridge. Leaves of the same node differing greatly in size, the smaller leaves sessile or 
subsessile, larger leaves with petioles 2-10 mm. long, glabrous, decurrent on the 
stem; smaller laminae 5-15 mm. long, about equally broad and asymmetric, ovate 
to orbicular-reniform, larger laminae 2-7 cm. long, 1-3 cm. broad, elliptic to elliptic- 
ovate, oblong or rarely obovate, with a rounded or acute terminal tooth at the apex, 
acute to obtuse or attenuate at the oblique and asymmetric base, sides of the lamina 
often 1-2 mm. distant on the petiole, margin usually coarsely crenate-serrate with 
2 to 4 teeth per cm., drying membranaceous to very thin chartaceous and dark 
above, glabrous, venation pinnate but with the basal secondaries often prominent 
and arising separately from the midvein and with 2 or 3 additional pairs of major 
secondary veins, cystoliths usually short-linear above and punctiform beneath. 
Inflorescences unisexual and very small (2-5 mm.), cymose of few (4-8) flowers 
sessile or on a peduncle 1-2 mm. long; male flowers borne on pedicels 1-3 mm. long, 
from a fasciculate base in leaf-axils or on lower leafless stems, perianth 1-2 mm. long 
before anthesis, minutely mucronate with subapical appendages 0.2-0.4 mm. long, 
glabrous; female flowers about 0.5 mm. long. Fruit about 1 mm. long, and 0.7 mm. 
broad, much flattened and ovoid-elliptic in outline, the edge and longitudinal central 
axis thickened, very pale in color (dry). 

Plants of wet evergreen forest formations from near sea level to 
1600 m. elevation on both the Caribbean and Pacific slopes of Costa 
Rica; probably flowering throughout the year. The species ranges 
from Costa Rica to Northern Peru and Amazonian Brazil. 

Pilea imparifolia is recognized by the climbing habit, leaves of a 
node very different in size, unequal oblique base of the large lami- 
nae, pinnate or subpalmate venation, glabrous parts, and very small 
inflorescences. The very small size of flowers and inflorescences has 
resulted in very few fertile collections (Lent 434, 1590, &2811 ). This 
species is closely related to P. pansamalana Bonn. -Smith of Guate- 
mala, but that species has longer and narrower large leaves with dis- 
tinctly palmate (triplinerved) venation. Pilea tilarana of the Sierra 
de Tilaran and adjacent areas is a terrestrial with very different 
fruit but rather similar aspect vegetatively. Our material of P. im- 
parifolia differs from South American material in the shorter appen- 
dages on the male perianth-parts (0.2 mm.) and somewhat different 
lamina-form. However, the form of the leaves varies greatly in this 
and related species, even on the same plant. 

Pilea involucrata (Sims) Urban, Symb. Antill. 1:298. 1899. Urtica 
involucrata Sims, Bot. Mag. 51: pi. 2481. 1824. 

Herbs, lower stems often repent, erect stems 5-30 cm. tall, bisexual or unisexual, 
leafy internodes 0-5 (40) mm. long, about 1.5 mm. thick, with appressed ascending 



264 FIELDIANA: BOTANY, VOLUME 40 

often curved hairs 0.2-0.5 mm. long; stipules 3-4 mm. long equally broad, rounded at 
the apex, persisting. Leaves of the same node usually similar in size and shape, the 
leaves often clustered near or at the ends of erect stems, petioles 3-7 mm. long, 
about 1 mm. thick, puberulent; laminae 2-6 cm. long, 1.3-3.8 cm. wide, bluntly ob- 
tuse to rounded at the apex, narrowed below the middle to the obtuse or slightly 
rounded base, obovate to elliptic-obovate or oblong, margin very finely crenate- 
serrate in the distal half with 4 to 6 obscure teeth, laminae drying membranaceous 
or very thin chartaceous and dark above, ciliolate along the edge, puberulent on the 
veins beneath, venation palmate with 3 primary veins, cystoliths linear to fusiform 
and usually confined to the margin above. Inflorescences usually unisexual, sub- 
sessile in the axils of the distal leaves near the stem apex, 5-30 mm. long, much 
branched. Fruit about 0.5 mm. long and 0.4 mm. thick, ovoid or very slightly flat- 
tened, drying yellowish or pale brown, stigma becoming curved and subterminal. 

Apparently an escape from cultivation near the Lankester gar- 
dens in the province of Cartago at 1300 m. elevation. The species 
ranges naturally from Central Panama to Colombia, Venezuela, and 
the West Indies. 

Pilea microphylla (L.) Liebm., Danske Vidensk. Selsk. Skrivt. 
ser. 5, 2:296. 1851. Parietaria microphylla L., Syst. ed. 10. 1308. 
1759. Pilea portula Liebm., loc. cit. 297. 1851, (photo). Figure 25. 

Herbs, erect or procumbent, usually much branched and often forming flat mats, 
2-25 cm. tall, usually bisexual, stems succulent, leafy internodes (0) 1-20 mm. long, 
0.3-3 mm. thick and longitudinally ridged when dry, glabrous; stipules minute or 
undeveloped. Leaves usually differing greatly in size at the same node, petioles 0.3- 
8 mm. long, glabrous; laminae 0.5-10 (14) mm. long, 0.5-4 (5) mm. broad, broadly 
elliptic to ovate or obovate, rounded to bluntly obtuse at the apex, usually cuneate 
at the base, margins entire, laminae drying thin to stiffly chartaceous (succulent 
in life), smooth and glabrous on both surfaces, venation pinnate, the 3 or 4 pairs of 
secondary veins obscure, linear cystoliths 0.2-0.4 mm. long usually visible on the 
upper surface and mostly transverse (at right angles to the midvein). Inflorescences 
of small axillary clusters 0.5-4 mm. long with 3 to 8 flowers, sessile or subsessile; 
male and female flowers about 0.5 mm. long. Fruit 0.3-0.5 mm. long and about 0.3 
mm. broad, ovoid and somewhat flattened, smooth and lustrous brown. 

Plants of open sites in wet evergreen areas or wet situations or 
periods in seasonally dry areas between sea level and 1500 m. eleva- 
tion in Costa Rica but not collected from below 800 m. on the Pacific 
slopes; flowering throughout the year but collected most often from 
July to January. The species ranges throughout the American 
Tropics to altitudes as high as 2500 m. (fide Killip). 

Pilea microphylla is recognized by its very small opposite and 
unequal leaves, small dense growth-form, and flowers in small axil- 
lary clusters. This species is often found in the moist crevices of 
walls and pavements in the towns of the Meseta Central during the 



BURGER: FLORA COSTARICENSIS 265 

wet season. It is common in the Caribbean lowlands, but the species 
is not found in the deep shade of dark forest. The species varies 
greatly in size and aspect, from dense moss-like little plants to more 
diffuse forms with long (12 mm.) narrow leaves on slender inter- 
nodes to 20 mm. long ( as in the type of P. portula). 

Pilea nummularifolia ( Sw. ) Weddell, Ann. Sci. Nat. ser. 3, 18:255. 
1852. Urtica nummularifolia Swartz, Svensk. Vet. Akad. 8:63. 1787. 
Figure 2 7. 

Herbs, usually unisexual, repent with adventitious roots at many nodes, leafy 
internodes 5-30 mm. long, puberulent with very thin hairs about 0.5 mm. long; 
stipules 2-3 mm. long, equally broad, translucent and ciliolate, rounded at the apex, 
persistent. Leaves usually of similar size at each node, petioles 3-12 mm. long; 
laminae 3-15 mm. long and equally broad, very broadly ovate to suborbicular, round- 
ed or bluntly obtuse at the apex, rounded and subtruncate to subcordate at the 
base, margin minutely crenulate, the lamina drying opaque and membranaceous, 
upper surface with slender transparent hairs about 1.5 mm. long and with shorter 
hairs beneath, venation palmate with the 3 primary veins often obscure, cystoliths 
often obscure. Inflorescences axillary or terminal, about 1 cm. long, with few very 
short lateral branches. Fruit about 0.5 mm. long and 0.4 mm. broad, ovate in out- 
line, slightly flattened and lenticular, surfaces smooth and pale brown. 

Plants apparently escaped from cultivation and known only from 
the cities of San Jose and Limon in Costa Rica. The species ranges 
naturally from the West Indies to northern South America and 
Amazonian Peru. The very small round leaves crenate, puberulent, 
and of similar size at the same node on slender trailing stems make 
these plants especially attractive when grown in hanging baskets. 

Pilea pallida Killip, Journ. Wash. Acad. Sci. 15:295. 1925. Figure 
26. 

Herbs, unisexual, 0.3-0.8 m. tall, stems usually unbranched, often thickened be- 
tween the nodes, leafy internodes 1-6 cm. long, 1-3.5 mm. thick (dry), minutely 
puberulent with appressed hairs 0.1-0.3 mm. long; stipules 2.5-4 mm. long, triangu- 
lar, acute or blunt at the apex, persisting or deciduous. Leaves equal or subequal 
at a node (rarely differing greatly in size at the lower nodes), similar in shape, the 
petioles often differing in length at the same node, 4-50 mm. long, 0.6-1.7 mm. thick, 
glabrous or minutely puberulent, sulcate above; laminae 5-19 cm. long, 1.4-6 cm. 
broad, lanceolate to very narrowly elliptic or very narrowly ovate, long-acuminate 
at the apex, acute at the base, margin with 3 to 5 obtuse serrations per cm., lamina 
drying thin chartaceous, smooth and glabrous above, minutely puberulent or glab- 
rous below, palmately 3-veined, the midvein with 10 to 16 secondary veins, minute 
punctate and short (0.4 mm.) linear cystoliths prominent on the darker upper sur- 
face. Male inflorescences tightly congested globose clusters in the axils of leaves, 
5-10 mm. in diameter, branches of the cymes and pedicels not visible; male flower 



266 FIELDIANA: BOTANY, VOLUME 40 

buds about 2 mm. long including prominent (0.4 mm.) subapical appendages. Fe- 
male inflorescences short-branched cymose clusters 3-15 mm. long and equally 
broad, the flowers closely approximate but not congested, female flower with the 
larger perianth-part 0.6-1 mm. long. Fruit 0.7-0.9 mm. long, broadly ovate in out- 
line, lenticular, dark reddish brown to black and minutely papillose when dry, with 
raised circular areas on the 2 flat faces. 

Plants of shaded sites in wet forest formations and common on 
the Osa peninsula but rarely found in montane forests to as high as 
1700 m. elevation; flowering collections have been made from 
March through August. This species is known only from the areas 
between the Rio Sardinal (Heredia) in Costa Rica and El Valle de 
Anton ( Cocle) in Panama. 

Pilea pallida is recognized by the large narrow and prominently 
serrate leaves usually subequal at a node that dry pale greenish- 
gray beneath, the dense axillary clusters of male flowers, and the 
small female inflorescences with unusual fruit. 

Pilea parietaria (L.) Blume, Mus. Bot. Lugd. Bat. 2:48. 1856. 
Urticaparietaria L., Sp. PL 985. 1753. Figure 27. 

