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William Burger, Editor 


#97 Krameriaceae 
#98 Oxalidaceae 
#99 Geraniaceae 
#100 Tropaeolaceae 
#101 Linaceae 
#10 la Humiriaceae 
#102 Erythroxylaceae 
#103 Zygophyllaceae 

October 31, 1991 
Publication 1428 


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William Burger, Editor 


Department of Botany 

Field Museum of Natural History 

Chicago, Illinois 60605-2496 

Family #97 Krameriaceae 

William Burger and Beryl B. Simpson 

Family #98 Oxalidaceae 

William Burger 

Family #99 Geraniaceae 

William Burger 

Family #100 Tropaeolaceae 

William Burger 

Accepted March 20, 1991 
Published October 31, 1991 
Publication 1428 

Family #101 Linaceae 

William Burger 

Family #101a Humiriaceae 

William Burger and Nelson Zamora 

Family #102 Erythroxylaceae 

Timothy Plowmanf 

Family #103 Zgyophyllaceae 

William Burger 

JAN 2 7 1992 


1 99 1 Field Museum of Natural History 
Library of Congress Catalog Card Number: 91-75909 

ISSN 00 15-0746 

Table of Contents 

List of Illustrations 



KRAMERIACEAE by William Burger and 

Beryl B. Simpson 1 

OXALIDACEAE by William Burger 2 

GERANIACEAE by William Burger 16 

TROPAEOLACEAE by William Burger 21 

LINACEAE by William Burger 23 

HUMIRIACEAE by William Burger and 

Nelson Zamora 25 

ERYTHROXYLACEAE by Timothy Plowman . . 30 

ZYGOPHYLLACEAE by William Burger 36 


INDEX . 42 

1 . Krameriaceae: two species of Kramer ia . . 3 

2. Oxalidaceae: two species of Biophytum . . 7 

3. Oxalidaceae: four smaller species of 

Oxalis 10 

4. Oxalidaceae: four larger species of 

Oxalis 13 

5. Geraniaceae: two species of Geranium ... 19 

6. Humiriaceae: four Costa Rican species . . 27 

7. Erythroxylaceae: Erythroxylum hava- 

nense 34 

8. Zygophyllaceae: four Central American 
species 38 



This is the seventh issue in the Flora Costari- 
censis series. The first dealt with families num- 
bered 40 and 41, Casuarinaceae and Piperaceae 
(Fieldiana, Bot. 35, 1971). The second included 
families 42 through 53, Chloranthaceae through 
Urticaceae (Fieldiana, Bot. 40, 1977). The third 
issue covered family 15, the Gramineae, authored 
by Richard Pohl (Fieldiana, Bot., new series, No. 
4, 1980). The fourth issue included families 54 
through 70, Podostemonaceae through Cary- 
ophyllaceae (Fieldiana, Bot., new series, No. 13, 
1983). The fifth issue covered families 200 and 
201, the Acanthaceae, authored by L. H. Durkee, 
and Plantaginaceae (Fieldiana, Bot., new series, 
No. 18, 1986). The sixth issue covered families 80 
and 8 1 , the Lauraceae and Hernandiaceae (Field- 
iana, Bot., new series, No. 23, 1990). The alpha- 
betical listing and the sequence of families are giv- 
en inside the front and back covers. 

This issue includes the Geraniales and the fam- 
ilies traditionally associated with them in the En- 
gler sequence. Several recent collections repre- 
senting new species for Costa Rica's flora are 
included here. However, the most important con- 
tribution in these pages is that for the Erythrox- 
ylaceae. Timothy Plowman's untimely death cut 
short his monographic work in Erythroxylum, but 
he was able to complete a number of floristic treat- 
ments, and we have the benefit of his insights in 
these works. We were fortunate to have so gifted, 
friendly, and conscientious a botanist on our staff 

at the Field Museum, and we greatly mourn his 


Beginning in 1961, fieldwork in Central Amer- 
ica by Field Museum staff and their associates in 
Honduras and Costa Rica was supported in part 
by grants from the National Science Foundation. 
The most recent of those grants was DEB-8 1 03 1 84. 
Collections made with this support together with 
many other herbarium holdings provide the basis 
for much of our descriptive and geographic infor- 

The staff and facilities of the Natural History 
section of the Museo Nacional de Costa Rica have 
been a primary resource for this project and have 
been most helpful in carrying out field programs 
for more than two decades. Recent work by col- 
lectors associated with the Museo Nacional, Duke 
University, and the Missouri Botanical Garden 
have greatly expanded our knowledge of Costa 
Rica's rich flora. Pablo Sanchez, Jorge Gomez- 
Laurito, Nelson Zamora, Barry Hammel, and 
Beryl Simpson have been especially helpful in pro- 
viding information regarding the families included 
in this issue of the Rora. An anonymous reviewer 
made many helpful suggestions. Sadly, the pub- 
lication of this group of families was initiated by 
Timothy Plowman's contribution of the Erythrox- 
ylaceae during the last year of his life. 

Family #97 Krameriaceae 
Family #98 Oxalidaceae 
Family #99 Geraniaceae 
Family #100 Tropaeolaceae 
Family #101 Linaceae 
Family #101a Humiriaceae 
Family #102 Erythroxylaceae 
Family #103 Zygophyllaceae 


By William Burger and Beryl B. Simpson 

REFERENCE B. B. Simpson, Krameriaceae. 
Flora Neotropica Monogr. 49: 1-108. 1989. 

Perennial herbs, shrubs, or rarely small trees, usually 
vestitured with single-celled hairs, hemiparasitic on the 
roots of other plants; stipules absent. Leaves alternate or 
fasciculate, simple in Central America (rarely trifolio- 
late), petiolate or sessile, the leaf blades with entire mar- 
gins. Inflorescences of single axillary flowers, terminal 
racemes (by condensation of internodes and loss of leaves) 
or open panicles, peduncles with 2 opposite foliaceous 
bracts, pedicels variable. Flowers bisexual, bilaterally 
symmetrical (zygomorphic), hypogynous, colorful parts 
pink, rose, or purple, rarely reddish brown to yellow, 
imbricate, deciduous, sepals (4-)5, free and petaloid, 
showy, unequal with the 3 outer usually larger than the 
inner sepals and the petals; petals (4-)5, unequal and 
dimorphic, small, the 3 upper (adaxial) long-clawed, 
united near the base in some species, the petal-laminae 
small or absent, the 2 lower (abaxial) petals smaller, 
thick, sessile, laterally flanking the ovary, glandular on 
the dorsal surfaces (and called elaiophores); stamens 
(3-)4, usually alternating with the 3 upper petals and 
angled downward and outward, filaments thick, free or 
united near the base or adnate to the bases of the adaxial 
petals, anthers basifixed, dehiscing near the apex by 
membranous pores, pollen 3-porate (3-colporate), the 
pores often expanded equatorially; pistil 1 , of 2 united 
carpels with one developing and the other vestigial, ova- 
ry with 1 locule with 2 pendulous ovules from an axial 
placenta near the top of the locule, style obliquely ter- 
minal, stigma simple. Fruit 1 -seeded, dry and indehis- 

cent, usually covered with spines, the spines often with 
retrorse barbs; seeds globose with a smooth seed coat, 
with a straight embryo and 2 thick cotyledons, endo- 
sperm absent. 

A monogeneric New World family with 1 7 spe- 
cies ranging from the southwestern United States 
(with disjunct populations in Florida and Geor- 
gia), Mexico, and the West Indies southward to 
northern Chile and Argentina. Major centers of 
species diversity are in northern Mexico and cen- 
tral and eastern Brazil. All the species are found 
on sandy or rocky soils in arid or seasonally dry 
climates. The family is not now of commercial 
importance, but the roots have been used medic- 
inally and as a source of yellow and reddish brown 
dyes. TJie Krameriaceae were once thought to be 
closely related to the Leguminosae, but a relation- 
ship with the Polygalales is more likely. 

Krameria Loefling 

With the characters of the family (see above). The 
genus is quite distinctive because of its zygomorphic 
flowers, the unique configuration of calyx and corolla, 
and its unusual fruit. The flowers are usually held erect 
with the longitudinal plane of the open perianth vertical, 
somewhat like those of Senna or Cassia (Leguminosae). 
This orientation and the unusual morphology of the 
flowers are part of an interesting pollination syndrome 
in which the lower petals secrete lipids that are collected 
by female Centris bees. The flora parts were misinter- 
preted in the past; see the article by B. B. Simpson (1982) 
and the monograph cited above. 

Key to the Species of Krameria 

1 a. Leaves with distinct petioles, leaf blades narrowly elliptic to lanceolate and gradually narrowed at 
the base; flowers pinkish fading to white K. ixine 

Ib. Leaves sessile or subsessile, leaf blades linear to linear-lanceolate, abruptly narrowed at the base; 
flowers yellow and dusky rose K. revoluta 

FIELDIANA: BOTANY, N.S., NO. 28, OCTOBER 31, 1991, PP. 1-43 

Krameria ixine Loefl., Iter hispan. 195. 1758. K. 
cuspidata K. Presl, Reliq. haenk. 2: 103. 1835. 
Figure 1. 

Small shrubs, erect to 1(-1.5) m tall, often many 
branched and to 1 m broad, internodes l-15(-25) mm 
long, leafy stems l-3(-4) mm thick, densely strigillose 
with thin whitish or grayish hairs 0.2-0.8 mm long. Leaves 
simple, petioles 3-7(-9) mm long, merging gradually with 
the decurrent lamina-base, strigillose; leaf blades 8-20 
(-33) mm long, 3-8 mm broad, narrowly oblong or nar- 
rowly elliptic to narrowly obovate or lanceolate, acute 
with a spinose tip 0.5-1.5 mm long, acute at the base 
and decurrent on the petiole, obscurely palmately 
3-veined, densely strigillose. Inflorescence in lateral or 
terminal racemes, peduncles usually shorter than the 
subtending leaves, with a pair of opposite bracts in the 
middle, densely strigillose. Flowers ca. 8 mm long and 
1 2 mm broad when dry, perianth rose-pink to deep red, 
magenta or reddish brown, turning white with age, sepals 
4-10 mm long, broadly oblong, densely whitish sericeous 
on the outer surfaces; upper petals united in the lower 
half; stamens didynamous with anthers ca. 1 mm long. 
Fruit globose, body of the fruit 4-7 mm in diameter, 
covered with short ( 1 mm) whitish hairs and longer (1.6- 
4.6 mm) orange or reddish spines with thin retrorse bar- 
bules distally. 

Plants of seasonally deciduous vegetation along 
the Pacific slope of Mexico and Central America. 
Growing from near sea level to 400 m elevation 
in Costa Rica (to 1000 m in Honduras and 1500 
m in Guatemala). Flowers and fruits have been 
collected during the wet season in Costa Rica (late 
May to December). This species ranges from west- 
ern Mexico (Sonora) to northwestern Costa Rica, 
through most of the Greater and Lesser Antilles, 
and into South America in northeastern Colom- 
bia, northern Venezuela, and eastern Guyana. 

Krameria ixine is recognized by its short shrub- 
by habit, grayish puberulence, small, petiolate, 
narrowly elliptic and spine-tipped leaves, unusual 
pink flowers with the sepals turning white with 
age, and distinctive rounded fruits with dense 
whitish hairs and longer barbed spines. The spe- 
cies is known only from northern Guanacaste 
Province in Costa Rica, where it ranges over a 
wider area than its congener, K. revoluta. 

Krameria revoluta Berg, Bot. Zeitung (Berlin) 14: 
751. 1856. Figure 1. 

Small shrubs or herbs with woody bases, to 50 cm tall, 
with many branches, woody stems 2-5 mm thick, dark 
gray to blackish and glabrescent, with longitudinal fis- 
sures or smooth, leafy internodes l-4(-8) mm long, 0.6- 
2 mm thick, grayish white with appressed ascending 
strigulose hairs 0.9-1.5 mm long. Leaves alternate, pale 

grayish or grayish white, sessile or subsessile (petioles 
less than 2 mm long if present); leaf blades 6-22 mm 
long, 1 .2-2.8(-3.5) mm broad, linear to linear-lanceolate 
(narrowly lanceolate), tapering gradually to the acute apex, 
with a small gland I i kc tip or spine that dries dark, abrupt- 
ly narrowed at the base, margins usually revolute when 
dried, covered with white or pale grayish appressed-as- 
cending strigose hairs ca. 0.5 mm long. Inflorescences 
terminal racemes (but flowers may appear to be solitary 
in distal leaf axis in early stages because of the leaflike 
bracts), flowers borne on slender strigulose peduncles 4- 
1 2 mm long, usually with 2 opposite leaflike linear bracts 
in the middle, larger outer sepals 5-9 mm long and ca. 
3 mm broad, appressed whitish sericeous on the outside, 
petaloid (upper) petals ca. 6 mm long and 2.5 mm broad, 
basally connate for 3.44 mm, blades yellow or dull red 
to brownish red, glandular petals orbicular, 2-3 mm in 
diameter; stamens ca. 4 mm long. Fruits 4-6 mm in 
diameter (to 1 1 mm measuring the spines), globose to 
ovoid, covered by short dense whitish hairs and slender 
red and yellow spines to 3.5 mm long, spines with re- 
trorse barbs. 

Plants of seasonally very dry deciduous forest 
and shrub communities, from 50 to 250 m ele- 
vation in Costa Rica (to 1400 m elsewhere). Flow- 
ers and fruits have been collected in September 
and October in Costa Rica. The species flowers 
from July through December elsewhere. The spe- 
cies ranges along the Pacific side of middle Amer- 
ica, from southern Mexico to northwesternmost 
Costa Rica. 

Krameria revoluta is recognized by its almost 
linear alternate leaves covered with whitish hairs, 
unusual yellow and dusky rose flowers, puberulent 
fruit with barbate spines, and restriction to very 
dry habitats. In Costa Rica the species is known 
only from two collections made in Santa Rosa 
National Park, Guanacaste (Salas & Poveda s.n. 
[1974] CR, Callaway 485 CR). 


By William Burger 

REFERENCE Alicia Lourteig, Oxalidaceae, in R. 
E. Woodson, R. W. Schery et al., Flora of Panama, 
Ann. Missouri Bot. Gard. 67: 823-850. 1980. 

Herbs, rarely shrubs or small trees; stipules present 
and adnate to the petiole or absent. Leaves alternate, 
subopposite or closely clustered (sometimes all basal), 
pinnately or palmately compound, often (in Oxalis) tri- 
foliolate, rarely unifoliolate, often folding up at night, 
petiolate, the leaf blades usually entire. Inflorescences 
axillary or cauliflorous, usually cymes, sometimes in 
compound racemiform or umbelliform panicles, some- 


Krameria ixine 

2 mm 

5 mm 

Krameria revoluta 

FIG. 1 . Krameriaceae: two species of Krameria. 


times densely clustered or reduced to solitary flowers. 
Flowers bisexual, radially symmetrical (plant rarely with 
apetalous and minute cleistogamous flowers), hypogy- 
nous, often with trimorphic heterostyly, sepals 5, united 
only near the base, imbricate (valvate), persisting in fruit; 
petals 5, free or connate near the middle, contorted or 
imbricate in bud, narrowed at the base (clawed), nectar 
glands often present between petals and stamens and 
alternating with the petals; stamens basically 10 in 2 
whorls of 5 ( 1 5 in Hypseocharis), the outer stamens usu- 
ally shorter and opposite the petals, all the stamens func- 
tional or 2-5 not bearing anthers and staminodial, fila- 
ments slender and united in the lower half or only at the 
base, anthers ovoid, versatile, 2-thecous, dehiscing lon- 
gitudinally and introrse; pistil 1, (3-)5-carpellate, ovary 
(3-)5-locular and lobed, each locule with (l-)2-l 5 ovules 
pendulous from axile placentae, styles 5 and free (1 in 
Hypseocharis), persisting, stigmas bifid or bicapitate. Fruit 
a 5-lobed capsule (rarely a berry), usually 5-locular, calyx 
and style persisting, dehiscence loculicidal, seeds often 
ejected by a basal aril (the elastic outer integument); seed 

with fleshy endosperm (rarely endosperm absent), em- 
bryo straight. 

A family of six genera and about 950 species 
found throughout the world in cold climates and 
warm. The largest genus of the family is Oxalis, 
with over 800 species worldwide. Averrhoa is 
widely planted in the tropics for its fruit, and 
Biophytum is pantropical. Hypseocharis is endem- 
ic to the tropical Andes, but Boesewinkel has re- 
cently suggested this genus be transferred to Ge- 
raniaceae (see Acta Bot. Neerl. 37: 1 1 1-120. 1988). 
The family is recognized by the compound leaves, 
5 -parted flowers, obdiplostemonous stamens, pis- 
til with usually five styles and five locules, and 
loculicidal capsule or berry. The following treat- 
ment is based largely on the herbarium annota- 
tions and publications of Alicia Lourteig. 

Key to the Genera of Oxalidaceae 

1 a. Trees, leaves pinnate; fruit over 5 cm long, fleshy and edible; plants grown in gardens and parks . . 


1 b. Herbs or small (to 3 m) subshrubs; fruit a small dehiscent capsule; ornamental and wild plants . . 


2a. Leaves usually 3-foliolate; capsule dehiscing by longitudinal slits, carpels (mericarps) remaining 

attached to the central axis of the fruit Oxalis 

2b. Leaves long-pinnate with many small leaflets; capsules loculicidal in a radial form, carpels remaining 

attached only at the base Biophytum 

Averrhoa Linnaeus 

Trees, usually small and widely branching, puberulent; 
stipules minute or absent. Leaves alternate, compound 
and imparipinnate, petiolate, leaflets short-petiolulate, 
alternate or subopposite on the rachis, margins entire. 
Inflorescences solitary and axillary or cauliflorous, of 
cymes in racemiform panicles, bracts and bracteoles su- 
bulate and caducous. Flowers bisexual and regular, het- 
erostylous, sepals 5, imbricate, united near the base; pet- 
als 5, free or united near the middle, contorted in bud; 
stamens 10 in 2 series or 5 fertile and 5 staminodial; 

ovary 5-lobed, each lobe with 1 locule and 2-7 ovules. 
Fruit an elongate fleshy indehiscent berry, pendant at 
maturity, usually with 5 longitudinal ridges or lobes; 
seeds 2-several in each locule, endosperm fleshy. 

A genus of only two species, probably native to 
Southeast Asia. Both species are widely planted in 
the tropics and subtropics. The fleshy, usually yel- 
low or orange fruits have a pleasant but acidic 
flavor and are used to make drinks or preserves 
or are eaten raw. 

Key to the Species of Averrhoa 

la. Leaves with 6-15 leaflets, leaves evenly spaced along the distal branchlets; petals to 9 mm long, 
fertile stamens 5; fruit longitudinally deeply 5-lobed; commonly planted A. carambola 

1 b. Leaves with 14-40 leaflets, leaves clustered near the tips of branchlets; petals 10-20 mm long, fertile 
stamens 10; fruit smooth or slightly lobed; less common . . .A. bilimbi 

Averrhoa bilimbi L., Sp. PI. 428. 1753. 

Trees to 1 5 m tall, trunks to 30 cm thick, branches 
usually ascending, leafy branchlets ca. 7 mm thick, densely 

brownish or yellowish puberulent. Leaves clustered at 
the tips of branchlets, to 65 cm long, petioles 4-13(-17) 
cm long, ca. 2.5 mm thick and expanded at the base, 
densely puberulent; leaf blades 2.5-8(-15) cm long, 1.2- 
3(-5) cm broad, oblong to ovate-oblong, asymmetrical, 


acuminate at the apex, rounded to truncate at the base, 
minutely puberulent above and below. Inflorescences 
axillary or cauliflorous on aborted branchlets, racemi- 
form or paniculate, 1 5-20-flowered, puberulent and 
glandular, bracts ca. 4 mm long, bracteoles 1.5-2 mm 
long, subulate, pedicels 4-20 mm long, articulate near 
the middle. Flowers small, sepals 1.5-2.5 mm long, 1.5- 
3 mm wide, ovate to elliptic (1 internal sepal oblong), 
pubescence appressed and glandular on both surfaces; 
petals 10-20 mm long, 2-5 mm wide, narrowly spa tu- 
la to. reddish purple, caducous; stamens 10, all fertile, 
biseriate with longer (10 mm) and shorter (4 mm) fila- 
ments; pistil 7.5-12 mm long, ovary 4-7.5 mm long. 
Fruits 5-10 cm long, ca. 3.5 cm in diameter, smooth or 
longitudinally 5-lobed (circular to pentagonal in cross 

Averrhoa bilimbi has smaller, more sour fruits 
than its congener, and the fruits are not so prom- 
inently ridged. The fruits are used for preserves or 
for flavoring. This species is not commonly plant- 
ed in Central America. It is called mimbro and 
tiriguro in Costa Rica. 

Averrhoa carambola L., Sp. PI. 428. 1753. 

Trees to 10(-25) m tall, much branched, leafy branch- 
lets 2-3 mm thick and minutely (0.1 mm) puberulent 
with ascending thin whitish hairs, becoming glabrous 
and brownish. Leaves separate along the distal twigs, 
10-20 cm long, petioles 15-35 mm long, thickened near 
the base and minutely puberulent; distal leaf blades (leaf- 
lets) 5-8 cm long, 2-3 cm broad, ovate to ovate-oblong, 
short-acuminate at the apex, truncate or rounded at the 
base, proximal laminae 1.5-3 x 1-2 cm, minutely pu- 
berulent on the major veins above and below. Inflores- 
cences axillary or cauliflorous, to 8 cm long, of cymes 
borne on racemiform panicles or fasciculate, peduncle 
to 1 cm long, pedicels 3-4 mm long. Flowers ca. 8 mm 
long, sepals 2.5-3.5 mm long, 1-2 mm wide, oblong; 
petals 6-9 mm long, 1 .5-3 mm broad, spatulate, connate 
at the middle, papillate-glandular within, violet to purple 
and white; fertile stamens 5 with longer (2-2.5 mm) fil- 
aments, 5 inner stamens/staminodes with shorter fila- 
ments and usually without anthers; pistil 3-4 mm long, 
cylindrical-ellipsoid. Fruits 8-13 cm long, 5-6 cm thick, 
elliptic-oblong to ovoid, with 5 prominent longitudinal 
ridges and grooves (strongly pentagonal or star-shaped 
in cross section), yellowish translucent, mildly acidic to 

Averrhoa carambola is widely planted, both as 
an ornamental and for its value as a fruit tree. The 

acidic fruits are eaten fresh and are used in salads 
and desserts. The glabrous, 5-ribbed, lustrous yel- 
low fruits are distinctive. The fruit is often called 
carambola, both in Spanish and English. 

Biophytum DeCandolle 

Herbs or subshrubs, sometimes woody at the base, 
erect or decumbent, stems usually bearing a ring of stiff 
retrorse hairs at the apex; stipules obscure. Leaves fas- 
ciculate at the apex of the stem or at ground level on the 
rootstock, pi 11 na ic I > compound with many leaflets, short- 
petiolate, paripinnate (the terminal leaflet has been re- 
duced to a bristle), the leaf blades (leaflets) opposite, very 
short petiolulate and articulate at the rachis, gradually 
differing in shape from base to apex (along the rachis) 
with the lower pairs reniform to broadly ovate and small- 
er than the more distal leaflets, puberulent. Inflores- 
cences solitary and axillary, cymose or few-flowered, 
pseudo-umbellate, peduncles long, pedicels subtended 
by the spiral and imbricate bracteoles. Flowers bisexual 
and regular, 5-parted, sepals essentially free, imbricate, 
scarious; petals coherent near the middle, white to yel- 
low, orange, pink, or red; stamens 10, biseriate with 5 
shorter and 5 longer filaments, connate near the base, 
all fertile or sometimes the shorter without anthers; ovary 
5-lobed and 5-locular, each locule with 2-6 ovules al- 
ternating along 2 rows within each locule, styles 5, free, 
each with an enlarged bifid subcapitate or papillate stig- 
ma. Fruits capsular and covered by the persisting sepals, 
obovoid to subglobose or ellipsoid, each valve (carpel) 
1-6-seeded, loculicidally dehiscent, the valves opening 
upward over the sepals in a 5-pointed star pattern and 
remaining attached at their base (centrally); seeds ex- 
pelled explosively from the outer integument, usually 

Biophytum is a pantropical genus of about 75 
species, with one species in northern Central 
America and five additional species in Panama. 
Only one species has been recorded in Costa Rica, 
but it seems likely that a second will be found in 
Costa Rica. The plants are quite distinctive be- 
cause of the relatively long, narrow leaves clus- 
tered at the ends of unbranched stems, and the 
many opposite little leaflets that change their shape 
along the length of the leaf. The plants look like 
miniature palms or tree ferns. The following ac- 
count is based on the treatment for the Flora of 
Panama by Lourteig (Ann. Missouri Bot. Gard. 
67: 825-834. 1980). 

