Albizia subdimidiata

Title

Albizia subdimidiata

Author(s)

Rupert C. Barneby

Scientific Name

Albizia subdimidiata (Splitg.) Barneby & J.W.Grimes

Description

16.Albizia subdimidiata (Splitgerber) Barneby & Grimes, comb. nov. Acacia subdimidiata Splitgerber, Tijdschr. Natuurl. Gesch. Physiol. 9: 112. 1842.-Typus infra sub var. subdimidiata indicatur.

Amply, often rather coarsely foliate trees 5-20 (-25) m with single or multiple trunk attaining 1-3 (-4) dm dbh, the hornotinous branches ridged and sulcate lengthwise, buttressed under each lf, with smooth, castaneous or atrocastaneous, at length vertically splitting and striped epidermis, the lf-stks (at least ventrally) and axes of inflorescence always, the branchlets sometimes, pilosulous with pallid hairs to 0.1-0.25 mm, the lfts glabrous facially except for midrib proximally barbellate on its anterior side beneath, bicolored, olivaceous (brunnescent) and dull or sublustrous above, pallid and usually microscopically pallid-papillate beneath, the simple pseudoracemes of very small, fragrant, greenish white or ochroleucous capitula arising singly or 2-3 together from the axil of coeval (or newly shed) lvs and much surpassed by them, the fruits long persistent on defoliate annotinous branches. Stipules deltate or triangular-ovate 0.8-1.8 mm, very early dry caducous, lacking from mature lvs. Lf-formula ii—iv(—v)/(7—)8—13(—14), in saplings the pinnae sometimes to 5-jug.; lf-stks of larger lvs mostly (5-)6-16(-20), in var. minor only 1.5-5 cm, the petiole (3-)3.5-7, in var. minor 1.5-3.2 cm, at middle 0.7-1.9 mm diam, the ventral groove continuous between the often not exactly opposite pinna-pairs, the longest interpinnal segments (1.5-) 2-4, in var. minor 0.6-1.6 cm; near or below midpetiole (exceptionally near first pinna-pair) a shallow-cupular or rarely almost plane, round or elliptic, glabrous nectary (0.7-) 1-2.6 mm diam, in profile not over 0.4 mm tall, rarely a second nectary at tip of lf-stk and nearly always yet smaller ones between furthest 1-2 pairs of lfts; pinnae a little decrescent proximally, the rachis of longer ones (5—)6—9(—11) or in var. minor only 3-5.5 cm, the longer interfoliolar segments (5—)6—11 or in var. minor only 3-6 mm; lft-pulvinules 0.7—1 x 0.5—0.8 mm; lfts a little decrescent proximally, thence subequilong, in outline lance- oblong, oblong, semi-ovate, or asymmetrically ovate-elliptic, from inequilaterally rounded or semicordate base, either acutely or obtusely deltate-apiculate, straight or gently incurved near apex, the larger ones 16—25(—29) x 6-9(-12.5) or in var. minor only 11-14 x 3-5 mm, (2-)2.2-3.3(-3.6) times as long as wide; venation of (4)5-6 primary nerves from pulvinule, the straight or near apex incurved midrib forwardly displaced to divide blade 1:2-3 and giving rise on anterior side to ±5-7 widely ascending major secondary venules and on posterior side to fewer, more narrowly ascending ones, the inner posterior primary nerve produced far beyond midblade to anastomosis well within the plane or loosely revolute margin, the outer posterior ones progressively shorter, the 1 anterior primary nerve very short or subobsolete, all these, together with random tertiary venulation, sharply prominulous dorsally, less so but commonly pallid ventrally. Primary axis of pseudoraceme 7-21 cm; peduncles fasciculate by 2-6, the longer of each fascicle 3—9(—11) mm; capitula (8—)11—22-fld, without filaments 5-8.5 mm diam, the globose or claviform receptacle 0.6-2 mm; bracts rhombic-ovate or spatulate 0.4-0.7 mm, glabrate dorsally but ciliolate, persistent; fls dimorphic, the terminal one of each head hardly longer than the rest but wider and with modified androecium, the perianth 5(or that of terminal fl 6-7)-merous, all greenish white and either glabrous except for minutely ciliolate calyx-teeth or the calyx- tube and tip of corolla-lobes microscopically puberulent; PERIPHERAL FLS: sessile or raised on an obscure pedicel <0.6 mm, the calyx campanulate or turbinate-campanulate (0.65-)0.7-1.2 x 0.7-1 mm, the depressed-deltate or deltate-ovate teeth 0.1-0.25 mm; corolla (2-)2.2-3.3 mm, the lobes 0.9-1.5 x 0.65-0.9 mm; androecium (12-)18-25-merous, 6-9 mm long, the stemonozone 0.2-0.5 mm, the tube (0.5-)l.5-2.2 mm; ovary glabrous, symmetrically conical at apex; style a little surpassing the longest stamens, slightly dilated at tip; TERMINAL FL: always sessile, the shallowly campanulate calyx (0.75-)0.8-1.3 x 1.3-2.1 mm, the corolla 2-3.7 mm; tube (1.2-) 1.8-3 x 1.2-3 mm, dilated upward; filaments (20-)24-32, irregularly 2-ranked, the free part of stronger ones proximally dilated. Pods solitary, subsessile or commonly contracted at base into a laterally sulcate pseudostipe 1.5—5 mm, the body undulately linear in profile, either straight or decurved, (8—)9—14(—15) or in var. minor only 6-8 mm wide, when well fertilized (6—)8—17 cm long and (8—)10— 15-seeded, the leathery, at first piano-compressed, atrocastaneous and lustrous, and elaborately venulose valves at length sordid-brown or dull buff, low- convex over each seed, and transversely sulcate between them, the obtuse wiry sutures 0.6-1.1 mm wide, evenly crenately indented their whole length, each seed-chamber (7—)8—15 mm long; fruit lomentiform but not truly dehiscent, the valves often cracking along sulcus between seeds but the sutures continuous and tenaciously attached to the 1-seeded segments, the seeds not individually dispersed; seeds nearly round in broad view, or obtusely quadrate or broad-ellipsoid, compressed but plump, in broad profile 5.3-7(8) mm diam, the bone-white, putty-colored or fawn-brown testa ±0.1-0.15 mm thick, closely investing the hard embryo and charged on each face with a complete pleurogram 2.7-4.5 mm diam.