AMARANTHUS L
63. LEGUMINOSAE (FABACEAE)
Trees, shrubs, or herbs, sometimes scandent, tendriled, and/or armed. Leaves alternate (opposite in Platymis- cium), petiolate; blades simple, pinnate or bipinnate, entire or subentire; venation pinnate (palmate in Bauhinia and the blades bilobed); stipules usually present. Inflores- cences terminal or axillary, paniculate, racemose, spicate, or sometimes globose heads; flowers bisexual, actino- morphic or zygomorphic; calyx 5-lobed, the lobes sub- equal, rarely free, rarely obsolete; petals 5, equal or un- equal, free, or the 2 anterior petals united, usually showy;
stamens 10 to many, free, monadelphous or diadelphous;
anthers 2-celled, dehiscing longitudinally; ovary superior, 1-locular, 1-carpellate; placentation parietal; ovules 2 to many, in 2 rows on the ventral suture, anatropous; style 1, simple; stigma 1. Fruits legumes, loments, follicles, or drupes; seeds generally lacking endosperm.
An exceedingly diverse, large, and important tropical family most easily confused with the Connaraceae (62), which differ in having follicles with arillate seeds.
Because of the nature of the leguminous fruit, which generally offers little in the way of a meal for larger
63A. MIMOSOIDEAE
Leaves bipinnate (merely pinnate in Inga and Pithecello- bium rufescens); stipules present. Flowers actinomorphic, in cylindrical spikes or globose heads; floral bracteoles present in Mimosa; calyx cupular, rarely obsolete, the lobes imbricate or valvate; corolla lobes usually valvate;
stamens many, often polyadelphous, equal, considerably longer than corolla.
Members of the subfamily Mimosoideae are most easily distinguished by their bipinnate leaves (except Inga and Pithecellobium rufescens, which usually have conspicuous glands at the apex of their petioles) and by their actinomorphic flowers with numerous stamens (at least twice the number of petals).
The flowers of the Mimosoideae are open with exserted sexual parts. In most cases the pollination unit includes the entire inflorescence; in all cases the pollen is easily accessible. Flowers may be pollinated by unspecialized pollen feeders, which crawl over the surface of the inflo- rescence, or by fluttering or hovering insects or birds.
In general, the larger flowers or inflorescences, which provide nectar in quantity, are probably visited by bats or birds. Inga vera is known to be pollinated by several
KEY TO THE TAXA OF MIMOSOIDEAE Leaves pinnate:
Inflorescences racemose or spicate Inga (in part) Inflorescences umbelliform to globose (short capituliform racemes in Inga quaternata):
Leaf rachis winged at least near apex Inga umbellifera (Vahl) Steud.
Leaf rachis not winged:
Heads small, globular, less than 3 cm diam; flowers sessile; legumes moniliform, reddish with black seeds Pithecellobium rufescens (Benth.) Pitt.
Heads (including stamens) more than 3 cm diam; flowers pedicellate; legumes not as above Inga quaternata Poepp.
424 DICOTYLEDONEAE Leaves bipinnate:
Inflorescences various, not globular or subglobular; flowers arising from an elongated rachis more than 2 cm long; leaflets at least in part 1 cm or more wide:
Pinnae bifoliolate; stems with paired, recurved, nodal thorns; corollas ca 10 mm long; legumes reddish, linear-moniliform, less than 3 cm wide
• • • • Pithecellobium hymeneaefolium (H. & B.) Benth.
Pinnae with 3 or more pairs of leaflets; stems unarmed; corollas less than 5 mm long; legumes more than 5 cm wide:
Inflorescences terminal racemes of spikes; legumes less than 7 cm wide; seeds ellipsoid, less than 1.5 cm long, dispersed with transverse segments of legume Adenopodia polystachya (L.) J. Dixon Inflorescences in supra-axillary spikes; legumes more than 8 cm wide; seeds disk-shaped,
5-6 cm diam, not dispersed with transverse segments of legume
Entada monostachya DC.
Inflorescences globular or with very brief floral rachises less than 5 mm long:
Leaflets more than 1 cm wide:
Peduncles more than 3 cm long; flowers pedicellate; petioles bearing large cupular gland 1 cm long at apex; legumes curled:
Pedicels less than 2.5 mm long; gland between basal pair of pinnae ca 1 cm long, the others at successively higher nodes small; mature fruits curved into nearly complete
clrcie Pithecellobium macradenium Pitt.