Key to the Species of Biophytum 

la. Middle leaflets usually oblong to slightly falcate in outline, the larger leaves usually with less than 
22 pairs of leaflets (range: 9-26 pairs); cymes condensed and 2-4 mm broad B. dendroides 

1 b. Middle leaflets usually slightly falcate in outline, the larger usually with more than 22 pairs of leaflets 
(range: 13-34 pairs); cymes ca. 5 mm broad B. falcifolium 


Biophytum dendroides (H.B.K.) DC., Prodr. 1 : 690. 
1824. Oxalis dendroides H.B.K., Nov. gen. & 
sp. 5: 194. 1822. Figure 2. 

R hi/omatous herbs, with leaves from the apex of an 
underground stem or from an erect or decumbent stem 
to 15(-35) cm long and 0.5-3(-5) mm thick, stems un- 
branched (rarely with 2-4 branches), puberulent with 
retrorse appressed hairs but glabrescent, roots to 10 cm 
long, fibrous. Leaves pseudoverticillate at the ends of 
stems, pinnate with 9-18(-26) pairs of leaflets, petioles 
1-4 cm long, leaflets sometimes overlapping, rachis 2- 
10 cm long and hirsutulous, petiolules ca. 0.2 mm long; 
proximal leaf blades (leaflets) 1-2.5 mm long, 1-2.5 mm 
wide, asymetrically ovate to triangular, middle leaflets 
5-10 mm long and 1.5-4 mm wide, subrectangular to 
subfalcate, distal leaflets 6-1 1 mm long and 2.5-5 mm 
wide, asymmetrically obovate, glabrous to sparsely hir- 
sutulous on 1 or both surfaces, midvein with 8-18 as- 
cending secondary veins on each side, a submarginal 
vein present but obscure. Inflorescences from the axils 
of the fasciculate leaves, with a distal cluster of flowers 
but only 1 flower blooming at a time, peduncles 1-8 cm 
long, minutely puberulent to hirsutulous, pilose beneath 
the flowers, bracts subulate to 6 mm long, bracteoles 2- 
7 mm long, 0.3-1.5 mm wide, linear to lanceolate, inner 
bracteoles equaling or exceeding the pedicels, pedicels 
1-5 mm long, articulate in the lower half, glabrous or 
finely puberulent. Flowers whitish pink or lilac, sepals 
5-7 mm long, 1-1.5 mm wide, lanceolate and acuminate 
with a slender tip, glabrous or with ascending hairs, 
densely hirsutulous at the base, with parallel raised ve- 
nation; petals 6-10 mm long, spatulate to obovate, nar- 
rowed at the base, slightly retuse at the apex; stamens 
with filaments enlarged at the base, longer stamens 4.5- 
5.5 mm long, shorter stamens 3-4 mm long; pistil mi- 
crostylous or macrostylous, puberulent apically, stigmas 
small and bifid. Fruits capsular, 2.5-4 mm long, oblong 
to subglobose, yellowish to violet, puberulent near the 
apex, valves 1-6-seeded, short pubescent within; seed 
ca. 1.5 mm long, semiovoid to triquetrous, planar on 
one side and convex on the other, longitudinally tuber- 

Herbs of evergreen formations from near sea 
level to 1 200 m elevation. This species ranges from 
Mexico through Guatemala, Honduras, Nicara- 
gua, and Panama to Ecuador; it has not been re- 
corded from Costa Rica. 

Biophytum dendroides is recognized by its un- 
usual habit (resembling miniature palms or tree 
ferns) with the verticillate long-pinnate leaves aris- 
ing from the apex of a small, usually unbranched, 
erect woody stem. The opposite asymmetrical sub- 
sessile leaflets that change their size and shape 
along the length of the rachis, and the long, thin, 
few-flowered peduncles also help make these plants 
distinctive. This species has fewer leaflets on the 
mature leaves than does B. falcifolium. The ap- 
parent absence of B. dendroides in Costa Rica is 

Biophytum falcifolium Lourteig, Ann. Missouri 
Bot. Gard. 67: 829. 1980. Figure 2. 

Erect or decumbent herbs, erect stems 5-12 cm long 
and branched only near the base, ca. 2 mm thick, puber- 
ulent in early stages and drying blackish. Leaves pseu- 
doverticillate at the end of the stem, 5-1 1(-15) cm long 
and 7-14 mm broad, pinnate with 13-34 pairs of op- 
posite or subopposite leaflets, the leaves linear-cuneate 
in outline, petioles 4-11 mm long, ca. 0.5 mm thick, 
rachis minutely puberulent above and hirsutulous be- 
neath, petiolules 0-0.2 mm long, thick; proximal leaf 
blades (leaflets) 3-6 mm long and 1.5-3 mm wide, ob- 
long to rhombic-oblong and slightly falcate (curved for- 
ward), central leaflets 5-1 1 mm long and 2-4 mm wide, 
falcate and oblong-rhombic, the distal leaflets equal to 
or shorter than the middle leaflets, usually with a short 
(1-2 mm) filamentous mucro at the apex, broadly obtuse 
to subtruncate at the base, glabrous to finely puberulent 
above, puberulent beneath. Inflorescences 1-3, subses- 
sile and subcapitate with the condensed cymes globose 
to cylindrical, with 1-5 flowers in various stages of de- 
velopment, pedicels 8-16 mm long, minutely puberu- 
lent, bracts ca. 2.5 mm long, subulate, purplish, brac- 
teoles 1.5-3 mm long, 1 -veined, keeled, spirally 
overlapping and green, puberulent and glandular. Flow- 
ers whitish, sepals 4.5-7 mm long, 0.7-1.3 mm wide, 
linear-elliptic, 5-7 veined, densely glandular; petals 6- 
10 mm long, oblong-spatulate, cream-white with pink 
veins and yellowish near the base, narrowed at the base; 
longer stamens 3-3.5 mm long and unequal, anthers ovoid 
and cordate at the base, shorter stamens 1-1.5 mm long, 
with sterile anthers or reduced to glands; pistil 3-4 mm 
long, ovary pilose near the apex and 5-lobed, each locule 
with 3-4 ovules, styles glandular-puberulent, styles ca. 
1.5 mm long, stigma bifid. Fruits capsular, globose, ca. 
3-5 mm long, shorter than the persisting calyx, glandular 
and puberulent at the apex; mature seeds unknown. 

Plants of wet evergreen forest formations from 
about 300 to 1 200 m elevation. The species is only 
known from Costa Rica and Panama. 

Biophytum falcifolium is recognized by the larg- 
er number of leaflets on each leaf, the narrower, 
more falcate leaflets, and the whitish petals. The 
species has only recently been collected in Costa 
Rica (L. D. Gomez et al. 23843 CR, MO) from Rio 
Uren, Limon Province, at an altitude of ca. 1000 
m. This species is closely related to B. panamense 
Lourteig, but that species has more oblong leaflets. 

Oxalis Linnaeus 

REFERENCES Melinda Denton, a monograph of 
Oxalis, section lonoxalis (Oxalidaceae) in North 
America. Publ. Mus. Michigan State Univ. 4(10): 
459-615. 1973. Alicia Lourteig, Oxalidaceae ex- 
tra-austroamericanae. I. Oxalis L. Sectio Tham- 
noxys Planchon. Phytologia 29: 449^71. 1975; 



FIG. 2. Oxalidaceae: two species of Biophytwn. 


II. Oxalis L. Sectio Corniculatae DC, Phytologia 
42: 57-198. 1979. 

Perennial herbs or subshrubs (rarely vines), stems rhi- 
zomatous, bulbous, or aerial, herbaceous or woody, pu- 
berulent or rarely glabrous; stipules present or absent, 
sometimes glandlike or interpetiolar. Leaves alternate or 
subopposite to pseudoverticillate, basal or cauline, pin- 
nately or palmately 3-foliolate (rarely 1-foliolate or 
4-foliolate), petiolate, leaf blades (leaflets) usually entire, 
often obcordate. Inflorescences axillary, umbelliform 
cymes or solitary flowers, bracts small, bracteoles 2. 
Flowers usually showy, often heterostylous (rarely cleis- 
togamous and reduced), sepals 5 (4), free or united near 
the base, imbricate, persisting in fruit; petals 5 (4), free, 
narrowed at the base, contorted in bud, caducous; sta- 
mens 1 0, the outer shorter stamens opposite the petals 
and alternating with the sepals, filaments slender, united 
near the base; pistils heterostylous and bi- or trimorphic, 
ovary 5-locular, with 1-15 ovules in each locule, styles 
5 and free, stigmas capitate. Fruits cylindrical to oblong 
or globose capsules, glabrous or puberulent, loculicidally 
dehiscent, each locule with (l-)2-15 seeds, valves con- 
nate to the central axis and persisting; seeds usually ovoid, 
flattened on the sides, oblong to apiculate, testa char- 

taceous, longitudinally ribbed to transversely striate or 
sculptured and densely verrucate, external integument 
fleshy and ariliform, breaking elastically and expelling 
the ripe seed, endosperm fleshy. 

A worldwide genus of more than 800 species in 
both warm and cold environments. The trifolio- 
late leaves that are narrowed to the base and, to- 
gether, form an almost circular outline character- 
ize many species. The leaves usually fold together 
at night and in inclement weather; they are often 
marked with red or purple. Species of the genus 
are often cultivated as ornamentals. Oxalis tub- 
erosa (Oca) is an important tuber crop in the high 
Andes. Some species are called acedera and vin- 
agrillo in Central America. The following work is 
based on Lourteig's treatment in the Flora of Pan- 
ama (Ann. Missouri Bot. Gard. 67: 835-850. 1980) 
and includes three species not yet known to occur 
in Costa Rica (O. dombei, O. microcarpa, and O. 

Key to the Species of Oxalis 

1 a. Leaves pinnately 3-foliolate, the distal leaflet borne on a petiole-like extension of the rachis, laminae 

rounded apically, never deeply emarginate or obcordate distally 2a 

Ib. Leaves digitately (palmately) 3- or 4-foliolate, all the leaflets arising from the apex of the petiole, 

laminae usually emarginate to obcordate distally (except in O. rhombifolid) 5a 

2a. Petals pinkish distally (white or yellowish at the base); terminal leaflets ovate to ovate-oblong 

O. barrelieri 

2b. Petals yellowish throughout 3a 

3a. Leaflets with small white punctate cystoliths, leaflets broadly ovate to oblong-orbicular; 

inflorescences often with foliaceous bracts; plants not yet collected in Costa Rica 

O. dombei 

3b. Leaflets lacking small white punctate cystoliths; inflorescences with small linear bracts; plants 

known to grow in Costa Roca 4a 

4a. Inflorescences umbelliform with 2-7 (-15) flowers; capsule ovoid to oblong; terminal leaflets 
often narrowly ovate to narrowly triangular (lanceolate), bluntly obtuse to slightly emarginate 

at the apex; sepals 2.5-5 mm long; a common species O. frutescens 

4b. Inflorescences elongate, with 5-1 2( 40) flowers; capsule globose; leaflets usually ovate-elliptic 
to rhombic, rounded at the apex; sepals 2-3 mm long; a wide-ranging species, but not yet 

collected in Costa Rica O. microcarpa 

5a. Leaves and inflorescences arising from a single bulbous or woody rootstock, elongate woody or 
herbaceous internodes absent, petioles and peduncles usually over 10 cm long; flowers pink to 

lavender 6a 

5b. Leaves and inflorescences arising from aerial or rhizomatous stems, elongate internodes present; 

flowers yellow 9a 

6a. Leaves and inflorescences arising from a short, rhizomatous woody stem covered with the 

bases of old leaves; leaflets broad distally, rounded and deeply notched O. articulata 

6b. Leaves and inflorescences arising from a basal bulb, bulb with many subulate scales and 

fibrous roots at the base 7a 

7a. Leaflets 4, usually with rounded divergent distal lobes O. tetraphylla 

7b. Leaflets 3, deeply notched to slightly emarginate distally 8a 


8a. Leaflets often broadly triangular with relatively straight margins, usually retuse to slightly 

obcordate distally; sepals with distal brownish calli 0.3-1 mm long O. latifolia 

8b. Leaflets rounded, broadly obovate in general outline; sepals with distal brownish calli 0.3- 

0.5 mm long o . debilis 

9a. Petiole base without adnate stipules; stems erect and often climbing, clambering, or shrublike, to 

2.5 m tall; distal leaflets often rhombic to ovate-triangular and acute at the apex O. rhombifolia 

9b. Petiole base with adnate stipules (these sometimes difficult to see among the hairs); herbaceous 

plants rarely more than 50 cm tall; leaflets usually obovate with incised (notched) apex lOa 

lOa. Stems slender and decumbent, outer cortex often splitting off in age; leaflets usually less than 1 
cm long; capsules densely and minutely puberulent, sepals usually more than half the length of 

the capsule; petals 8-14 mm long o. filiformis 

lOb. Stems slender and decumbent to erect, outer cortex not splitting off; leaflets (0.5-)l-3 cm long 

1 la 

11 a. Stipules with an abruptly truncated apex or the apex gradually merging with the petiole; distal 
leaflets broadly obovate to triangular; capsules covered with minute hairs, persisting calyx ^ -Vi 

as long as the capsule; petals 5-1 3 mm long O. corniculata 

lib. Stipules with a short acute apex (often difficult to see among the hairs); distal leaflets narrowly 
obovate to obovate-oblong with a notch (ca. 3 mm deep in large leaflets); capsule with few erect 

multicellular hairs, persisting sepals equaling the capsule in length; petals 1 1-18 mm long 

O. spiralis 

Oxalis articulate Savigny, in Lamarck, Encycl. 4: 
686-687. 1797. 

Herbs, to 40 cm high, stem rhizomatous, to 15 cm 
long and (l-)2 cm in diameter, covered distally with the 
short bases of leaves and their adnate stipules, roots 
tuberous, cylindrical, to more than 10 cm long; stipules 
4-16 mm long and adnate to the leaf-base. Leaves fas- 
ciculate from the apex of the stem, 5-15(-30) cm long, 
erect or ascending, petioles (4-)9-18(-30) cm long, slen- 
der, pubescent to glabrate with thin hairs ca. 0.5 mm 
long, petiolules 0.5-1 mm long, thick, pubescent; leaf 
blades (leaflets) 5-20(-30) mm long, 7-35(-45) mm wide, 
obcordate and widely obovate in outline, rounded dis- 
tally and emarginate to retuse at the apex, cuneate at the 
base, usually with appressed ascending thin whitish hairs 
ca. 0.7 mm long on both surfaces, with dark or orange 
punctations or lines (calli) 0.2-0.5 mm long near the 
margins (less often scattered over the surface). Inflores- 
cences umbelliform and cymose with 6-20 flowers, pe- 
duncles usually longer than the leaves (2.5-40 cm), pu- 
bescence similar to the petioles, bracts and bracteoles 
0.5-3 mm long, lanceolate, pedicels l-3(-5.5) cm long, 
slender and articulate at the base. Flowers violaceous to 
pink, sepals 2-5(-6.5) mm long, 1-2 mm broad, narrowly 
elliptic to lanceolate, appressed puberulent with thin 
straight ascending hairs; petals 5-15(-20) mm long, ob- 
ovate, connate near the middle, areas exposed in bud 
covered with appressed whitish hairs; longer stamens ca. 
3.5 mm long, shorter stamens ca. 2 mm long, united for 
more than half their length; pistil ca. 5.5 mm long, ovary 
usually pilose distally, each locule with 4-8 ovules, styles 
puberulent, the flower with long, medium or short styles, 
stigma small and capitate. Fruits cylindrical to oblong, 
8-1 1 mm long, acute at the apex, with ascending ap- 
pressed hairs distally on the carpels or all over, the per- 
sisting calyx ca. l h as long; seeds 1-1.3 mm long, ovoid 
to ellipsoid and acute at both ends, with 8 or 9 ribs and 
48 pits, pale brown. 

A cultivated species originally from Uruguay 
and adjacent areas, escaping and becoming natu- 
ralized in some areas. Oxalis articulata is recog- 
nized by the short, thick stems bearing the closely 
clustered leaves and inflorescences, the pink to 
violaceous flowers, and the rounded leaflets punc- 
tate along the margin. 

Oxalis barrelieri L., Sp. PI. ed. 2, 624. 1762. Fig- 
ure 4. 

Herbs or subshrubs, to 1 m tall, leafy internodes 
(0-)0.5-8 cm long, 0.5-3 mm thick, sparsely puberulent 
with thin whitish hairs, glabrescent, roots fibrous; stip- 
ules linear and ca. 3 mm long or absent. Leaves alternate 
to subopposite, petioles 1-4 cm long, ascending, cana- 
liculate, sparsely puberulent with thin hairs, more dense- 
ly puberulent and articulate near the base, the rachis 3- 
15 mm long, petiolules 0.5-1 mm long, with thin hairs; 
leaf blades (leaflets) 10-55 mm long, 8-25 mm broad, 
ovate to elliptic-oblong (rarely suborbicular), bluntly ob- 
tuse to acute at the apex, obtuse to rounded at the base, 
asymmetric at the base in lateral leaflets, sparsely pu- 
berulent above and below. Inflorescences usually axillary 
cymes longer than the leaves, (l-)3-l l(-30)-flowered, 
peduncles to 6.5 cm long, 0.5-0.8 mm thick (dry), gla- 
brescent, terminated by a flower and with 2 unbranched 
secondary branches to 3 cm long, bracts and bracteoles 
1-2 mm long, pedicels 1.5-3.5(-5) mm long, articulate 
above the base. Flowers pink, sepals greenish, 34 mm 
long, 1-2 mm wide, linear to narrowly oblong, acute and 
minutely mucronate, sparsely and minutely puberulent; 
petals 7-9 mm long, ca. 3.5 mm broad, retuse, obovate 
to spatulate, pink distally, white or yellow in the lower 
half; longer stamens ca. 3 mm long, I igulate at the middle, 


O. corniculata 

O. latifolia 


FIG. 3. Oxalidaceae: four smaller species of Oxalis. 



shorter stamens 1.5-2 mm long; pistil 3.5-4 mm long, 
ovary glabrous and ovoid, each locule with 3 or 4 ovules, 
styles puberulent, stigma bifid and subcapitate. Fruits 5- 
9 mm long, to 4 mm thick, ovoid, persisting calyx half 
as long; seeds 1.5-2 mm long, ca. 1 mm broad, ovoid 
with slightly flattened sides, with 6-8 prominent trans- 
verse ridges/grooves, and minutely tuberculate, brown. 

Plants of the evergreen lowland Caribbean forest 
formations from near sea level to 1 000 m elevation 
(rarely from as high as 2000 m in the Chiriqui 
highlands); flowering collections have been made 
throughout the year. This species is native to trop- 
ical and subtropical America and has been intro- 
duced into the Old World tropics. 

Oxalis barrelieri is recognized by its erect, slight- 
ly woody stems, pinnately trifoliolate leaves (ter- 
minal leaflet borne on a slender rachis), leaflets 
acute to rounded distally (neither retuse nor emar- 
ginate), and pink flowers. 

Oxalis corniculata L., Sp. PI. 435. 1753. Figure 3. 

Annual herbs, much branched and with prostrate or 
decumbent stems to 50 cm long (rarely with erect stems 
to 40 cm tall), often rooting at the nodes, internodes 
variable in length (0-)l-4 cm long, 0.3-1.3 mm thick 
(dry), usually with a few slender whitish hairs ca. 0.5-1 
mm long, roots usually fibrous; stipules 0.8-3 mm long 
and adnate to the petiole-base, l-2(-3) mm wide and 
truncated at the apex, ciliate along the margin. Leaves 
alternate to subopposite or often fasciculate, petioles 1- 
5(-7) cm long, slender and ascending, with thin ascend- 
ing whitish hairs, petiolules ca. 1 mm long, thick and 
pubescent; leaf blades (leaflets) 4-12(-20) mm long, 5- 
20 mm broad, broadly obovate and usually wider than 
long, rounded and retuse to deeply emarginate distally 
(obcordate) with a notch to 6 mm deep in large leaflets, 
cuneate to obtuse at the base, margin entire and ciliate, 
the pubescence variable with sparse to dense slender 
ascending or appressed hairs 0.5-1 mm long (often gla- 
brous above). Inflorescences cymose or umbelliform, 
( l-)2-7-flowered, peduncles to 2-7(-2 1 ) cm long, slender 
with thin appressed hairs, bracts and bracteoles 0.5-4 
mm long, linear to lanceolate, pedicels slender, ca. 10 
mm long (lengthening in fruit). Flowers yellowish, sepals 
2.5-5.5 mm long, elliptic-oblong to narrowly ovate (lan- 
ceolate), acute at the apex, translucent, lacking calli; pet- 
als 5-13 mm long, 1-3 mm broad, often pinkish or 
whitish within, yellow distally; longer stamens 4-6 mm 
long, shorter stamens 3.5-4 mm long and united in the 
lower third; pistils micro-, meso-, or macrostylous, to 8 
mm long, ovary oblong and acute, each locule with 2-15 
ovules, stigma 2-lobed and papillose. Fruits 5-25 mm 
long, 1-3 mm thick, subcylindrical and 5-ribbed, acute 
apically, minutely puberulent or with multicellular glan- 
dular hairs, persisting sepals !4-'/ 3 the length of the fruit; 
seeds ca. 1 mm long, ovoid but flattened on the sides, 
apiculate at the apex, with 6 longitudinal ribs (3 on each 
side) and prominent transverse ridges, brown or reddish 

A species originating in the Mediterranean area 
but now distributed worldwide. In Central Amer- 
ica it is primarily found between 1000 and 2000 
m elevation in open secondary vegetation, flow- 
ering throughout the year. The species is weedy 
and capable of hybridizing with indigenous spe- 

Oxalis corniculata is recognized by its small 
stature, trifoliolate leaves with laminae rounded 
and notched distally, unusual stipules, and yellow 
petals. The flowers usually open in the morning 
and close by the middle of the day. This species 
represents a complex of forms that have been 
treated as three subspecies and several varieties 
by Lourteig. It has been called acederilla in Costa 

Oxalis debilis H.B.K., Nov. gen. sp. 5: 236, t. 466. 
1822. 0. martianaZuccarini, Denkschr. Konigl. 
Akad. Wiss. Munchen 9: 144. 1825. Figure 3. 

Herbs, arising from a globose, ovoid, or oblong bulb 
1-2 cm long, the bulb covered with scales and leaf- bases, 
the scales 7-13 mm long, 3-5 mm broad near the base, 
lanceolate and with 3 longitudinal ribs, roots fibrous; 
stipules to 13 mm long and 2 mm wide, completely 
connate to the leaf-bases (difficult to see). Leaves trifo- 
liolate, petioles to 30 cm long, 0.4-1.5 mm thick, with 
thin transparent hairs 0.8-1 .5 mm long or glabrous, pet- 
iolules 0.5-1 mm long; leaf blades (leaflets) 1.2-5.5 cm 
long, 1.5-6 cm broad, broadly obovate to suborbicular 
in outline, obcordate, broadly rounded distally and 
emarginate to retuse with a notch 2-7 mm deep, glabrous 
to sparsely puberulent above, more densely puberulent 
beneath with thin hairs ca. 1 mm long, minutely (0.1 
mm) dark punctate along the margin and more sparsely 
scattered over the surface. Inflorescences bifid cymes 
(sometimes twice bifid), with 6-15 flowers, to 30(-45) 
cm long, peduncles similar to the petioles, bracteoles (at 
the base of the pedicels) 1-3 mm long, often with brown- 
ish calli, pedicels to 3 cm long, slender. Flowers pinkish 
to red-violet, sepals 4-7 mm long, 0.7-1.5 mm wide, 
narrowly ovate-elliptic or oblong, glabrescent, usually 
with 2 brown or orange antherlike calli ca. 0.5 mm long 
on the outside of the sepal apex; petals 2-3 times the 
length of the sepals, obovate and narrowed at the base; 
longer stamens 4.5 mm long, puberulent near the apex, 
shorter stamens ca. 3 mm long and glabrous, connate in 
the lower '/,; pistil ca. 7.5 mm long, ovary glabrous, 
macro- or mesostylous (rarely microstylous), with scat- 
tered thin hairs and glandular hairs, each locule with 2- 
1 2 ovules. Fruits ca. 1 8 mm long with styles 2 mm long, 
cylindric, calyx V 4 -Y^ the length of the capsule; seeds ovoid 
with flattened sides, with 12 longitudinal ribs and 12 
transverse ridges, brown. 

