380
DICOTYLEDONEAEously articulate at apex; tepals 4(5), ovate, 2.5-3.5 mm long; stamens usually 6, exserted, ca 3.5 mm long; ovary lenticular; styles 2, 2-3 mm long. Achenes lenticular, 2-2.5 mm long, 1.5-2 mm wide, brown to black, beaked.
White 142.
Rare, in marshy habitats. Seasonal behavior uncertain.
Probably flowers and fruits throughout the year.
Mexico to Argentina; West Indies. In Panama, known only from tropical moist forest in the Canal Zone.
Polygonum hydropiperoides Michx., Fl. Bor. Amer.
1:239.1803
Slender herb, to ca 1 m tall, often ± reclining, subgla- brous. Petioles usually less than 5 mm long; blades linear- lanceolate, long-acuminate at apex, acute and decurrent on petiole at base, 4-15 cm long, 0.5-1.5 cm wide, incon- spicuously pellucid-punctate, usually strigose on midrib and veins below, minutely ciliate; ocreae 1-3 cm long, with strigose apical cilia to 8 mm long. Inflorescences terminal, spikelike racemes or panicles of few branches;
flowers interrupted along rachis, fasciculate, light pur- plish to greenish, subtended by ciliate ocreolae 2-3 mm long; pedicels exceeding ocreolae ca 1 mm, articulate at apex; tepals usually 5, ovate, 2-3 mm long; stamens usu- ally 9, ca 1.5 mm long; ovary trigonous; styles 3, ca 1 mm long. Achenes trigonous, 2-3 mm long, brown to black, inconspicuously beaked. Shattuck 840.
Collected once by Shattuck at Gigante Bay. Apparently flowering and fruiting throughout the year.
Canada to South America. In Panama, known only from BCI.
Polygonum punctatum S. Elliott, Bot. S. Carolina &
Georgia 1:455. 1817 Chilillo, Chili de perro
Slender herb, to 70 cm tall, nearly glabrous. Leaves, ocreae, and tepals conspicuously dark-punctate; petioles less than 5 mm long; blades linear-lanceolate, acuminate at apex, narrowly decurrent on petiole at base, 2-10 cm long, 0.5-2 cm wide, glabrous but minutely ciliate and sometimes with the midrib near base sparsely strigose;
ocreae 5-15 mm long, with strigose cilia at apex usually 7-10 mm long. Inflorescences terminal, spikelike racemes or panicles of few branches; flowers interrupted along rachis, fasciculate, white or greenish, subtended by ciliate ocreolae 2-3 mm long; pedicels exceeding ocreolae 1-2 mm, articulate at apex; tepals 5, ovate, 3-4 mm long;
stamens usually 8, 1.5-2 mm long; ovary trigonous;
styles 3, ca 1 mm long. Achenes trigonous, 2.5-4 mm long, brown to black, somewhat beaked. Croat 5247.
Rare, in marshy places, especially sandbars. Flowers throughout the year, possibly with a peak in the late rainy and early dry seasons.
Canada to Argentina; West Indies. In Panama, known from tropical moist forest in the Canal Zone and Panama, from tropical dry forest in Code, and from premontane wet forest in Chiriqui and Code.
TRIPLARIS Loefl.
Triplaris cumingiana Fisch. & C. Meyer, Mem. Acad.
Imp. Sci. Saint-Petersbourg, Ser. 6, 6:149. 1840 Palo santo, Guayabo hormiguero, Vara santa Dioecious tree, usually 10-20 m tall; trunk smooth,
12-30 cm dbh; bark light brown, thin, peeling off; stems hollow. Petioles very short or to 2 cm long, canaliculate;
blades mostly oblong-elliptic, acuminate, obtuse at base, 15-30 cm long, 4-12 cm wide, glabrous but with the veins below strigose (especially midrib). Inflorescences from upper axils; staminate inflorescences of spikes to 35 cm long and 1.5 cm wide; flowers subsessile, usually in pairs, emerging one at a time from densely pubescent, spathaceous ocreolae; perianth greenish, in one series of 3 linear and 3 narrowly triangular tepals 3-4 mm long, connate for about half their length; stamens 9, exserted;
anthers introrse, versatile. Pistillate inflorescences of racemes to ca 20 cm long (to 30 cm in fruit); pedicels 2-9 mm long; calyx sericeous, ca 1 cm long at anthesis (greatly accrescent and becoming red in age), the lobes narrowly triangular to linear, 2-3 times the length of the tube and spreading at anthesis; petals ± linear, exceeding tube, fused to base of tube; styles 3, the inner surface stigmatic in upper two-thirds. Achenes sharply trigonous (the surfaces ± flat), 8-12 mm long, shiny, brown, persistent within and dispersed by the enlarged calyx, the calyx to 6 cm long, pubescent, 3-winged, the wings pinkish, spreading, 3.5-4.5 cm long, 6-7 mm wide. Croat 4633, 8165.
Usually locally common; otherwise only occasional in both the young and old forests. Plants may begin to flower when as litde as 11 m tall and 12 cm dbh. Flowers from February to April, chiefly in March. The fruits begin to mature by February and are dispersed chiefly in March and April but also in May. Plants lose their leaves in July and August.