Pedicels more than 8 mm long; gland between all pairs of pinnae minute; mature fruits oblong-linear, never curved into circle Albizia guachapele (Kunth) Dug.
Peduncles less than 2 cm long; flowers sessile; petioles bearing small gland at apex:
Inflorescences paniculate with many globose heads ca 1 cm wide; individual flowers tiny, difficult to distinguish without magnification; pinnae usually in (2)4 pairs Leucaena multicapitula Schery Inflorescences of several spikes issuing from nodes along stem; individual flowers clearly
visible, the corolla ca 5 mm long; pinnae usually in 2 (3) pairs Pithecellobium dinizii Ducke Leaflets less than 1 cm wide:
Plants conspicuously armed:
Petiole and rachis eglandular; stamens fewer than 10; legumes armed Mimosa Petiole or rachis with small glands; stamens more than 10; legumes unarmed Acacia Plants unarmed:
Flowers on pedicels usually more than 1 cm long; legumes flat, straight, more than 15 cm
lonS Albizia guachapele (Kunth) Dug.
Flowers sessile or on pedicels less than 3 mm long, in small globular heads (less than 2 cm diam); legumes curled:
Leaflets in fewer than 15 pairs per pinna; leaves with petiole, rachis, and lower leaflet surface tawny-tomentose; legumes less than 2 cm wide, reddish inside Pithecellobium barbourianum Standl.
Leaflets usually in more than 15 pairs per pinna; leaves not tawny-tomentose; legumes more than 2 cm wide, not reddish inside Enterolobium bat species (Heithaus, Fleming & Opler, 1975).
Sphingid moths have been seen visiting the flowers in the early morning and early evening in Costa Rica (G.
Frankie, pers. comm.). R. Heithaus (pers. comm.) also suggests hummingbirds and large trap line bees as pollinators.
Evidence exists of specialization in the pollen arrange- ment in the Mimosoideae. Different taxa form polyads with varying numbers of pollen grains per polyad (Gui- net, 1969; Sorsa, 1969). The number of pollen grains per polyad usually correlates very well with the number of ovules per carpel (T. Elias, pers. comm.). This probably indicates a specialization in pollinators, and clusters of pollen are probably carried by nectar feeders rather than by the relatively unspecialized pollen feeders.
The largest dispersal category of Mimosoideae is endo- zoochory, especially mammalian. Examples are Enterolo- bium cyclocarpum, E. schomburgkii, and possibly all
species of Inga. Oppenheimer (1968) reported that fruits of perhaps all species of Inga are eaten by the white-faced monkey. Some Inga may be water dispersed as well, especially those occurring only along the lakeshore. Quite likely these species of Inga, as well as similar shoreline species of Pithecellobium, are dispersed in part by fish or reptiles as is suggested by van der Pijl (1968).
Birds are probably the chief agents of dispersal for seeds of all Pithecellobium but especially for those of P. barbourianum and P. rufescens, which have well- developed arilloids clearly suited to bird dispersal. Seeds of some species of Acacia, such as A. hayesii and A.
riparia, as well as those of Leucaena multicapitula, may also be bird dispersed, because the fruits open at maturity and the dark seeds are then displayed against the light inner valve surface.
Seeds of all Mimosa on BCI are chiefly epizoochorous.
They are perhaps also wind dispersed, since they are
much flattened and break up into small segments. Water may also play a part in the dispersal of M. casta and M.
pigra, since these generally occur near water; water cur- rents play an important role in the dispersal of Entada monostachya. Van der Pijl (1968) suggested that Albizia, which lacks arilloids, is frequently wind and water dis- persed; the seeds themselves sink but are dispersed while enclosed in the buoyant pod (Ridley, 1930).
ACACIA P. Mill.
Acacia acanthophylla (Britt. & Rose) Standl., Publ.