A weedy species found in evergreen areas from near 
sea level to 1 500 m elevation in our area. The species 
is originally South American, but it is now widespread. 



Oxalis debilis is recognized by its scaly bulbs, lack of 
visible internodes, rounded trifoliolate leaves with shal- 
low distal notches, pinkish flowers, and unusual brown- 
ish calli at the tips of the sepals. These plants fruit in- 
frequently, reproducing by bulblets. 

Oxalis dombeii St. Hilaire, Fl. bras, merid. 1: 111. 
1825. O. darienensis Woodson, Ann. Missouri 
Bot. Gard. 27: 312-313. 1940. 

Herbs, stems erect, to 60 cm tall, leafy internodes to 
10 cm long, to 4(-6) mm thick and woody near the base, 
glabrous to sparsely puberulent (sometimes more dense- 
ly viscous-puberulent near the base), rhizome cylindri- 
cal, roots fibrous; stipules obscure. Leaves alternate, sub- 
opposite or pseudoverticillate, pinnately trifoliolate, 
petioles 1-4 cm long, 0.2-0.4 mm thick (dry), articulate 
near the base, glabrescent, canaliculate above, rachis 3- 
6 mm long, petiolules ca. 0.5 mm long and drying dark; 
leaf blades (leaflets) 9-25 mm long, 5-22 mm broad, 
obovate to suborbicular, rounded at the apex, cuneate 
to the base, lateral leaflets often asymmetric, essentially 
glabrous above and below (fine ciliate on the margin), 
with whitish minute (0. 1 mm) cystoliths usually visible 
on the dried leaf. Inflorescences bifid-cymose (the pe- 
duncle terminated by a flower and with 2 racemose 
branches), 10-25-flowered, peduncle to 7 cm long, 0.5- 
1.1 mm thick, glabrous, bracteoles 1-2 mm long, linear- 
lanceolate, pedicels about 3 mm long, articulate near the 
base, usually glabrous. Flowers yellow, sepals 4.5-7 mm 
long, 1-2.5 mm broad, ovate-oblong, acute, thin, gla- 
brous; petals 7-14 mm long, obovate to subspatulate; 
longer stamens 2.5-4.5 mm long, minutely puberulent, 
shorter stamens 1-2 mm long, glabrous; pistil 2-5 mm 
long, ovary ca. 3 mm in diameter, each locule with 7- 
10 ovules, stigma capitate. Fruits 10-12 mm long, ob- 
long to ellipsoid, the persisting styles 1-2 mm long, sepals 
V 2 - 2 / 3 of the length of the capsule; seeds 1-1.2 mm long, 
ca. 1 mm broad, obovoid and slightly flattened on the 
2 sides, with 5 or 6 weakly developed longitudinal ribs, 
the transverse ridges weakly developed, orange-brown. 

Plants of drier deciduous forest vegetation and 
in semideciduous areas, ranging from central Pan- 
ama to Peru and in the Galapagos Islands. 

Oxalis dombeii is recognized by its short, erect 
habit, almost glabrous parts, pinnately trifoliolate 
leaves, white punctate cystoliths, and yellow flow- 
ers. Although not recorded from our area, it may 
become introduced into the seasonally dry Pacific 

Oxalis filiformis H.B.K., Nov. gen. sp. 5: 190, t. 
460. 1822. O. bradei Knuth, Repert. Spec. Nov. 
Regni Veg. 23: 276. 1927. Figure 3. 

Short, creeping herbs to 10 cm tall, stems horizontal 
or rhizomatous, to 50 cm long, internodes 0-5 cm long, 
0.5-1 mm thick, dark brown or reddish, sparsely pu- 
berulent, outer layers splitting off in age; stipules 1.5-3 

mm long, 0.5-1.7 mm broad, adnate to the petiole, cil- 
iate. Leaves alternate or fasciculate, palmately trifolio- 
late, petioles 8-25 mm long, slender, sparsely to densely 
puberulent with thin ascending whitish hairs, petiolules 
ca. 0.5 mm long; leaf blades (leaflets) 2-10(-15) mm 
long, 3-15(-20) mm broad, broadly obcordate to ob- 
ovate and retuse distally, rounded at the notched apex, 
cuneate at the base, both surfaces with thin, white, ap- 
pressed hairs 0.5-1 mm long or the upper surface gla- 
brous, ciliate along the edge. Inflorescences 1 -flowered, 
l-4(-8) cm long and exceeding the leaves, peduncles 
(measured to the bracteoles) about twice the length of 
the pedicels, filiform and with thin hairs, bracteoles 1- 
3 mm long, linear, pedicels 0.5-2.5 cm long. Flowers 
yellow, sepals 3-5 mm long, 1-2 mm wide, oblong, ob- 
tuse at the apex, usually with thin whitish hairs; petals 
8-14 mm long, narrowly obovate; longer stamens 4-5.5 
mm long, shorter stamens 34 mm long and connate to 
V 4 of their length; pistils 5-7 mm long, all longistylous, 
each locule with 3-6 ovules, style densely puberulent, 
stigmas bifid. Fruits 10-15 mm long, 2-3 mm thick, 
densely minutely puberulent, calyx V 2 - 2 / 3 as long as the 
capsule, persistent styles 2-5 mm long; seeds 1-1.5 mm 
long, broadly ellipsoid and flattened on 2 sides, reddish 
brown, with 6 longitudinal ribs and transverse ridges. 

Small plants of open sites in highland evergreen 
areas from 1 1 00 to 2000 m elevation in Costa Rica 
and Panama. Flowering and fruiting material has 
been collected from December through May. The 
species ranges from Costa Rica southward to Ec- 
uador at elevations from 1000 to 3000 m. 

Oxalis filiformis is recognized by its small stat- 
ure, creeping stems with older exfoliating surfaces, 
small obcordate leaflets, single-flowered inflores- 
cences, and yellow petals. It appears to be native, 
and it prefers open sunny habitats, such as road- 

Oxalis frutescens L., Sp. PI. 435. 1753, subsp. an- 
gustifolia (H.B.K.) Lourteig, Phytologia 29: 463- 
471, fig. 3. 1975. O. angustifolia H.B.K., Nov. 
gen. sp. 5: 193. 1822. O. neaei DC., Prodr. 1: 
690. 1 824. O. coccinea Woodson & Schery, Ann. 
Missouri Bot. Gard. 28: 431. 1941. Figure 4. 

Herbaceous subshrubs or small shrubs to 40 cm tall, 
usually with several erect or ascending branches from a 
short (2-10 cm), woody base, leafy internodes 0.8-2 mm 
thick, with thin, ascending, straight or crooked whitish 
hairs to 1 mm long (shorter and curved in age); stipules 
obscure. Leaves alternate, subopposite or verticillate, 
pinnately trifoliolate, petioles 1-4 cm long, ca. 0.3 mm 
thick (dry), puberulent as the stems, rachis 2-5(-10) mm 
long, petiolules minute; distal leaf blades (leaflets) 7- 
23(-45) mm long, 3-12(-20) mm broad, about twice as 
long as the lateral leaflets, narrowly ovate to narrowly 
triangular or ovate-oblong, tapering to the apex and 
emarginate (or slightly notched), rounded to obtuse (acute) 
at the base, the smaller lateral leaflets usually more ob- 



O. spiralis 

ssp. vulcanicola 


O. f rutescens 
ssp. angustifolia 


FIG. 4. Oxalidaceae: four larger species of Oxalis. 



long and asymmetric, densely puberulent on both sur- 
faces or glabrescent above. Inflorescences somewhat ex- 
ceeding the leaves, cymes or umbelliform cymes, (l-)3- 
7(-15)-flowered, peduncles to 3.5 cm long, ca. 0.3 mm 
thick, puberulent, bracteoles ca. 1 mm long, pedicels 3- 
6 mm long, articulate ca. 1 mm above the base. Flowers 
yellow, sepals 2.5-5 mm long, ca. 1 mm broad, narrowly 
oblong, carpels ciliate on the back, calyx '/ 2 - 3 / 4 the length 
obovate, emarginate at the apex, narrowed to the base; 
longer stamens ca. 3 mm long, shorter stamens ca. 1.5 
mm long, connate to the lower !/ 3 ; pistil 3-5 mm long, 
minutely pilose, each locule with up to 8 ovules, stigmas 
bifid. Fruits 5-8 mm long, ca. 3 mm thick, ovoid to 
oblong, carpels ciliate on the back, calyx '/ 2 -% the length 
of the capsule; seeds 1.5-2 mm long, ovoid and convex 
on two sides, apiculate, with 6 or 8 longitudinal ribs and 
10-12 transverse ridges, pale brown. 

Herbs and subshrubs of open and shaded sites 
in seasonally dry deciduous and partly deciduous 
forest formations from near sea level to 800(- 
?1 600) m elevation on the Pacific slope of northern 
and central Costa Rica. Flowering material has 
been collected throughout the year except October 
and November. The species ranges from the Mex- 
ican-U.S. border through Central America and the 
West Indies to Argentina. 

Oxalisfrutescens is recognized by the preference 
for seasonally dry vegetation, herbaceous or 
shrublike habit with a slightly woody base, pin- 
nately trifoliolate leaves with the terminal leaflet 
usually narrowed to the apex, and the yellow pet- 
als. It is found in open savannas as well as partly 
shaded sites. 

(Kalis latifolia H.B.K., Nov. gen. sp. 237, t. 467. 
1822. O. ramonensis Knuth, Notizbl. Bot. Gart. 
Berlin-Dahlem 7: 313. 1919. O. chiriquensis 
Woodson, Ann. Missouri Bot. Card. 24: 190. 
1937. Figure 3. 

Herbs, stems not apparent, leaves and inflorescences 
from an ovoid or globose bulb to 25 mm long and 20 
mm thick, with scales 7-1 5 mm long and 4-6 mm broad 
near the base, conspicuously 3-veined and with a long 
narrow tip; stipules connate to the petioles, often difficult 
to see among the leaf-bases, translucent brownish, au- 
riculate at the apex. Leaves closely clustered on the bulb, 
erect or ascending, petioles 5-17(-25) cm long, 0.5-1.5 
mm thick (dry), glabrous or with scattered thin hairs, 
petiolules ca. 1 mm long, thick; leaf blades (leaflets) 10- 
25(-45) mm long, 15-45(-75) mm broad, broadly ob- 
cordate to triangular in outline, the distal margin round- 
ed and emarginate, slightly notched or deeply V-shaped 
with divergent lobes, cuneate to obtuse with straight sides 
at the base, glabrous or rarely with few hairs and cilia. 
Inflorescences exceeding the leaves in length, erect, to 
35 cm long, umbelliform cymes with 5-20 flowers, pe- 
duncles 1 0-30 cm long, similar to the petioles, bracteoles 

1-2 mm long, at the base of the umbel, pedicels 14-28(- 
40) mm long, filiform, glabrous. Flowers pink to purplish 
or lavender distally, sepals 3-6 mm long, 0.5-1.5 mm 
wide, narrowly oblong, thin translucent, glabrous, usu- 
ally with 2 brown or reddish calli 0.3-1 mm long near 
the tip (the calli sometimes resembling anthers); petals 
10-20 mm long, obovate to spatulate; longer stamens 4- 
7 mm long, shorter stamens 3-4 mm long and connate 
near the base; pistils 4-6(-8) mm long, usually microsty- 
lous, each locule with 4-8 ovules, stigmas bifid and pa- 
pillose. Fruits 4-9 mm long, oblong and acute, glabrous, 
calyx '/4-'/2 the length of the capsule; seeds ca. 1 mm long, 
ellipsoid and slightly lenticular, with 8-9 longitudinal 
ribs and 9-12 transverse ridges, pale brown. 

Plants of moister situations in evergreen and 
partly deciduous vegetation from 1000 to 
2000(-2700) m elevation. Most of our flowering 
collections have been made from May through 
August. The species ranges from Mexico and the 
Antilles southward along the Andes to Bolivia. 

Oxalis latifolia is recognized by the bulbous base 
(without stems or internodes), largely glabrous 
parts, long peduncles, palmately trifoliolate leaf- 
lets with triangular or V-shaped form, and pink- 
lavender petals. Denton interpreted O. latifolia 
more narrowly in her monograph (see reference at 
the beginning of the genus). Central American ma- 
terial here considered O. latifolia was placed under 
O. galeotti Turcz. in that monograph. 

Oxalis microcarpa Benth., PI. hartw. 115. 1839. 

Herbs or subshrubs, to 0.7(-1.2) m tall, internodes 2- 
1 6 mm long, ca. 1 mm thick, with thin, straight or curved 
whitish hairs 0.2-0.5 mm long, stems becoming slightly 
woody, 2-3.5 mm thick, gray and glabrescent; stipules 
obscure. Leaves alternate to subopposite, pinnately tri- 
foliate, petioles 2-4 cm long, filiform (only 0.2-0.3 mm 
thick when dry), puberulent, slightly thickened and ar- 
ticulate at the base, rachis 4-10 mm long, petiolules ca. 
0.7 mm long, thick and puberulent; terminal leaf blades 
(leaflets) 10-24(-38) mm long, 6-14(-20) mm wide, ovate- 
elliptic to somewhat rhombic or elliptic, tapering to the 
rounded apex, obtuse to slightly rounded at the base, 
lateral leaflets smaller and slightly asymmetric at the 
base, sparsely to densely puberulent with thin appressed- 
ascending hairs 0.4-0.9 mm long on both surfaces. In- 
florescences solitary and axillary, to 12 cm long in fruit, 
bifid cymes with 5-12(-40) flowers, peduncles to 6 cm 
long, filiform, the 2 branches to 6 cm long in fruit, brac- 
teoles linear, pedicels 1.5-3 mm long, slender, articulate 
near the base. Flowers yellow, sepals 2-3 mm long, 0.5- 
1 mm broad, narrowly ovate to elliptic, acuminate, gla- 
brous; petals 5-7 mm long, obovate to subspatulate; 
longer stamens ca. 2.5 mm long, shorter stamens 1.5-2 
mm long; pistil ca. 2.5 mm long, ovary glabrous, each 
locule with 1 or 2 ovules, stigmas slender. Fruits 2-3 
mm long, oblate to subglobose, glabrous, calyx usually 
equaling or slightly exceeding the capsule, walls of the 



capsule thin; seeds ca. 1.5 long and 1 mm thick, ellipsoid, 
with 6-8 prominent longitudinal ribs and transverse 

A species of seasonally dry areas of the Pacific 
slope in Central America, to 1500 m elevation, 
and flowering in the wet season. The species has 
not been reported from Costa Rica, but is found 
in Mexico, Honduras, and from Panama to Ec- 

Oxalis microcarpa is recognized by the small 
stature, pinnately trifoliolate leaflets that are 
rounded distally, glabrous yellow flowers, and 
short, few-seeded capsules. The unusual distri- 
bution may imply that the species is not native to 
Central America. This species resembles O. fru- 

Oxalis rhombifolia Jacquin, Oxalis 22, pi. 2. 1 794. 
O. maxonii Standley, J. Wash. Acad. Sci. 17: 
311-312. 1927. Figure 4. 

Shrubs, erect or climbing over others, to 2(-6) m high, 
internodes (l-)3-15(-40) cm long along the main 
branches, 1-3 mm thick, puberulent with thin curved 
hairs, dark brown; stipules obscure. Leaves alternate or 
fasciculate on short shoots, palmately trifoliolate, peti- 
oles 1-6 cm long, ca. 0.3 mm thick (dry), puberulent, 
thickened and articulate at the base, petiolules ca. 1 mm 
long, thick and puberulent; distal leaf blades (leaflets) 
14-38(-^5) mm long, 10-20(-25) mm broad, lateral leaf- 
lets slightly shorter, rhombic-ovate to ovate-elliptic, ta- 
pering to the obtuse or acute apex, acute to obtuse at the 
base, glabrescent on both surfaces or ciliate-puberulent 
with thin hairs ca. 0.5 mm long. Inflorescences solitary 
and axillary, bifid cymes to 9 cm long, 3-5 -flowered, 
peduncles to 6 cm long, resembling the filiform petioles, 
bracts 3-7 mm long and linear, bracteoles 1.5-2 mm 
long, pedicels 2-5 mm long, puberulent, articulate at the 
base. Flowers yellow, sepals 4-6 mm long, 1-1 .5(-2) mm 
wide, narrowly oblong, puberulent and densely ciliolate 
at the tip; petals 10-18 mm long, obovate to subspatu- 
late; longer stamens 5-8 mm long, shorter stamens 3-6 
mm long, connate for V 3 above the base; pistils macro-, 
meso-, or microstylous, 6-10 mm long, ovary and styles 
puberulent, each locule 3-ovulate, stigmas bifid. Fruits 
6-9 mm long, oblong or ovoid, densely puberulent, calyx 
'/2 as long as the capsule; seed ca. 2.2 mm long, lenticular, 
with 13 or 14 longitudinal ribs. 

Plants of open and partially shaded sites in ev- 
ergreen forest formations from 1000 to 2300 m 
elevation in our area. Flowering material has been 
collected from December to August in Central 
America. The species ranges from Mexico through 
Central America to Colombia and Venezuela. 

Oxalis rhombifolia is recognized by its shrublike 
or clambering habit, palmately trifoliolate leaves 

with somewhat rhombic leaflets, filiform petioles 
and peduncles, few-flowered inflorescences, and 
yellow petals. This species appears to be rare in 
Costa Rica, though common in the Chiriqui high- 
lands of Panama. 

Oxalis spiralis Ruiz & Pavon ex G. Don, Gen. 
hist. 1: 755. 1831. O. vulcanicola J. D. Smith, 
Bot. Gaz. 23: 241. 1897. O. spiralis subsp. vul- 
canicola (J. D. Smith) Lourteig, Ann. Missouri 
Bot. Card. 67: 846. 1980. Figure 4. 

Herbs, scandent, decumbent, or erect to 50 cm tall or 
1.5 m long, internodes 2-30(-80) mm long, succulent, 
with thin yellowish to brown hairs 0.4-0.9 mm long, 
often reddish in life; stipules adnate to the petiole, thin 
and translucent, reddish, 2-5 mm long, narrow and acute 
at the free apex. Leaves alternate, palmately trifoliolate, 
petioles l-5(-7) cm long, 0.3-1.2 mm thick (dry), gla- 
brous or puberulent, petiolules 0.5-1 mm long; distal 
leaf blades (leaflets) 8-25(-38) mm long, 5-18(-25) mm 
broad, oblong-obovate to suborbicular-obovate, with a 
shallow (1-4 mm) distal notch and rounded distal lobes, 
cuneate at the base, glabrous or sparsely puberulent above, 
puberulent beneath with thin whitish appressed-ascend- 
ing hairs ca. 0.5 mm long, laminae often purplish be- 
neath. Inflorescences solitary and axillary or terminal, 
exceeding the foliage in length, cymes with 3-17 flowers 
or sometimes with only 1 or 2 flowers, peduncles 1.5- 
9(-12) cm long, puberulent, bracteoles ca. 1 mm long, 
linear, pedicels 5-12(-16) mm long, articulate above the 
base. Flowers yellow, sepals 4-8 mm long, 0.7-1.5 mm 
broad, narrowly lanceolate, gradually narrowed to the 
acute apex, usually glabrous; petals 11-18 mm long, ob- 
ovate, veins usually red or dark violet; longer stamens 
4-6 mm long, shorter stamens 2-3 mm long and connate 
for half their length; pistils micro-, meso-, and macrosty- 
lous, 6 mm long, ovary glabrous, each locule with 3 or 
4 ovules, stigmas capitate and minutely papillose. Fruits 
4-8 mm long, ellipsoid-oblong, glabrous, calyx about the 
same length as the capsule; seeds ca. 1.2 mm long, el- 
lipsoid, somewhat muricate, without prominent longi- 
tudinal ribs or transverse ridges, dark reddish brown. 

Plants of evergreen montane forests and sub- 
paramo formations from 1400 to 3300 m eleva- 
tion. Flowering material has been collected in all 
months but June; most flowering collections have 
been made between November and March. The 
species is found in the Cordillera de Talamanca, 
around Volcan Irazu and, in a few collections, as 
far west as the Alajuela-Heredia border (Vara 
Blanca). The species ranges from southern Mexico 
to Peru and is grown as an ornamental. 

Oxalis spiralis is recognized by its reddish stems, 
sparse (less often dense) puberulence, palmately 
trifoliolate leaves with oblong-obovate leaflets 
slightly notched distally, yellow petals with red- 
dish veins, and seeds without ribs or ridges. Dif- 



ferent plants may differ greatly in the size of their 
leaves, probably as a result of environmental fac- 
tors; some have terminal leaflets averaging only 
10 mm long, others have terminal leaflets aver- 
aging 30 mm. There is also great variation in the 
degree of pubescence and growth pattern. 

All our material belongs to subspecies vulcani- 
cola, which is found in the highlands of Chiapas, 
El Salvador, Costa Rica, and adjacent Panama. 
This species can be grown in hanging pots; its pen- 
dulous reddish stems and yellow flowers make an 
attractive display. 

(Kalis tetraphylla Cavanilles, Icon, descr. 3: 19- 
20, t. 237. 1794. O. deppei Loddiges, Hot. cab. 
15, t. 1500. 1828. O. hayi Knuth, Notizbl. Bot. 
Gart. Berlin-Dahlem 7: 316. 1919. 

Herbs, stems not apparent, leaves and inflorescences 
from the apex of an ovoid to globose bulb to 4 cm long 
and 3 cm in diameter, bulb covered with scales and leaf- 
bases, outer scales 4-18 mm long, 1-12 mm wide, 3-5- 
veined, sometimes lost during collection, inner scales 
with 5-14 prominent veins, acute; stipules adnate to the 
petioles, 12-30 mm long, 4-13 mm wide at the base, 
thin or scarious. Leaves palmately 4-foliolate (rarely 
3-foliolate in young plants), petioles 5-20(-30) cm long, 
1-1.5 mm thick (dry), glabrous or sparsely puberulent, 
pctiolulcsca. 1 mm long, puberulent; leaf blades (leaflets) 
20-40(-70) mm long, 25-55(-75) mm broad, broadly 
obovate to subtriangular (rarely suborbicular or with di- 
vergent distal lobes), straight (truncate) to slightly con- 
cave distally with rounded corners, cuneate to the base, 
sparsely puberulent or glabrescent. Inflorescences to 50 
cm tall, umbelliform or bifid cymes, 3-12-flowered, pe- 
duncles 10-45 cm long, similar to the petioles, bracts 
and bracteoles 2-4 mm long, pedicels to 17 mm long, 
articulate at the base. Flowers pink to lavender or violet, 
sepals 4-7.5 mm long, 1-2 mm broad, narrowly oblong, 
bluntly acute at the apex and usually with 2 dark calli 
ca. 0.5 mm long, glabrous or with a few hairs; petals to 
3 cm long, usually glabrous; longer stamens 2.5-4 mm 
long, shorter stamens 1.5-2.5 mm long, with filaments 
connate '/i-'/ 2 ; pistils mostly macrostylous, 5-7 mm long, 
each locule with 3-6 ovules, stigma bifid and papillose. 
Fruits ca. 13 mm long, cylindrical, acute at the apex, 
styles ca. 1.5 mm long; seeds ca. 1.2 mm long, ovoid- 
lenticular, with 9-14 longitudinal ribs and 12-16 trans- 
verse ridges, yellowish brown. 

Plants escaped from cultivation in Panama and 
growing wild; the species is a native of Mexico and 
Guatemala at elevations from 1000 to 3000 m. 

Oxalis tetraphylla is recognized by its bulbous 
base, long-petiolate, palmately 4-foliolate leaves, 
almost triangular rounded leaflets with slightly in- 
dented distal margins, and pink to violet flowers. 
This species appears to have become naturalized 
in the Chiriqui Highlands of Panama, but it has 
not yet been found in Costa Rica. 


By William Burger 

REFERENCE K. R. Robertson, The genera of 
Geraniaceae in the southeastern United States. J. 
Arnold Arbor. 53: 182-201. 1972. 

