Narratives – The Barneby Catalogue

Abarema levelii

39. Abarema levelii (Cowan) Barneby & Grimes, comb. nov. Pithecellobium levelii Cowan, Mem. New York Bot. Gard. 10: 69, fig. 48. 1961. — "VENEZUELA: Amazonas: Caño Cupaven, opposite mouth of Río Atabapo, alt. 150 m . . . 11 May 1954, J. Silverio Level 73 .. . along Río Orinoco just about [above] mouth of Río Atabapo, alt. 125 m. . . 1 Jun 1959, Wurdack & Adderley 42730" — Holotypus, Level 73, US 2281812!; isotypi, NY (2)!; paratypi, (Wurdack & Adderley 42730), NY!, P!, US!, VEN!.

Macrophyllidious unarmed trees ±8-10 m with vertically wrinkled branchlets, the young stems and all axes of the terminal, shortly exserted panicle of few- but long-fld capitula densely brownish-puberulent, the amply 4-foliolate lvs glabrous, the lfts lustrously olivaceous and venulose on both faces, a little darker above, the capitula borne singly or 2-3-nate in the axil of a short efoliolate lf-stk charged near apex on ventral side with a gross verruciform nectary. Stipules 0 (no scar). Lf-formula i/1; lf-stks including livid wrinkled pulvinus 5-23 mm, at middle 1-1.6 mm diam, shallowly openly sulcate ventrally; a sessile or impressed, shallowly concave, elliptic nectary 2-3 mm in long diameter at apex of petiole, and a similar, slightly smaller one at tip of each pinna-rachis; rachis of pinnae 12-35 mm; lft-pulvinules livid wrinkled 4-8 x 1.1-1.7 mm; paraphyllidia 0; lfts ovate from equilaterally rounded or slightly oblique base, bluntly short-acuminate, 7-12 x 3-6 cm, 1.9-2.8 times as long as wide; the straight centric midrib giving rise on each side to 3-5 strong incurved-ascending and many, much finer, widely ascending secondary nerves, the strong ones brochidodrome close within the plane corneous margin, these all engendering a mesh of 3-4-nary venules, the whole venation prominulous on both faces, strongly so beneath. Primary axis of inflorescence ±4-10 cm, its branches about half as long; peduncles ±20-33 mm; capitula densely 6-14-fld, the fls ascending, the receptacle including terminal pedestal 1.5-3 mm; bracts deltate-ovate ±0.5-0.75 mm, caducous; fls dimorphic, all sessile, the perianth of all 5-merous, densely appressed-strigulose with minute sordid-bronze hairs; PERIPHERAL FLS: calyx campanulate 3-3.5 x 1.4-1.8 mm, the ovate, often unequal teeth to 0.5 mm; corolla tubular- infundibuliform 11.5-15.5 mm, the involutely lanceolate lobes ±4 x 1.3 mm; androecium in the type collection ±30-merous, nearly 4.5 cm, the filaments white, the stemonozone ±1.7 mm, the tube ±14 mm, in Brazil (scarcely known) shorter, the tube ±8 mm; ovary very slenderly fusiform, minutely puberulent; ovules 9; TERMINAL FL: calyx 3-4 x 2.5-3 mm, corolla ±13 mm; androecium ±45-merous, the tube 11.5 x 2 mm. Pods unknown.

In blackwater igapó woodland, 120-150 m, known from only two localities: at mouth of Río Atabapo in T. F. Amazonas, Venezuela (near 4°N); and on Río Abacaxis in SE state of Amazonas, Brazil (near 4°22'S). — Map 31. — FL V-VII.

In the protologue of Abarema levelii, Cowan found no close relative in Pithecellobium sens. lat., but remarked that the species differed from all congeners in leaflet-number and inflorescence. In reality it is not essentially different in either of those features from A. leucophylla, the reduction of distal leaves to a rudimentary leaf-stalk with nectary being the same in both, and a leaf-formula of i/1, apparently stablized in all leaves of A. levelii, being frequent in distal leaves and sometimes uniform in all leaves of A. leucophylla. Both species have the dimorphic flowers of Abarema. A shadow of doubt will linger over the attribution of Pithecellobium levelii to Abarema until the fruit and seeds are procured, as flowering specimens are a little unusual in Abarema for the length of the peripheral corollas. However, the species is otherwise fully compatible with our concept and definition of Abarema, and it cannot be accommodated in any other described genus of Ingeae.

The one Brazilian collection of A. levelii (S. Hill 12937, GH, US), from the middle Amazon basin at a point 1400 km distant from the type locality, seems to differ from the Venezuelan plants in slightly shorter corolla and androecium, but it is a good match for the type in other respects. Obviously much remains to be learned about the morphology and dispersal of A. levelii.

Because of a technical difference in leaf-apex, A. levelii is contrasted in our key to species with A. laeta, but not with its seemingly closer relative A. leucophylla var. leucophylla, which may be separated as follows:

1. Lfts bicolored, lustrous above, pallid dull beneath, broadly rounded at apex; corolla of peripheral fls of the capitulum 3-6.5 mm, not more than twice as long as calyx: A. leucophylla var. leucophylla

1. Lfts concolorous, lustrous on both faces, shortly bluntly acuminate; corolla of peripheral fls 11.5 mm, 3-4.5 times as long as calyx: A. levelii

References: [Article] 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.