Herbs, erect or procumbent, (10) 20-80 (100) cm. tall, bisexual, leafy internodes 
(5) 10-60 mm. long, 0.7-4 mm. thick, glabrous and succulent, becoming reddish; 
stipules 1-3 mm. long, with prominent linear cystoliths, persisting. Leaves of the 
same node usually of similar size but often differing in petiole-length, petioles 3- 
40 mm. long, 0.5-1 mm. thick, glabrous or with slender hairs, sulcate above; laminae 
(0.6) 1-6(8) cm. long, (4) 6-28 mm. broad, elliptic to elliptic-ovate or ovate-lanceolate, 
the smaller laminae often ovate or broadly elliptic, acute or short-acuminate at the 
apex, obtuse or slightly rounded at the unequal base, margins entire, the laminae 
drying membranaceous or very thin chartaceous, smooth above with sparse slender 
transparent hairs 0.5-1.5 mm. long, with similar hairs along the margin and shorter 
hairs on the veins beneath, venation palmate with 3 primary veins, lateral veins 
occasionally forming cavities at the junction with the midvein, secondary veins 
thin and obscure, linear or slender curved cystoliths usually visible on both surfaces. 
Inflorescences solitary or paired in the leaf-axils, bisexual or unisexual, 1-4 cm. long, 
pedunculate and branched or unbranched, the flowers in clusters of 5 to 30 on a 
glabrous succulent rachis drying 0.2-0.6 mm. thick; male flowers usually borne on 
the distal inflorescences, perianth parts with very short (0.2 mm.) subapical appen- 
dages; female flowers about 1 mm. long, short-stipitate. Fruit 0.5-0.7 mm. long, 
0.4-0.5 mm. broad, lenticular and ovoid to ellipsoid, pale brown and smooth, margin 
slightly thickened. 

Plants of wet evergreen montane (premontane and lower montane 
wet and rain forest) formations between 1100 and 2200 m. elevation 
along the Caribbean slopes and in the central highlands of Costa 
Rica; flowering throughout the year but collected most often be- 
tween January and August. The species ranges from Guatemala 
to Western Panama and the West Indies. 



BURGER: FLORA COSTARICENSIS 267 

Pilea parietaria is recognized by the isomorphic opposite leaves 
with entire margins often on petioles of differing lengths, the thin 
laminae with slender hairs, the short persisting ligulate stipules, 
and the small fruit. This species is common in many areas, but it is 
not usually found in primary habitats. However, these primary 
areas do have relatively open, partly shaded sites similar to those 
favored by this species, and this may indicate that the species is not 
native to Costa Rica. 

Pilea pittieri Killip, Journ. Wash. Acad. Sci. 15:298. 1925. P. 
phenacoides Killip in Standl., Field Mus. Bot. 18: 1548. 1938. Figure 
26. 

Herbs, stems erect, procumbent, or climbing with adventitious roots, bisexual or 
unisexual, leafy internodes 1-8 ( 14) cm. long, 0.8-2.5 mm. thick, minutely puberulent 
with crooked hairs 0.1-0.5 mm. long or glabrescent; stipules 4-8 mm. long, about 2 
mm. broad, blunt at the apex, oblong or obovate, glabrous, usually persisting with 
the leaves. Leaves of the same node of similar size or rarely one 75 per cent the 
length of the larger, petioles 6-50 mm. long, 0.7-1.5 mm. thick, minutely puberulent; 
laminae (1.5) 4-14 cm. long, 1.3-7 cm. broad, narrowly to broadly ovate or rarely 
elliptic-lanceolate, acuminate at the apex, obtuse to abruptly rounded at the base, 
margin conspicuously serrate to bluntly crenate-serrate with 1 to 4 teeth per cm., 
the laminae usually drying thin-chartaceous and dark above, glabrous and smooth 
above, puberulent on the veins beneath with very minute (0.1 mm.) curved hairs, 
venation palmate with 3 primary veins, midvein with 7 to 10 pairs of secondary 
veins, linear cystoliths 0.2-0.5 mm. long and apparent on the upper surface. Inflor- 
escences unisexual, the male and female very different, male flowers in globose 
clusters 1-2 cm. in diameter on short (1-20 mm.) peduncles in the axils of older or 
fallen leaves, female inflorescence (2) 3-10 cm. long in the axils of distal leaves, pani- 
culate in form with several major branches and the flowers in small open clusters; 
male flowers about 2 mm. long before anthesis with minutely puberulent clavate 
appendages about 1 mm. long subapically attached to the perianth-parts; female 
flowers narrowly tubular, about 1 mm. long, 1 perianth segment longer than the 
others and hooded. Fruit about 1.2 mm. long and 0.8 mm. broad, flattened and 
lenticular but often with a longitudinal central rib, ovate to elliptic in outline, dry- 
ing reddish-brown. 

Plants of the shade of very wet forest formations subject to the 
wet Caribbean winds between (500) 700 and 2300 m. elevation in 
Costa Rica; flowering material has been collected between February 
and August. This species is known only from the Caribbean slopes 
and adjacent highlands of Central Costa Rica, from above the San 
Carlos plain ( Alajuela) eastward to the western edge of the General 
Valley ( Cartago and San Jose). 

Pilea pittieri is recognized by the generally isomorphic leaves 
often with petioles of different lengths, coarsely serrate laminae, 



268 FIELDIANA: BOTANY, VOLUME 40 

glabrous above and minutely puberulent on the veins beneath, large 
stipules, the male flowers in short-pedunculate subsessile heads and 
with unusual perianth-appendages, and the female flower on open 
branched inflorescences near the apex of the erect shoots. The 
plants often climb on the bases of tree trunks. The appendages on 
the male perianth-parts are quite variable. They may become 2 mm. 
long and clavate, but this may be a very unusual occurrence (Burger 
& Gentry 8697). The leaves vary from coarsely serrate to inconspic- 
uously crenate. Pilea pittieri is closely related to, and may be diffi- 
cult to distinguish from, P. acuminata. 



Pilea ptericlada Donn.-Smith, Hot. Gaz. 31:121. 1901. Figure 
26. 

Herbs, lower stems often decumbent, erect shoots 15-40 cm. tall, usually un- 
branched, bisexual or unisexual, leafy internodes (2) 5-35 mm. long, 1.5-4 mm. 
thick, at first with ascending brownish hairs 0.3-0.8 mm. long but becoming 
glabrescent; stipules (2) 5-8 mm. long, 3-5 mm. broad, blunt at the apex, thick 
and opaque, usually glabrous. Leaves of the same node usually of similar size and 
shape, petioles 5-18 mm. long, 0.7-1.5 mm. thick, glabrous or with ascending 
curved hairs 0.1-0.5 mm. long, sulcate above; laminae (3) 6-20 cm. long, 3-8.5 cm. 
broad, narrowly to broadly elliptic, elliptic-oblong, or narrowly obovate, usually 
acuminate at the apex, acute to attenuate at the base and often long decurrent, 
margin bluntly serrate with 1 to 4 prominent teeth per cm., laminae drying mem- 
branaceous to very thin chartaceous and dark above, glabrous above and with 
short (0.1-0.5 mm.) usually curved ascending yellowish-brown hairs on the veins 
beneath, venation palmate with 3 primary veins united for 5-20 mm. near the 
base, midvein with about 8 to 12 pairs of major secondary veins joining with the 
lateral veins, cystoliths punctate or short -linear and often obscure above. Inflor- 
escences usually solitary in the upper leaf-axils, unisexual, 2-6 cm. long, peduncu- 
late, with secondary and tertiary branching, paniculate with flowers in relatively 
open clusters; male flowers pedicellate, flower -buds narrow in early stages, about 
1.5 mm. long before anthesis, perianth with subapical appendages about 0.3 mm. 
long; female flowers subsessile or borne on slender pedicels, pistil about 0.7 mm. 
long. Fruit 1.5-1.8 mm. long, 0.8-1 mm. broad, ovate to elliptic in outline, quite 
flat, edges and a central circular area outlined by very small brown spots on a 
pale yellowish background, slightly narrowed beneath the terminal stigma. 

Plants of wet situations in shaded swamp forest and stream 
sides in evergreen lowland formations and on the forest floor in very 
wet evergreen forest formations from near sea level to 1800 m. 
elevation; flowering and fruiting collections have usually been made 
between March and June. The species is restricted to the Caribbean 
slopes and adjacent areas of Costa Rica and Panama. 

Pilea ptericlada is recognized by the isomorphic leaves at each 
node that are serrate and resemble the leaves of Melastomaceae, 



BURGER: FLORA COSTARICENSIS 269 

the laminae usually long-decurrent on the petiole with the lateral 
veins arising from the midvein well above the petiole, complex 
inflorescences, and unusual flat fruit with an ellipsoid area out- 
lined by a narrow line of minute brown marks (dry). The decur- 
rent lamina-base is unusual among our species but similar to P. 
irrorata Donn.-Smith of Guatemala. 

Pilea pubescens Liebmann, Danske Vidensk. Selsk. Skrivt. ser. 
5, 2:302. 1851. Figure 27. 



Herbs 10-50 cm. tall, usually bisexual, lower stems often repent and rooting at 
the nodes, the erect stems with 1 or several branches, terminal internodes often 
very short with a rosette of leaves, leafy internodes (0) 7-80 mm. long, 1-3 mm. 
thick, puberulent with curved or crooked thin hairs 0.2-0.8 mm. long; stipules 1-4 
mm. long, 1-2 mm. broad, rounded or obtuse at the apex, translucent, sparsely 
puberulent, persistent. Leaves of the same node similar in size, petioles 4-30 mm. 
long, 0.3-0.8 mm. thick, puberulent; laminae 1-6 (7) cm. long, 0.8-4 cm. broad, 
broadly ovate to triangular, acute to obtuse at the apex, obtuse to abruptly 
truncate at the base, margin coarsely serrate with 2 to 4 (6) teeth per cm., the 
laminae drying membranaceous to very thin chartaceous and dark above, smooth 
above but with translucent hairs 0.5-4 mm. long, with shorter thinner hairs on 
the veins beneath, venation palmate with 3 primary veins, the midvein with 3 
to 6 pairs of secondaries, short linear cystoliths apparent above. Inflorescences 
usually restricted to the distal leafy nodes, axillary, often bisexual, 3-8 cm. long, 
with several divergent branches from a primary peduncle 1-6 cm. long, the sec- 
ondary branches often with tertiary branches and the inflorescence a complex 
panicle, flowers in small (2-3 mm.) clusters along the branches of the panicle; 
male flowers in the lower parts of the panicle, about 2 mm. long before anthesis, 
perianth-parts with apical appendages about 0.3 mm. long; female flowers much 
more numerous than the male. Fruit 0.5-0.6 mm. long and 0.3 mm. broad, thick- 
lenticular, ovoid to ellipsoid in outline, smooth and reddish brown. 



Plants of wet and seasonally dry evergreen forest formations 
between 600 and 1600 m. elevation in the Sierra de Tilaran and 
around the Meseta Central in Costa Rica; flowering throughout 
the year but collected most often between May and September. 
The species ranges from Mexico to Southeastern Brazil. 