Annual, biennial, or perennial herbs, subshrubs (rarely 
small trees), stems sometimes succulent, often puberu- 
lent with simple or gland-tipped hairs; rhizomes, tubers, 
or thickened roots often present; stipules present and 
paired at the leaf-base. Leaves alternate or opposite (and 
often unequal at the node when opposite), basal or cau- 
line, simple and lobed to deeply divided or pinnately or 
palmately compound, petioles usually present; leaf blades 
lobed or toothed to deeply sinuate (rarely entire), pal- 
mately or pinnately veined. Inflorescences terminal or 
axillary, generally cymose to umbellate, rarely with only 
1 or 2 axillary flowers, pedicels usually subtended by 
subulate stipulelike bracts. Flowers bisexual (rarely uni- 
sexual), radially symmetrical (bilaterally symmetrical in 
Pelargonium), hypogynous, perianth 5-parted, sepals free 
or united at the base, imbricate (valvate), often awned 
or with a narrow tip, persisting in fruit; petals 5 (rarely 
4, 2, or 0), free, imbricate or convolute in bud, often 
narrowed at the base and emarginate at the apex, ca- 
ducous, usually with 5 small nectariferous glands alter- 
nating with the petals; androecium usually with 10 sta- 
mens and the outer opposite the petals (rarely with 1 5 
stamens), all the stamens fertile or some reduced and 
staminodial, filaments slender, united at the base, an- 
thers attached at the center of the back (versatile), 
2-thecous and dehiscing longitudinally, introrse; pistil 1 , 
of 3-5 (rarely 2 or 6) carpels united by their styles to a 
central axis (column) and forming a "beak" on the ovary 
and fruit, ovary superior and 3-5 -lobed, 3-5-loculate 
with 2 ovules pendulous from axile placentae in each 
locule, style present (rarely, absent), 5-parted near the 
apex and with 5 slender ligulate stigmas. Fruit a schizo- 
carp usually breaking up into 5 mericarps (carpel-bodies) 
and separating from the persisting central column with 
a part of the style forming an awn on the apex of the 
mericarp, dehiscing (often explosively) by the separation 
and contraction of the long stylar elements; seed smooth 
or minutely reticulate, without endosperm, embryo usu- 
ally curved. 

A family of five genera and 700 species widely 
distributed in temperate, subtropical, and mon- 
tane tropical areas. Geranium and Erodium have 
native New World species; Pelargonium of the Old 
World has several widely cultivated ornamental 
species. Erodium cicutarium has been used as a 
forage plant, but has become a weed in many areas. 
This family is closely related to Vivianiaceae of 
South America and Dirachmaceae of Socotra, and 
these taxa are sometimes included in a broader 
circumscription of the Geraniaceae. The Oxali- 
daceae are also closely related. 



Key to the Genera of Geraniaceae Found in Central America 

la. Leaves not deeply dissected, usually ovate to reniform and palmately veined; petals slightly unequal 
with the upper 2 usually larger than the lower 3, 1 sepal calcarate at the base and with a spur 

attached to the pedicel, lacking a disc or extrastaminal glands; cultivated ornamentals 


1 b. Leaves deeply dissected; petals all the same size and shape, sepals never calcarate and without an 
adnate spur, a disc or extrastaminal glands present; wild or weedy (rarely cultivated) 2a 

2a. Leaves palmately or radially dissected or lobed, usually (3-)5-7-parted or lobed, the lobes usually 
dentate; flowers with 1 stamens and 1 anthers; styles simply coiled in fruit, glabrous on the inner 
face; with 2 indigenous species Geranium 

2b. Leaves pinnately divided, the pinnate divisions pinnately veined and lobed; flowers usually with 
only 5 anthers; style spirally coiled in age and pubescent on the inner side; not yet collected in Costa 
Rica . . . Erodium 

Kr odium L'Heritier 

Annual or perennial herbs, beginning as acaulescent 
rosette plants and later with elongate stems, often with 
several elongate stems arising from unbranched taproots; 
stipules paired at each leaf. Leaves opposite or verticil- 
late, basal and cauline leaves similar, pinnately com- 
pound or deeply pinnately lobed (rarely simple or pal- 
mately lobed), petioles short; leaf blades (leaflets) toothed, 
lobed, or divided, sessile or petiolulate. Inflorescences 
solitary and axillary, umbellate, the ultimate peduncles 
usually with more than 2 flowers. Flowers bisexual (rare- 
ly unisexual and the plants dioecious), radially or slightly 
bilaterally symmetrical, sepals 5, free, often aristate- 
awned or mucronate at the apex; petals 5, glabrous, equal 
or subequal, pink to violet or purple, venation often 
more darkly colored, sometimes with a dark spot at the 
base of the upper 2 (or all) petals; androecium of 5 outer 
staminodia or scales and 5 inner fertile stamens; pistil 
with a puberulent ovary. Fruit a schizocarp, mostly de- 
hiscing downward from the top, mericarps and their awns 
becoming completely detached from the central axis, 

mericarps tapering toward the base and usually with per- 
sisting awns, awns puberulent on the inner (adaxial) sur- 
face and the lower part coiling into a spiral when freed 
from the central axis; seeds smooth. 

A temperate zone genus of 60-80 species, cen- 
tered in the area of North Africa and Mediterra- 
nean Europe to central Asia, with some species in 
Australia and southern South America. A few spe- 
cies have become weedy throughout the world. 
The elongate pinnately compound leaves with the 
leaflets deeply pinnatisect are very distinctive. Ma- 
terial of this genus has not been seen from Costa 
Rica, but two species have become naturalized in 
northern Central America at elevations from 1 500 
to 3500 m. These two species, E. cicutarium (L.) 
L'Her. ex Aiton and E. moschatum (Burm.f.) 
L'Her. ex Aiton, can be distinguished by the fol- 
lowing key. 

Key to the Species of Erodium in Northern Central America 

la. Leaflets deeply pinnatisect; tips of sepals with setiferous hairs, inflorescences lacking viscid hairs 

E. cicutarium 

Ib. Leaflets serrate or incised; tips of the sepals lacking setiferous hairs; inflorescences with viscid nairs 

. E. moschatum 

Geranium Linnaeus 

REFERENCE H. E. Moore, Jr., A revision of the 
genus Geranium in Mexico and Central America. 
Contr. Gray Herb. 146: 1-108. 1943. 

Annual or perennial herbs (rarely small shrubs), stems 
of 2 kinds: (1) herbaceous and leafy flowering stems with 

slightly swollen nodes, and (2) thickened basal or un- 
derground stems and rhizomes, often with dichotomous 
branching, with thick taproots or adventitious roots; 
stipules paired. Leaves alternate, opposite or closely con- 
gested, often alternate in the inflorescences, cauline or 
from the basal stem, simple but often deeply lobed or 
palmately compound, petioles expanded at the base, long 
in the basal leaves and shorter in the cauline leaves; leaf 
blades mostly circular to pentagonal in outline, pal- 
mately to radiately deeply cleft or lobed, the lobes usually 
lobulate or incised. Inflorescences terminal or axillary, 



often cymose and umbelliform, ultimate peduncles 1- or 
2-flowered and with 2 or 4 stipulelike bracteoles, usually 
long-pedunculate or long-pedicellate. Flowers bisexual 
and radially symmetrical, small (5 mm) to large (40 mm), 
sepals 5, free, imbricate, often with a narrow tip or awn 
at the apex; petals 5, free, imbricate, puberulent at the 
base and often emarginate at the apex, white to pink or 
reddish purple, a disc and glands present; stamens 10 in 
2 whorls, often of 2 lengths, filaments slender and con- 
nate near the base, anthers versatile; pistil with a 5-lobed 
ovary, often puberulent, with 2 ovules in each locule but 
only 1 developing, the 5 styles united to the central col- 
umn, stigmas 5. Fruit a schizocarp with a very unusual 
mode of dehiscence, the basal carpels splitting into 5 (or 
fewer) mericarps (carpel-bodies) and carried upward (of- 
ten explosively) by the bending of the revolute styles, 
which remain attached to the apex of the central column 
(carpophore), styles and central column form the beak 
on the pistil and developing fruit, mericarps rounded at 
the base and with a persisting awn (part of the style) 
distally; seeds usually ejected from the mericarps, surface 
reticulate or smooth, with little or no endosperm. 

A genus of 250-300 species widely distributed 
in temperate, montane tropical, and polar regions 
of the world. Major areas of diversification are the 
mountains of Europe, the Mediterranean region, 
and the major cordilleras of South America and 
western North America. The genus is much in 
need of a modern revision, both as regards the 
delimitation of species and their relationships. Only 
two species are recognized here, and these are like- 
ly to become submerged within larger more broad- 
ly defined species when the Neotropical taxa are 
studied more carefully. 

Geranium is a very distinctive genus with its 
herbaceous habit, simple but palmately deeply 
lobed leaves with incised margins, few-flowered 
inflorescences, 5 -parted hypogynous flowers with 
usually ten stamens, and beaked fruit with unusual 
mode of dehiscence. 

Key to the Species of Geranium in Costa Rica 

la. Leaves essentially glabrous on the upper and lower surfaces, but often minutely ciliate along the 
edges; short plants with stems covered with persisting and overlapping stipules, the distal internodes 
not usually visible; sepals glabrous or ciliate along the edge G. costaricense 

1 b. Leaves sparsely to densely puberulent on their surfaces; erect or decumbent plants with long, slender, 

conspicuous distal internodes; sepals puberulent and often with gland-tipped hairs 

G. guatemalensis 

Geranium costaricense H. E. Moore, Gentes. Herb. 
8: 253. 1951, based on G. cucullatum H.B.K. 
var. multifidum Suessenguth, Bot. Jahrb. Syst. 
72: 276. 1942 (non G. cucullatum L., nee G. 
multifidum Sweet). Figure 5. 

Perennial herbs, stems short (to 10 cm tall or 30 cm 
long) and partly horizontal, 5-10 mm thick (including 
the persisting stipules), arising from a vertical slightly 
woody rootstock; stipules (6-)8-15 mm long, lanceolate 
to subulate, thin, brownish and covering the stem. Leaves 
closely clustered at the apex of the stem, petioles (l-)3- 
10 cm long, 0.5-0.7 mm thick, expanded at the base and 
united with the stipules, minutely (0.1-0.3 mm) puber- 
ulent with whitish retrorse hairs, the hairs dense at the 
apex of the petiole; leaf blades 1 2-20 mm long, 1 5-25 
mm broad, rounded in outline, deeply divided, the pri- 
mary divisions forming 3 or 5 parts that are also deeply 
lobulate or divided, the secondary divisions usually with 
3 prominent lobules and each leaf with as many as 25 
distal lobules, acute and often reddish at the tips of the 
lobules, glabrous and the major veins impressed above, 
glabrous or ciliate along the distal margins, glabrous be- 
neath. Inflorescences apparently solitary and axillary from 
among the crowded leaves, 1 -flowered, peduncles (0.5-) 
3-5 cm long (to the narrowly lanceolate paired bracte- 
oles), bracteoles ca. 8 mm long, pedicels 1 .5-5.5 cm long, 

sparsely and minutely puberulent, more densely retrorse 
whitish puberulent beneath the perianth. Flowers ca. 10 
mm long, to 24 mm broad, sepals 6-8 mm long, 2-3 
mm broad at the base, narrowly ovate, with a short 
narrow tip, green and glabrous but ciliate along the trans- 
lucent margin and just beneath the tip; petals 9-15 mm 
long, 5 mm wide, obovate, rounded or truncated distally, 
white to pink with dark red or purple longitudinal lines; 
stamens ca. 6 mm long; pistil 7-8 mm long. Fruits (12-) 
14-17 mm long, united styles (beak) 0.8-1.2 mm thick, 
free stigmas 1-2 mm long, mericarps (carpel bodies) 2- 
2.5 mm long, sparsely puberulent. 

Plants of evergreen higher montane forest for- 
mations from 2600 to 3400 m elevation. Flowers 
and fruits have been collected from January to 
August. This species is only known from the Cor- 
dillera de Talamanca; it has been collected from 
the area near El Empalme to the area near Chirripo 

Geranium costaricense is recognized by its deep- 
ly divided and many-lobed leaves, short stipule- 
covered stems, and relative lack of pubescence. 
This species may prove to be a subspecific element 
of an Andean species when the genus is properly 
revised. The smaller leaves with more narrow lobes 



Geranium costancense 

FIG. 5. Geraniaceae: two species of Geranium. 


help distinguish this species from Geranium gua- 

Geranium guatemalense K nut h, /// Engler, Pflanz- 
enr. 4(129): 200. 1912. G. repens H. E. Moore, 
Contr. Gray Herb. 146: 78. 1943, based on G. 
pulchrumC. V. Morton, Phytologia 1: 147. 1935, 
non G. pulchrum N. E. Brown, 1895. Figure 5. 

Perennial herbs, stems 1 0-80(-1 50) cm long, erect when 
young, ascending to procumbent in age, lower stems ca. 
4 mm thick, distal stems 0.5-1 mm thick, often rooting 
at the nodes, internodes to 1 5 cm long, sparsely to dense- 
ly puberulent with thin whitish (sometimes gland-tipped) 
hairs ca. 0.5 mm long, roots fibrous to woody; stipules 
5-10 mm long, subulate or lanceolate, with a slender tip 
1-2 mm long, glabrous and ciliate to puberulent over 
the surfaces. Basal leaves few to many, not long persist- 
ing, with petioles 5-25 cm long and laminae deeply di- 
vided into 3-7 nearly equal narrowly rhombic lobes; 
cauline leaves with petioles (l-)2-8(-l 4) cm long, strigil- 
lose to hirsutulous, the hairs more dense beneath the leaf 
blades; cauline leaf blades (l-)2-5.5(-8) cm long, 2-6 
(-1 1) cm broad, deltoid to pentagonal or hastate in out- 
line, mostly with 3 or 5 major lobes (parts), distal lobes 
often rhombic and conspicuously toothed or cleft above 
the middle, lateral lobes broader than the distal but not 
as long, usually drying darker above than below, upper 
surface with slender ascending hairs paralleling the major 
veins, lower surface densely hirsutulous on the veins and 
surfaces beneath, the hairs thin, slightly curved or straight 
and 0.4-0.8 mm long. Inflorescences solitary and axil- 
lary, each peduncle usually 2-flowered, (l-)3-5(-10) cm 
long, 0.3-0.5 mm thick (dry), bracteoles 2.5-4 mm long, 
subulate, pedicels (3-)5-20(-35) mm long, with short 
pilose and longer (0.7 mm) gland-tipped hairs more dense 
beneath the flowers. Flowers 6-15 mm long and 8-20 
mm broad, cam pan u late to rotate, sepals (4.5-)6-7(-8) 
mm long (including a slender awn-tip 0.5-1 .5 mm long), 
1.5-3 mm broad, narrowly oblong, usually with glan- 
dular hairs ca. 0.7 mm long on the veins and margins; 
petals (6-)8-14 mm long (3-)4-7 mm wide, narrowly 
obovate, lilac to pale lavender, apex entire to deeply 
notched; stamens with filaments shorter than the sepals; 
stigmas ca. 2 mm long. Fruits 1 8-20 mm long, beak 0.8- 
1 .5 mm thick, hispidulous or with thin gland- tipped hairs 
0.5 mm long, mericarps 2.5-4 mm long and 1.5-2 mm 
thick; seeds 2-3 mm long, dark brown and reticulate. 

Herbs of evergreen higher montane forest for- 
mations from (1100-)1700 to 3300 m elevation 
in Costa Rica. Flowers and fruit have been col- 
lected in all months of the year except March. The 
species ranges from Guatemala to Panama. 

Geranium guatemalense is recognized by its pu- 
berulent flowers and foliage, deeply lobed leaves 
with cleft distal lobes, and spreading stems with 
slender internodes. The specimens placed under 
this name include a number of different species 

according to Moore's monograph, but the flowers 
are remarkably alike and the distinctions of length 
of the stylar beak in fruit seem insignificant. It 
seems best to place this material under a single 
name until the genus can be carefully revised. 
However, there seem to be ecologically correlated 
morphological distinctions among our material. 

Specimens from higher elevations (above 2800 
m) have smaller, more deeply divided leaves and 
the leaf-divisions are more deeply incised or lobed. 
Specimens from below 2200 m often have broader 
leaves that are less deeply incised and are thinner 
in texture. These differences can be quite striking 
in some specimens, but it does not appear that 
they are correlated with any consistent differences 
in flowers or fruit. These differences appear to be 
clinal and may be worthy of subspecific recogni- 
tion. (Compare the differences between G. gua- 
temalense and G. repens as outlined by MacBryde 
in the Flora of Panama, Ann. Missouri Bot. Gard. 
54: 202. 1967.) Also included here is material as- 
cribed to G. mexicanum H.B.K. by Standley in 
his Flora of Costa Rica (1937-1938, p. 560). 

Pelargonium L'Heritier 

Annual or perennial herbs to subshrubs or small shrubs, 
stems usually thick, usually puberulent, often viscid and 
aromatic; stipules various, often prominent. Leaves op- 
posite or alternate, simple (rarely compound) and peti- 
olate; leaf blades entire and lobed to crenate or serrate, 
or palmately to pinnately lobed or incised, often fleshy, 
venation palmate or pinnate. Inflorescences terminal, 
axillary or leaf-opposed, 2-many-flowered pseudo-um- 
bels (flowers rarely solitary). Flowers bilaterally sym- 
metrical, sepals 5, free, imbricate, or valvate, unequal 
and 1 forming a short spur or nectariferous tube which 
is decurrent on the pedicel and adnate to it; petals 5(0-4), 
free, imbricate, unequal, usually narrowed to the base, 
a disc or extrastaminal glands absent; stamens 10 but 
usually with only 5-7 bearing anthers and the others 
sterile, filaments linear, united only at the base; pistil 1 , 
ovary 5-lobed and 5-loculed, each locule with 2 pen- 
dulous ovules, styles forming a beak around a persistent 
central column, puberulent within, stigmas 5, usually 
filiform. Fruit a schizocarp, breaking into 5 basal 1 -seed- 
ed mericarps, the mericarps acute at the base and round- 
ed at the apex, thrown upward by the spirally coiled style, 
which is often puberulent or feathery distally, the central 
axis persisting; seeds oblong to ovoid, keeled and with 
2 grooves, smooth or foveolate, endosperm absent. 

A genus of over 200 species, nearly all from 
South Africa, with a few from tropical Africa and 
Australia. Many horticultural hybrids are culti- 
vated as garden and potted plants. 



Pelargonium x hortorum L. H. Bailey, Stand. Cycl. 
Hort. 2531. 1916. 

Succulent-stemmed herbs or subshrubs, to 1.5 m tall; 
stipules broad and expanded at the leaf-base, to 20 mm 
long and 15 mm broad. Leaves alternate or opposite, 
petioles 2-20 cm long, puberulent; leaf blades 4-12 cm 
long, 6-15 cm broad, ovate to rounded or reniform, 
crenate-dentate or scalloped around the edge, cordate at 
the base, often with zones of dark and light green on the 
leaf surface, puberulent on both surfaces with slender 
hairs. Flowers with nearly equal petals, double-flowered 
and other forms sometimes grown, red to pink, salmon, 
or white. 

A popular ornamental of complex hybrid origin 
used both for garden flower beds and as a pot plant; 
represented by many varieties. The brightly col- 
ored flowers, usually variegated foliage, and suc- 
culent aromatic vegetative parts make this a very 
distinctive plant. It is called geranio in Spanish 
and the "garden geranium" in English. According 
to Standley (Flora of Costa Rica, 1937-1938, p. 
560), Pelargonium graveolens (Thunb.) L'Her. is 
also grown in our area; it has deeply lobed and 
crisped leaves. 

lobes), inserted on the floral tube, equal or the lower 2 
larger, imbricate in bud; petals 5 (or the lower 3 rarely 
absent), free, imbricate, strongly narrowed to the base 
(clawed), the upper 2 adaxial petals usually differing from 
the 3 lower (abaxial) petals, the upper 2 often hairy at 
the base, with entire to serrate or laciniate distal margins; 
stamens 8 in 2 unequal whorls of 4, filaments free, slender 
or winged at the base, anthers small, 2-thecous, opening 
laterally by longitudinal slits, pollen tricolporate or di- 
colporate; pistil 1 (3-carpellate), glabrous, ovary 3-lobed 
and 3-locular, each locule with 1 pendulous ovule from 
the apex of the locule, style slender, 3-parted distally, 
stigmas simple. Fruits indehiscent, separating from the 
central axis into 1 -seeded drupaceous or nutlike men- 
carps (with a single samaroid mericarp in Magallana); 
seed with a large straight embryo and 2 thick cotyledons, 
endosperm absent. 

A New World family of three genera. Tropaeo- 
lum contains 86 species according to Sparre, rang- 
ing from Mexico to Chile and southern Argentina. 
The two other genera have three species and are 
found only in southernmost South America; they 
are very similar to Tropaeolum. Magallana pro- 
duces winged samara-like carpels, and Trophaeas- 
trum has erect peduncles and an almost regular 
calyx with a very small spur. 


By William Burger 

REFERENCE B. Sparre, Tropaeolaceae, in Flora 
of Panama, Ann. Missouri Bot. Card. 62: 15-20, 

Annual or perennial herbs, mostly climbers with long 
twining petioles, stems often glabrous and semisuccu- 
lent; stipules present and small or absent. Leaves alter- 
nate (sometimes opposite near the base of the plant), 
simple and peltate or subpeltate, the leaf blades pal- 
mately (radiately) veined, often palmately lobed or an- 
gled (to orbicular or reniform), margin entire. Inflores- 
cences of solitary axillary long-pedunculate (pedicellate) 
flowers, rarely umbellate or fasciculate, ebracteate in 
nearly all species, bird- or insect-pollinated. Flowers bi- 
sexual, bilaterally symmetrical (almost radially sym- 
metrical in Trophaeastrum), showy and yellow to orange, 
red, or dark purple, hypogynous to somewhat perigynous 
(with a floral tube or hypanthium), with a backward- 
projecting spur which has been interpreted as ( 1 ) an ex- 
tension of the hypanthium or (2) part of the upper se- 
pal(s) (the spur is little developed in Trophaeastrum), 
sepals 5, free or united near the base (and with 5 calyx 

Tropaeolum Linnaeus 

Characters of the family (see above). The genus is 
easily recognized because of its usually herbaceous twin- 
ing habit with long twisted petioles, peltate or subpeltate 
laminae, and solitary showy flowers with a conspicuous 
backward oriented nectariferous spur. 

Tropaeolum tuberosum R. & P. (anu) is an im- 
portant tuber crop in the high Andes. Tropaeolum 
majus, T. minus L., and T. peltophorum Bentham 
and their hybrids are important ornamental plants 
(the "garden nasturtiums") grown throughout the 
world. Tropaeolum peregrinum L. (the "canary- 
bird flower") is also an important garden orna- 

The following treatment follows Sparre, but it 
is possible that the native species recognized below 
are in reality only different elements of a single 
polymorphic species. More and better collections 
of the rarer taxa (T. moritziana and T. pendulum) 
are needed to assess variability within populations 
and the validity of our present species concepts. 

Key to the Species of Tropaeolum 

la. Flowers 4-7 cm long, petals about the same size, much exceeding the sepals; petioles attached near 
the center of the lamina; plants grown for ornament and rarely escaping T. majus 



Ib. Flowers 2.5-3.5 cm long, petals unequal and only slightly exceeding the sepals; petioles attached 
about halfway between the margin and the center of the lamina; wild climbers 2a 

2a. Leaves with 5 major veins, the 3 distal major veins not bifid (except near the margin), the leaves 
usually with 9 veins radiating from the petiole attachment; lower petals ciliate at the base of the 
lamina (lateral sepals ca. 10 mm long) T. moritzianum 

2b. Leaves usually with 3 major veins, the 2 lateral veins usually strongly bifid, the leaves usually with 
7 or 8 veins radiating from the petiole attachment, usually with 3 major distal veins and 4 or 5 
smaller veins; lower petals not ciliate at the base of the laminae 3a 

3a. Distal edge of the petals deeply serrate to laciniate, rarely extending beyond the sepals, lateral sepals 
ca. 6 mm long and 5 mm broad, outer parts of the flower usually orange to red; common plants . . 

T. emarginatum 

3b. Distal edge of the petals entire to serrate, usually extending slightly beyond the sepals, lateral sepals 
ca. 10 mm long and 7 mm broad, outer parts of the flower usually yellowish; rarely collected plants 

T. pendulum 

Tropaeolum emarginatum Turcz., Bull. Soc. Imp. 
Naturalistes Moscou 31: 425. 1858. T. guate- 
malense Suess., Repert. Spec. Nov. Regni Veg. 
51: 205. 1942. T. moritzianum sensu auctores, 
non Klotsch. 