Field Mus. Nat. Hist., Bot. Ser. 18:488. 1937 Lianas climbing into canopy; trunk and branches sulcate, generally glabrous, the ribs (3)4 (to several), pubescent, armed with prickles, the prickles numerous, 3-5 mm long, broad-based, recurved. Leaves bipinnate with 4-9 pairs of pinnae; rachis and petiole glabrous to puberulent, usually armed and sometimes with many slender stalked glands ca 0.5 mm long, the glands sometimes at nodes on rachis; leaflets in 8-25 pairs per pinna, oblong-elliptic, oblique, acute to ± rounded and apiculate at apex, trun- cate at base and attached at a corner, 8-14 mm long,
1.5-4 mm wide, the margins entire or sparsely ciliate.
Flowers in short, paniculate spikes; calyx and corolla glabrous. Legumes tan, 15-20 cm long, ca 3.5 cm wide, flat. Croat 15568.
Collected once in the old forest above the escarpment.
Seasonal behavior unknown. Immature fruits have been seen in December.
The flower and fruit description given here is taken from the Flora of Guatemala (Standley & Steyermark, 1946). BCI vegetative material differs from the descrip- tions of other authors by having larger leaflets (to 14 mm long and 4 mm wide, compared to 10 mm long and 2 mm wide).
Mexico, Guatemala, Honduras, Costa Rica, and Pan- ama. In Panama, known only from tropical moist forest on BCI.
63A.
MIMOSOIDEAE/ACACIA425
Acacia glomerosa Benth., Hooker's J. Bot. Kew Gard.
Misc. 1:521. 1842
Moderate to large tree, often buttressed, unarmed or armed with recurved prickles on stems and rachises;
branchlets becoming glabrous in age. Leaves bipinnate with 6-8 pairs of pinnae; petioles ca 4-5 cm long, glan- dular near the base; leaflets many (ca 30 pairs per pinna), oblong to subfalcate, apiculate at apex, truncate at base, 8-12 mm long, ca 2 mm wide, puberulent, the underside paler; midvein submarginal. Flowers cream or white, fragrant, in terminal panicles, the heads small, dense, globose, to 12 mm diam, bearing 12-20 flowers; calyx ca
1 mm long, strigillose; corolla ca 2 mm long, deeply 5-lobed; stamens numerous, showy, white, to 7 mm long.
Legumes narrowly oblong, flattened, 10-20 cm long, ca 3 cm wide, becoming glabrous; seeds few. Aviles 10b.
Collected once; not seen in recent years. Flowers mostly from September to January, especially from Sep- tember to November. The fruits mature mostly from January to May.
The species is perhaps conspecific with A. polyphylla DC, which ranges from Colombia to Brazil. Aviles 10b differs from most material of A. glomerosa in that both surfaces of the leaflets are more densely pubescent with appressed trichomes. The inflorescence is also somewhat more diffuse than the typical A. glomerosa, and the pedi- cels are more slender.
Mexico to southern Brazil. In Panama, collected only from tropical moist forest on BCI, but reported by Hold- ridge et al. (1971) from moist and wet areas at low ele- vations.
Acacia hayesii Benth., Trans. Linn. Soc. London 30:524. 1875
Large canopy liana; trunk to 12 cm diam near the ground, with prominent raised horizontal lenticels; all but the smallest woody parts glabrous, ± 5-sided, the angles with prominent retrorse prickles. Leaves 30-60 cm long, bipinnate with 9-14 pairs of pinnae, each pinna 6-24 cm
KEY TO THE SPECIES OF ACACIA
Plants armed with large, paired, stipular spines resembling bull horns; flowers yellow; fruits sub- terete A. melanoceras Beurl.
Plants armed with recurved prickles or unarmed; flowers usually white; fruits flat:
Plants large buttressed trees A. glomerosa Benth.
Plants lianas or small, vinelike or arching shrubs:
Leaflets 3-7 mm long (usually 4-5 mm), glabrous or with the lower edge nearest the rachis conspicuously pubescent; fruits less than 15 cm long and less than 2.5 cm wide, conspicu- ously rufous-pubescent; flowers in globular heads A. riparia H.B.K.
Leaflets 6-14 mm long (usually 8-12 mm), glabrous or pubescent, but the trichomes never restricted to lower inner edge; fruits more than 15 cm long and more than 2.5 cm wide, tan, inconspicuously pubescent; flowers in short, oblong spikes:
Branches predominantly quadrangular, sulcate; petioles usually displaying more than 2 large sessile glands; rachis usually armed with recurved prickles; interfoliar glands on rachis usually present A. acanthophylla (Britt. & Rose) Standl.