Pilea pubescens is recognized by its short stature, the leaves 
similar in size at a node and the upper ones closely clustered, 
presence of hairs on many parts, strongly serrate laminae with 
long hairs on the upper surface, complex often bisexual inflores- 
cences with a few male flowers in lower parts, and the small fruit. 
This species is related to P. acuminata of larger size and the very 
much smaller P. herniariodes. 



270 FIELDIANA: BOTANY, VOLUME 40 

Pilea quichensis Donn.-Smith, Bot. Gaz. 19:12. 1894. Figure 26. 

Herbs, unisexual or bisexual, 0.5-1 m. tall, stems erect and usually unbranched 
above the base, leafy internodes 0.6-6 cm. long, glabrous or rarely very sparsely 
puberulent; stipules 0.5-3 mm. long or apparently absent in ours (caducous?), 
deciduous. Leaves equal or subequal at a node, similar in form, the petioles simi- 
lar or very different at a node, 1-6 cm. long, 0.3-1.2 mm. thick (dry), sulcate 
above; laminae 6-15 cm. long, 1.3-3.5 cm. broad, very narrowly elliptic to narrow- 
ly elliptic-oblong or lanceolate, acuminate at the apex, acute at the base, the mar- 
gin minutely serrulate with about 3 teeth per cm., often entire along the proximal 
half of the lamina, drying thin chartaceous and dark, smooth and glabrous on 
both surfaces, venation palmate with the 3 primary veins separate or united just 
above the base, secondary veins numerous, the pale colored linear cystoliths 
prominent on the dark upper surface. Male inflorescences (not seen from Costa 
Rica) 1-3 cm. long, paniculate, male flowers pedicellate, buds 1.8 mm. long, peri- 
anth with short (0.2 mm.) subapical appendages. Female inflorescences 1-3 cm. 
long, short-branched panicles with clustered flowers. Fruit about 0.8 mm. long, 
broadly ovate in outline, lenticular, surface brown and smooth or very minutely 
puncticulate, the edge abruptly narrowed. 

A species of wet evergreen cloud forests ( premontane wet forest 
formations) between 500 and 700 m. elevation in our area and 
collected in January and from June to August. The species is 
known only from near Tilaran (Guanacaste) and Turrialba (Carta- 
go) in Costa Rica; it ranges northward to Guatemala. 

Pilea quichensis is recognized by the long narrow leaves similar in 
shape and subequal in size at a node, lack of prominent serrations, 
distinct cystoliths, glabrous parts, small short-branched open 
inflorescences, and restricted area (in Costa Rica). 

Pilea rugosissima Killip, Proc. Biol. Soc. Wash., 52:28. 1939. 
Figure 27. 

Herbs with erect stems 30-100 cm. tall, usually with few or no lateral branches, 
apparently unisexual, leafy internodes ( 1 ) 2-7 cm. long, 2-3 mm. thick, with pale 
yellowish ascending strigose hairs 0.5-1.5 mm. long; stipules 6-9 mm. long, 3-4 
mm. wide, rounded at the apex, auriculate at the base, translucent, slightly 
puberulent along the midrib abaxially, persistent. Leaves of the same node differ- 
ing by about 25 per cent in lamina size and often differing greatly in petiole- 
length, petioles 8-50 mm. long, 0.7-1.5 mm. thick, strigose; laminae (1.5) 3-12 cm. 
long, (1.5) 3-6 cm. broad, ovate to narrowly ovate, acute to acuminate at the 
apex, abruptly rounded at the obtuse to truncate base, margin sharply serrate 
with 3 to 6 curved teeth per cm., laminae drying thin chartaceous and dark 
above, strongly rugose above with groups of hairs to 2 mm. long on the pro- 
jections between the veins, much paler beneath with dense pale yellowish hairs 
0.5-1 mm. on the veins and veinlets, venation pinnate or occasionally subpalmate 
with the basal secondaries only slightly more prominent than the distal, the 5 
to 8 pairs of major secondary veins arising at angles of 30-60 degrees, minute 
punctate cystoliths present on the upper surface. Inflorescences unisexual and 1 



BURGER: FLORA COSTARICENSIS 271 

or 2 in the upper leaf-axils, the male flowers in a capitate cluster about 1-2 cm. in 
diameter borne on an unbranched glabrous peduncle 2-4 cm. long and 0.7 mm. 
thick, the male flowers subsessile or short-pedicellate, flower buds about 5 mm. 
long (before anthesis) including the narrowly subulate distal perianth-appendages 
2-3 mm. long; female flowers and inflorescences not known. Fruit unknown. 

A species known only from a single collection (Davidson 335) 
from Bajo Chorro, Boquete District, Chiriqui, Panama. This collec- 
tion was made in late February at an elevation of 1800 m. 

Pilea rugosissima is recognized by the deeply rugose leaves with 
pinnate venation and groups of hairs on the raised projections of the 
upper leaf-surface, male capitula on well developed peduncles, and 
subsessile male flowers with very long subapical projections on the 
perianth-parts. While unrecorded for Costa Rica, this species may 
occur in the eastern parts of the Cordillera de Talamanca. 

Pilea tilarana W. Burger, Phytologia31:270. 1975. Figure 25. 

Herbs, usually terrestrial and erect, 10-40 cm. tall, unisexual or bisexual, leafy in- 
ternodes (2) 5-20 mm. long, 1-3 mm. thick, glabrous, cystoliths apparent; stipules 
reduced to a ligulate ridge about 0.2 mm. high. Leaves of the same node very differ- 
ent in size and form but the small leaves on creeping (repent) stems sometimes iso- 
morphic, the small leaves of a pair sessile or subsessile, petioles of the larger leaves 
0.5-5 mm. long, decurrent on the stem; smaller laminae 5-20 mm. long, usually ovate 
to broadly elliptic, larger laminae 2-8 ( 12) cm. long, 0.7-2.5 (3.3) cm. broad, narrowly 
elliptic to elliptic-oblong or elliptic-lanceolate, obtuse at the apex, acute at the asym- 
metric and oblique base or slightly rounded on one side, crenate-serrate with 2 to 4 
slightly raised teeth per cm., laminae drying thin chartaceous and dark above, 
smooth and glabrous on both surfaces, venation subpalmate with the 2 lateral veins 
arising near the base of the midvein, secondary veins 3 to 12 pairs and often obscure, 
cystoliths mostly linear, apparent on both surfaces. Inflorescences unisexual, 1- 
2 cm. long, male inflorescences probably borne on the leafless lower portions of the 
stem, cymose (?), female flowers in cymose clusters of 4 to 20 flowers on a peduncle 
1-10 mm. long; male flowers not seen; female flowers with perianth parts of 2 
lengths, the longer 2 mm. long, pistil 1-2 mm. long with prominent (0.4 mm.) fim- 
briate stigma. Fruit about 3 mm. long and 2 mm. broad, flattened and lenticular, 
suborbicular to ovate in outline and narrowed at the apex, stigma often persisting, 
drying dark brown. 

This species is known only from the evergreen cloud forest (pre- 
montane wet forest) formations between 600 and 1000 m. elevation 
near Tilaran (Guanacaste) and near San Ramon (Alajuela) in Costa 
Rica; probably flowering throughout the year. The species occurs 
only along the Pacific side of northern Costa Rica. 

Pilea tilarana is recognized by the leaves very different in size at 
the same node, the larger leaves relatively narrow and with very 
shallow teeth, small inflorescences, large fruit narrowed at the apex, 



272 FIELDIANA: BOTANY, VOLUME 40 

terrestrial habit, and the restricted range. This species is closely 
related to P. chiriquina Killip of western Panama and P. seemannii 
Killip of northern South America. Pilea tilarana is generally of 
smaller stature than either of those species and possesses much 
larger fruit. Collections of this species were previously identified as 
P. pansamalana Bonn. -Smith of Guatemala but that species has 
smaller fruit, leaves that are more prominently serrate, and an epi- 
phytic life-style. The latter resembles P. diuersissima Killip among 
Costa Rican species. 

Collections by Standley and Valerio (44742, 44753 the type, & 
44758) from near Tilaran are generally larger and more robust than 
the collections from near San Ramon (Brenes 4527 & 20520 and 
Lent 2590), I expect that the species ranged across the Cordillera 
de Tilaran as far east as the area near San Ramon in a narrow altitu- 
dinal zone of forest that is now largely destroyed. 



POUZOLZIA Gaudichaud 

Shrubs, subshrubs, or rarely small trees or climbers, usually bisexual; stipules 
paired at the nodes and free, often persistent, distally ciliolate in ours. Leaves al- 
ternate (in American species) and simple, petiolate, usually entire, venation sub- 
palmate or pinnate with 2 prominent basal secondary veins, often trinerved, puncti- 
form cystoliths usually visible above. Flowers borne in small axillary clusters or 
glomerules (in ours), male flowers with usually 4 (3-5) perianth parts and stamens, 
the tepals narrowed at the apex and forming a narrowed tip in the unopened bud (in 
ours); female flowers with a perianth-tube toothed at the narrowed apex, the peri- 
anth-tube with prominent longitudinal ribs or veins, completely enclosing the ovary, 
stigma long and slender. Fruit a nutlet or achene, usually smooth and glabrous, en- 
closed in the persisting perianth. 

A pantropical genus of about 50 species. Our species may be diffi- 
cult to distinguish from species of Phenax and Boehmeria. They 
appear to be relatively rare in our flora and are poorly represented in 
the collections. Like many other members of the family, these 
plants are often found along stream edges. 

la. Leaves crenate-serrate, plants of evergreen montane forest formations between 
1500 and 1800 m. altitude P. phenacoides. 

Ib. Leaves entire, plants not known from above 1000 m. altitude 2. 

2a. Petioles usually less than 1 cm. long, base of the lamina asymmetric and often 
emarginate (cordulate) at the petiole P. obliqua. 

2b. Petioles often much more than 1 cm. long, base of the lamina usually symmetri- 
cal 3. 

3a. Laminae, with a minutely tomentulose grayish or whitish surface between the 



BURGER: FLORA COSTARICENSIS 273 

veins beneath, narrowed to an acute or obtuse base and usually narrow in 
outline P. guatemalana. 

3b. Laminae, lacking a whitish or grayish tomentum between the veins beneath, 

abruptly narrowed to a rounded or obtuse base, relatively broad 

P. occidentalis. 

Pouzolzia guatemalana (Bl.) Weddell in DC., Prodr. 16, pt. 1:233. 
1869. Boehmeria guatemalana Blume, Mus. Bot. Lugd. Bat. 2:206. 

