Abarema filamentosa (Benth.) Pittier
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Authors
Rupert C. Barneby
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Authority
Barneby, Rupert C. & Grimes, James W. 1996. Silk tree, guanacaste, monkey's earring: a generic system for the synandrous Mimosaceae of the Americas. Part I. Abarema, Albizia, and allies. Mem. New York Bot. Gard. 74: 1-292.
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Family
Mimosaceae
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Scientific Name
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Type
"Rio Doce in Brasil, Martius in herb. Hooker under the name of Inga filamentosa [nom nud. in syn.]." — Holotypus, K! = NY Neg. 2005
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Description
Species Description - Macrophyllidious trees with mottled bark, attaining 4—9 m, but sometimes flowering precociously as a shrub at 2-3 m, the twigs, all lf-axes and peduncles densely puberulent when young with brown-gold trichomes at most 0.2 mm, early glabrate, the broad coriaceous bicolored lfts lustrously brown-olivaceous above, paler dull beneath, glabrous overall, the short capituliform racemes arising solitary or geminate from the axil of contemporary lvs. Stipules subulate <1 mm, caducous from incipient lvs, none visible on most branchlets at or after anthesis. Lf-formula i or i—ii(—iii)/2—3, lfts 8-24 per lf; lf-stks (3-)4-47 mm, the petiole proper (3-)4-14 mm, either flattened or widely sulcate ventrally, the one interpinnal segment (or the longer of two) 16-35 mm; lf-nectaries (often pastured and incomplete) sessile verruciform, either hemispherical or depressed-dome-shaped, or subangulate, crumpled and only obscurely pored, lurid-brown or blackish, the first situated immediately below first (or only) pinna-pair and 1.2-2.5 mm diam, similar but smaller ones at insertion of further pinnae and always between the furthest pair of lfts; rachis of distal or only pair of pinnae (2-)2.5-8 cm, the distal or only interfoliolar segment 1.3-3.1 cm; lfts subequiform but larger upward, the blades symmetrically or a little obliquely obovate to broad-oblanceolate from scarcely or moderately inequilateral, broad-cuneate or subcordate base, broadly rounded and muticous or shallowly emarginate at apex, the anterior one of the furthest pair 4-8.5(-10) x 2.2-5(-5.4) cm, (1.3-) 1.5-2.3(-2.4) times as long as wide; venation of subcentric, straight or gently incurved midrib pinnately branched its whole length, the secondary veins brochidodrome well within the loosely revolute margin and giving rise to an elaborate reticulum of venules, the whole venation prominulous on both faces. Peduncles (2.5-)3-9 cm; racemes densely 20-45-fid, the narrowly clavate or almost linear receptacular axis becoming 6-19 cm; bracts ovate-triangular 0.15-0.5 mm, densely brown-puberulent dorsally, caducous; fls dimorphic, maturing in rapid succession upward, the proximal ones smallest and contracted at base into a distinct pedicel, the distal ones progressively a little larger and more shortly pedicellate, 1-3 terminal fls largest and appearing subsessile (the short pedicel nearly as stout as the calyx-tube), these fls with exserted filament tube but not precociously expanding; calyx and corolla of all fls greenish when fresh, minutely puberulent especially on the lobes, brunnescent in drying, the filaments white; pedicels 0.3-1.3(-2) mm; perianth of all fls 5-merous; PERIPHERAL FLS: calyx turbinate 1.7—3.2(—3.6) x 1.2-2 mm, the broad-triangular or depressed-deltate teeth 0.2-0.8(-0.9) mm; corolla (4-)4.2-6.2(-7.3) mm, the lanceolate, apically cucullate lobes 1.8-2.2(-2.6) mm; androecium 16-28(-32)- merous, 21-36 mm, the stemonozone ±1 mm, the tube 1.6-3.4 mm, shorter than corolla; ovary glabrous truncate; style scarcely dilated at tip, the stigma 0.1-0.15 mm diam; ovules 8-12; TERMINAL FLS: calyx campanulate 1.8-3.7 mm; corolla 6.5-9 mm; filaments united into a tube exceeding the corolla by 0.5-4 mm. Pods 1-3 per capitulum, subsessile, in profile broad-linear recurved through at least half and often through more than one circle, 7.5-13 x (1.3-) 1.5-2 mm, the leathery valves fuscous or fuscous-castaneous, papillate but glabrous, at first piano-compressed and framed by thickened sutures, becoming low-umbonate over seeds, the seminiferous (outer) suture undulately impressed between seeds, the dorsal (inner) one more evenly curved, the ripe endocarp lustrously castaneous in the seed-locules but tan and dull elsewhere; dehiscence elastic, through both sutures, the valves at once recurved and twisted; seeds suspended on a ribbonlike, distally coiled funicle, plumply obovoid, in broader profile 6-7 x 5.5-6 mm, the smooth, white or ivory testa closely investing the indigo-blue embryo, ±0.3 mm thick in section, largely opaque and lustrous but differentiated around the distal pole into a translucent zone which forms a U-shaped gray-blue blot lying between finely engraved elliptic pleurograms 4-4.5 x 3.3 mm.
Distribution and Ecology - In wet Atlantic forest and restinga, below 50 m, formerly common and continuously dispersed along coastal Bahia from the latitude of Salvador southward to the mouth of Río Doce in NE Espírito Santo; apparently isolated at 8°20'S in Pernambuco; an old report from Venezuela (Otto s.n., K!) is based on misidentified A. leucophylla. — Map 25. — Fl. II- VIII; fr. VII—II.
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Discussion
The cladistic analysis indicates that A. filamentosa is most closely related to A. cochliacarpos, on the basis of the externally papillate fruit. Characters of the leaf not amenable to cladistic analysis hint at a relationship to A. brachystachya and A. obovata’, for commentary on this relationship, see under A. brachystachya (p. 92). Abarema filamentosa is indistinguishable from A. turbinata by the characters used in the cladistic analysis, but differs from it also in leaf-formula and size of leaflets, characters not amenable to scoring.
Lewis (1987: 179) suggested that the Amazonian Pithecolobium microcalyx and P. parauaquarae (here treated as two varieties of Abarema microcalyx) are conspecific with Abarema filamentosa, but he must have overlooked substantial differences in shape of petiolar nectaries, organization of the pinnae, differences in morphology of the terminal flower, ovary, and internal coloration of the valves.
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Distribution
Bahia Brazil South America| Espirito Santo Brazil South America|