Branches predominantly 5-angled to several-angled; petioles with 1(2) conspicuous sessile glands; rachis usually not armed; interfoliar glands on rachis usually lacking A. hayesii Benth.
426
DICOTYLEDONEAElong; petiole and rachis puberulent; petioles bearing 1 or 2 round or oblong, sessile glands; rachis canaliculate above, often aculeate below, with glands at the nodes;
leaflets in 20-30 pairs per pinna, oblong, blunt at apex, truncate and very inequilateral at base, mostly 9-14 mm long, ca 2.5 mm wide, glabrate to pubescent especially below, the trichomes appressed or erect. Inflorescences large terminal panicles of pedunculate spikes; peduncles 1-2 cm long, puberulent; spikes 10-12 mm long, dense;
flowers glabrous, subsessile, greenish; calyx cupulate, ca 2 mm long, as broad as long; corolla cylindric-campanulate, ca 4 mm long; stamens numerous, 7-8 mm long. Legumes thin, linear to oblong, 15-24 cm long, 2.5-3.5 cm wide, softly puberulent, acute or acuminate apically, rounded at base, the margins markedly raised, the surface broadly undulate; seeds ± disk-shaped, 7-8 mm diam, dark, displayed against the light inner valve surface, borne on a slender funiculus to 13 mm long. Croat 6202.
Common within the forest, generally in the canopy, but the leafy branches may occasionally be seen at lower levels where the vine has fallen. Elsewhere this species becomes a tree (fide Flora of Panama), but on BCI its habit is always decidedly vinelike. Flowers in late Octo- ber and November. The fruits develop to more or less mature size by late January and are dispersed throughout the rest of the dry season and early rainy season (to early May). Plants lose their leaves during the dry season.
The flowering description is based on the Flora of Panama (Woodson & Schery, 1950).
Honduras, Costa Rica, and Panama. In Panama, known only from tropical moist forest in the Canal Zone, eastern Panama, and Darien.
Acacia melanoceras Beurl., Kongl. Svenska Vetenskap- sakad. Handl. 1854:123. 1856
Shrub or small tree, to 6 m tall; branchlets and rachis puberulent, otherwise glabrous; branchlets armed with large spines, the spines 3-4.5 cm long, hornlike, paired, hollow, black, stipular. Leaves bipinnate with 15-26 pairs of pinnae; petioles 1-3 cm long, with several raised glands on upper side near base; rachis 12-25 cm long, usually with a single raised gland between pairs of pinnae; leaflets in 15-30 pairs per pinna, oblong, rounded to obtuse at apex, truncate and inequilateral at base, to 7 mm long, 1-2 mm wide. Inflorescences terminal, raceme-like group- ings of pedunculate heads; peduncles short, subtended by a 3- or 4-parted involucre; heads globular, densely flowered; floral bracts peltate, ± equaling flowers; flowers minute, yellow; calyx cupulate, ca 1 mm long, obscurely lobed; corolla funnelform, somewhat longer than calyx, puberulent apically; stamens numerous, 2-3 mm long.
Legumes linear-oblong, to 11 cm long and 1.5 cm wide,
± compressed-subterete, short-beaked, longitudinally striate, glabrous, tardily dehiscent. Croat 6667.
Occasional, in the forest, especially on the west side of the island. Seasonal behavior uncertain. Probably flowering in February and March. Mature fruits have been seen in May.
Stipular spines often house ants that bite fiercely and remove any vegetation contacting the plant. The plant rewards the ants with sugars from the petiolar glands and with protein from the small beltian bodies along the margins of the leaflets (Janzen, 1967a). According to D.
Janzen (pers. comm.), seeds merely spill out of the pods at maturity but may be dispersed further from the ground.
Unless later regurgitated, seeds would probably not sur- vive the passage through a bird.
Costa Rica and Panama. In Panama, known from tropical moist forest in the Canal Zone and from tropical wet forest in Colon (Portobelo).
Acacia riparia H.B.K., Nov. Gen. & Sp. 6:276. 1824 Vine or scandent shrub, to 5 m tall; branchlets ± angu- late, the angles of the branchlets and sometimes the rachis armed with recurved prickles; petiole and rachis above puberulent and leaf margins ciliate, otherwise glabrous.