Twining herbaceous climbers to 3 m high (to 8 m 
long?) in shrubs and small trees, internodes to 20 cm 
long, 0.5-3 mm thick (dry), minutely (0.3 mm) whitish 
puberulent at the nodes and glabrous elsewhere; stipules 
2-3 mm long and linear or absent. Leaves peltate, petiole 
attached 3-12 mm from the proximal margin, petioles 
4-8 cm long, 0.4-1 mm thick (dry), glabrous, often twist- 
ed in the lower half; leaf blades ( 1 . 5-)3-8 cm long, ( 1 .8-)3- 
9 cm broad, bluntly triangular (with rounded corners) to 
ovate-triangular in outline, usually with a straight base 
and 3 or 5 distal and lateral lobes, sinuses shallow (2-5 
mm) and usually broadly rounded, apex obtusely round- 
ed, sometimes with a small (0.5-2 mm) tip, drying mem- 
branaceous to thin chartaceous, glabrous above and be- 
low, often glaucous beneath, venation radiating from the 
petiole attachment and with 3 major distal veins, the 2 
lateral major veins usually parallel with the base of the 
lamina and bifid in the proximal half. Inflorescence of 
solitary axillary flowers, peduncles (= pedicels) 3-12 cm 
long, filiform, pendant. Flowers 2.5-3.5 cm long, orange 
to reddish orange on the outer parts, spur 12-24 mm 
long, 1.5-3 mm in diameter, lateral sepals ca. 6 mm long 
and 5 mm broad, corolla ca. 8 mm long and 47 mm 
broad distally, fimbriate distally, yellow or marked with 
purple; filaments ca. 7 mm long, anthers ca. 0.7 mm 
long. Fruit a deeply lobed schizocarp 5-8 mm long, the 
mcricarps to 8 mm long (measured parallel to the central 
axis) and 1 2 mm broad, rectangular, fleshy. 

Plants of open secondary sites in montane ev- 
ergreen forest formations, from 1300 to 2800 m 
elevation on the wet Caribbean slope in Costa Rica. 
Probably flowering throughout the year. The spe- 
cies ranges from Chiapas, Mexico, to Chiriqui, 
Panama, and Colombia. 

Tropaeolum emarginatum is recognized by its 
slender, twining, almost glabrous stems, long 

twisted petioles, peltate leaves with three major 
veins, long-pendant showy flowers, and colorful 
rearward-projecting nectariferous spur. The leaf 
blades are usually broader than long with a straight 
or convex base and with five broad distal and lat- 
eral lobes. This species is very similar to T. moritzi- 
anum, and the differences in the flowers are very 
difficult to see in dried specimens. Also, the dis- 
tinction between five major veins and three major 
veins breaks down in some collections of T. emar- 
ginatum where the lateral veins are strongly bifid 
near the base (see the discussion under T. morit- 

Tropaeolum majus L., Sp. PL 345. 1753. 

Small erect herbs or climbing annual vines, stems of- 
ten to 5 mm thick and fleshy, internodes 1-15 cm long, 
usually glabrous; stipules absent or obscure. Leaves pel- 
tate with the petiole attached near the center of the lam- 
ina, petioles 8-20 cm long, 0.5-2 mm thick, usually gla- 
brous; leaf blades (3-)5-10 cm long, (3-)5-10 cm broad, 
suborbicular with 5-7 rounded (and weakly defined) lobes, 
often with 3 broadly rounded distal lobes and the sinuses 
only 1-3 mm deep, drying thin chartaceous, glabrous 
above, minutely (0. 1-0.2 mm) papillate puberulent be- 
neath, venation with 5-7(-9) major veins radiating out- 
ward from the peltate base. Inflorescence of solitary ax- 
illary flowers, peduncles to 25 cm long, often equaling 
the petioles, glabrous. Flowers 4-7 cm long, the spur 25- 
35 mm long, sepals 13-18 mm long, 4-8 mm broad, 
sepals and spur often yellowish green; petals subequal, 
upper petals 3-4 cm long with a lamina 1 5-20 mm long 
and equally broad and with a narrow clawed base 1 2- 
15 mm long, bright orange to yellow or dark purple. 
Fruits to 10 mm long, fleshy. 

A species probably of hybrid origin and not 
known in the wild, having originated in Peru. It 
is now grown as an ornamental throughout the 



world. It has been called capuchina, espuela del 
gelan, mastuerzo, and "garden nasturtium." The 
plants are sometimes used for medicinal purposes. 

Tropaeolum moritzianum Klotzsch, Allg. Garten- 
zeitung6: 241. 1838. 

Herbaceous climbers to 10 m long, internodes to 25 
cm long, 0.5-2.5 mm thick (dry), glabrous; stipules ab- 
sent. Leaves peltate with the petiole attached about half- 
way between the center and the basal margin, petioles 
5-15 cm long, 0.3-1 mm thick, glabrous; leaf blades 3- 
9 cm long, 2.5-8.5 cm broad, broadly ovate-triangular 
to suborbicular, usually with a straight or rounded (con- 
vex) base and 5 or 7 distal lobes, the lobes often weakly 
denned with shallow (1-3 mm) sinuses, tips of the lobes 
mucronate to emarginate, the leaf blades drying mem- 
branaceous and usually glaucous beneath, glabrous above 
and below, with usually 9 veins radiating from the petiole 
attachment, with 5 major veins, the 3 major distal veins 
unbranched and the 2 lateral veins often bifid. Inflores- 
cences of solitary axillary flowers, peduncles 7-20 cm 
long, ca. 0.5 mm thick, pendant, glabrous. Flowers ca. 
3 cm long, glabrous, spur 20-25 mm long, straight or 
slightly curved upward, sepals (calyx-lobes) 10-12 mm 
long, 4-5 mm broad, broadly elliptic, reddish; upper 
petals 8-9 mm long, 4-5 mm broad distally, lower petals 
10-12 mm long, with a narrow ciliate base and distal 
lamina ca. 7 mm long and 4-5.5 mm broad, the petals 
yellow to orange or reddish (with darker purple veins) 
and with a deeply serrate-ciliate distal margin. Fruits 
becoming 10 mm long, triangular, and deeply ribbed 
before separation of the mericarps. 

Plants often clambering over shrubs in open for- 
est edges in evergreen forest formations, from 1000 
to 2000 m elevation. Flowering collections are few 
and range from September to January in our area. 
The species is said to range from Guatemala to 
Colombia and Venezuela (but see below). 

Tropaeolum moritzianum is recognized by the 
climbing habit with long twisted petioles, weakly 
lobed peltate leaves, laminae with five major veins, 
lack of pubescence, and solitary pendant reddish 
flowers with long nectariferous spurs. This species 
seems to be very similar to both T. emarginatum 
and T. pendulum, differing in leaf venation and 
subtle characters of the flowers. It is possible that 
all three are different forms of a single polymor- 
phic species, for which T. moritzianum would be 
the oldest name. It is highly likely that T. war- 
scewiczii Buchenau (Bot. Jahrb. Syst. 26: 582. 
1899), based on Warscewicz 2-15 from "Costa 
Rica et Veragua" (not seen), is a synonym of this 

Tropaeolum pendulum Klotzsch, Allg. Gartenzeit- 
ung 18: 377. 1850. 

Annual herbaceous climbers to 5(-8) m long, inter- 
nodes 3-18 cm long, 0.5-2.5 mm thick (dry), sparsely 
puberulent at the nodes and glabrous elsewhere; stipules 
small (0.5 mm) and caducous. Leaves peltate with the 
petioles attached halfway between the center and margin 
(4-14 mm from the edge), petioles 4-10 cm long, often 
much twisted in the lower half, sparsely puberulent with 
thin whitish hairs near the base or glabrous; leaf blades 
3-7 cm long, 4-9 cm broad, pentagonal to very broadly 
ovate-triangular (suborbicular), usually 5- or 3-lobed 
distally, the lobes broadly rounded and separated by very 
shallow (0-3 mm) sinuses, often short-mucronate with 
tips 0.3-1.5 mm long, base straight to slightly concave 
or rounded, lamina drying membranaceous and green- 
ish, glabrous, major veins 3(-5) with the lateral veins 
usually bifid. Inflorescences of solitary axillary flowers, 
peduncles 2.5-5(-7) cm long, pendant, and filiform (dry), 
glabrous. Flowers 2.5-3 cm long, yellowish, spur 12-16 
mm long, 0.7-1.2 mm thick distally, greenish, lower se- 
pals ca. 12 mm long and 3-4 mm broad, upper sepals 
ca. 10 mm long and 6-8 mm broad; upper (larger) petals 
8-12 mm long and exceeding the calyx-lobes, with a 
narrow base ca. 5 mm long and expanded lamina to 8 
mm broad, entire to slightly serrate on the distal petal 
margins. Fruits 5-6 mm long, longitudinally ribbed (be- 
fore separation of mericarps). 

Rarely collected climbing plants of montane ev- 
ergreen forest formations, from 1600 to 2300 m 
elevation on the Pacific slope and along the central 
highlands in Costa Rica. Flowering material has 
been collected in July-September, December, and 
January. The species ranges from Costa Rica to 
Colombia and Ecuador. 

Tropaeolum pendulum is distinguished by its 
yellow flowers with greenish spurs, peltate leaves 
with rounded, often mucronate lobes, long calyx- 
lobes, and petals with entire to serrate distal mar- 
gins. This species resembles the more common T. 
emarginatum and T. moritzianum, but those spe- 
cies tend to have deep orange flowers with fim- 
briate petal margins that barely exceed the calyx- 
lobes. The flowers of T. pendulum tend to dry 
thinner, more whitish, and more translucent than 
the other two species. However, there is the pos- 
sibility that all three are part of a single polymor- 
phic complex (see the discussion under T. moritzi- 
anum). The original description of T. pendulum 
was based on plants grown in Europe from seeds 
originating in Costa Rica. 


By William Burger 

REFERENCE K. R. Robertson, The Linaceae in 
the Southeastern United States. J. Arnold Arbor. 
52: 649-665. 1971. 



Herbs, rarely subshrubs or shrubs, stipules present and 
small (sometimes glandlike or interpetiolar) or absent. 
Leaves alternate or opposite (whorled), simple, sessile or 
petiolate, leaf blades entire, often narrow. Inflorescences 
cymose or paniculate, few-flowered to racemose or spi- 
cate, axillary or terminal. Flowers bisexual, radially sym- 
metrical, hypogynous, 5-parted (4-parted in Radiola), 
sepals 5 (4), free or united near the base, imbricate, per- 
sisting; petals 5 (4), free, contorted or convolute in bud, 
narrowed to the base or clawed, fugacious, a disc absent; 
stamens the same number as the petals, alternate with 
the petals (opposite in Anisadenia), sometimes alternat- 
ing with small staminodes, filaments united to form a 
short tube or cup, anthers basifixed and 2-thecous, de- 
hiscing by longitudinal slits, introrse; pistil 1 , composed 
of (2-)3-5 united carpels, ovary superior, (2-)3-5-locular 
or unilocular near the apex, with 2 axile pendulous ovules 
in each locule, styles (2-)3-5, free or united below, stig- 
mas capitate. Fruit a septicidal capsule, usually 3-5- 
valved (of 2 indehiscent 1 -seeded mericarps in Anisa- 
denia); seed with a usually straight embryo and with flat 
cotyledons, endosperm oily, little, or none. 

This family is now delimited more narrowly 
than in the past, and only one genus is represented 
in Central America. Cronquist (198 1) included six 
genera within the family and estimated 220 spe- 
cies. The largest genus by far is Linum, with about 
200 species in temperate and subtropical areas of 
the world. Woody genera formerly considered part 
of the family have now been separated as Hugonia- 
ceae (Old World tropics), Ixonanthaceae (five pan- 
tropical genera), and Humiriaceae (see the follow- 
ing family). 

Linum Linnaeus 

Annual or perennial herbs or small shrubs woody at 
the base, usually glabrous; stipules absent or reduced to 

Key to the Species of Linum 

1 a. Petals yellow, ca. 6 mm long, sepals 2-3 mm long; rarely collected wild plants of higher (ca. 2000 
m) elevations L. guatemalense 

Ib. Petals blue or white, 10-15 mm long, sepals 5-7 mm long; plants cultivated for ornament, fiber, or 
oil seeds . . L. usitatissimum 

small paired glandlike structures. Leaves alternate, less 
often opposite or in whorls of 4, simple, sessile or pet- 
iolate, leaf blades elliptic or ovate to lanceolate or linear, 
entire, pinnately veined. Inflorescences terminal or ax- 
illary, racemose to corymbose, less often cymose to fas- 
ciculate or in spicate heads, bracts present and with 2 
dark glands at the basal margins. Flowers bisexual and 
radially symmetrical, blue to white or yellow (red), hy- 
pogynous, sepals 5, free or united at the base, lanceolate 
to ovate, usually with long narrow apices, often with 
gland-tipped teeth, with 1-5 veins and persisting in fruit; 
petals 5, free or slightly united at the base, obovate and 
narrowed at the base, with 5 small nectar-glands opposite 
the petals and adnate to the staminal tube; stamens 5, 
alternating with the petals, united at the base to form a 
short tube or cup, sometimes with small filamentlike 
staminodia on the edge of the tube, filaments linear, 
anthers dehiscing introrsely by longitudinal slits; pistil 
superior, ovary 5-locular or 10-locular by the formation 
of false septa, styles 5, stigmas 5, capitate to clavate. 
Fruits 5-valved or apparently 10-valved, 5-locular with 
2 seeds in each locule or 10-locular with 1 seed in each 
locule, usually dehiscing along the false septa or locules; 
seed with a straight embryo and mucilaginous testa. 

A genus of about 200 species in temperate and 
subtropical regions, especially the Northern 
Hemisphere. About 40 species are found in North 
America, and 36 in the Mediterranean. Three spe- 
cies are native to Guatemala, of which one ranges 
southward into Honduras and Nicaragua and one 
into Costa Rica. These slender, few-branched herbs 
can be confused with Schwenkia of the Solanaceae 
or Evolvulus of the Convolvulacea, but those gen- 
era have corolla tubes. 

Linum guatemalense Benth., Bot. voy. Sulphur 67. 

Herbs 50-110 cm long, annual or perennial, erect, 
branched at the base or distally (within the inflorescence), 
internodes 1-3 mm thick, terete, glabrous or sparsely 
and minutely (0.2 mm) puberulent, with slightly elevated 
and slender longitudinal ridges. Leaves alternate and as- 
cending (occasionally fasciculate on the short shoots), 
petioles absent; leaf blades 14-30 mm long, 4-8 mm 
broad, lanceolate to linear-lanceolate, acute at the apex, 

contracted or slightly rounded at the base, drying mem- 
branaceous and grayish brown, with 3-6 obscure sec- 
ondary veins on each side, glabrous above and below. 
Inflorescences terminal, 7-30 cm long, 2.5-1 5 cm broad, 
racemose to corymbiform panicles, with slender alter- 
nate lateral branches subtended by linear-lanceolate leaf- 
like bracts 6-20 mm long, 0.7-4 mm broad, glabrous. 
Flowers glabrous, sepals 2-3 mm long, 1.5-2 mm broad, 
ovate with a sharp acuminate or acute apex, margin 
occasionally with a few minute (0.2 mm) teeth; corolla 
yellow; petals ca. 6 mm long. Fruits ca. 3 mm long and 
3 mm broad, ovate with a conical apex, appearing to 



split into 10 parts; seeds 1.3-1.5 mm long, 0.8-1 mm 
broad, lenticular and lustrous brown. 

Linum guatemalense was collected in 1 989 by 
G. Hen-era and W. Gamboa (3606 CR, MO) at 1 900 
m elevation in the Sabanas de Murur-Biruk, north 
of Buenos Aires, southern Puntarenas Province. 
This is the first record of the species south of Gua- 
temala. The unbranched erect stems with broad 
distal inflorescence, alternate sessile lanceolate 
leaves, lack of pubescence, yellow flowers with five 
separate sepals and petals, and 1 0-locular capsules 
are characteristic. 

Linum usitatissimum L., Sp. PI. 277. 1753. 

Annual herbs, 20-80(-120) cm tall, single-stemmed 
or branched only at the base or below the inflorescence, 
stems slender, internodes 0.5-1.5 mm thick, glabrous; 
stipules absent. Leaves alternate and sessile; leaf blades 
6-20(-25) mm long, (0.5-)l-4 mm broad, linear to lan- 
ceolate, glabrous, with 3 major veins from the base. In- 
florescences distal corymbs or panicles, pedicels 8-14 
mm long, slender and elongating in fruit. Flowers to 1.5 
cm long, ca. 1.2 cm broad, sepals 5.5-7.5 mm long, ca. 
2 mm broad, acuminate at the apex, inner sepals with 
scarious or denticulate margins but without glandular 
dentations; petals blue or white, 10-15 mm long; stigma 
clavate. Fruits 7-10 mm long, ca. 8 mm in diameter, 
pale yellowish brown, capsule slightly longer than the 
persisting sepals, usually 1 0-locular with 5 thicker walls 
and 5 thinner walls (false septa). 

Linum usitatissimum is recognized by its slen- 
der erect stems, narrow sessile leaves, usually bright 
blue 5 -parted flowers, and capsular fruit with usu- 
ally 1 locules. These plants are not known to be 
naturalized in Costa Rica, though they are occa- 
sionally cultivated. This species has been in cul- 
tivation for more than 5,000 years in Europe and 
western Asia. Today, special varieties are grown 
for their oil seeds or their excellent fiber. Linseed 
oil is used for paints, varnishes, and coatings as 
well as an edible oil. Flax fiber is flexible, strong, 
and durable and absorbs water, making it very 
useful for towels and table coverings. The bright 
blue flowers have made this species an ornamental 
as well. This species is called linaza, linaza lino, 
and lino in Spanish, and flax or linseed in English. 


By William Burger and Nelson Zamora 

REFERENCES!. Cuatrecasas, A taxonomic re- 
vision of the Humiriaceae. Contr. U.S. Natl. Herb. 

35: 25-214. 1961. A. H. Gentry, Humiriaceae, in 
Flora of Panama, Ann. Missouri Bot. Gard. 62: 
35^4, 1975. 

Evergreen trees or shrubs, wood hard and often red- 
dish; stipules absent or minute, paired, deciduous. Leaves 
alternate, often distichous, simple petiolate or rarely ses- 
sile; leaf blades often coriaceous, entire to slightly serrate, 
pinnately veined, often glandular punctate near the mar- 
gin on the undersurface. Inflorescences axillary or pseu- 
doterminal (rarely terminal), paniculate, often corym- 
biform with trichotomous, dichotomous, or alternate 
branching, bracts and bracteoles small, persistent or de- 
ciduous, pedicels short. Flowers bisexual, radially sym- 
metrical, hypogynous, calyx 5-lobed, united to form a 
cup or short tube, glabrous to puberulent, equal or the 
outer 2 lobes smaller, imbricate in bud; petals 5, free, 
oblong-lanceolate to oblong or linear, white to yellowish 
(red), contorted or imbricate along the edges in bud (but 
appearing to be valvate); stamens 10-30 in 1-2 series or 
many and multiseriate, filaments united in the lower part 
to form a short staminal tube, free filaments usually 
alternating in length, sterile filaments (antherless stam- 
inodia) often present, anthers dorsifixed or basifixed, 
2-thecous and bilocular with longitudinal dehiscence, or 
2- or 4-thecous and unilocular and dehiscing by detach- 
ment (the 4 thecae separate on the connective with 2 
proximal and 2 distal), connective usually thick and pro- 
longed beyond the thecae, an intrastaminal disc sur- 
rounding the ovary and cupular to tubular and dentate 
to laciniate or of 10-20 free scales; pistil 1, composed 
of (4-)5(-7) united carpels, ovary sessile, ovoid to ellip- 
soid, with (4-)5(-7) locules and 1 or 2 ovules from axile 
placentae in each locule, style 1 , stigmas (4-)5(-7) and 
often capitate. Fruits drupaceous with a hard, usually 
plurilocular stone, small ( 1 cm) to large ( 1 2 cm), exocarp 
pulpy to fibrous and coriaceous in texture, endocarp 
(stone) hard and woody, the surface smooth to deeply 
rugose or costate, (4-)5(-7)-locular but with only l-2(- 
5) seeds, valves of the endocarp visible as grooves on 
the surface of the hard stone; seeds oblong, embryo 
straight or slightly curved, endosperm fleshy and oily. 

A family of eight genera and about 50 species, 
ranging from Nicaragua to southern Brazil and 
with a single species in western Africa. The family 
includes tall trees of lowland rain forests as well 
as smaller trees of deciduous forests and savannas. 
Because our species are tall trees of lowland rain 
forests, some have been little collected and are 
poorly known. For this reason, many of the floral 
details described below are based on the excellent 
monograph by Jose Cuatrecasas (see reference 

The family is recognized by the stiff" simple al- 
ternate leaves, these glabrous and lustrous with 
entire to undulate, serrulate, or crenulate margins, 
the 5-parted flowers with short calyx cup, narrow 
petals, ten or more stamens with filaments united 
at the base, cupular or scaly disc, 4-7-locular ova- 
ry, and fruit with an unusually sculptured hard 



stone. The petals are imbricate only at their edges 
and may appear valvate. The anthers are quite 
unusual, with the thecae usually borne on the low- 

er part of a thick and distally expanded connective. 
The wood is very hard and heavy. 

Key to the Genera of II umiriaceae 

la. Flowers with 50-180 stamens, anthers with 2 bilocular thecae; locules 2-ovulate; endocarp with 5 

separate Ungulate valves; leaves bluntly obtuse to rounded at the apex, margins usually entire . . . 


Ib. Flowers with 10-20 stamens, anthers with 2 unilocular thecae; locules 1-ovulate; leaves acuminate 

or abruptly short-acuminate at the apex, margins undulate to sinuate, bluntly serrulate, or crenulate 


2a. Stamens 10, anthers with lateral thecae; endocarp with inconspicuous furrows, without dorsal fo- 
ramina (apertures), alternating ribs thin; leaf margins mostly undulate to sinuate Sacoglottis 

2b. Stamens 20, anthers with basal thecae; endocarp with 5 foramina at the apex, with 5 short opercular 
valves; leaf margins mostly bluntly serrulate to crenulate Humiriastrum 

Humiriastrum (Urban) Cuatrecasas 

Evergreen trees, stipules small and deciduous or lack- 
ing. Leaves petiolate to subsessile, subcoriaceous to co- 
riaceous, entire to denticulate. Inflorescences axillary or 
pseudoterminal, paniculate and usually with dichoto- 
mous or trichotomous (cymose) branching, bracts de- 
ciduous or persistent. Flowers with calyx united to form 
a cup, calyx-lobes broadly rounded and imbricate; petals 
free, oblong to linear, stiff; stamens 20 and of 2 alternate 
lengths, glabrous, filaments united at the base, anthers 
ovate-lanceolate to oblong, basifixed, thecae 2 and uni- 
locular, ellipsoid or rounded, borne at the base of the 
expanded connective, connective well developed beyond 
the thecae, thick and acute at the apex, disc a dentate 
ring around the ovary or of free scales; pistil with carpels 
(locules) opposite the sepals, ovary 5-locular, 1 pendu- 
lous ovule in each locule, style short, stigma smooth and 
capitate. Fruit a small to medium-sized (1-5 cm) drupe, 
ellipsoid to subglobose, smooth, exocarp fleshy to hard- 
carnose, endocarp woody, usually lacking resinous cav- 
ities, with 5 foramina (openings) around the apex and 5 
oblong germination valves (opercula) on the upper half; 
seeds oblong, usually 1 or 2 per fruit. 

A genus of 1 2 species, mostly in South America, 
but with one species reaching Costa Rica and Pan- 

Humiriastrum diguense (Cuatr.) Cuatrecasas, 
Contr. U.S. Natl. Herb. 35:141.1961. Sacoglot- 
tis diguense Cuatr., Trop. Woods 96: 38. 1950. 
H. diguense subsp. costaricense Cuatr., Contr. 
U.S. Natl Herb. 35: 142. 1961. Figure 6. 