1856. Figure 28. 

Shrubs or subshrubs 1-2 (3)m. tall, leafy internodes 8-30 mm. long, 1-4 mm. thick, 
sparsely to densely hirsutulous with thin whitish hairs 0.2-1 mm long; stipules 
about 6 mm. long and 1-2 mm. broad at the base, ciliolate along the edges and mid- 
vein distally. Leaves usually of similar size at adjacent nodes, petioles (0.5) 1-9 cm. 
long, 0.4-1 mm. thick, minutely hirsutulous; laminae (3) 6-14 cm. long, (1) 2-7 cm. 
broad, very narrowly ovate to lanceolate or elliptic, tapering gradually to the acumi- 
nate apex, tapering to the acute or obtuse and equal base, the margins entire, lamina 
membranaceous to very thin chartaceous, usually somewhat scabrous above 
with slender appressed hairs 0.5-1 mm. long, soft-puberulent with thin whitish hairs 
and a whitish or grayish tomentum covering the surfaces between the veins beneath, 
the 2 to 4 pairs of major secondary veins arising at angles of 30-50 degrees and 
strongly ascending, minute (0.05 mm.) cystoliths usually visible on the upper sur- 
face. Male flowers borne in dense axillary clusters usually below the female flowers 
in the same cluster, male flowers sessile or subsessile, perianth parts about 1 mm. 
long; with female flowers in dense axillary clusters, perianth-tube 1-1.5 mm. long, 
with 12-20 longitudinal ribs, densely appressed puberulent, stigma 2-3 mm. long, 
minutely brownish puberulent. Fruit enclosed within the persisting perianth-tube, 
nutlet 1-1.5 mm. long, about 1 mm. broad, broadest below the middle and ovoid, 
slightly flattened laterally, the surface smooth and very lustrous, drying very pale 
yellowish. 

Plants of both evergreen and seasonally very dry and semideci- 
duous forest formations on the Caribbean and Pacific watersheds of 
Costa Rica between sea level and 1000 m. altitude; probably flower- 
ing from August to December in the seasonally very dry areas and 
throughout the year in evergreen areas. The species occurs in Costa 
Rica, Panama, and Ecuador; the type was collected from Aguacate, 
Costa Rica, and not from Guatemala. 

Pouzolzia guatemalana is distinguished by its alternate leaves 
usually pale grayish beneath and borne on long thin petioles. The 
isomorphic entire leaves, ribbed female perianth- tube, and ciliolate 
stipules help distinguish this species from rather similar looking 
plants in the genera Boehmeria and Phenax, 

Pouzolzia obliqua (Poepp.) Weddell, Archiv. Mus. Paris 9:405. 

1857. Margarocarpus obliquus Poepp. ex Wedd., Ann. Sci. Nat. 
Paris ser. 4, 1:204. 1854. Figure 28. 



274 FIELDIANA: BOTANY, VOLUME 40 

Scandent or shrub-like plants 1-3 (5) m. tall, leafy internodes 5-50 mm. long, 0.5- 
3 mm. thick, usually densely puberulent with slender stiff whitish hairs 0.3-1 mm. 
long; stipules 3-8 (12) mm. long, narrowly triangular, puberulent along the edges 
and midrib abaxially. Leaves of approximately the same size at adjacent nodes, 
petioles (1) 2-7 (12) mm. long, 0.5-1.2 mm. thick, densely puberulent; laminae 2-12 
cm. long, 0.8-5 cm. broad, very narrowly ovate or oblong to lanceolate, tapering 
gradually to the sharply acuminate apex, obtuse to slightly rounded at the unequal 
and asymmetric base, often slightly cordulate at the petiole in larger leaves, margin 
entire or slightly undulate, drying thin-char taceous, smooth or slightly scabrous 
and with slender ascending hairs 0.5-1 mm. long above and below, the 2 to 4 pairs 
of major secondary veins strongly arcuate ascending, minute (0.05-0.1 mm.) round 
cystoliths visible above. Male flowers borne in axillary clusters of 5 to 15 flowers, 
perianth about 1.5 mm. long, united near the base, anthers about 0.7 mm. long 
(dry); female flowers borne in axillary clusters, sessile or subsessile, female perianth 
about 1 mm. long, styles and stigmas about 5 mm. long, minutely pale brownish 
papillate-puberulent. Fruit included within the persisting perianth-tube, perianth- 
tube about 2 mm. long, minutely puberulent and with prominent longitudinal ribs, 
fruit smooth and lustrous, about 1.5 mm. long, ovoid and very slightly flattened 
laterally. 

Plants of lowland wet evergreen formations between sea level and 
1000 m. on both the Caribbean and Pacific slopes of Costa Rica; 
flowering throughout the year. The species ranges from Guatemala 
to Venezuela and Peru. 

Pouzolzia obliqua is recognized by the isomorphic entire short - 
petioled leaves asymmetric at the base, sessile flowers in axillary 
groups, female flowers with ribbed perianth-tube, and scandent 
or shrubby habit. This species is poorly represented in collections 
and appears to be rare but can be locally common; like other mem- 
bers of the family the plants are often found along streams. 



Pouzolzia Occident alis (Liebm.) Weddell, Archiv. Mus. Paris 9: 
410. 1857. Leucococcus occidentalis Liebmann, Danske Vidensk. 
Selsk. Skrivt. ser. 5, 2:311. 1851. Figure 28. 

Shrubs or small trees 2-5 m. tall, leafy internodes 8-40 mm. long, 1.5-3 mm. thick, 
minutely (0.3-0.9 mm.) hirsutulous with whitish slender hairs; stipules about 6 mm. 
long, 1-2 mm. broad at the base, ciliolate along the edges and midvein distally. 
Leaves about the same size at adjacent nodes, petioles 1.5-8 cm. long, about 1 mm. 
thick and longitudinally ridged when dry, minutely hirsutulous; laminae (7) 8-13 
(15) cm. long, 3-7 (9) cm. broad, ovate to broadly elliptic-ovate, tapering gradually 
to the acuminate apex, abruptly narrowed at the obtuse or rounded and equal base, 
margins entire, laminae drying membranaceous or very thin chartaceous, smooth 
or slightly scabrous above with short (0.5 mm.) appressed hairs, soft -puberulent 
below with thin whitish hairs, lower surfaces between the veins drying dark and 
without a grayish or whitish tomentum, the usually 3 pairs of major secondary 
veins arising at angles of 30-50 degrees and strongly ascending, minute (0.05 mm.) 



BURGER: FLORA COSTARICENSIS 275 

round cystoliths usually visible above. Male flowers in dense axillary clusters usual- 
ly together with female flowers, the male flowers sessile or subsessile, perianth 
parts 1-1.5 mm. long; female flowers with a perianth- tube about 1 mm. long, stigma 
2-3 mm. long. Fruit enclosed within the persisting and strongly 10-16 ribbed per- 
ianth-tube 1.5-2 mm. long, nutlet about 1.5 mm. long and 1 mm. broad, slightly 
lenticular, smooth, and very lustrous. 

Rare plants of the wet evergreen formations of the Caribbean 
lowlands. I have seen only two collections from our area: Oersted 
14257 (the type) from the Rio San Juan and Woodson, Allen, & 
Seibert 1528 from the Isla Taboga, Panama. These were collected in 
June and July, respectively. The species ranges from Honduras to 
Colombia and Venezuela and is found in Puerto Rico (fide Killip). 

Pouzolzia occidentalis is recognized by its relatively broad leaves 
on long slender petioles and lacking a whitish or grayish tomentum 
beneath. In other respects it is very similar to P. guatemalana. 

Pouzolzia phenacoides Killip, Journ. Wash. Acad. Sci. 15:299. 
1925. Figure 28. 

Herbs or subshrubs 1-2 m. tall, leafy internodes 3-30 mm. long, 0.6-2 mm. thick, 
puberulent with short (0.1-0.5 mm.) slender curved whitish hairs; stipules 3-8 mm. 
long, 1-2 mm. broad at the base, ciliate along the margins and midrib abaxially, 
drying pale brown. Leaves approximately the same size at adjacent nodes, petioles, 
(4) 8-40 mm. long, 0.3-0.6 mm. thick (dry), sparsely puberulent; laminae 1-7 cm. 
long, 0.6-3.5 mm. broad, ovate to narrowly ovate, acuminate at the apex, obtuse or 
slightly rounded at the equal and symmetrical base, margin with 3 to 6 conspicuous 
serrations per cm., the laminae drying membranaceous, smooth or somewhat scab- 
rous with stiff slender hairs 0.5-1 mm. long on both surfaces, the 2 or 3 pairs of 
major secondary veins strongly ascending, minute cystoliths apparent on both sur- 
faces. Male flowers 1 to 10 and sessile or with short (1 mm.) pedicels in the axils of 
leaves, perianth about 1.5 mm. long, anthers about 0.7 mm. long; female flowers 
subsessile or very short-pedicellate in axillary clusters (often beneath the male 
flowers), perianth-tube weakly 10-20 ribbed. Fruit finally breaking through the per- 
sisting perianth tube, 2-3 mm. long, ellipsoid and somewhat lenticular, smooth and 
very lustrous. 

This species is apparently confined to shaded sites within lower 
montane moist forest formations between 1500 and 1800 m. eleva- 
tions and is known from the collections of Paul Standley on the 
slope of Volcan Poas (Alajuela), above Escazu and Sta. Maria de 
Dota (San Jose), and the Cerro de la Carpintera (Cartago), made 
between December and February. The species is known only from 
Costa Rica and Guatemala. 

Pouzolzia phenacoides is recognized by the thin isomorphic leaves 
with conspicuous teeth, ciliate stipules, weakly ribbed perianth- 
tube, and the small number of very lustrous fruit. This species looks 



276 FIELDIANA: BOTANY, VOLUME 40 

very much like species of Phenax or Boehmeria, but those differ in 
the secondary veins not strongly ascending, larger numbers of 
flowers per cluster, and lack of a perianth-tube ( in Phenax ). 



URERA Gaudichaud 

Large herbs, shrubs or small trees, usually unisexual but occasionally bisexual, 
sharp stinging spines often present; stipules paired and free or more often connate 
across the base of the petiole and ligulate. Leaves alternate in a spiral, simple, 
petiolate, the laminae entire, serrate, or deeply lobed, usually pinnately veined, 
cystoliths often visible on the upper surface of older leaves. Inflorescences axillary 
or cauliflorous, dichotomously or irregularly branched and cymose or paniculate, 
occasionally simple with only a few clustered flowers. Male flowers with 4 or 5 im- 
bricate perianth-parts, stamens 4 or 5, a pistillode present. Female flowers sub- 
tended or loosely enclosed or subtended by 4 equal or very unequal (in ours) peri- 
anth-parts, stigma minutely fimbriate and persisting in fruit. Fruit enclosed in the 
accrescent perianth or the perianth remaining thin and bract-like, achene usually 
lenticular with an apical or subapical stigma and glabrous surfaces. 

The genus is found in tropical America, Africa, and Asia. The 
neotropical species are in need of a careful monographic study. 
Among our species, those with large spines that give a very painful 
sting ( U. baccifera and U. laciniata) are poorly represented in collec- 
tions, while those species that do not sting so fiercely (U. caraca- 
sana and U. elata s.l. ) display a wide and complex pattern of vari- 
ation. 

la. Leafy stems with many sharp stinging spines 1-10 mm. long; laminae deeply 
lobed or with conspicuous teeth 1-4 cm. apart; perianth remaining thin and 
bract-like in fruit 2a. 