Leaves bipinnate with 8-15 pairs of pinnae, each pinna 2.5-4(5) cm long; petioles 1-3 cm long, with 2 oblong glands on upper side; rachis 5-8 cm long, with an oblong gland at base of each pinna mostly in upper portions;
leaflets in 20-40 pairs per pinna, oblong, rounded at apex, rounded to truncate at base, 4-7 mm long, ca 1 mm wide, glabrous but ciliate and sometimes with tufts in inside axil at base of leaf; midrib subcentral. Inflorescences terminal or upper-axillary; peduncles 1-2 cm long; flow- ers ± glabrous, sessile, clustered in white globular heads to ca 2 cm wide; rachis less than 5 mm long; calyx 1-2 mm long, acutely lobed; corolla tubular, 3-4 mm long, acutely lobed. Legumes flat, thin, mostly 10-15 cm long, 2-2.5 cm wide, tomentulose, stipitate, with a sharp beak 5 mm long at apex of fruit; seeds disk-shaped, ca 6 mm long, borne on a slender funiculus, the funiculus attached laterally to the seed, with a sharp bend near its middle.
Croat 8000, Foster 1392
Uncommon, on the shore on the eastern and southern sides of the island. Flowers in the rainy season. The fruits are of mature size by January and February, but probably are not dispersed until late in the dry season (April).
Panama to Ecuador, Bolivia, and southern Brazil. In Panama, known from tropical moist forest on BCI and from tropical dry forest in Panama (Taboga Island).
See Fig. 257.
ADENOPODIA Presl
Adenopodia polystachya (L.) J. Dixon, comb. nov.
Mimosa polystachya L., Sp. PI. 520. 1753; Entada polystachya (L.) DC, Prodr. 2:425. 1825; Mem. Leg. 422, 434, t. 61, 62. 1826
Liana; trunk to 15 cm dbh; stems striate; pinnular rachises and inflorescences puberulent, otherwise ± glabrous.
Leaves bipinnate with 2-5 (mostly 3 or 4) pairs of pinnae;
petiole and rachis lacking glands; leaflets in 5-7 pairs per pinna, oblong, rounded at both ends, oblique at base, 1.5-4 cm long, 0.5-1.8 cm wide. Inflorescences terminal racemes to 25 cm long, of many slender spikes to 10 cm
Fig. 257. Acacia riparia
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tliggr :>-?'?"
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Fig. 258. Albizia guachapek
llfip>
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Fig. 259. Entada monostachya
Fig. 260. Enterolobium cyclocarpum
•»•'
long; flowers small, sessile or short-pedicellate, mostly white, but reportedly also reddish, with a foul odor; calyx cupulate, shallowly lobed to subentire, ca 1 mm long;
corolla of 5 petals, the petals ± free, 2.5-3 cm long, acute; stamens 10, somewhat exserted, ca 4 mm long.
Legumes oblong, 15-30(40) cm long, 5-7.5 cm wide, flat, thin, curved; exocarp thin, peeling away at maturity, the valves then breaking into narrow, wind-dispersed, transverse segments, each carrying a small seed; seeds ellipsoid, 1-1.4 cm long, shiny, brown. Foster 731, Starry 318.
Occasional, in the canopy of the forest; seldom seen, except for its fallen rectangular fruit segments. Flowers from July to September. Mature fruits were seen in December.
The transfer of Entada polystachya (L.) DC. to Adeno- podia was convincingly argued by John Dixon (unpub- lished Ph.D. dissertation, University of Southern Illinois, Carbondale, 1965). Adenopodia and Entada as repre- sented on BCI are two very different taxa both mor- phologically and ecologically.
Mexico to central South America; West Indies. In Panama, known from tropical moist forest in the Canal Zone, Bocas del Toro, Chiriqui, and Panama and from tropical dry forest in Herrera (Pese).
ALBIZIA Durazz.