Small to large trees, 25-40 m tall, with trunks 50-70 
cm d.b.h., heartwood reddish brown, leafy branchlets 
0.7-4 mm thick, internodes 1-6 cm long, glabrescent, 
becoming grayish; stipules obscure or absent. Leaves al- 

ternate, subsessile with petioles only 1-2 mm long; leaf 
blades (4-)5-8.5(-9.5) cm long, 2-4.5(-5.5) cm broad, 
elliptic to obovate-elliptic, acuminate (acute) at the apex, 
cuneate (obtuse) to subtruncate at the base, margin blunt- 
ly serrulate or crenulate with 2-5 teeth per centimeter, 
laminae drying stiffly chartaceous to subcoriaceous and 
dark brown, glabrous above, with sparse, thin, incon- 
spicuous hairs ca. 0.2 mm long beneath, with 12-25 
obscure secondary veins on each side, central second- 
aries arising at angles of 50-70, the secondaries difficult 
to differentiate from the parallel tertiary veins. Inflores- 
cences paniculate to corymbiform, usually with trichot- 
omous branching, (5-)8-15 cm long, peduncles 1-2 cm 
long, 1-2 mm thick, minutely (0.2 mm) puberulent, ra- 
chis with 2 longitudinal ridges, pedicels 0.5-1 mm long. 
Flowers ca. 3 mm long, greenish white, calyx ca. 0.5-0.7 
mm long, calyx-lobes ca. 0.5-1.1 mm broad, glabrous 
on the surfaces (in ours) and minutely ciliolate along the 
margin; petals ca. 2.3 mm long and 1 mm broad, oblong, 
sparsely puberulent with thin whitish ascending hairs; 
stamens 20, glabrous, filaments connate at the base, un- 
equal, the larger 1.2 mm long and the shorter 0.9 mm 
long, anthers 0.7-0.8 mm long, ovate-lanceolate, disc 
made up of small (0.2 mm) scales; ovary ca. 1 mm long 
and puberulent, stigma 5-lobed. Fruits 20-26 mm long, 
11-16 mm in diameter, ellipsoid to obovoid with bluntly 
rounded or obtuse apex and truncated base, exocarp dry- 
ing hard, smooth, and glabrous, becoming black at ma- 
turity, endocarp hard woody, with 5 rounded apertures 
near the apex. 

Large trees of lowland rainforest formations from 
near sea level to 250(-400) m elevation in Costa 
Rica. Flowers have been collected in January-Feb- 
ruary and July-November. Fruits have been col- 
lected in January-April. This species is found on 
both the Caribbean slope (near Tirimbina, Here- 
dia) and the southern Pacific slope (General Valley 
to Osa Peninsula) in Costa Rica; it ranges south- 
ward through Panama to western Colombia. 

Humiriastrum diguense is recognized by its small 



Humiriastrum diguense 

Sacoglottis trichogyna 

5 mm 


Vantanea barbourii Sacoglottis holdridgei 

FIG. 6. Humiriaceae: four Costa Rican species. 



alternate subsessile leaves with bluntly serrulate 
laminae with many weakly denned secondary 
veins, small 5-parted flowers with 20 stamens, and 
unusual drupes with hard outer surface and woody 
endocarp with five distal apertures. The large size 
of these trees explains why they are poorly rep- 
resented in herbaria. They are important timber 
trees and their hard wood has been used for heavy 
construction. In Costa Rica the names chiricano, 
lorito, laurelito, and mspero have been used for 
this species. All our material belongs to subspecies 
costaricense, which is distinguished from other el- 
ements of the species by its glabrous calyx-surface, 
narrow leaves, less puberulent petals, and more 
puberulent stems. These are not very significant 
characteristics, but they do seem to be consistent. 
Paul Allen mistakenly placed this species under 
the name Sacoglottis excelsa Ducke in his book, 
The Rain Forests of Golfo Dulce (p. 317. 1956). 

Sacoglottis Martius 

Evergreen trees; stipules minute or absent. Leaves al- 
ternate, petiolate; leaf blades subcoriaceous to coria- 
ceous, margin entire to crenate. Inflorescences axillary 
or subterminal, paniculate with dichotomous or tri- 
chotomous branching, bracts persisting or deciduous. 

Flowers with united calyx, calyx-lobes 5, broadly round- 
ed and imbricate; petals 5, free, imbricate (or appearing 
valvate), stiff; stamens 10, unequal, with the 5 opposite 
the sepals longer than those alternate with the sepals, 
glabrous, filaments flattened and united near the base, 
anthers ovoid to ovoid-oblong, dorsifixed near the base, 
thecae 2 and unilocular, ellipsoid, attached to the lower 
side of the expanded connective, dehiscing by detach- 
ment, connective prolonged, acute, disc forming a thin 
cup with a dentate margin, surrounding the base of the 
ovary; pistil with 5 united carpels opposite the sepals, 
ovary 5-locular, with 1 pendulous ovule in each locule, 
style equaling or exceeding the length of the stamens, 
stigma capitate and lobed. Fruits medium to large drupes, 
ellipsoid to subglobose, exocarp carnose and smooth, 
drying coriaceous, endocarp woody and bullate, without 
apical openings, usually with 10 obscure longitudinal 
furrows, resinous cavities present within the woody tis- 
sue; seeds oblong, usually 1 or 2 per fruit. 

A genus of about ten species, most South Amer- 
ican, but with one species in western Africa and 
the two listed below reaching Costa Rica. One of 
our species marks the northern limits of the genus 
in Central America and the other is endemic to 
Cocos Island. The relatively few stamens, small 
inflorescences, slightly undulate leaf-margins, loop- 
connected secondary veins, and woody endocarps 
without apertures distinguish this genus from our 
other representatives of the family. 

Key to the Species of Saccoglottis 

la. Laminae elliptic-oblong, 2.5-5 cm broad, acute to cuneate at the base, major secondary veins arising 
at angles of 50-70; isthmian Costa Rica S. trichogyna 

Ib. Laminae oblong, 4-8 cm broad, rounded to truncate at the base, major secondary veins arising at 
angles of 70-90; Cocos Island S. holdridgei 

Sacoglottis holdridgei Cuatrecasas, Ciencia (Mex- 
ico) 27: 171. 1972. Figure 6. 

Medium to large trees, to 25 m tall and with trunks 
to 1 m d.b.h., leafy branchlets with internodes 1-3.5 cm 
long, 1.5-5 mm thick, glabrous, subterete; stipules 0.5- 
1 mm long, caducous. Leaves alternate and distichous, 
petioles 4-7 mm long, 2-4 mm thick, with adaxial ridges 
continuous with the lamina margins, glabrous; leaf blades 
7-13(-15) cm long, 4.2-6.5(-8) cm broad, oblong-ovate 
to ovate-elliptic, abruptly short-acuminate at the apex, 
rounded to truncate at the base, margin entire or slightly 
sinuate-crenate, minutely glandular punctate at the mar- 
gin, drying dark grayish brown to almost black above, 
paler beneath, glabrous above and below, with 8-1 1 ma- 
jor secondary veins on each side, the central secondaries 
arising at angles of 70-90, weakly loop-connected near 
the margin. Inflorescences axillary, 0.5-3 cm long, cy- 
mose-paniculate, subsessile or sessile (and appearing as 
several inflorescences in the leaf axil), peduncle 0-4 mm 
long, branches dichotomous, 1-4 mm long, sparsely and 

minutely papillate-puberulent, bracts ca. 2.5 mm long, 
1 mm broad, deciduous, pedicels ca. 0.5 mm long. Flow- 
ers green to greenish yellow, calyx 1.7-2 mm high, calyx- 
lobes ca. 2 mm broad, broadly rounded and suborbicu- 
lar, glabrous but minutely ciliolate along the edge; petals 
ca. 5.5 mm long and 2 mm broad, narrowly oblong; 
stamens 10, glabrous, the longer filaments 4 mm long 
and sepal-opposed, the shorter filaments 3 mm long and 
petal-opposed, anthers ca. 1 mm long, ovate, thecae or- 
ange, attached at the base of the connective, annular disc 
cupulate, ca. 0.8 mm high, with denticulate margin; ova- 
ry ca. 1.5 mm long, ovoid, style ca. 2.5 mm long, co- 
lumnar. Fruits 32-40 mm long, 21-32 mm in diameter, 
oblong-ellipsoid, sepals persisting at the base, exocarp 
2-4 mm thick, endocarp woody, irregularly 5-septate, 
resin vesicles with lustrous interior surfaces; seeds ca. 
12 mm long, 4 mm in diameter, oblong. 

A dominant large tree on Cocos Island. Flowers 
have been collected in January, March, April, and 



October. Fruits were collected in January, April, 
August, and October. This species is said to in- 
clude the tallest trees on Cocos Island; it is en- 
demic there. 

Sacoglottis holdridgei is recognized by its stiff 
oblong to ovate leaves abruptly rounded at the 
base and with crenulate-undulate margin, lack of 
pubescence, small inflorescences, hard endocarp 
with internal resinous chambers, and isolated hab- 
itat. Sterile specimens of this species were origi- 
nally placed under S. ovicarpa Cuatr. in the mono- 
graph (pp. 168-169), but additional material has 
shown the Cocos Island population to merit the 
status of an endemic species. Sacoglottis amazon- 
ica Mart, is closely related, but has larger fruit and 
thinner elliptic leaves. Sacoglottis ovicarpa also 
has larger fruit (5x4 cm), and the leaves are 
similar to those of S. holdridgei but not as abruptly 
truncated at the base. 

Sacoglottis trichogyna Cuatrecasas, Ciencia (Mex- 
ico) 27: 171. 1972. Figure 6. 

Trees to 35 m tall, trunks 40-90 cm d.b.h., lower 
branches often drooping, leafy branchlets 0.8-3.7 mm 
thick, glabrous (the terminal bud minutely puberulent), 
tuberculate-lenticellate, becoming terete; stipules minute 
(ca. 0.5 mm) and caducous. Leaves alternate, petioles 
(4-)5-l 1 mm long, 0.9-1.7 mm thick, with adaxial mar- 
gins continuous with the lamina-margins, glabrous; leaf 
blades (4-)5-12(-15) cm long, (1.5-)2-5(-7) cm broad, 
elliptic-oblong to narrowly elliptic, gradually narrowed 
to the acuminate apex, the tip 0.5-2 cm long, acute to 
obtuse at the base, margin subentire to crenate-undulate 
with a few reddish glands along the edge beneath, leaf 
blades drying stiffly chartaceous to subcoriaceous and 
dark grayish brown above, paler beneath, glabrous above 
and below, major secondary veins (5-) 7-1 1 on each side, 
central secondaries arising at angles of 50-70, arcuate 
and loop-connected near the margin. Inflorescences ax- 
illary, paniculate, 1-3 cm long, peduncle and rachis to 
1 cm long, minutely puberulent, lateral branches 1-3 
cm, bracts 0.7-1 mm long, triangular, deciduous, pedi- 
cels 1 mm long. Flowers in bud to 4.5 mm long and 2 
mm in diameter, calyx ca. 1 mm long, calyx-lobes broad- 
ly rounded, 1.5 mm broad, minutely ciliate along the 
margin, usually eglandular, greenish; petals 4-6 mm long, 
1-1.6 mm broad, oblong-linear, yellow; stamens 10, gla- 
brous, united near the base, longer stamens 3.5-4.3 mm 
long and 0.5-0.6 mm broad at the base, shorter stamens 
3-3.2 mm long and 0.7-0.8 mm broad at the base, an- 
thers 1-1.3 mm long, connective thick and acute, thecae 
ca. 0.5 mm long, disc closely surrounding the ovary- 
base, ca. 0.8 mm high, glabrous and minutely denticu- 
late; ovary 1.5 mm long, ovoid, minutely puberulent, 
style ca. 4 mm long, stigma 5-lobed. Fruits 3-5 cm long, 
2-2.8 cm in diameter, oblong-ellipsoid to oblong-ob- 
ovate, glabrous, exocarp 1-2 mm thick, endocarp with 
5 longitudinal ridges and pitted warty surface, woody 

interior with spherical resin cavities 1-4 mm in diam- 
eter; seeds 1 cm long. 

Trees of lowland rainforest formations, from near 
sea level to 500 m elevation. Flowers have been 
collected in February, June, and August; fruits were 
collected in June, August, and December. The spe- 
cies ranges from the Departments of Rio San Juan 
and Zelaya in Nicaragua, the northern Caribbean 
lowlands, and southern Pacific slopes of Costa Rica 
through Panama. 

Sacoglottis trichogyna is recognized by its stiff 
alternate, slightly crenulate-undulate, and acu- 
minate leaves with weakly loop-connected sec- 
ondary veins, small flowers in small axillary in- 
florescences, ten stamens of two lengths, thecae 
near the base of an expanded connective, and el- 
lipsoid drupe with unusual woody endocarp. The 
reddish glands (punctate to linear) terminating 
small veins in the proximal sinuses beneath the 
leaf margin can help in the determination of sterile 
collections. The young foliage has a conspicuous 
pinkish red coloring, and leaf size can vary greatly. 
This species is called campano, danto plomillo, 
lorito, manteca, rosita, and titor in Costa Rica. 
Material of this species was assigned to 5. ama- 
zonica Mart, in the monograph of the family. 

Vantanea Aublet 

Tall trees, wood hard; stipules absent or obscure. Leaves 
alternate, petiolate or sessile; leaf blades subcoriaceous 
to coriaceous, usually entire. Inflorescences axillary or 
terminal, paniculate or corymbiform, with alternate or 
dichotomous branches, bracts deciduous. Flowers white 
or whitish (reddish in K guianensis), calyx cupular, calyx 
5-lobed distally; petals 5, free, oblong to linear-oblong, 
stiff, contorted in bud; stamens (15-18-)50-120(-180), 
filaments united at the base, linear, glabrous, anthers 
ovate-lanceolate, basifixed, thecae 2 and bilocular, at- 
tached near the base of the anther, dehiscing by longi- 
tudinal slits, connective extended beyond the thecae and 
acuminate to bluntly obtuse, disc cupular and closely 
surrounding the base of the ovary, dentate to fimbriate 
at the margin; pistil with 5 carpels opposite the sepals, 
ovary glabrous or puberulent, 5-locular, each locule with 
2 pendulous ovules, the lower ovule with a longer funicle, 
style simple and straight, stigma thickened and 5-lobed. 
Fruit a medium to large (2-8 cm) drupe, pericarp smooth 
(tuberculate in V. tuberculata), exocarp carnose and co- 
riaceous when dry, thick or thin, endocarp woody, with- 
out resiniferous cavities, opening (when the seeds ger- 
minate) by linear or oblong valves or operculae pushed 
out by the emerging radicle; seeds l(-3) in each fruit. 

A genus of 14 species in lowland (below 1000 
m) tropical rainforest formations. The genus rang- 



es from southeastern Nicaragua to southern Brazil. 
It is distinguished by its small flowers with cupular 
calyx, five free (almost valvate), long, narrow pet- 
als, many stamens of uniform length, 5-locular 
ovary with two pendulous ovules in each locule, 
and the hard (when dry) drupe with unusual woody 
stone. A species with only 15-18 stamens has re- 
cently been described from central Panama (see 
Ann. Missouri Bot. Gard. 75: 1 148-1 150. 1988). 
The large number of stamens is probably a derived 
feature and not primitive as many authors have 
suggested. The unusual expansion of the connec- 
tive with the thecae at the base is similar to that 
in other genera of the family. 

Vantanea bar hour ii Standley, Trop. Woods 75: 5. 
1943. Figure 6. 

Large trees up to 50 m tall, trunks to over 1 m d.b.h., 
leafy branchlets 2-5 mm thick, glabrous; stipules ap- 
parently absent (or reduced to small tuberculae). Leaves 
with petioles 4-10 mm long, 1-2 mm broad, with lateral 
margins continuous with the lamina-margins, thickened 
at the base; leaf blades 5-14 cm long, 2.4-7 cm wide, 
broadly elliptic to oblong-elliptic, bluntly obtuse to 
rounded and emarginate at the apex, obtuse to cuneate 
at the base and decurrent on the petiole, margins entire 
or slightly undulate, the leaves drying dark brownish 
above and slightly paler beneath, subcoriaceous, slightly 
lustrous above, glabrous above and below, with 7-10 
major secondary veins on each side, the central second- 
aries arising at angles of 45-65, not clearly loop-con- 
nected near the margin. Inflorescences axillary or sub- 
terminal, cymose and paniculate to corymbiform, 2-8 
cm long, often subtended by caducous small leaves, pe- 
duncles 1-2 mm thick, branches of the inflorescences 
dichotomous, very minutely (0.2 mm) puberulent, ped- 
icels 1-2 mm long. Flowers whitish, ca. 12 mm long, 
calyx 1-1.5 mm high, with rounded ciliolate lobes ca. 
0.5 mm broad; petals 7-9 mm long, 1.5-2.5 mm wide, 
oblong and narrowed toward the apex, glabrous within 
and appressed retrorse puberulent on the outside except 
for the thin glabrous margins; stamens ca. 50-60, fila- 
ments 5-7 mm long, glabrous, anthers ca. 0.8 mm long, 
ovate-lanceolate, thecae 0.4 mm long, disc 1 mm high, 
thick, with short denticulate margin; ovary 1.5-2 mm 
high, tomentulose-hirsutulous, style ca. 4 mm long, slen- 
der. Fruits 2.8-3 cm long, 1.8-2 cm in diameter, ovoid- 
oblong to ellipsoid, narrowed to the apex, abruptly 
rounded at the base, smooth, endocarp hard woody, ca. 
2.5 cm long and 1.6 cm in diameter, with 5 oblong 
U-shaped grooves (valves). 

Tall trees of lowland rainforest formations on 
the northern Caribbean and southern Pacific slopes 
of Costa Rica, from near sea level to 800 m ele- 
vation. Flowers are probably produced in Novem- 
ber-June; fruits have been collected in June and 
September. The species ranges from Costa Rica to 

Vantanea barbourii is recognized by its tall stat- 
ure, stiff glabrous alternate leaves with entire or 
slightly undulate margins, small flowers with many 
stamens, unusual anthers, and fruit with woody 
endocarps that have five longitudinal U-shaped 
grooves. The short calyx-cup with broadly round- 
ed lobes, narrow petals puberulent along the back, 
and the apically blunt to emarginate leaves are also 
distinctive. Paul Allen noted that these trees tend 
to lose all their leaves for a brief period at the end 
of the heavy rains in November or December (The 
Rain Forests of Golfo Dulce, p. 351. 1956). The 
species has been called ira chiricana, chiricano, 
chiricano triste, and nispero. The very hard and 
durable wood has been used for bridge timbers. 
Only the following Costa Rican collections have 
been seen: Allen 6546 and 6681, Barbour 1018, 
Dayton & Barbour 3129 (the type), and Hartshorn 
2139. Vantanea occidentalis Cuatr. of Colombia 
is very similar to V. barbourii and may prove to 
be a synonym. 

By Timothy Plowman 

REFERENCES N. L. Britton, Erythroxylaceae, N. 
Amer. Flora 25: 59-66. 1907. W. G. D'Arcy & N. 
Schanen, Erythroxylaceae, in Flora of Panama, 
Ann. Missouri Bot. Gard. 62: 21-33. 1975. T. 
Plowman, Erythroxylaceae, in R. A. Howard, Flo- 
ra of the Lesser Antilles, 543-551. 1988. O. E. 
Schulz, Erythroxylaceae, in A. Engler, Pflanzenr. 
4(134): 1-176. 1907. P. C. Standley & J. A. Stey- 
ermark, Erythroxylaceae, in Flora of Guatemala, 
Fieldiana: Bot. 24(5): 390-393. 1946. 

Glabrous shrubs or small trees, bisexual (hermaph- 
roditic) or rarely dioecious; stipules on twigs persistent 
or caducous. Leaves alternate (opposite in Aneulophus), 
simple, stipulate, petiolate, entire, pinnately veined. In- 
florescences fasciculate at nodes, with 1-many flowers, 
sometimes short-pedunculate, subtended by small scar- 
ious bracteoles, flowers pedicellate. Flowers radially 
symmetrical, bisexual or unisexual, often heterostylous; 
calyx persistent, the 5 valvate sepals united below; petals 
free, 5, alternate with sepals, imbricate in bud, caducous, 
usually appendaged on the inner (adaxial) surface and 
narrowed at the base; stamens 10, biseriate, united at the 
base by the filaments and usually forming a short tube, 
anthers 2-locular, longitudinally dehiscent; pistil soli- 
tary, ovary superior, 3-locular (2-locular in Nectarope- 
talum), usually only one locule ovuliferous; ovules sol- 
itary (2 in Nectaropetalum), axile, pendulous, styles 3 (2 
in Nectaropetalum), free or connate from the base, stig- 



mas capitellate, rarely subsessile. Fruits small, drupa- 
ceous, and 1 -seeded (in Aneulophus rarely capsular and 
2- or 3-seeded); embryo straight, with or without en- 

Four genera with about 230 species; three of the 
genera, with few species, are restricted to tropical 
Africa and are incompletely known. Erythroxylum 
is by far the largest genus and occurs in tropical 
parts of Australia, Asia, Africa, and the Americas. 

Erythroxylaceae are recognized by the lack of 
indumentum, the intrapetiolar stipules, the usu- 
ally alternate, simple, entire leaves, the fascicled, 
axillary flowers, the persistent 5-lobed calyx, the 
appendaged petals, and the small, drupaceous fruit. 

Erythroxylum P. Browne 

Glabrous shrubs or small trees, evergreen or decidu- 
ous, rarely dioecious or subdioecious, the twigs com- 
pressed at apex, often bearing persistent, distichous, im- 
bricated cataphylls and stipules; stipules intrapetiolar, 
united and appearing as a single organ, dorsally bicostate, 
often 2- or 3-setulose at apex, persistent or caducous, 
often leaving an obliquely transverse scar. Leaves alter- 
nate, often distichous, petiolate, simple, entire, with in- 
volute vernation that sometimes imprints 2 parallel lines 
and/or a distinct central panel on lower surface, pin- 
nately veined. Inflorescences of fasciculate or solitary 
axillary flowers, rarely short-pedunculate, the flowers 
arising from small, scarious, often persistent bracteoles, 
pedicellate. Flowers radially symmetrical, small, heter- 
ostylous; calyx of 5 valvate sepals, united below, persis- 
tent; petals 5, free, imbricate in bud, appendaged on the 
adaxial surface with a 2-lobed ligule, caducous; stamens 
10 in 2 whorls of 5, the outermost alternate with the 
petals, the filaments united at base and forming a short 
tube surrounding the ovary, persistent, anthers 2-locular, 

longitudinally dehiscent; ovary 3-locular but with only 
one locule ovuliferous, the ovule solitary in the fertile 
locule, pendulous from an axile placenta, anatropous, 
epitropous, styles 3, free or partly connate from base, 
stigmas capitellate. Fruit a small, fleshy, reddish, one- 
seeded drupe, the endocarp 1 - or 3-locular but with only 
one fertile locule; seed with or without endosperm, the 
embryo straight. 

About 230 species, of which at least 180 are 
found in the Neotropics; the centers of diversity 
for the genus are found in Venezuela, eastern Bra- 
zil, and Madagascar; six species, including one cul- 
tivated, occur in Costa Rica. Costa Rica seems to 
be one of the less diverse areas of Central America 
in species of Erythroxylum, being surpassed even 
by Nicaragua. Most if not all of the species have 
originated elsewhere (South America, Antilles) with 
subsequent dispersal to Costa Rica. 

In Costa Rica, Erythroxylum species fall into 
two main groups: those with relatively large, api- 
cally acute or acuminate leaves and conspicuously 
striate-nerved stipules (E. macrophyllum, E. citri- 
folium, E. fimbriatum), and those with small to 
medium-sized, apically obtuse or rounded leaves 
and smooth, nonstriate stipules (remaining spe- 
cies). Identification within either of these groups 
may be difficult, especially if complete material is 
not available. I therefore provide multiple char- 
acters in the key to help distinguish flowering, 
fruiting, and/or vegetative material. The impor- 
tant stipule characters should be observed in newly 
formed (subapical), undamaged stipules or cata- 
phylls. The character of relative positions of calyx 
and staminal tube is easily observed in flowers 
whose petals have fallen, or in young fruit. 

Key to the Species of Erythroxylum in Costa Rica 

la. Stipules longitudinally striately veined, caducous or persisting; mature endocarps terete 2a 

Ib. Stipules smooth, not striately veined, persistent (sometimes withering but not caducous); mature 

endocarps variously ribbed or sulcate, not terete 4a 

2a. Stipules apically acute or tapered to a long point; bracteoles 2-5.5 mm long; calyx-lobes broadly 

ovate, oblong or obovate and abruptly acuminate at the apex E. macrophyllum 

2b. Stipules apically obtuse or rounded and 2- or 3-setulose; bracteoles 0.5-2 mm long; calyx lobes 

triangular to triangular-ovate or ovate-lanceolate, acute or acuminate at the apex 3a 

3a. Stipules persistent, 1.5-2 mm long (not including seti), the 2 lateral apical seti conspicuous, 

often fimbriate and strongly recurving, persisting; staminal tube equaling or longer than the 

calyx; endocarps acute to obtuse at the apex E. fimbriatum 

3b. Stipules usually caducous, 4-1 2 mm long, the apical seti slender, weakly filamentous, evanescent; 

staminal tube shorter than the calyx; endocarp obtuse at apex E. citrifolium 

4a. Flowers manifestly unisexual, produced near apex of current season's shoots, often on short shoots; 
mature drupe 3-locular with 1 fertile and 2 empty locules; petiole longer than '/ 5 the length of leaf 
bl at l e E. rotundifolium 



4b. Flowers bisexual, produced on year-old twigs of past season; mature drupe unilocular; petiole shorter 

than '/ 5 the length of the leaf blade 5a 

5a. Staminal tube less than 50% as long as the calyx; plants completely deciduous; flowers produced 
on last season's twigs before the leaves, never in leaf-bearing axils; leaf blades never bilineate 

nor with distinct central panel on lower surface; a native species E. havanense 

5b. Staminal tube 50-1 00% as long as the calyx; plants evergreen or incompletely deciduous; flowers 
produced in axils of year-old twigs (in Costa Rica), often with leaves present; leaf blades usually 

bilineate and/or with distinct central panel on lower surface; cultivated species 

E. novogranatensis 

Erythroxylum citrifolium St. Hil., Fl. bras. mend. 
94. 1829. E. citrifolium St. Hil. var. minus O. 
Schulz, 1/1 Engl., Pflanzenr. 4(134): 37. 1907. 
D'Arcy & Schanen, Ann. Missouri Bot. Gard. 
62: 29. 1975. 