Ib. Leafy stems usually lacking large sharp stinging spines except in juvenile 
plants; laminae entire to closely serrate or dentate; stipules united across the 
petiole-base and ligule-like; perianth enclosing the ovary and becoming succu- 
lent in fruit, usually orange or red 3a. 

2a. Leaves pinnately deeply lobed; stipules united only near the base 

U. laciniata. 

2b. Leaves unlobed but distantly serrate or dentate; stipule usually united but 
with 2 separate apices U. baccifera. 

3a. Laminae usually broad and cordate or subcordate at the base, usually soft 
puberulent beneath, often bullate above, becoming as much as 40 cm. broad; 
stipules 12-18 mm. long and usually densely puberulent; fruiting inflorescence 
reddish to orange U. caracasana. 

3b. Laminae narrow to broad and usually acute to truncate at the base, glabrescent 
to sparsely puberulent beneath; stipules 5-14 mm. long and sparsely puberu- 
lent; fruiting inflorescence bright orange U. elata. 



BURGER: FLORA COSTARICENSIS 277 

Urera baccifera (L.) Gaudichaud, Voy. Uran. Bot. 497. 1826. Ur- 
tica baccifera L., Sp. PI. ed. 2, 1398. 1762. Urtica grandidentata 
Liebm., Danske Vidensk. Selsk. Skrivt. ser. 5, 2:296. 1851. Figure 
30. 

Erect herbs, shrubs or few-branched trees 1-4 (6) m. tall, leafy internodes 1-20 
cm. long, 6-20 mm. thick, hollow, minutely puberulent with slender hairs 0.2-0.5 
mm. long and with short ( 1-4 mm.) broad-based stinging spines; stipules united for 
much of their length but usually with 2 separate apices and sometimes split in two, 
10-16 mm. long, sparsely to densely puberulent. Leaves quite variable in size and 
form on different plants, petioles 3-30 cm. long, 2-6 mm. thick (dry), minutely puber- 
ulent and usually with a few stinging spines; laminae (10) 20-40 cm. long, (6) 18- 
40 cm. broad, ovate to very broadly ovate (rarely narrowly ovate to elliptic), short- 
acuminate at the apex, rounded to truncate or cordate (rarely obtuse) at the base, 
margin with prominent short (2-6 mm.) teeth 1-4 cm. distant, laminae drying mem- 
branaceous to thin-chartaceous, scabrous above with scattered distant minute 
(0.1-0.4 mm. ) spines or these absent, usually with slender soft hairs 0.2-0.7 mm. long 
(in ours) and with sharp stinging spines 0.5-3 mm. long on the major veins beneath, 
the 6 to 8 pairs of major secondary veins arising from the midvein at angles of 50- 
70 degrees, cystoliths not conspicuous above. Male inflorescences separate or 
(rarely ?) the male flowers borne at the base of the large, essentially female inflores- 
cence, the male flower 2-3 mm. broad before anthesis. Female inflorescences 4-12 cm. 
long, paniculate and much branched, female flowers separate or clustered, usually 
borne on a slender pedicel, pistil 1 mm. long in early anthesis, stigma about 0.3 mm. 
long and equally thick. Fruit often subtended by 2 thin broad bract-like perianth 
parts 1-2 mm. long, achene 3 mm. long and 2 mm. broad, lenticular, glabrous, with a 
thickened rim around the periphery, stigma terminal or subterminal. 

Plants of evergreen or partly deciduous formations between sea 
level and 1200 m. elevation on both the Caribbean and Pacific slopes 
of Costa Rica and probably flowering throughout the year. The 
species ranges from southern Mexico to tropical South America 
and the West Indies. 

Urera baccifera is readily recognized by the stinging spines and 
unlobed leaves with prominent teeth. These plants are poorly repre- 
sented in herbaria and probably for good reason: this is said to be 
one of the most severely stinging plants in Central America (see 
Standley in Fieldiana: Bot. 24, pt. 3:426. 1952). The plant is often 
used for hedgerows, and much of its present distribution may be 
attributable to man's use of the species for this purpose. 

Urera caracasana (Jacq.) Grisebach, Fl. Brit. W. Ind. 154. 1859. 
Urtica caracasana Jacq., Hort. Schoenbr. 3:71, pi. 396. 1798. Urtica 
verrucosa Liebm., Danske Vidensk. Selsk. Skrivt., ser. 5, 2:295. 
1851. Figure 30. 

Shrubs or small trees 2-8 (?15) m. tall, leafy internodes, 5-60 mm. long, 2-10 mm. 



278 FIELDIANA: BOTANY, VOLUME 40 

thick, at first densely puberulent with short (0.1-0.5 mm.) grayish hairs; stipules 
united and 2-ribbed, 12-18 mm. long, usually densely puberulent with hairs 0.5-1 
mm. long. Leaves varied in different plants, petioles 3-15 (25) cm. long, 1-5 mm. 
thick, usually densely puberulent; laminae 10-32 (44) cm. long, 7-26 (40) cm. broad, 
broadly ovate or ovate (rarely broadly elliptic), acute to acuminate at the apex, 
rounded to the base and cordate to subcordate (rarely obtuse), margin serrate with 
2 to 4 teeth per cm., lamina drying thin-chartaceous, scabrous to smooth above with 
scattered small (0.5-1.5 mm.) hairs, the hairs often elevated and the surface bullate, 
soft or slightly scabrous to the touch beneath with grayish-white hairs 0.5-1.5 mm. 
long on the veins beneath, the 7 to 11 pairs of major secondary veins arising at 
angles of 40-60 degrees, cystoliths usually small (0.05-0.1 mm.) and round, rarely 
long and narrow. Male inflorescence occasionally borne above the female when 
found on the same twig (?rare), 3-12 cm. long and variously branched, the branches 
with short thin hairs, male flower 1-2 mm. broad before anthesis, often clustered in 
small (3-6 mm) glomerules and pink in color. Female inflorescences 2-10 cm. long and 
enlarging in fruit, the flowers separate or occasionally in glomerules, female flowers 
sessile or pedicellate, pistil about 0.7 mm. long in early stages of anthesis. Fruiting 
inflorescence becoming as much as 30 cm. long and often with sharp stinging spines 
about 1 mm. long, fruit enclosed in the succulent perianth, drying irregularly, about 
1.5 mm. long, orange when ripe, achene about 1 mm. long and equally broad, lenti- 
cular, glabrous, or slightly pusticulate. 

Plants of evergreen or partly deciduous forest formations between 
sea level and 2500 (72800) m. elevation in Costa Rica; flowering 
throughout the year but collected most often between January and 
July. The species ranges from Mexico to northern South America 
and the West Indies. 

Urera caracasana is recognized by its generally broad laminae 
often cordate at the base and soft-puberulent beneath and the 
bright orange fruit. The members of this species vary less than 
those of the closely related U. elata, but there is sufficient variation 
among these plants so that about 10 per cent of the material seen 
cannot be identified with confidence. The patterns of variation of 
the two species overlap, but it is not possible to say whether the 
plants possessing intermediate characteristics are hybrids or 
whether they are simply unusual individuals of one or the other spe- 
cies. Whoever chooses to revise the neotropical species of this genus 
will encounter some of the most perplexing patterns of variation 
that the neotropical flora has to offer. These plants, like those of U. 
elata, are referred to as ortiga, ortiga blanca, and tabaquillo in Costa 
Rica. 

Urera elata (Sw.) Grisebach, Fl. Brit. W. Ind. 154. 1860. sensu 
lato. Urtica elata Sw., Prodr. 37. 1788. Urera killipiana Standl. & 
Steyerm., Fieldiana: Bot. 24, pt. 3:427-428. 1952. Figure 30. 



BURGER: FLORA COSTARICENSIS 279 

Shrubs, trees or occasionally scandent, 3-8 m. tall, leafy internodes 3-50 mm. long, 
2-5 (7) mm. thick, minutely puberulent with grayish slender hairs 0.1-1 mm. long; 
stipules united and 2-ribbed, 5-14 mm. long, sparsely puberulent with short (0.1- 
0.5 mm.) hairs. Leaves extremely variable in size and shape (often on the same tree), 
petioles 2-10 (22) cm. long, 1-3 mm. thick, minutely puberulent and lacking spines; 
laminae 8-18 (28) cm. long, (3) 4-18 cm. broad, narrowly to broadly ovate, elliptic- 
ovate or narrowly elliptic to slightly obovate, short- to long-acuminate at the apex, 
obtuse to abruptly rounded (rarely subcordate) at the base, entire or with shallow 
(1-3 mm.) serrations with 2 to 4 teeth per cm., lamina drying membranaceous to 
thin-chartaceous smooth or somewhat scabrous above and glabrous or with scat- 
tered short (0.5 mm.) hairs, smooth or slightly scabrous beneath with slender hairs 
0.1-1 mm. long or more often glabrescent, the 4 to 7 pairs of major secondary veins 
arising at angles of 20-60 degrees, cystoliths usually visible above on the older 
leaves, small (0.05-0.1 mm.) and round or longer (0.5 mm.) and narrow and radiat- 
ing outward from small aereoles. Male inflorescences 1-5 cm. long, of 1 to many 
glomerules or the flowers separate on a simple, few-branched, or many-branched 
(paniculate) rachis, the rachis minutely puberulent and often with small (1 mm.) 
stinging spines; male flower about 2 mm. broad before anthesis, sometimes be- 
coming exserted on slender peduncles to 4 mm. long and the pedicels persisting. 
Female inflorescence 2-5 (9) cm. long, usually much branched, minutely puberulent 
and often with a few stinging spines, female flowers about 1 mm. long in early anthe- 
sis, stigma about 0.3 mm. long and equally thick. Fruit enclosed by 2 broad imbri- 
cate and accrescent perianth parts with a minutely verrucose surface, 1-2 mm. long, 
seed about 1 mm. long (? immature), lenticular, and with smooth glabrous surfaces. 

Widespread plants of evergreen or partly deciduous formations 
from near sea level to 2200 m. elevation in Costa Rica and flowering 
throughout the year. The species ranges from Mexico and the West 
Indies to South America (but see below). 

Urera elata is recognized by the bright orange fruit, quite variable 
leaves that are usually narrowed to the base and only sparsely pu- 
berulent beneath, and the small united stipules. Plants differ in the 
presence of stinging hairs on mature parts; often the stinging hairs 
are only found in the female inflorescences. The species, here inter- 
preted in a very wide sense, encompasses a great deal of variation. 
In some collections the narrow radiating cystoliths on the upper 
leaf-surface is correlated with a consistently narrow leaf-form. 
These specimens have often been referred to as U. alceifolia ( Poir. ) 
Gaud., which, according to Killip (1960), is synonymous with U. 
caracasana. The present interpretation and circumscription of U. 
elata is very tentative, and the name may not apply to our material. 
This species was originally described from Jamaican material, and 
C.D. Adams (Flowering Plants of Jamaica 237. 1972) states that the 
species is endemic to Jamaica. He is probably correct (in a strict 
sense), but I prefer continuing to use this old name in a very broad 



280 FIELDIANA: BOTANY, VOLUME 40 

sense until the genus is given intensive monographic study; see the 
discussion under U. caracasana. 