Albizia guachapele (Kunth) Dug., Phytologia 13:389. 1966
Albizia hngepedata (Pitt.) Britt. & Rose
Deciduous tree, to 15 m tall, tomentose to sparsely to- mentose all over. Leaves bipinnate with 3-5 pairs of pinnae; petioles 3-6 cm long with a round sessile gland near the middle of upper surface; stipules acicular, ca- ducous; rachis 7-15 cm long, usually with a sessile gland at insertion of each pair of pinnae; pinnular rachis 8-12 cm long, with similar glands at insertion of each pair of leaflets; leaflets in 3-7 pairs per pinna, variable, ovate to obovate, asymmetrical, rounded or emarginate at apex, obtuse and inequilateral at base, 1.5-3(4) cm long, 1-2(2.5) cm wide. Inflorescences 1-3, subterminal in axils; peduncles 3-7(9) cm long; pedicels 8-20 mm long;
bracts linear, caducous, small; flowers in dense umbels, dimorphic, the central flower large and sessile; calyx 5-7 mm long (10 mm long in central flower), the lobes acute, ca 1 mm long; corolla green, 8-11 mm long (20 mm long in central flower), the lobes acute, ca 2 mm long, gla- brous inside; stamens long-exserted, ca 2 cm long, white, the staminal tube included. Legumes oblong-linear, flat, 15-20 cm long, 2-3.5 cm wide, markedly short- pubescent, with a narrow marginal rib, tardily dehiscent.
Croat 8707.
Apparently rare, known only from the cove between Slothia Island and Colorado Point. Flowers from Decem- ber to March, in the early dry season. The fruits mature from January to May. Leaves are lost in the early dry season.
63A.
MIMOSOIDEAE/ENTEROLOBIUM429
Guatemala to northern South America. In Panama, known from low elevations in moist, monsoon areas (Holdridge, 1970).
See Fig. 258.
ENTADA Adans.
Entada monostachya DC, Prodr. 2:425. 1825 E. gigas (L.) Fawc. & Rendle
Tendriled liana; trunk to 40 cm diam near the ground;
larger stems with densely and minutely fissured, rusty- brown outer bark; smaller stems green, shiny, almost glabrous. Leaves bipinnate with usually 2 pairs of pinnae, the pinnae opposite, each 6-10 cm long; rachis 6-12 cm long, ending with a simple tendril to 15 cm long; petio- lules short, with prominent basal pulvinus; leaflets in (3) 5 (6) pairs per pinna, asymmetrically oblong, blunt to emarginate at apex, unequal at base, mostly 2.5-5 (7) cm long, 1.2-3 cm wide, glossy above, dull below; midrib puberulent. Inflorescences densely flowered, slender, spikelike racemes inserted shortly above leaf axils, to 25 cm long; flowers green, with a strong and sweet but disagreeable odor, maturing from base of rachis upward;
pedicels short; calyx cupulate, about 1 mm long, the lobes minute; petals elliptic, ca 3 mm long and 1 mm wide, the margins sometimes scarious; stamens 10, ca 6 mm long;
filaments white, the connective bearing a minute, stalked, papillate food body at apex. Legumes very large, 30-120 cm long, 10-13 cm wide, forming a broad spiral, the margins raised; seeds button-shaped, 5-6 cm diam, to 2 cm thick, dark and shiny at maturity. Croat 4957, 7869.
Occasional, in the canopy of the forest and pendent from the trees on the lakeshore. Seasonal behavior uncer- tain. Flowers from November to May. The fruits reach mature size by the late rainy season, but it is not known when they are dispersed, perhaps during the dry season.
Recognized by the huge fruits, which require about a year to mature. Seeds either are removed from the stout valves by animals, which tear holes in the valves, or fall from the weathered valves. The species is common in riparian situations, and water is known to play an impor- tant role in seed dispersal. Seeds are apparently carried great distances by rivers and may often be found in great abundance on ocean beaches.
Central America and tropical South America; West Indies; West Africa. In Panama, known from tropical moist forest in the Canal Zone, Bocas del Toro, Panama, and Darien.
See Fig. 259.
ENTEROLOBIUM Mart.
Enterolobium cyclocarpum (Jacq.) Griseb., Fl. Brit.
W. Ind. 226. 1860
Coratu, Corotu, Cururu, Ear tree, Genisero, Guanacaste, Jarina
Tree, to 30 m tall and 1.5 (3) m dbh, branched from near the ground, the crown widely spreading; outer bark with