Albizia buntingii

  • Title

    Albizia buntingii

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Albizia buntingii Barneby & J.W.Grimes

  • Description

    11. Albizia buntingii Barneby & Grimes, sp. nov., A. niopoidi, A. barinensi, A. glabripetalae, et A. subdimidiatae notulis multis similis, affinitatis verae leguminis defectu incertae, a prima pinnarum lon- giorum foliolis 11-12 (nec 28-63)-jugis usque, majoribus 4-5 (nec 0.9-2.5) mm latis et e pulvinulo palmatim 5-6 (nec 3-4)-nerviis, flosculisque periphericis pedicello 0.9-1.4 mm usque longo elevatis (nec subsessilibus); a secunda foliolorum numero minori, pedicellis flosculisque glabris; a tertia foliolorum numero minori sed ambitu multo majori (13-14 x 4—5, nec 5-8 x 1.4-2.3 mm usque) androecioque 28-30 (nec 16)-mero; a quarta, quoad foliolorum numerum comparabili, pinnis 6-7 (nec 2-4, raro 5)-jugis, flosculisque et pedicellatis et majori- bus (4-4.5, nec 2-3.3 mm longis) diversa. —VENEZUELA. Zulia: alrededores de Casigua El Cubo, 100 m, al este del empalme de la vía hacia Casigua con la carretera Machiques-La Fría. Alt. ca. 125 m, 25.11.1985 (fl.), George S. Bunting 13370. — Holotypus, NY.

    Rather coarsely microphyllidious trees, so far as known ±3 m with trunk 1 dm dbh and dark brown, angulately ribbed branchlets, except for glabrous or subglabrous upper face of dull olivaceous, thin-textured lfts puberulent throughout, the branchlets microscopically so and early glabrate, the axes of lvs and inflorescences pilosulous with incurved hairs to 0.2 mm, the umbelliform capitula of greenish fls borne singly and geminate at nodes of short efoliate pseudoracemes arising singly or 2-3 together from the axil of fully expanded or lately shed lvs, the inflorescence consequently immersed in foliage. Stipules not seen, probably very small and evanescent, the scar minute. Lf- formula vi-vii/11-12; lf-stks 11-16 cm, the petiole 5-6 cm, at middle 1.2-1.5 mm diam, the ventral sulcus continuous between pinnae, the longer interpinnal segments ±15-18 mm; a sessile, shallow-cupular nectary ±1 mm diam a little below midpetiole, a smaller one at tip of lf-stk, and yet smaller ones between 1-2 furthest pairs of lfts; pinnae gently accrescent distally, the rachis of furthest and penultimate pairs 6-7 cm, the longer interpinnal segments 5-5.5 mm; pulvinules 0.5-0.6 mm diam, blackish; lfts decrescent near base of rachis, the first pair represented by subulate or falcate paraphyllidia 0.3-0.7 mm, the rest inequilaterally oblong from obliquely subtruncate base (the posterior angle acutely rectangular), depressed-deltate-apiculate, the larger ones 13-14 x 4-5 mm, 2.8-3.3 times as long as wide; venation of 5-6 nerves from pulvinule, the straight midrib giving rise on each side to 4-5 weak secondary nerves, the inner posterior primary produced well beyond midblade to anastomosis well within the loosely revolute margin, the outer posterior primaries progressively short, the one anterior primary nerve either very short or obsolete, all these and a random oblique or irregular tertiary venulation bluntly prominulous above. Primary axis of pseudoracemes ±6-7 cm; longer peduncles 9-14 mm; capitula 12-26-fld, without the cream-white filaments 9-10 mm diam; bracts linear-oblanceolate, to 2 mm, caducous long before anthesis; fls moderately or strongly dimorphic, all at least shortly pedicellate, 1-3 terminal ones at least a little and sometimes much longer than the rest and their androecial tube much longer; perianth of all fls 5-merous and glabrous except for a few minute pallid hairs on calyx-teeth and toward tip of corolla-lobes; PERIPHERAL FLS: pedicel 0.9-1.4 x 0.2 mm; calyx campanulate 1.2-1.6 x 1-1.2 mm, the triangular teeth ±0.4 mm; corolla 4-4.5 mm, the ovate lobes 1.2-2 x 0.8-1.3 mm; androecium 28-30- merous ±10 mm, the stemonozone ±0.5 mm, the tube 3.5-4.5 mm; ovary glabrous, conical at apex; style as long as or a little longer than longer filaments, scarcely dilated at the stigma; TERMINAL FL(S): pedicel 0.5 mm or less; calyx 1.6-1.7 x 1.2-1.7 mm; corolla 4-6 mm; androecium 9.5-13 mm, the tube 4.5-8 mm. Pods unknown.

    In unrecorded habitat at ±125 m, to be expected in seasonally dry brush-woodland, known only from the type locality in the Maracaibo basin, Venezuela. — Fl. II-III.

    Albizia buntingii belongs to a group of species that are separable at anthesis by rather subtle characters of pubescence, leaflet-number, -size, and -venation, flower-size, and number of filaments in peripheral flowers of the capitulum, but are suprisingly diverse in ultimate form of the pod. In absence of this, the true close affinity of A. buntingii cannot be assessed, and we have contrasted it in the diagnosis with species that are known to occur nearest to it, and with which in practice it is most likely to be confused. Albizia niopoides, the one of these that is known to occur also, and in two varieties, in the Maracaibo basin, differs most obviously in that its longer pinnae are composed of 30-40 (not 11-12) pairs of leaflets at most 1-2 (not 4-5) mm wide. Albizia barinensis, primarily of the Orinoco basin in Venezuela, has both pinnae and leaflets rather more numerous and peripheral flowers at once subsessile and pilosulous. Albizia glabripetala, from the periphery of Guayana far to the southeast of the Maracaibo basin, resembles A. buntingii in often pedicellate flowers, but has narrower, more numerous leaflets and only half as many (±16, not 28-30) stamens per flower. Finally, the widely dispersed A. subdimidiata differs in fewer, mostly 2-4 pairs of pinnae, somewhat broader leaflets, almost or truly sessile peripheral flowers, and substantially smaller corolla about 2-3.3 (not 4-4.5) mm long. Of the four species just compared with A. buntingii, the first two have piano-compressed acacia-like pods inertly dehiscent through the sutures, whereas the pods of the last two are lomentiform, indehiscent in the strict sense, but tend to split transversely between seeds. It is not possible to foretell to which type, if either, the pod of A. buntingii will conform.