Urera laciniata (Goudot) Weddell, Annal. Sci. Nat. Paris ser. 3, 
18:203. 1852. Urtica lacinata Goudot ex Wedd., loc. cit., as syno- 
nym. Urera girardinioides Seem., Bot. Voy. Herald 194. 1854. 
Figure 30. 

Erect herbs or few branched shrubs or little trees 1-5 m. tall, leafy internodes 0.5- 
10 (20) cm. long, 5-20 mm. thick (dry), hollow, sparsely puberulent with minute (0.1- 
0.4 mm.) slender hairs and with numerous sharp stinging spines 2-9 mm. long; 
stipules apparently paired or partly fused near the base, 5-15 mm. long, sparsely 
puberulent. Leaves quite variable in size on the same plant, petioles 6-30 cm. long, 
2-7 mm. thick, very minutely puberulent and armed with sharp stinging spines; 
laminae 15-40 cm. long, 10-45 cm. broad, broadly ovate or triangular in general 
outline but deeply pinnately lobed with the lobes diminishing in size toward the 
apex, acuminate apically, truncate to cordate at the base, margins of the lobes entire 
or with a few distinct teeth, laminae drying membranaceous to thin-chartaceous, 
upper surface slightly rough to the touch and with a few isolated spines, lower sur- 
face with spines 1-6 mm. long on the major veins and with very minute (0.05-0.2 
mm.) hairs on all the veins, the 4 to 7 pairs of major secondary veins arising at 
angles of 50-80 degrees, cystoliths not apparent or minute on the upper surface. 
Male flowers said to be borne in glomerules (not seen). Female inflorescences 4-20 
cm. long, paniculate and usually much-branched, the female flowers separate or oc- 
casionally clustered in small glomerules, sessile or subsessile, pistil 1-2 mm. long, 
the stigma long (1 mm.) and narrow. Fruit subtended by usually 2 thin bract-like 
perianth parts about 1 mm. long, achene 1.5-2 mm. long, about 1.6 mm. broad, thin 
and lenticular, essentially glabrous, stigma subapical on the fruit and curved. 

An uncommon species of apparently evergreen formations and 
often found along streams and rivers between sea level and 800 m. 
elevation on both the Caribbean and Pacific sides of Costa Rica. 
The species ranges from Costa Rica southward to Venezuela and 
Peru. 

Urera laciniata is easily recognized by its stinging spines, deeply 
lobed leaves with the basal lobes much larger than the distal, and 
few-branched habit. The stinging hairs may explain, in part, the 
scarcity of material in herbaria. 



URTICA Linnaeus 

Annual or perennial herbs with stinging hairs, unisexual or bisexual, stems simple 
or branched; stipules paired and free or united across the stem (interpetiolar). 
Leaves opposite and simple, petiolate, the laminae serrate, dentate, or incised, 
usually thin, punctate cystoliths usually present. Inflorescences bisexual or uni- 



BURGER: FLORA COSTARICENSIS 281 

sexual, the flowers in clusters in subsessile groups, branched panicles, or spikes; 
male flower with 4 perianth-parts, the perianth-parts equal and without appenda- 
ges; female flowers with 2 minute and 2 larger perianth parts, the larger erect and 
opposite, enclosing the pistil, persisting in fruit. Fruit ovate to elliptic in outline, 
compressed laterally and lenticular, enclosed by the larger inner perianth-parts, 
stigma terminal. 

A genus of about 30 species found primarily in temperate regions 
and on high mountains in the tropics. The genus is represented by a 
single species in Costa Rica, but other species have been introduced 
and will continue to be introduced as weeds. However, these have 
apparently not persisted or spread extensively. The stinging hairs 
facilitate recognition of the genus. The common Spanish name 
"ortiga" or "hortiga" is a direct derivative of the Latin urtica. 

Urtica leptophylla H.B.K. Nov. Gen. & Sp. 2:39. 1815. U. nicara- 
guensis Liebm., Danske Vidensk. Selsk. Skrivt. ser. 5, 2:292. 1851. 
U. copeyana Killip in Standl., Field Mus. Hot. 18:398. 1937. Figure 
24. 

Herbs or subshrubs 0.4-1.5 m. tall with stinging hairs on stems, leaves, and in- 
florescences, usually bisexual, erect stems usually with branches, basal stems be- 
coming woody, leafy internodes (1) 2-6 (10) cm. long, 0.7-3 mm. thick, with small 
(0.2 mm.) appressed hairs and sharp translucent stinging hairs 1-2 mm. long; sti- 
pules united across the stem for at least half their length, 2-5 mm. long, 1-3 mm. 
broad, bifurcate apically, sparsely puberulent, persistent. Leaves of the same node 
usually similar in size and shape, petioles 0.5-6 cm. long, 0.3-1.5 mm. thick (dry); 
laminae (1.5) 3-12 cm. long, 1-5 (8) cm. broad, narrowly ovate to triangular, tapering 
gradually to the acute or acuminate apex, usually abruptly narrowed at the trun- 
cate to subcordate base, margin prominently serrate with 2 to 4 teeth per cm., 
laminae drying thin chartaceous and usually dark on both surfaces, with isolated 
stinging hairs above and smaller (0.1-0.5 mm.) hairs on both surfaces, venation sub- 
palmate with a pair of lateral secondary veins from the base, with 2 or 3 pairs of 
major secondary veins from the distal part of the midvein, minute punctate cysto- 
liths present above. Inflorescences usually bisexual, usually paired in the axils of 
leaves throughout the length of the stem, 1-4 cm. long, spicate with flower clusters 
along the length of the unbranched rachis or rarely branched near the base, male 
flowers usually present at the base of the spikes, about 1.5 mm. long before anthesis, 
perianth-parts without appendages; female flowers densely or loosely clustered, the 
2 larger perianth-parts becoming about 1 mm. long. Fruit about 1.2 mm. long and 
1.1 mm. broad, ovate in outline and thick-lenticular, smooth and pale brown, nar- 
rowed slightly below the terminal stigma, loosely enclosed in the persisting peri- 
anth-parts. 

Plants of partly open secondary vegetation in the wet evergreen 
montane forest formations between (500) 2000 and 3200 m. eleva- 
tion in Costa Rica; flowering collections have been made in August 
and from December to March. The species is found in Costa Rica, 
Colombia, and Ecuador. 



282 FIELDIANA: BOTANY, VOLUME 40 

Urtica leptophylla is recognized by the stinging hairs, opposite 
conspicuously serrate leaves, spike-like inflorescences, and unusual 
stipules united ( interpetiolar) for more than half their length and 
often quite broad. This species is closely related to U. magellanica 
Juss. ex Poir., but the latter has larger fruit and ranges no further 
north than Peru. This species resembles U. mexicana Liebm. but 
that species has separate stipules. Despite the name of one of the 
synonyms, this species has never been recorded from Nicaragua; 
the name referred to a small town on Volcan Irazu. 



A SPECIES OF UNCERTAIN POSITION. Figure 24. 

Herbs or subshrubs, erect to 50 cm. tall or scandent, usually with slender roots at 
most nodes, apparently bisexual, leafy internodes ( 1 ) 2-9 cm. long, 0.7-3.5 mm. thick, 
puberulent with short (0.1-1.3 mm.) thin whitish hairs, becoming sparsely puberu- 
lent and dark reddish in color; stipules 5-10 mm. long, 1.5 mm. broad at the base, 
aculeate and persisting, glabrescent. Leaves opposite, isomorphic or differing 
slightly in size or petiole-length at the same node, petioles (2) 4-30 (50) mm. long, 
0.5-1.3 mm. thick, puberulent; laminae 2-11 cm. long, 1-7 cm. broad, ovate, acumi- 
nate at the apex, abruptly narrowed at the obtuse to subtruncate base, coarsely 
serrate with 2 to 6 teeth per cm., laminae drying membranaceous to thin charta- 
ceous and dark in color, becoming slightly rugose in age, sparsely puberulent with 
thin lustrous hairs 0.7-2 mm. long, more densely puberulent with shorter hairs on 
the veins beneath, venation palmate with 3 primary veins, midvein with 2 to 4 pairs 
of prominent secondary veins, minute dark-punctate cystoliths visible above. In- 
florescences fasciculate in the leaf axils, flower clusters about 8 mm. long and usual- 
ly subtended by the 4 persisting stipules; male flowers sessile or pedicellate, peri- 
anth about 2.5 mm. long, including a narrow subapical projection 1-1.5 mm. long, 
filaments about 2 mm. long, anther 1 mm. long; female flowers about 1 mm. long 
with a central longitudinal groove and 2 short stigmas. Fruit sessile in the axils of 
lower leaves, 1-2 mm. long, 2- or 3-angled, stigmas apparently persisting, locules 
usually 2 (3), the fruit very tightly enclosed within the (apparent) perianth-tube. 

Plants of the very wet Caribbean slopes of Central Costa Rica 
between 1000 and 1500 m. elevation; apparently flowering through- 
out the year. This species is known only from the Rio Claro (Rio 
Hondura drainage) below La Palma (Burger et al. 4137, 6270, & 
7651) in the province of San Jose and above Cachi (Lent 1607) in 
Cartago Province. 

This species is recognized by the opposite leaves subtending small 
clusters of flowers, the usually four persisting stipules at each leafy 
node, the 4-parted male flowers with projections on the perianth- 
parts, the 2- or 3-angled fruit tightly enclosed within a perianth- 
tube that is unlobed apically and the presence of usually two 
locules, each with a seed. The latter condition violates a basic char- 



BURGER: FLORA COSTARICENSIS 283 

acter of the Urticaceae: an ovary with a single locule containing a 
single ovule. I believe the present situation may be attributable to 
the growing together of two female flowers. The longitudinal groove 
favors this interpretation. Because the stigmatic areas of these 
flowers are so small, it may be that the fruit develop without pol- 
lination. 

The unusual fruit and opposite leaves make it difficult to place 
these plants. Because they have the four separate stipules and 
sessile clusters of flowers, I believe that these plants are closely 
allied to the genus Boehmeria. 



INDEX 

New taxa and references to illustrations are in bold face. Common 
names and Latin names in synonomy are italicized. 