Evergreen shrubs or small trees to 10 m tall, the 
branchlets smooth, the bark dark reddish or grayish 
brown, developing a tan suberous outer bark, the len- 
ticels if present minutely punctate; cataphylls scattered 
at base of shoots, 5-7, early caducous, similar to foliar 
stipules; foliar stipules caducous, sometimes tardily so, 
(2-)4-8(-12) mm long, oblong-lanceolate, membrana- 
ceous, densely longitudinally striate-nerved, obtuse at 
apex with three slender, short, often evanescent setae 1- 
2 mm long. Leaves with petiole 4-7 mm long, the leaf 
blades 8-14 cm long, 2-7 cm wide, oblong, oblong-el- 
liptic or lanceolate, long-acuminate at apex, short-acu- 
minate to rounded at base, coriaceous or subcoriaceous, 
the upper surface drying dark grayish green or brown, 
the secondary nerves often obscure, the lower surface 
drying somewhat ferruginous, not bilineate and a central 
panel lacking or faint, the lateral nerves prominulous, 
more or less shiny on both surfaces. Inflorescence pro- 
duced in the axils of leaves or cataphylls on mature twigs 
of current season, many-flowered; bracteoles 0.5-2 mm 
long, lightly striate-nerved, strongly keeled, at apex acute 
or obtuse, 1-setulose; pedicels 3-5 mm long, strongly 5- 
ribbed. Flowers bisexual; calyx ca. 1.5 mm long, trian- 
gular to ovate-lanceolate, often spreading after anthesis; 
Staminal tube ca. l h as long as calyx. Drupe 7-10 mm 
long, 4-5 mm in diameter, red, the endocarp oblongoid, 
obtuse at apex, terete. 

Evergreen forest formations of the Pacific slope, 
700-1 200 m elevation, the General Valley (Skutch 
4351 F, Skutch & Barrantes 5057 F), and near Las 
Alturas in Puntarenas Province ( Wilbur et al. 22658 
F). It appears to be uncommon in Costa Rica. 
Flowering specimens have been collected between 
June and August. This species is widely distrib- 
uted, often in secondary forest, from Nicaragua to 
Bolivia; the Guianas; and southeastern Brazil. 

Erythroxylum citrifolium is recognized by its ca- 
ducous, striate-nerved, apically obtuse, 3-setulose 
stipules, by relatively large (8-14 cm long), oblong, 
apically acuminate leaves, and by dense axillary 
clusters of small (ca. 1.5 mm long) flowers. 

Erythroxylum fimbriatum Peyr., in Mart., Fl. bras. 
12(1): 162. 1878. 

Evergreen shrubs or treelets, 2-6(-10) m tall, the 
branchlets initially with smooth bark without discrete 
lenticels, becoming superficially suberose, light tan; cat- 
aphylls scattered at base of new shoots, 4 or 5, similar 
to foliar stipules; foliar stipules persistent, 1.5-2 mm 
long (excluding setae), broadly ovate, subcoriaceous, dis- 
tinctly longitudinally striate-nerved with 4-6 nerves per 
side, obtuse or truncate at apex, 3-setulose, the 2 lateral 
setae persistent, conspicuous, (l-)3-5 mm long, ribbon- 
like, extending from subalate keels, often fimbriate, man- 
ifestly recurved, the medial seta filamentous, evanescent. 
Leaves persistent, scattered on twigs, the petiole 3-5 mm 
long; leaf blades 5-10(-14) cm long, 2.5-5.5 cm wide, 
elliptic to elliptic-oblong, short to long-acuminate at 
apex, rarely acute, the tip itself obtuse or acute, broadly 
to narrowly cuneate at base, chartaceous, the upper sur- 
face drying dark grayish green, the adaxial midrib some- 
times impressed-sulcate with a slender medial ridge, the 
lateral nerves obscure or sometimes impressed-sulcate, 
the lower surface drying ochreous or ferruginous, without 
parallel lines, the lateral nerves sometimes conspicuous. 
Inflorescences in axils of leaves or cataphylls on current 
or year-old shoots, with l-3(-8) flowers per node; brac- 
teoles ca. 1 mm long, striate-nerved, acute and 1-setulose 
at apex; pedicels 4-6 mm long, pentagonal in cross sec- 
tion, the fruiting pedicels 5-7 mm long. Flowers bisexual; 
calyx 1-2 mm long, the lobes narrowly triangular to 
lanceolate, narrowly acute or acuminate at apex; sta- 
minal tube equaling or slightly longer than the calyx. 
Drupes 10-12 mm long, 4-5 mm in diameter, red, the 
endocarp oblongoid, acute or obtuse at apex, terete at 

In Central America known only from Costa Rica, 
Provincia de Heredia, Finca La Selva, in lowland 
moist primary forest, 45-100 m elevation (Hart- 
shorn 1243 and 1413 F, Opler 1740 F, Kress 76- 
526 DUKE). In Costa Rica, Erythroxylum fimbria- 
tum flowers in March-May and fruits in April- 
June. In South America, the species is sporadically 
distributed throughout the greater Amazon basin, 
from Colombia to French Guiana, south to Peru 
and western Brazil. 

Erythroxylum fimbriatum is easily recognized 
by the well-developed (3-5 mm long), persistent, 
fimbriate, and recurved lateral setae on the striate- 



nerved stipules. The Costa Rican and some Pe- 
ruvian material of this species differs modestly 
from the typical, lowland Amazonian form in hav- 
ing smaller leaves and the stipular setae much 
shorter and not so markedly fimbriate and re- 
curved. Moreover, the lower surface of the leaves 
in the Amazonian collections shows conspicuous 
secondary nerves diverging at near right angles 
from the midrib. 

Erythroxylum havanense Jacq., Enum. Syst. PI. 
21. 1760. Select. Stirp. Amer. Hist. t. 87, fig. 2. 
1763. D'Arcy & Schanan, Ann. Missouri Bot. 
Gard. 62: 32. 1975. E. overturn Cav., Diss. 404, 
t. 233. 1789. E. obtusum DC., Prodr. 1: 574. 
1824. E. havanense Jacq. var. continentis O. 
Schulz, in Engl., Pflanzenr. 4(134): 92. 1907. E. 
chiapense Lundell, Wrightia 4: 175. 1971. Fig- 
ure 7. 

Deciduous shrubs or treelets 1-5 m tall, the branchlets 
1.5-2.0 mm in diameter, weakly differentiated into long 
and short shoots, smooth, light grayish brown to dark 
reddish brown, dotted with whitish punctate or elongate 
lenticels, becoming longitudinally fissured; cataphylls 
persistent, produced at base of long shoots or congested 
on short shoots, similar to foliar stipules, turning dark 
brown with age; foliar stipules persistent, 2.0-3.5 mm 
long, triangular-ovate, not striate-nerved, acute and brief- 
ly 2-setulose at apex, drying reddish brown. Leaves de- 
ciduous, sometimes tardily so, scattered on long shoots 
or 1-3 produced at tips of short shoots, the petiole 2.5- 
5 mm long; leaf blades (3-)3.5-8 cm long, (1.2-)1.5-3(- 
4) cm wide, obovate or elliptic, rounded, obtuse or slight- 
ly retuse at apex, acute at base, chartaceous, strongly 
bicolorous, the upper surface drying medium green, dull, 
the lower surface drying very pale green or glaucous to 
whitish, without parallel lines nor with a distinct central 
panel, the lateral nerves 12-14, inconspicuous. Inflores- 
cence produced in axils of leaves or cataphylls on leafless, 
year-old twigs just prior to leaf flush, with 1-8 flowers 
per node; bracteoles 1-1.5 mm long, ovate, acuminate 
at apex; pedicels slender, 4-9 mm long. Flowers bisexual; 
calyx-lobes triangular-ovate, reflexing after an thesis; sta- 
minal tube much shorter than calyx (in Costa Rica). 
Drupes 5-7 mm long, 4-5 mm in diameter, the endocarp 
ellipsoid to oblongoid, rounded or obtuse at apex, un- 
equally and shallowly 4-sulcate at maturity. 

Lowland Guanacaste and adjacent Puntarenas, 
seasonally dry, deciduous forest and adjacent sa- 
vannas, often along water courses, sea level to 250 
m elevation. This species flowers in March-June 
and fruits in May-June. It ranges over Cuba, the 
Lesser Antilles, and Mexico to Panama and the 
northern coast of South America. 

Erythroxylum havanense is recognized by its de- 

ciduous habit, with flowers appearing before the 
leaves, by the relatively small, apically obtuse or 
rounded, strongly bicolorous leaves that are 
elineate beneath, by the staminal tube much shorter 
than the calyx lobes, and by the short, obtuse, 
sulcate endocarps. The illustrations of E. hava- 
nense (fig. 7) are based on the following collections: 
A, E, F, drawn from Frankie 380c from Costa 
Rica; B, C, drawn from Sandino 2888 from Nic- 
aragua; D, drawn from Plowman 3597 from Co- 
lombia; G, H, I, drawn from Berry 3502 from 
Venezuela. All the specimens are represented at F. 
In the Flora of Panama (Ann. Missouri Bot. 
Gard. 62: 32. 1975), D'Arcy and Schanen erro- 
neously placed several species in synonymy under 
E. havanense. Erythroxylum cumanenseKunlh and 
E. hondense Kunth are distinct species that occur 
in northern South America, and E. mexicanum 
Kunth is found in dry areas of Mexico, El Salva- 
dor, and Nicaragua. Erythroxylum pringlei Rose 
is here considered a synonym ofE. rotundifolium 
Lunan sens. lat. (see below). 

Erythroxylum macrophyllum Cav., Diss. 401, t. 
227. 1789. E. lucidum H.B.K., Nov. Gen. sp. 
5: 138. 1822. E. costaricense J. D. Smith, Bot. 
Gaz. 23: 240. 1897. E. ellipticum Ramirez, An- 
ales Inst. Med.-Nac. Mexico 3: 36. 1897. E. 
tabascense Britton, N. Amer. Fl. 25: 66. 1907. 
Standl. & Steyerm., Fieldiana: Bot. 24(5): 393. 
1946. E. lucidum H.B.K. var. costaricense (J. 
D. Smith) O. Schulz, in Engl., Pflanzenr. 4(1 34): 
25. 1907. D'Arcy & Schanen, Ann. Missouri 
Bot. Gard. 62: 28. 1975. E. skutchii Standl., 
Publ. Field Mus. Nat. Hist., Bot. Ser. 22: 344. 
1 940. E. multiflorum Lundell, Amer. Midi. Nat- 
uralist 29: 474. 1943. D'Arcy & Schanen, Ann. 
Missouri Bot. Gard. 62: 24, t. 1. 1975. 

Shrubs 2-3 tall or small trees to 10 m tall; branchlets 
2-4 mm in diameter, smooth, becoming tan or light 
grayish brown, with obliquely transverse scars of fallen 
stipules and cataphylls, without distinct lenticels; cata- 
phylls produced at base of shoots, caducous, 10-60 mm 
long, similar to but sometimes larger than foliar stipules; 
foliar stipules 4-35 mm long, longitudinally striate- 
nerved, at apex acutely tapered to a point, sometimes 
with 2-3 filamentous setae, caducous, leaving obliquely 
transverse scars on twigs. Leaves with petiole 3-10 mm 
long; leaf blades (5-)7-30 cm long, (2-)3-15 cm wide, 
oblong to elliptic-oblong, long- to short-acuminate at 
apex, the tip itself sharply acute, acuminate to acute, 
obtuse or rounded at base, the upper surface often drying 
rather shiny and leaden gray, the lateral nerves incon- 
spicuous, rarely impressed-sulcate, the lower surface dry- 
ing dull and ferruginous, usually without parallel lines 




Fio. 7. Erythroxylaceae: Erythroxylum havanense. A, flowering branch; B, fruiting branch; C, leaf showing ve- 
nation; D, stipule; E, short-styled flower; F, petal; G, drupe with attached calyx; H, cross section of endocarp; I, 



or distinct central panel, the lateral nerves inconspicuous 
or rarely prominulous. Inflorescences produced in the 
axils of leaves or cataphylls on new shoots, often ap- 
pearing "knobby" at the nodes, the flowers usually nu- 
merous; bracteoles 2.0-5.5 mm long, persistent, 1 -keeled, 
striate-nerved, apically acute, 1-setulose; pedicels 3-10 
mm long, 5-ribbed. Flowers bisexual; calyx 2.5-5.0 mm 
long, the lobes broadly ovate, obovate or oblong, often 
subfoliose, lightly striate-nerved, abruptly acuminate at 
apex, the margins often overlapping or touching; sta- 
minal tube about half as long as the calyx. Drupes 8-1 1 
mm long, 4-5 mm in diameter, the endocarp oblongoid 
or ovoid-oblongoid, obtuse or acutish at apex, terete at 

In Costa Rica, widespread on both Atlantic and 
Pacific slopes (Guanacaste, Puntarenas, Alajuela, 
San Jose, Heredia, Limon) in evergreen moist to 
wet forests, seasonally dry or cloud forests, sea 
level to 1600 m elevation. Rowers in January- 
September; fruits in February-November. The 
species ranges from southern Mexico to Bolivia 
and Brazil. 

Erythroxylum macrophyllum is recognized by 
the relatively large (4-30 mm long), apically acute, 
striate-nerved, caducous stipules that leave 
obliquely transverse scars on the stem, by the rath- 
er thick, apically acuminate leaves, by the persis- 
tent, striate-nerved bracteoles, and by the broadly 
ovate, abruptly acuminate calyx-lobes. 

Erythroxylum macrophyllum is a highly poly- 
morphic, complex, and wide-ranging species, oc- 
curring from southern Mexico to Bolivia. Many 
names have been proposed to accommodate the 
numerous minor and major variants in both Cen- 
tral and South America. I am treating the species 
here in the widest sense. In Central America, sub- 
specific taxa are difficult to characterize with any 
degree of constancy. However, in Costa Rica two 
general forms occur, corresponding to E. costari- 
cense J. D. Smith, with leaves generally less than 
1 4 cm long, and E. skutchii Standley, with leaves 
more than 1 5 cm long. The former, small-leaved 
form is far more widespread, occurring from sea 
level to 1 600 m elevation in most of Costa Rica. 

Erythroxylum skutchii was described from a 
specimen (Skutch 4847 F) collected in the General 
Valley. The leaves are distinguished adaxially by 
impressed-sulcate nerves and abaxially by prom- 
inulous, reticulate venation. Two other collections 
from Limon Province (Gomez et al. 20463 F) and 
the Osa Peninsula (Gomez 19681 F) more or less 
match the type of E. skutchii. Several other col- 
lections from the lowlands of Heredia and Limon 
Provinces have exceptionally large leaves but 
without the impressed-sulcate nerves of E. skut- 
chii(Chacon 716, Hartshorn 1198, Kennedy 3790A, 

Stevens 23797, 23964, Wilbur 34408, all at F). 
These collections differ from the common high- 
land forms primarily in the larger leaf size and 
greater number of flowers per node. A number of 
intermediate specimens connect the extremes of 
variation. Until this group can be thoroughly re- 
vised, I decline to designate formally subspecific 
taxa in Costa Rica. 

Erythroxylum multiflorum Lundell from Pan- 
ama is also included in synonymy under E. mac- 
rophyllum. This distinctive plant with large leaves 
and cataphylls is obviously related to both E. 
skutchii and two distinctive South American va- 
rieties: E. macrophyllum var. macrocnemium 
(Mart.) Plowman and var. ecuadorense Plowman. 

Bawa and Opler (Evolution 29: 167-179. 1975) 
erroneously reported that " Erythroxylum lucidum 
var. costaricense" from Guanacaste is dioecious. 
This error resulted from a misidentification of E. 
rotundifolium Lunan. 

Erythroxylum novogranatense (Morris) Hieron., 
Bot. Jahrb. Syst. 20, Beibl. 49: 353. 1895. O. 
Schulz, i/i Engl., Pflanzenr. 4(134): 85, t. 18. 
1907. E. coca Lam. var. novogranatense Morris, 
Bull. Misc. Inform. 5, t. 2. 1889. 

Evergreen shrubs or small trees to 6 m tall, the branch- 
lets ca. 2 mm in diameter, without short shoots, flexuous, 
often appearing zigzag, reddish brown, the lenticels 
punctate or absent, if present rarely breaking the surface; 
cataphylls lacking or few, if present resembling foliar 
stipules; foliar stipules 2.5-3.5 mm long, narrowly ovate 
to triangular, acute to obtuse at apex, minutely 2-setu- 
lose, membranous, not striate-nerved, soon withering 
and disintegrating. Leaves persistent, scattered on twigs, 
the petiole 2-5 mm long; leaf blades 2.5-7.5 cm long, 
1.2-3.6 cm wide, elliptic to obovate or oblong, at apex 
obtuse, rounded or retuse, at base acute to attenuate, 
nrm-membranaceous, the upper surface bright yellowish 
green when fresh, the adaxial midrib flat not ridged, the 
lower surface very pale green, usually bilineate and/or 
with a distinct central panel, the laminas drying pale 
green or yellowish and dull on both surfaces, the lateral 
nerves 10-15, inconspicuous. Inflorescence produced in 
axils of the previous season's twigs, with or without leaves 
present, l-3(-10) flowers per node; bracteoles 1-1.5 mm 
long, cymbiform-deltoid, acuminate at apex, pedicels 3- 
7(-12) mm long. Flowers bisexual; calyx 1.5-2.5 mm 
long, divided V 2 -% its length, the lobes narrowly to broad- 
ly ovate; staminal tube half as long as to equaling the 
calyx. Drupes 8-13 mm long, 4-7 mm in diameter, the 
endocarp ovoid to ellipsoid, rounded to obtuse at apex, 
unequally 4-sulcate. 

Ornamental shrubs cultivated at I.I.C.A., Turri- 
alba, ca. 635 m, flowering in June-August (Brown 
CR-221 F, Rossbach 3570 GH, Leon 591 us). Na- 



live to Colombia and cultivated throughout the 
tropics and in Central America as an ornamental 
or medicinal plant, or as a minor commercial 
source of the alkaloid cocaine. 

Erythroxylum novogranatense is recognized by 
the relatively delicate, bright yellowish green (when 
fresh), apically obtuse leaves that are usually bilin- 
eate beneath, by the thin stipules that soon dis- 
integrate, and by the sulcate endocarps. This spe- 
cies has long been confused with E. coca Lam., 
which is the commercially important species from 
which both coca leaves and cocaine are principally 
derived (Plowman, J. Linn. Soc., Hot. 84: 329- 
353. 1982. Bohm et al., Syst. Bot. 7: 121-133. 
1982). Because it is more difficult to grow, E. coca 
is rarely seen outside of the tropical Andean mon- 
tana where it is native. No unambiguous collec- 
tions of E. coca are known from Central America. 
The common name of E. novogranatense is "coca." 

Erythroxylum rotundifolium Lunan, Hort. Jamaic. 
2:116.1814. Standl. & Steyerm., Fieldiana: Bot. 
24(5): 393. 1946. E. obovatum Macfad., Fl. Ja- 
maica 143. 1837, non Griseb.. E. pallidum Rose, 
Contr. U.S. Natl. Herb. 8: 314. 1905. Standl. & 
Steyerm., Fieldiana: Bot. 24(5): 392. 1946. E. 
pringlei Rose, Contr. U.S. Natl. Herb. 8: 314. 
1905. E. compactum Rose, Contr. U.S. Natl. 
Herb. 8: 313. 1905. E. suave O. Schulz, in Ur- 
ban, Symb. Antill. 5: 197. 1907. E. suave O. 
Schulz var. compactum (Rose) O. Schulz, in 
Engl., Pflanzenr. 4(134): 68, t. 15. 1907. E. ses- 
silijlorum O. Schulz, in Engl., Pflanzenr. 4(134): 
69. 1907. E.fiscalense Standl., Publ. Field Mus. 
Nat. Hist, Bot. Ser. 22(1): 33. 1940. Standl. & 
Steyerm., Fieldiana: Bot. 24(5): 391. 1946. E. 
tikalense Lundell, Wrightia 4: 177. 1971. 

Semideciduous, dioecious shrubs or small trees to 8 
m tall, highly variable in habit with branches long and 
slender, or short and compact with well-developed short 
shoots, the branchlets dark brown to dark gray, abun- 
dantly supplied with lenticels; cataphylls persistent, scat- 
tered at base of long shoots or crowded on short shoots, 
similar to foliar stipules; foliar stipules persistent, 1.5- 
2.5 mm long, at apex obtuse and briefly 2-setulose, fim- 
briate at margin. Leaves persistent or partly deciduous, 
the petioles 3-6 mm long, very slender, often drying 
orange or ferruginous; leaf blades 8-30 mm long, 7-25 
mm wide, obovate, elliptic, or rounded, rounded or shal- 
lowly retuse at apex, acute at base, bicolorous, drying 
medium green on upper surface, very pale green on lower 
surface, without parallel lines or central panel on lower 
surface, the lateral nerves 4-6, inconspicuous. Inflores- 
cence produced in the axils of leaves or cataphylls near 
apex of current season's shoots, the flowers 1 (or rarely 

2 or 3) per node; bracteoles ca. 0.8-1.0 mm long, ovate, 
fimbriate; pedicels 0.5-4 mm long, 5-angled, thickened 
at the apex into the calyx. Flowers unisexual; calyx 1.2- 
1.5 mm long, the lobes triangular to triangular-ovate, 
acute at apex; pistillate flowers bearing a staminal tube 
with very short filaments and rudimentary anthers, the 
ovary with subsessile, flattened stigmas, 0.5 mm long; 
stamina te flowers with 10 stamens in two unequal series, 
the staminal tube about half as long as the calyx, and a 
pistil rudiment. Drupes 5-8 mm long, 3-5 mm in di- 
ameter, the endocarp ellipsoid or curved, rounded at 
apex, trigonal in cross section, subequally 3-locular 
with 1 fertile and 2 empty locules. 

In Costa Rica, known only from Guanacaste and 
northwestern San Jose provinces, in dry forest, 
often along water courses, 50-900 m elevation. 
Flowering specimens have been collected in late 
May and in August-September, fruits in Septem- 
ber. This species ranges from the Bahamas, Great- 
er Antilles, and Mexico to Costa Rica. 

Erythroxylum rotundifolium is recognized by the 
small, rounded leaves with long, slender, orangish 
petioles and by the small, unisexual, solitary, sub- 
terminal flowers and trilocular drupes. Erythrox- 
ylum rotundifolium is treated here in the widest 
sense as a highly polymorphic species with either 
slender and open or compact and dense branching 
habit, and the leaves variable in shape and size of 
lamina and relative length of petiole. After further 
study, some of the Central American segregate 
populations such as E. pallidum Rose and E. com- 
pactum Rose may need to be recognized at least 
at the varietal level. Much Central American ma- 
terial of this species has been misidentified as E. 
brevipes DC., a species from Puerto Rico and His- 
paniola closely related to E. havanense. 


By William Burger 

REFERENCE D. M. Porter, The genera of the 
Zygophyllaceae in the southeastern United States. 
J. Arnold Arbor. 53: 531-552. 1972. 