Stems are inhabited by very aggressive ants (Pseudo- myrmex triplaridis ForeL), whose sting is quite severe.
Costa Rica to Ecuador; cultivated in the West Indies and elsewhere. In Panama, known from tropical moist forest in the Canal Zone, San Bias (Perme), Los Santos, Panama, and Darien and from tropical wet forest in Panama (Cerro Campana).
See Fig. 223.
47-
AMARANTHACEAE/ALTERNANTHERA381
KEY TO THE SPECIES OF AMARANTHACEAE Leaves alternate:
Sepals 5; flowers bisexual; leaf blades usually more than 7 cm long; plants occasional Chamissoa altissima (Jacq.) H.B.K.
Sepals 3; flowers monoecious or polygamomonoecious; leaf blades less than 6 cm long; plants rare or no longer present on the island Amaranthus viridis L.
Leaves opposite:
Inflorescences ± globose, not more than 2 cm long:
Mature leaves pilose; stigmas 2 Gomphrena decumbens Jacq.
Mature leaves at most sparsely villous; stigma 1:
Sepals longer than utricle, 3-5-veined Alternanthera ficoidea (L.) R. Br.
Sepals shorter than utricle, 1-veined Alternanthera sessilis (L.) R. Br.
Inflorescences not globose, usually more than 2 cm long:
Inflorescence a simple spike, the flowers in glomerules, becoming reflexed and hooked Cyathula prostrata (L.) Blume Inflorescence a panicle of spikes, the flowers not reflexed and not associated with hooks:
Leaf blades near base of plant ovate Iresine celosia L.
Leaf blades near base of plant lanceolate to linear Iresine angustifolia Euphr.
tachment, dehiscing by longitudinal slits; ovary superior, unilocular; ovule solitary (in ours), basal, campylotro- pous; style single, conspicuously trifid; stigma capitate or long-bifurcate or trifurcate. Fruits indehiscent or circum- scissily dehiscent utricles (1-seeded, with a loose peri- carp); seed usually with a shiny testa and abundant endosperm.
Distinguished by their small, densely bracteate, usually greenish inflorescences with inconspicuous apetalous flowers and small shiny seeds.
The flowers are probably wind pollinated or self- pollinated (H. Baker, pers. comm.).
Seeds are dispersed chiefly by small birds. Ridley (1930) reported that seeds of some genera, including Gomphrena, are possibly wind dispersed by means of the plumelike pubescence of the achene or the glumaceous flower and broad persistent bracts. Some seeds are eaten by browsing animals and passed unharmed (Ridley,
1930), and some are harvested by ants (Wheder, 1910).
About 50-65 genera with 500-850 species; mostiy in the tropics of Africa and America.
ALTERNANTHERA Forssk.
Alternanthera ficoidea (L.) R. Br., Prodr. 1:417. 1810 Decumbent, sprawling perennial herb; stems branching, to ca 1 m long; stems velutinous above and on nodes below, the trichomes antrorsely hispidulous. Leaves opposite; petioles 2-10 mm long; blades broadly ovate to elliptic or obovate, acute and mucronulate at apex, cuneate at base, to 6 cm long and 3 cm wide, villous when young, becoming sparsely villous to glabrate. Inflores- cences of sessile, whitish, axillary, ovoid or globose tufts to 1 cm long; bracts and bracteoles ± equal, ± ovate, to 3 mm long, acuminate; flowers bisexual; sepals 5, similar to bracts but the outer 3 broader, 3-veined, 3-5 mm long;
stamens 5, united below, exceeded by pseudostaminodia;
style 2-3 times longer than the single, capitate stigma.
Utricles indehiscent, suborbicular, membranaceous, to 1.5 mm long, shorter than sepals; seeds reddish-brown, to 1.2 mm long. Croat 9240.
Abundant in the Laboratory Clearing, usually growing over and supported by other low vegetation. Flowers and fruits all year though probably with a peak of activity in the dry season.
BCI plants apparently intergrade with A. halimifolia (Lam.) Standl., as they show characters intermediate with that species, especially the moderate to dense, plumose pubescence.
Florida and central Mexico south to Paraguay; West Indies. In Panama, an occasional weed growing in clear- ings and along streams; known from tropical moist forest in the Canal Zone, Bocas del Toro, Chiriqui, Veraguas, Panama, and Darien, from premontane moist forest in the Canal Zone, from premontane wet forest in Code, and from tropical wet forest in Colon.
See Fig. 224.
Alternanthera sessilis (L.) R. Br., Prodr. 1:417. 1810 Sanguinaria
Similar to A. ficoidea except the petioles 1-5 mm long;
the blades to 4 cm long and 1.5 cm wide; the inflores- cences of axillary tufts to 4 mm long; the bracts and bracteoles 1 mm long or less; the sepals 5, 1-veined, to
1.5 mm long; the utricles 1.5-2 mm long, slightly ex- ceeding the sepals. Standley 40948.
Perhaps no longer present on the island, but reported by Standley to have been frequent. Probably flowers all year, but especially during the rainy season.
Honduras to Brazil; West Indies. In Panama, the few collections are widely scattered and the plant occasionally extends to aquatic habitats; known from tropical moist forest in the Canal Zone, Bocas del Toro, Los Santos, Panama, and Darien.