Acanthinophyllum 110 

Achote de Monte 87 

Aepito 87 

Alchornea costaricensis 213 

Alfaroa29,32,33,36,37 

costaricensis 31, 34, 38, 39, 40 

guanacastensis 33, 36, 40, 41, 42 

guatemalensis 37 

hondurensis 37 

manningii 33, 36, 42, 43, 44 

mexicana 37 

williamsii subsp. tapantiensis 31, 
36, 44, 45 

williamsii subsp. williamsii 45 
Alnus56, 57 

acuminata 57, 58 

arguta 57, 58 

jorullensis 57, 58 
Ampelocera 85, 86 

hottlei 85, 86, 87 
Annona 111 
Anonocarpus 110, 111 
ants, relationship with 175 
Arbolde la cera 22 
Array an 22 
Artocarpus 108, 109 

communis 109 

heterophyllus 110 

incisus 109 

integrifolius 110 



Bara blanca 92 
Bataceae 54, 55 
Batidaceae 54, 55 



Batis54,55 

argillicola 54 

maritima 54, 55 
Batocarpus 97, 110, 111 

costaricensis 97, 111 

orinocensis 111 
Berba 114 

Betulaceae 56, 57, 58 
Bloodwood cacique 118 
Boehmeria 221, 225, 228, 229, 283 

angustifolia 242 

aspera 225, 229, 230 

caudata221,230, 231 

coriaceae 225, 231 

cuspidata 234 

cylindrica224,232 

flagelliformis 230 

guatemalana 273 

nivea221,233 

radiata 225, 233, 234 

ramiflora 225, 234, 235 

ramiflora var. cuspidata 234 

ulmifolia 225, 235 
Bread fruit, Bread-nut 109 
Breadnutll2, 114,215 
Brosimopsi s lactescens 116 
Brosimum97, 112, 113 

alicastrum 97, 113, 114 

alicastrum subsp. alicastrum 97, 1 14 

alicastrum subsp. bolivarense 97, 114 

allenii 118 

bernadetteae 113 

caloxylon 117 

costaricanum 97, 114 

gent lei 113 



285 



286 



FIELDIANA: BOTANY, VOLUME 40 



guianense97, 115, 116 
lactescens 97, 116, 117 
o joe he 116 
panamense 115 
ramonense 204 
rubescens97, 117, 118 
sapi folium 114 
spurium 205 
terrabanum 113 
utile97, 118 
utile subsp. allenii 118 
Bucephalon racemosum 214 



Cagalera 88 
Campano chile 39 
Cannabaceae216, 217 
Cannabinaceae 216 
Cannabis216, 217 

sativa216, 217 
Capaslan 92 
Capulin bianco 92 
Carpinus 56 
Carya 29 
Casearia 11 
Castanea saliva 59 
Castano 59 
Castilla98, 119,120 

costaricana 120 

elastica98, 120,121 

elastica subsp. costaricana 121 

elastica subsp. elastica 121 

fallax 121 

nicoyensis 120 

tunu98, 121 
Castilloa, see Castilla 
Cecropia, 105, 122, 123 

arachnoidea 126 

asperrima 126 

eximia 124 

humboldtiana 125 

insignis 105, 124 

maxonii 126 

mexicana 125 

mexicana var. macrostachya 125 

obtusifolia 105, 125 

palmatisecta 128 

panamensis 125 
peltata 105, 126 
pittieri 127 



polyphlebia 105, 127, 128 

sandersoniana 124 

standleyana 124 
Celtis 85, 87 

hot t lei 86 

iguanaea 85, 87 

schippii 85, 88, 89 
Ceniza, Cenizo 93 
Chaetoptelea 92 

mexicana 92 
Chloranthaceae 1-10 
Chlorophora 96, 128, 129 

scandens 95 

tinctoria 96, 129 
Clarisia 96, 130 

biflora96, 130,131 

mollis 96, 209 

panamensis 130 

urophylla 214 
Concha de India 193 
Conocephaloideae 95, 104, 105, 123, 

132 

Contrahierba 139 
Contrayerba 139 
Cornaceae 18 
Coussapoa 104, 131, 132 

brenesii 136 

chagresiana 134 

contorta 104, 132, 133 

donnell-smithii 135 

glaberrima 104, 133 

magnifolia 135, 136 

nymphaeifolia 104, 134 

panamensis 104, 135 

parviceps 104, 136 

Discocnide 219 

Dorstenia 99, 137 
choconiana 99, 137, 138 
choconiana var. integn folia 137 
contrajerva 99, 138, 139 
contrajerva, subsp. tenuiloba 138 
contrajerva, var. houstoni 138 
cordato-acuminato 137 
drakena 99, 139, 140 
houstoni 138 
mexicana 139 

Enema 59-6 1,62, 63 



BURGER: FLORA COSTARICENSIS 



287 



Encinillo 27 

Engelhardia 47 
mexicana 47 
nicaraguensis 48 
roxburghiana 49 

Engelhardtia46,47 
pterocarpa 50 

Erythrobalanus 61, 62 



Fagaceae 59, 60, 61,62, 63 
Ficus 99-103, 140-148 

aurea 165 

benjamina 148 

brenesii 162 

brevibracteata 99, 148 

bulleneilOl, 149 

caldasiana 99, 150 

carica 151 

cervantesiana 100, 151, 152 

citrifolia 100, 152, 153 

colubrinae 102, 153 

costaricana 101, 154 

cotinifolia 101, 155 

crassiuscula 103, 156 

crassivenosa 103, 157 

cuatrecasana 99, 158 

davidsoniae 102, 159 

donnell-smithii 100, 159, 160 

dugandiilOO, 160, 161 

duquei 171 

elastica 161 

eugeniae folia 175 

georgii 175 

g la brat a 163 

goldmaniilOl, 161, 162 

hartwegii 100, 162, 163 

hemsleyana 162 

hondurensis 155 

inamoena 155 

insipida 103, 163, 164 

involute 172 

isophlebia 102, 165 

jimenezii 102, 166 

kellermanii 155 

lapathifolia 169, 170 

laterisyce 102, 166, 167 

lyrata 168 

macbridei 103, 168, 169 

maxima 103, 169, 170 



meistosyce 179 

morazaniana 101, 170, 171 

multinervis 186 

nitida 178 

nymphaeifolia 102, 171, 172 

obtusifolia 102, 172, 173 

oerstediana 175 

ovalislOl, 173,174 

padi folia 176 

palmata 174 

panamensis 174 

pandurata 168 

paraensis 100, 174, 175 

perez-arbelaezii 171 

perforata 100, 175, 176 

pertusa 100, 176, 177 

popenoi!01,177, 178 

proctor-cooperi 172 

pumila 178 

radula 169 

religiosa 178 

retusa 178 

richteri 158 

sanguinosa 171 

schippii 100, 179 

subgenus Pharmacosycea 103, 141 

subgenus Urostigma 99-102, 142 

tequendamae 184 

tolimensis 177 

tonduzii 103, 180 

torresiana 168 

trachelosyce 100, 180-181 

trigonatalOl, 181, 182 

tuerckheimii 102, 182, 183 

turbinata 160 

turrialbanalOl, 183 

velutinalOl, 184, 185 

verrucosa 161, 162 

werckleana 103, 185, 186 

yoponensis 103, 186, 187 
Flacourtiaceae 1 1 
Fleurya 236 

aestuans 236 
Fustic 129 



Galactodendrum utile 118 
Garrya 18, 19 

fadyeni 18 

laurifolia 19, 20 



288 



FIELDIANA: BOTANY, VOLUME 40 



Garryaceae 18, 19, 20 

Gavilan bianco 50 

Gavilan Colorado 43 

Goalin 39 

Gsi-Kra 119 

Gualin 39 

Guarumo 123 

Guarumo de montafta 202 

Guarumo macho 202 

Gyrotaenia microcarpa 219 

Hamamelidaceae 56 
Hedyosmum 1, 2, 3 

arborescens 7 

brenesii 3, 4 

calloso-serratum 3, 4, 5, 8, 9 

costaricense 3, 5, 6 

mexicanum 1, 2, 3, 7 

montanum 3, 7, 8, 9 

nutans 4 

scaberrimum 3, 9, 10 

scabrum 7 
Helicostylis 98, 187,188 

montana 114 

ojoche 113 

pedunculata 188 

tomentosa 188 

tovarensis98, 188, 189 

urophylla 188 
Hemistylis219 
Hiedra 178 
Hi go 151 

Higueron de Kabul 174 
Hule 119 
Humulus216, 217 

Iupulus216, 217 

Jack, Jackfruit 110 
Jaul 58 



Juglandaceae 28-53 
Juglans 29 
boliviano 30 



Lacistema 11, 12, 13 
aggregatum 12, 13 

Lacistemaceae 11, 12, 13 

Laportea 226, 236 
aestuana 226, 236, 237 



Laurel de la India 178, 179 
Lechosa 208, 209 
Lepidobalanus 61 
Leucococcus occidentalis 274 
Lozanella84,89 

enantiophylla 84, 89, 90 

trematoides 89 
Lozania 11, 12, 13 

montana 13 

mutisiana 11, 12, 13 

pedicellata 11 

pittieri 11, 12, 13 



Macano 129 
Madura 95, 129 

brasiliensis 95 
Maquira 98, 189 

costaricana 98, 189, 190 
Majao de India 193 
Malayan banyan 178-179 
Manteca 87 

Margarocarpus obliquus 273 
Medicinal value 164 
Mora, 129 
Mora de espina 129 
Moraceae 94, 95, 96-105 
Morillo brasil 129 
Morus96, 190, 191 

alba 191 

celtidifolia 191 

insignis96, 191-192 

tinctoria 129 
Musanga 123 
Myrica21,22,23 

arguta 26 

cerifera 22, 23, 24, 25 

lindeniana 25 

mexicana 22 

phanerodonta 23, 25, 26 

p ring lei 25 

pubescens 23, 26, 27 

xalapensis 22 
Myricaceae21.22,23 
Myriocarpa 227, 237, 238 

cordifolia 227, 238 

inaequilateris 239 

longipes 227, 239 

longipes, var. yzabalensis 239 

yzabalensis 239 



BURGER: FLORA COSTARICENSIS 



289 



Naucleopsis98, 192, 193 
naga 98, 193 



Ogcodeia naga 193 
Ojeche, Ojoche 112, 114 
Ojochillo Colorado 214-215 
Olmedia 98, 194 

angustifolia 196 

armata 199 

aspera98, 194,195 

falci folia 194 

tovarensis 188 
Oreomunnea 29, 32, 35, 46, 47 

mexicana 47 

mexicana subsp. costaricensis 34, 
35, 48, 49 

mexicana subsp. mexicana 35, 49 

pterocarpa 35, 36, 50, 51 
Ortiga, Ortiga blanca 278 
Ostrya 56 



Pacica 202 
Palo de pan 109 
Parietaria 226, 240 

debilis226, 240, 241 

microphylla 264 

sonneratii 245 
Perebea98, 195, 196 

angustifolia 98, 196, 197 

castilloides 197 

costaricana 189 

guianensis98, 197, 198 

guianensis subsp. castilloides 198 

hispidula 198 

molliflora 198 

trophophylla 189 

xanthochyma 98, 198 
Pharmacosycea 103, 141 
Phenax 226, 241,242 

angustifolius 226, 242 

hirtus 226, 243 

mexicanus 226, 243, 244 

rugosus 226, 244,245 

sonneratii 226, 245 

vulgaris 245 
Picrodendraceae 30 
Pilea 222-224, 246-250 

acuminata 223, 250 



angustifolia 223, 251 

auriculata 224, 251, 252 

beguinotti223,252,253 

cadierei 247 

centradenioides 253 

chiriquina 222, 253, 254 

cormanae251 

cornuto-cucullata 224, 254, 255 

costaricensis 222, 255, 256 

daucidora 224, 256, 257 

deltoidea 261 

diversissima 222, 257, 258 

donnell-smithiana222, 258-259 

ecbolophylla 256, 258 

fallax 255 

gomeziana 223, 259, 260 

gracilipes 224, 260, 261 

herniariodes 224, 261, 262 

hyalina224, 262 

imparifolia 222, 262, 263 

involucrata263,264 

irrorata 269 

microphylla 222, 264 

myriantha 253 

nummularifolia 224, 265 

pallida 223, 265, 266 

pansamalana 258, 272 

parietaria 224, 266, 267 

phenacoides 267 

pittieri 223, 267 

portula 264 

ptericlada 223, 268 

pubescens224,269 

purulensis 259 

quichensis 223, 270 

riparia 258 

rugosissima 224, 270, 271 

standleyi 260 

tilarana222, 271 
Piratinera guianensis 115 

panamensis 115 
Platycarya 29 
Populus 14, 15 

alba 15 
Poulsenia 97, 199 

armata 97, 199 
Pourouma 104, 200, 201 

aspera!04,201,202 

johnstonii 201 

minor 104,202,203 



290 



FIELDIANA: BOTANY, VOLUME 40 



scobina 201 

umbellifera 202 
Pouzolzia 225, 272, 273 

guatemalana 225, 273 

obliqua 225, 273,274 

occidentalis 225, 274, 275 

phenacoides 225, 275 
Procris rugosa 244 
Pseudojaca 108 
Pseudomedia 98, 203, 204 