Annual or perennial herbs, subshrubs, shrubs, or trees, 
often strongly scented and with sticky resin, growth usu- 
ally sympodial, branches often with swollen or articu- 
lated nodes, with simple hairs; stipules paired at each 
leaf base, free, persisting or rarely deciduous, sometimes 
modified as spines. Leaves opposite or less often alter- 
nate, often distichous, usually evenly pinnate, occasion- 
ally simple to bifoliolate or 3-7-parted, petiolate; leaf 
blades (leaflets) petiolulate or subsessile, inequilateral, 
usually entire, stiff to fleshy in texture, often strongly 



resinous. Inflorescences racemose or fasciculate (rarely 
cymose), usually with the flowers solitary on axillary 
peduncles/pedicels. Flowers bisexual (rarely unisexual 
and dioecious), radially symmetrical or rarely somewhat 
bilaterally symmetrical, hypogynous, perianth (4-)5(-6) 
parted, sepals free or united at the base, imbricate or 
valvate in bud; petals imbricate or convolute in bud 
(rarely valvate), narrowed at the base, a disc usually 
present and often with extra- or intrastaminal glands; 
androecium usually with twice as many stamens as the 
petals (rarely 3 x or 1 x as many), free, the outer stamens 
opposite the petals, filaments with or without append- 
ages at the base, anthers 2-thecous, versatile or basifixed, 
dehiscing introrsely with longitudinal slits; pistil solitary, 
of (2-)4-5(-6) united carpels, ovary sessile or short-stip- 
itate (with a gynophore), 2-6-locular, with axile placen- 
tation and l-several(-many) ovules in each locule, ovules 
pendulous or ascending, style slender and terminal, stig- 
ma solitary and lobed or 2-6-parted. Fruit a 2-6-lobed 
I ocu 1 icidal or septicidal capsule, or a schizocarp breaking 

up into few to several mericarps or nutlets (rarely ber- 
rylike or drupaceous), the mericarps often thickened and 
spinose to tuberculate on the outer (abaxial) surface; seed 
with a straight or curved embryo, cotyledons linear or 
oblong, endosperm hard and oily or absent, an aril pres- 
ent or absent. 

A family of about 25-30 genera and 250 species, 
best represented in arid, saline, or seasonally dry 
tropical and subtropical environments. The family 
consists of somewhat diverse elements, several of 
which are often segregated as separate families (such 
as Balanites of Africa-Eurasia and Nitraria of the 
Old World subtropical deserts). This family has 
been classified with both the Geraniales and the 
Sapindales; the Rutaceae of the Sapindales may 
be the most closely related family. 

Key to the Genera of Zygophyllaceae 

la. Trees with very hard heavy wood; petals blue or purplish Guaiacum 

Ib. Herbs or subshrubs, usually prostrate on the ground; petals white to yellow or orange 2a 

2a. Fruiting mericarps armed with spines; each leaf with more than 1 leaflets (in our species) 


2b. Fruiting mericarps without spines; each leaf with 8 or fewer leaflets (in our species) Kallstroemia 

Guaiacum Linnaeus 

Small to medium-sized trees, wood very hard, heavy 
and resinous, branches often with thickened nodes; stip- 
ules small. Leaves opposite, parapinnate, petiolate, leaf- 
lets in 2-6 opposite pairs. Inflorescences of fasciculate 
flowers at distal nodes, each flower borne on a slender 
unbranched peduncle (= pedicel) from the axil of a distal 
node. Flowers 4- or 5 -parted, sepals slightly united at 
the base, petals 4 or 5, blue or purple, strongly narrowed 
at the base (clawed); stamens 8 or 10, filaments slender, 
anthers cordate or sagittate at the base; pistil with a short 
stipe (gynophore), ovary 2-5-lobed and 2-5-locular, 
ovules 8-10 in each locule. Fruits slightly fleshy when 
ripe, but drying smooth and coriaceous, with 2-5 prom- 
inent longitudinal lobes or rounded ridges (rarely wings); 
seeds ovoid to ellipsoid. 

A genus of about six species, ranging from 
southern Florida, USA, and the West Indies to 
northern South America. This is the genus of lig- 
num vitae, the hardest of commercial timbers, of- 
ten used for construction in salt water. The med- 
ical resin guaiacum is obtained from these plants 
by heating. Unfortunately, the usefulness of these 
trees has resulted in their decimation in many ar- 
eas. Guaiacum sanctum grows wild in northwest- 
ern Costa Rica, while G. officinale L., with larger 
more rounded leaflets, occurs in the West Indies. 

These species are sometimes planted as ornamen- 
tals for their showy blue flowers. 

Guaiacum sanctum L., Sp. PI. 382. 1753. Figure 8. 

Small trees up to ca. 10m tall, leafy branchlets 0.8- 
3 mm thick, minutely puberulent with thin ascending 
hairs ca. 0.2 mm long, becoming pale gray and glabrous; 
stipules 2-4 mm long, triangular and acute, appressed 
puberulent distally, thick and persisting. Leaves oppo- 
site, 3-9 cm long, pinnately compound with (2-)3-5(-6) 
pairs of leaflets, petiole 3-8 mm long, petiole and rachis 
to 5 cm long, rachis 0.3-0.8 mm thick, minutely puber- 
ulent or glabrescent, deeply sulcate above; leaf blades 
(leaflets) 12-28(-32) mm long, 4-14(-16) mm broad, 
asymmetric and narrowly oblong to oblong-obovate, the 
middle leaflets the longest on each leaf, bluntly obtuse 
to acute at the apex, subsessile and unequal on the thick 
petiolule, with the proximal side usually rounded at the 
base and the distal side more straight, leaflets drying 
stiffly chartaceous, glabrous above and below or sparsely 
sericeous near the base, venation palmate with 1-3 major 
veins and more weakly defined lateral veins, all these 
veins strongly ascending and loop-connected distally. In- 
florescences fascicles of (l-)4-8 flowers at distal nodes, 
peduncles (= pedicels) 12-20 mm long, slender (0.3-0.5 
mm thick when dry), sparsely and minutely puberulent. 
Flowers ca. 15 mm long and 20 mm broad, sepals 4-6 
mm long and ca. 3 mm broad, broadly imbricate in bud; 



Tribulus cistoides 

Kallstroema maxima 

Kallstroemia pubescens Guaiacum sanctum 

FIG. 8. Zygophyllaceae: four Central American species. 



petals 8-12 mm long and 6-8 mm broad, broadly ob- 
ovate and clawed at the base, bright blue; stamens ca. 6 
mm long, anthers 1.5-2 mm long, becoming curved; 
pistil ca. 10 mm long, with a short (2 mm) stipe, and 
slender style 2-3 mm long, ovary obovoid and drying 
dark. Fruits 14-16 mm long and 12-18 mm broad, ob- 
ovoid and prominently 2-5-lobed or ridged, the longi- 
tudinal lobes 7-9 mm thick and rounded, fleshy or moist 
at maturity but drying to a yellowish and lustrous hard 
surface; seeds ellipsoid, ca. 1 cm long, brown to black 
and with a red aril. 

Trees of the seasonally very dry and deciduous 
forest formations in northwestern Costa Rica. The 
species is found from 1 0-200 m elevation in Costa 
Rica, and up to 700 m in Nicaragua. Flowering 
material has been collected in March; fruit has 
been collected in July. The species ranges from 
southern Florida and eastern Mexico through the 
West Indies and Central America to northern South 

Guaiacum sanctum is recognized by its opposite 
compound leaves with 2-5 pairs of small subses- 
sile asymmetric leaflets, the bright sky-blue flow- 
ers, and the restriction to lowland deciduous forest 
formations. The leaflets resemble those of some 
Leguminosae, but the opposite leaves and lobed 
capsular fruit are quite different. The hard and 
heavy heartwood is said to become bluish on ex- 
posure to air (Janzen & Liesner, Brenesia 18: 90. 
1980). For a discussion of uses of this species and 
the closely related G. officinale see the Flora of 
Guatemala (in Fieldiana: Bot. 24(4): 395. 1946, 
reprinted 1985). 

Kallstroemia Scopoli 

REFERENCE D. M. Porter, The genus Kallstroe- 
mia (Zygophyllaceae). Contr. Gray Herb. 198: 41- 
153. 1969. 

Annual or less often perennial herbs, stems herbaceous 
or slightly woody, prostrate or decumbent to ascending, 
often spreading outward from a central taproot, terete 
and slightly succulent, becoming longitudinally striate 
when dry; stipules paired at each leaf-base, free. Leaves 

opposite and parapinnate, petiolate, with 2-10 pairs of 
opposite subsessile leaflets, the distal leaflets larger and 
often somewhat falcate and asymmetric, the basal (prox- 
imal) leaflets often unequal in size; leaf blades (leaflets) 
entire, pubescent to glabrescent, subsessile on short slen- 
der petiolules. Inflorescences represented by usually sol- 
itary axillary or pseudoaxillary flowers, each peduncle 
(= pedicel) with a single flower. Flowers bisexual and 
radially symmetrical, sepals 5(-6), free, pubescent, usu- 
ally persisting in fruit; petals 5(-6), free, rotate, white to 
bright yellow or orange, convolute in bud, broadly ob- 
ovate and rounded distally, narrowed to the clawed base, 
fugaceous and quickly withering but often persisting; sta- 
mens 10(-12), the outer 5(-6) opposite the petals and 
somewhat larger than the inner 5(-6), these latter often 
subtended at the base by small lobed glands, filaments 
filiform (rarely winged near the base), inserted on the 
disc, anthers ovoid to oblong-linear; a fleshy annular disc 
present, obscurely 10(-12)-lobed; pistil 1, ovary broadly 
sessile, 10(-12)-ribbed and 10(-12)-locular, globose to 
conical, glabrous to pubescent, 1 pendulous ovule in each 
locule, style simple and cylindrical to conical, persisting 
in fruit, stigma capitate to clavate, with 10(-12) ridges 
or lobes. Fruits broadly ovoid to conical, with 10(-12) 
longitudinal ridges or lobes and the persisting style (beak), 
glabrous or puberulent at maturity, breaking septicidally 
into 10(-12) or fewer mericarps and those separating 
from the persisting central axis, each mericarp with 1 
locule and 1 seed, the mericarps wedge-shaped (trian- 
gular in cross section) with a rounded tuberculate or 
rugose abaxial surface; seeds oblong to ovoid, testa mem- 
branaceous, endosperm absent. 

An American genus of 1 7 species, ranging from 
the southern United States, Mexico, and the West 
Indies through Central America to central Argen- 
tina. The genus has become naturalized in western 
Africa and India. Nearly all the species are found 
in arid and seasonally very dry environments, or 
in early stages of open secondary succession. The 
mericarps are quite unusual in form, and a mer- 
icarp may leave an oblong opening in the side of 
the fruit if adjacent locules fail to develop. In ad- 
dition, the mericarps can be mistaken for seeds. 
The two species of Kallstroemia found in Costa 
Rica are quite similar in overall appearance; they 
appear to be native to Central America. These 
plants may be mistaken for Portulaca oleracea L. 
(verdolaga or purslane), of similar habit but with 
alternate or clustered leaves. 

Key to the Species of Kallstroemia 

la. Ovary and fruit glabrous or strigose only at the base; sepals lanceolate in fruit, often curved over 
the fruit; stipules narrowly lanceolate; leaflets as many as 8 per leaf . K. maxima 

Ib. Ovary and fruit usually with appressed thin pilose hairs; sepals linear-lanceolate with involute 
margins and usually spreading laterally beneath the fruit; stipules usually linear; leaflets as many as 
6 per leaf K - Pubescens 



Kallstroemia maxima (L.) Hook. & Arnott, Bot. 
Beechey Voy. 282. 1838. Tribulus maximus L., 
Sp. PI. 386. 1753. Figures. 

Annual herbs or herbaceous vines, stems prostrate to 
decumbent, to 1 m long, leafy internodes 1-3 mm thick, 
with thin whitish ascending hairs of varying (0.3-1 mm) 
length; stipules 3-4 mm long, lanceolate. Leaves 1.2-6 
cm long and 1-3.5 cm broad, obovate or oblong in gen- 
eral outline, paripinnate with (2-)3-4 pairs of leaflets, 
terminal leaflets the largest, a slender tip ca. 1 mm long 
often present at the end of the rachis; leaf blades (leaflets) 
2-1 6(-l 8) mm long, 1 .5-7(-l 1) mm broad, distal leaflets 
strongly asymmetric, oblong-obovate to obovate-falcate, 
obtuse at the apex, unequal at the base with the proximal 
(outer) side rounded and the distal (inner) side straight 
or concave, surfaces with slender appressed hairs ca. 1 
mm long, with 1 midvein and several ascending sec- 
ondary veins. Inflorescences of solitary axillary flowers, 
peduncles (= pedicels) (7-)12-20(-28) mm long, gla- 
brescent. Flowers with sepals 4-5 mm long, ca. 2 mm 
wide, narrowly ovate, with stiff slender hairs to 1.5 mm 
long, persisting, petals 4-6 mm long, to 6 mm wide, 
obovate, pale yellow to orange; ovary ca. 1 mm in di- 
ameter, style cylindrical, to 2 mm long, stigma capitate. 
Fruits broadly ovoid to broadly conical, 6-9 mm long, 
4-7 mm broad near the base, pale yellowish white, gla- 
brous or strigose at the base, the beak 3-4 mm long and 
darker in color, mericarps 3-4 mm high, 1-1.5 mm wide, 
abaxially tuberculate and transversely ridged, with pitted 

Plants of open recently cleared ground and early 
secondary growth in seasonally dry and deciduous 
formations and in evergreen areas; ranging from 
sea level to 500(-1400) m elevation. The species 
probably flowers throughout the year in Central 
America, but has been collected most often in May- 
August and in November. The species ranges from 
the southeastern United States through Mexico, 
Central America, and the West Indies to northern 
South America. 

Kallstroemia maxima is recognized by the low- 
growing habit on open ground, the opposite evenly 
pinnate leaves, the 3 or 4 pairs of leaflets with the 
distal leaflets largest, and the unusual fruit (see 
discussion under the genus). 

Kallstroemia pubescens (G. Don) Dandy, in Keay, 
KewBull. 10: 138. 1955. Tribulus pubescens G. 
Don, Gen. Hist. 1 : 769. 1 83 1 . K. caribaea Rydb., 
in Vail and Rydb., N. Amer. Fl. 25: 111. 1910. 
Figure 8. 

Annual herbs, stems prostrate to decumbent, up to 1 
m long, leafy internodes 0.5-2 mm thick, with thin as- 
cending hairs 0.5-1 mm long; stipules 34 mm long, 
linear, with thin straight hairs. Leaves opposite, to 4.5 

cm long and 2.5 cm broad, often rectangular to obovate 
in outline, paripinnately compound with 2-3 pairs of 
subsessile leaflets, the terminal leaflets the largest, peti- 
olules ca. 0.5 mm long; leaf blades (leaflets) 5-14(-20) 
mm long, 3-8(-10) mm broad, proximal (lower) leaflets 
broadly oblong or ovate-oblong, distal leaflets asym- 
metric and oblong-falcate or obovate-falcate, rounded 
at the apex or with an apiculate tip, unequal at the base 
with the proximal (outer) part rounded and the distal 
(inner) side straight or convex, with straight slender stiff 
appressed ascending hairs ca. 0.5-1 mm long on the 
surfaces and along the edges, midvein with 1-3 diverging 
secondary veins on each side. Inflorescences represented 
by solitary, axillary flowers, peduncles (= pedicels) 5-15 
mm long. Flowers with sepals 3.5-5 mm long, 0.5-1.5 
mm broad, lanceolate, with thin hairs ca. 1 .2 mm long; 
petals ca. 6 mm long and 5 mm broad, obovate, white 
to yellow, withering but persistent; pistil 4-6 mm long, 
ovary broadly ovoid to conical, densely appressed-pu- 
berulent with fine white hairs, style 34 mm long, gla- 
brous distally. Fruits 5-6 mm in diameter near the base, 
with 10 longitudinal ridges, the ridges with tubercles or 
transverse striations, with dense short hairs, mericarps 
3-4 mm long and 1 mm thick, the subtending persisting 
sepals linear-lanceolate with involute margins. 

Plants of open sunny early successional sites in 
seasonally dry deciduous formations and in ev- 
ergreen areas, from sea level to 200 m elevation 
in Central America. Flowers and fruits have been 
collected in March-October in Central America. 
The species ranges from central Mexico through 
Central America and the West Indies to Colombia, 
Venezuela, Ecuador, and Peru. This species has 
become naturalized in West Africa and India. 

Kallstroemia pubescens is recognized by the low 
habit on open ground, the paripinnate leaves with 
only four or six leaflets, the yellow flowers, the 
pubescent ovary and fruit, and the unusual mer- 
icarps. All our Costa Rican collections come from 
lowland Guanacaste. 

Tribulus Linnaeus 

Annual herbs (occasionally perennial, sometimes 
woody at the base, rarely small shrubs), plants diffusely 
branched and often spreading radially from a central 
taproot, prostrate to decumbent or ascending, stems her- 
baceous to slightly woody, often somewhat succulent, 
terete and longitudinally striate on drying, densely pu- 
berulent to glabrescent; stipules paired at the leaf-bases, 
leaflike. Leaves opposite with one of each pair usually 
shorter than the other, occasionally alternate when an 
opposing leaf fails to develop, evenly pinnate (paripin- 
nately compound) with 3-10 pairs of opposite leaflets 
(rarely 1 leaflet of a pair aborting), petiolules very short 
or the leaflets subsessile, rachis often extending beyond 
the terminal pair of leaflets; leaf blades (leaflets) oblong 
to ovate-oblong or elliptic, often somewhat oblique and 
asymmetric at the base, the terminal pair usually point- 



ing forward, puberulent with thin straight whitish hairs, 
with a single midvein. Inflorescences represented by sol- 
itary axillary flowers (usually from the axil of the smaller 
leaf of the node), borne on long peduncles (= pedicels). 
Flowers bisexual, radially symmetrical, sepals 5, free, 
puberulent, caducous or sometimes persisting; petals 5, 
free, bright yellow (white), spreading to rotate, imbricate 
in bud, narrowed at the base, deciduous; stamens 10 
(rarely 5), the 5 outer longer and united to the base of 
the opposing petals, the 5 inner (antesepalous) stamens 
with nectariferous glands at the base, anthers cordate to 
oblong, interstaminal glands free or connate beneath the 
base of the ovary; pistil sessile, globose to ovoid, 5-lobed 
and 5-locular, densely puberulent, with 3-5 lobules in 
vertical rows on axile placentae in each locule, style cy- 
lindrical, stigma 5-angular or 5-lobed, pyramidal to ob- 
long. Fruits usually breaking up into 5 (or fewer) hard 
mericarps but not leaving a central axis, mericarps broadly 
triangular, each mericarp divided internally by trans- 
verse septa to produce 2-5 1 -seeded locules, the meri- 
carps with hard spines or wings (or tuberculate) on their 

outer (abaxial) surface; seeds oblong-ovoid, testa mem- 
branaceous, endosperm absent, embryo straight. 

A genus of about 25 species of seasonally dry 
habitats and desert communities. Originally re- 
stricted to the Old World; a few species have be- 
come widespread and are now found throughout 
the tropics and warm-temperate areas of the world. 
The genus is recognized by the bright yellow flow- 
ers with free parts, the somewhat unequal usually 
opposite leaves with (3-)5-10 pairs of small (4- 
1 5 mm) opposite subsessile leaflets, and the fruit 
breaking up into hard spiny mericarps. Two spe- 
cies (T. cistoides L. and T. terrestris L.) have been 
found in Central America, but neither has been 
collected in Costa Rica. The following key distin- 
guishes these two distinctive species. 

Key to the Species of Tribulus Collected in Central America 

la. Rowers borne on peduncles usually longer than the leaves, sepals 5-12 mm long; intrastaminal 
glands united and forming a lobed cup at the base of the ovary; stigma oblong, on a short prominent 
style T. cistoides 

Ib. .Flowers borne on peduncles equaling or shorter than the leaves, sepals 3-6 mm long; intrastaminal 
glands free; stigma hemispheric, subsessile T. terrestris 

Literature Cited 

CRONQUIST, A. 1981. An Integrated System of Clas- 
sification of Flowering Plants. Columbia University 
Press, New York, 1262 pp. 

SIMPSON, B. B. 1982. Krameria flowers: Orientation 
and elaiophore morphology. Taxon, 31: 517-528. 

STANDLEY, P. C. 1937-1938. Flora of Costa Rica. Publ. 
Field Mus. Nat. Hist., Bot. Ser., 18: 1-1571. 




The index includes all accepted names (in Roman type), synonyms (in italics), and vernacular names 
(Spanish names in italics). The page numbers of illustrations are in boldface. Hyphenated words and 
multiple words are alphabetized by letter. 

Acedera 8, 1 1 
Acederilla 1 1 
Aneulophus 3 1 
ami 21 
Averrhoa 4 
bilimbi 4 
carambola 5 

Balanites 37 

Biophytum 5 
dendroides 6, 7 
falcifolium 6, 7 
panamense 6 

campano 29 
canary-bird flower 2 1 
capuchina 23 
carambola 5 
Centris bees 1 
chiricano 28, 30 
chiricano trieste 30 
coca 36 
cocaine 36 

danto plomillo 29 
Dirachmaceae 16 

Erodium 17 

cicutorium 17 

moschatum 17 
espuela del gelan 23 
Erythroxylaceae 30 
Erythroxylum 31 

brevipes 36 

chiapense 33 

citrifolium 32 

citrifolium var. minus 32 

coca 36 

coca var. novogranatense 35 

compactum 36 

costaricense 33, 35 

cumanense 33 

ellipticum 33 

fimbriatum 32 

fiscalense 36 

havanense 33, 34 

havanense var. continents 33 

hondense 33 

lucidulum var. costaricense 33 

lucidum 33 

macrophyllum 33 

macrophyllum var. ecuadorense 

macrophyllum var. macrocne- 

mium 35 
mexicanum 33 
multiflorum 33, 35 
novogranatense 35 
obovatum 36 
obtusum 33 
ovatum 33 
pallidum 36 
pringlei 33, 36 
rotundifolium 36 
sessiliflorum 36 
skutchii 33, 35 
suave 36 

swave var. compactum 36 
tabascense 33 
tikalense 36 

flax 25 
forage 16 

garden geranium 21 
garden nasturtium 2 1 
Geraniaceae 16 
geranio 21 
Geranium 17 

costaricense 18, 19 

cucullatum 18 

cucullatum var. multifidum 1 8 

guatemalense 19, 20 

mexicanum 20 

multifidum 18 

pulchrum 20 

repens 20 
Guaiacum 37 

officinale 37 

sanctum 37, 38 

Hugoniaceae 24 
Humiriaceae 25 
Humiriastrum 25 

diguense 26, 27 

diguense var. costaricense 26 
Hypseocharis 4 

/ra chiricana 30 
Ixonanthaceae 24 

Kallstroemia 39 
caribaea 40 
maxima 38, 40 
pubescens 38, 40 

Krameria 1 
cuspidata 2 
ixine 2 
revoluta 2 

Krameriaceae 1 

laurelito 28 

Linaceae 23 

linaza 25 

linaza lino 25 

///jo 25 

linseed 25 

linseed oil 25 

Linum 24 
guatemalense 24 
usitatissimum 25 

lorito 28, 29 

Magallana 2 1 
manteca 29 
mastuerzo 23 
medicinal plants 1, 23 
mimbro 5 

nasturtium 23 
Nectaropetalum 30 
nispero 28, 30 
Nitraria 37 

Oxalidaceae 2 
Oxalis 6 

angustifolia 12 

articulata 9 

barrelieri 9, 13 

bradei 12 

chiriquensis 14 

coccinea 12 

corniculata 10, 1 1 

darienensis 12 

debilis 10, 1 1 

dendroides 6 

deppi 16 

dombei 12 

filiformis 10, 12 

frutescens subsp. angustifolia 12, 

galeotii 14 

hayi 166 

latifolia 10, 14 

martiana 1 1 

maxonii 15 

microcarpa 14 



neaei 12 diguense 26 moritzianum 23 

ramonensis 14 excelsa 28 peltophorum 21 

rhombifolia 13, 15 holdridgei 27, 28 pendulum 23 

spiralis 1 5 ovicarpa 29 peregrinum 2 1 

spiralis subsp. vulcanicola 13, 1 5, trichogyna 27, 29 tuberosum 2 1 

16 warscewiczii 23 

tetraphylla 16 Trophaeastrum 2 1 

vulcanicola 1 5 tiriguro 5 

Tribulus 40 Vantanea 29 

Pelargonium 20 cistoides 38, 41 barbourii 27, 30 

graveolens 21 maxima 40 occidentalis 30 

x hortorum 2 1 pubescens 40 tuberculata 29 

Portulaca oleracea 39 terrestris 4 1 vinagrillo 8 

Tropaeolaceae 21 Vivianiaceae 16 

Tropaeolum 21 
rosita 29 emarginatum 22 

guatemalense 22 Zygophyllaceae 36 

majus 22 

Sacoglottis 28 minus 2 1 

amazonica 29 




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