malacocarpa 204 

mollis 204 

oxyphyllaria 98, 204 

simiarum 204 

spuria 98, 205 
Pterocarya 29 



Quercus59,6061,62,63 
aaata 67, 68 
anglohondurensis 66 
baruensis 76 
benthamii 77 
boquetensis 77 
borucasana 77 
brenesii63, 65, 66 
bumelioides 11 
citrifolia 77, 79 
conspersa 66 
copeyensis 62, 67 
corrugata62,68, 69 
costaricensis 63, 69, 70 
costaricensis, f. kuntzei 67 
davidsoniae 73 
endresi 69 
eugeniaefolia 11 
eugeniaefolia f . petiolata 11 
gracilior 66 
granulata 11 

gulielmi-treleasei 63, 70, 71 
insignis 62, 71,72 
irazuensis 69 
oleoides62,73, 74 
oleoides var,australis 73 
oocarpa62, 74,75 
panamandinea 61, 77, 79 
pilarius 62, 75, 76 
pilgeriana 68 
rapurahuensis 63, 76, 77 



retusa 73, 74 
sapotaefolia 11, 79 
schippi 72 
seemannii63, 77, 78 
seibertii 72 
skinneri 66 

subgenus Erythrobalanus 61, 63 
subgenus Quercus 61, 62 
tenuiaristata 66 
tomentocaulis 75 
tonduzii 63, 79,80 
trichodonta 66 
wesmaeli 79 
Quiri 119 



Rabo de goto 231 
Rademachia incisa 109 
Ramon 112, 114,214 
Ramoon 214 
Rhamnus iguaneus 87 

micranthus 91 
Rhoipteleaceae 30 
tfoft/e 59-6 1,62, 63 
Rousselia 219 
Rubber 119 
Rutales 30 



Sahagunia urophylla 214 
Salicaceae 14, 15, 16 
Salix 15, 16 

babylonica 17 

chilensis 17 

humboldtiana 15, 16 
Sapindales 32 
Sarcandra 1 
Seru 119 
Skutchia213 

caudata 212 
Soro 119 
Sorocea 96, 206, 207 

affinis 96, 207 

cufodonti 208 

cufodontisii 96, 208, 209 

mexicana 212 

pubivena 96, 209 

trophoides 96, 210 
species of uncertain position 221, 

282, 283 



BURGER: FLORA COSTARICENSIS 



291 



Tabaaquillo 278 
Tinajita 181 
Trema84,90,91 

enantiophylla 89 

micrantha84, 91 
Trophis96, 211 

chiapensis 212 

involucrata 96, 211, 212 

macrostachya 209 

mexicana 96, 212,213 

racemosa 96, 214 

ramon 214 
Tsini 119 



Ule 119 

Ulmaceae83,84,85 

Ulmus84,92 

mexicana 84, 92,93 
Urera 227, 276 

alceifolia 279 

baccifera 227, 277 

caracasana 227, 277, 278 

elata 227, 278, 279 

girardinioid.es 280 

killipiana 278 

Iaciniata227,280 
Urostigma99-102, 142 

costaricanum 154 

eugeniaefolium 175 



intramarginale 136, 184 

involutum 172 

paraensis 174 

oerstedianum 175 

ovale 173 

verrucosum 161 
Urtica221,280, 281 
aestuans 236 
baccifera 277 
caracasana 277 
copeyana 281 
cylindrica 232 
daucidora 256 
e/ata 278 

grandidentata 277 
herniarioides 261 
fo'rta 243 
involucrata 263 
laciniata 280 
Ieptophylla221,281,282 
magellanica 282 
mexicana 282 
nicaraguensis 282 
muea 233 

nummularifolia 265 
parietaria 266 
verrucosa 277 
Urticaceae 218-220, 221-227, 282-283 

Fa/; a/ 202 



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



1 Cycadaceae 

2 Taxaceae 

3 Podocarpaceae 

4 Araucanaceae 

5 Pinaceae 

6 Cupressaceae 

7 Gnetaceae 

8 Typhaceae 

9 Potamogetonaceae 

10 Najadaceae 

11 Alismataceae 

12 Butomaceae 

13 Hydrpcharitaceae 

14 Triuridaceae 

15 Gramineae 

16 Cyperaceae 

17 Palmae 

18 Cyclanthaceae 

19 Araceae 
Lemnaceae 
Mayacaceae 
Xyridaceae 
Eriocaulaceae 
Bromeliaceae 
Commelinaceae 
Pontederiaceae 
Juncaceae 
Liliaceae 
Haemodoraceae 
Amaryllidaceae 
Velloziaceae 
Dioscoreaceae 
Iridaceae 

_ . Musaceae 

35 Zingiberaceae 

36 Cannaceae 

37 Marantaceae 
Burmanniaceae 
Orchidaceae 
Casuarinaceae 
Piperaceae 
Chloranthaceae 
Lacistemaceae 
Salicaceae 
Garryaceae 
Myricaceae 

47 Juglandaceae 

48 Batidaceae 

49 Betulaceae 
Fagaceae 
Ulmaceae 
Moraceae 
Urticaceae 
Podoatemonaceae 
Proteaceae 

. Olacaceae 

67 Opiliaceae 

68 Loranthaceae 

69 Aristolpchiaceae 

60 Rafflesiaceae 

61 Balanophoraceae 

62 Polygonaceae 

63 Chenopodiaceae 

64 Amaranthaceae 
66 Nyctaginaceae 

66 Phytolaccaceae 

67 Aizoaceae 

68 Portulacaceae 

69 Basetlaceae 

70 Caryophyllaceae 

71 Nympnaeaceae 

72 Ceratophyllaceae 

73 Ranunculaceae 

74 Berberidaceae 

75 Menispermaceae 

76 Magnoliaceae 

77 Anonaceae 

78 Myristicaceae 



79 


Monimiaceae 


154 


Cactaceae 


80 


Lauraceae 


155 


Thymelaeaceae 


81 


Hernandiaceae 


156 


Elaeagnaceae 


82 


Papaveraceae, 
incl. Fumariaceae 


157 
158 


Lythraceae 
Punicaceae 


83 


Capparidaceae 


159 


Lecythidaceae 


84 


Cruciferae 


160 


Rhizophoraceae 


85 


Tovariaceae 


161 


Combretaceae 


86 


Resedaceae 


162 


Myrtaceae 


87 


Moringaceae 


163 


Melastomataceae 


88 


Droseraceae 


164 


Onagraceae 


89 


Crassulaceae 


165 


Halorrhagaceae 


90 


Saxifragaceae 


166 


Araliaceae 


91 


Brunelliaceae 


167 


Umbelliferae 


92 


Cunoniaceae 


168 


Cornaceae 


93 


Hamamelidaceae 


169 


Clethraceae 


94 


Rosaceae 


170 


Monotropaceae 


95 


Connaraceae 


171 


Pyrolaceae 


96 


Leguminosae 


172 


Ericaceae 


97 
98 


Krameriaceae 
Oxalidaceae 


173 
174 


Theophrastaceae 
Myrsmaceae 


99 


Geraniaceae 


175 


Primulaceae 


100 


Tropaeolaceae 


176 


Plumbaginaceae 


101 


Linaceae, 


177 


Sapotaceae 




incl. Humiriaceae 


178 


Ebenaceae 


102 


Erythroxylaceae 


179 


Symplocaceae 


103 


Zygophyllaceae 


180 


Styracaceae 


104 


Rutaceae 


181 


Oleaceae 


105 


Simarubaceae 


182 


Loganiaceae 


106 


Burseraceac 


183 


Gentianaceae 


107 


Meliaceae 


184 


Apocynaceae 


108 


Malpighiaceae 


185 


Asclepiadaceae 


109 


Trigoniaceae 


186 


Convolvulaceae 


110 


Vochysiaceae 


187 


Polemoniaceae 


111 


Poiygalaceae 


188 


Hydrophyllaceae 


112 


Dichapetalaceae 


189 


Boraginaceae 


113 


Euphorbiaceae 


190 


Verbenaceae 


114 


Callitrichaceae 


191 


Labiatae 


115 


Buxaceae 


192 


Solanaceae 


116 


Coriariaceae 


193 


Scrophulariaceae 


117 


Anacardiaceae 


194 


Bignoniaceae 


118 


Cyrillaceae 


195 


Pedaliaceae 


119 


Aquifoliaceae 


196 


Martyniaceae 


120 


Celastraceae 


197 


Orobanchaceae 


121 
122 


Hippocrateaceae 
Staphyleaceae 


198 
199 


Gesneriaceae 
Lentibulariaceae 


123 


Icacinaceae 


200 


Acanthaceae 


124 
125 


Hippocastanaceae 
Sapindaceae 


201 
202 


Plantaginaceae 
Rubiaceae 


126 


Sabiaceae 


203 


Caprifoliaceae 


127 


Balsaminaceae 


204 


Valerianaceae 


128 


Rhamnaceae 


205 


Dipsacaceae 


129 


Vitaceae 


206 


Cucurbitaceae 


130 


Elaeocarpaceae 


207 


Campanulaceae 


131 


Tiliaceae 


208 


Compositae 


132 


Malvaceae 






133 


Bombacaceae 






134 


Stereuliaceae 






135 


Dilleniaceae 






136 


Actinidiaceae 






137 


Ochnaceae 






138 


Caryocaraceae 






139 


Marcgraviaceae 






140 


Quiinaceae 






141 


Theaceae 






142 


Guttiferae 








incl. Hypericaceae 






143 


Elatinaceae 






144 


Cistaceae 






145 


Bixaceae 






146 


Cochlospermaceae 






147 


Violaceae 






148 


Flacourtiaceae 






149 


Turneraceae 






150 


Passifloraceae 






151 


Caricaceae 






152 


Loasaceae 






153 


Begoniaceae 







Publication 1270 



UNIVERSITY OF ILLINOIS URBANA