Pithecellobium macrandrium

Title

Pithecellobium macrandrium

Author(s)

Rupert C. Barneby

Scientific Name

Pithecellobium macrandrium Donn.Sm.

Description

18. Pithecellobium macrandrium  J. D. Smith, Bot. Gaz. (Crawfordsville) 40: 3 (sub Pithecolobio sect. Chloroleuco). 1905. — "In silvis ad Cubilquitz, Depart. Alta Verapaz, Guat[emala], alt. 350 m, Jul. 1902, Nov. 1904, von Tuerckheim, nn. 8193, 8667, ex Pl. Guat." — Lectotypus, no. 8193, US 576512!; isotypus, NY!; paratypi, no. 8667 NY!, US!.

Pithecellobium macrandrium sensu Britton & Rose, 1928: 23; Pithecolobium macrandrium sensu Standley & Steyermark, 1946: 78.

Amply foliate, normally arborescent but occasionally diffuse or sarmentose shrubs (l-)2-7 m with coarse canaliculate stems, armed at most nodes with a pair of conic or straight, ascending, long-tapering spinescent stipules, the young stems, the lf-axes, and the inflorescence densely or thinly either pilosulous or puberulent with fine, erect or incumbent, sordid- gray hairs to 0.15-0.4 mm, the lvs discolored, the lfts dull olivaceous (when dry brown) above, paler beneath, pubescent either on both faces, or beneath only, or facially glabrous ciliolate, the massive, relatively long-pedunculate spikes of greenish white, white-stamened fls either solitary or paired in the axil of coeval lvs, but the furthest lvs sometimes much reduced upward and the inflorescence then pseudoracemose exserted. Stipules associated with ampler lvs persistent, mostly 5-25 mm, angulate and vulnerant, but at random nodes much shorter, those of reduced or rudimentary distal lvs and of axillary buds acicular and <2.5 mm. Lf-formula v-xii/9-30 (of some distal lvs, no further described, iii-v/5-12); lf- stks of major lvs (9-) 12-19 cm, the petiole (0.7—)1— 3.5(-5.5) cm, at middle 1.5-2.8 mm diam, the longer interpinnal segments ±1.5—4 cm, the deep ventral sulcus interrupted at insertion of each pinna-pair by a cupular nectary; proximal nectary either sessile or shortly stoutly stipitate 1-2.5 mm diam, in profile not over 0.5 mm tall, succeeding ones similar or a little smaller, and much smaller, more evidently stipitate nectaries on pinna-rachises between third to ninth distal lft-pairs; pinnae decrescent proximally and often somewhat so distally, the rachis of longer ones 5-11 cm, the longer interfoliolar segments (2.5-) 7 mm; leaflets elliptic, ovate- or lance-elliptic from a scarcely inequilateral, cuneate or shallowly cordate base, rounded or shortly bluntly acuminate, the larger ones 11-28 x 3-7 mm, 2.6-3.6 times as long as wide; venation pinnate, the straight centric midrib giving rise on each side to ±5-7 major (but slender) ascending secondary venules brochidodrome well within the plane margin and to sinuous minor ones with tertiary connecting venules, the whole venation of mature lfts immersed or almost so on upper face, finely prominulous beneath. Peduncles stout ascending 4-12 cm; spikes densely (25-)35-80-fld, the axis at maturity (2-)3-9.5 cm; bracts commonly ovate short- acuminate, sometimes lanceolate, 1.5-2.5 mm, firm and persistent; fls homomorphic, widely spreading- ascending, sessile or almost so, the firm thick-textured perianth gray-strigulous overall; calyx hemispheric or shallowly campanulate 1.9-3.2 x 2.3-3.2 mm, the depressed-deltate teeth 0.3-0.6 mm; corolla pyriform in bud becoming widely funnel-shaped 9-13 mm, the ascending lobes 2-4.6 x 2.2-2.9 mm; androecium 52-76-merous (2.8-)3.2-5.5 cm, the stemonozone 1-2.4 mm, the tube (15-) 17.5-22 mm, somewhat thickened internally at base into distinct callosities 0.3-0.5 mm tall but these often wanting; ovary (exceptionally 2) subsessile, narrowly ellipsoid, shallowly grooved laterally, glabrous. Pods (few seen fully ripe) subsessile, in profile undulately narrow-oblong or broad-linear, compressed but plump, straight or gently decurved, obtuse, 5.5-9.5 x 1.2-1.8 cm, 3-8- seeded, the broad sutures not prominent, undulately constricted between seeds, the subsucculent (partly resinous), minutely puberulent valves becoming stiffly leathery or ligneous, externally fuscous wrinkled, internally reddish brown; dehiscence follicular [?]; seeds obliquely ascending, semi-imbricate, plumply ellipsoid attaining 14—18 x 9.5-10 mm, halfenclosed in an elaborately lobed, orange or scarlet aril, the thin testa lustrous black, smooth or wrinkled, pleurogram 0.

In pine-palmetto savanna and disturbed or regenerating woodland, from sea level to 350 m in the interior, locally plentiful in Belize, from coastal lowlands to foothills of Maya Mts., W across Petén, Guatemala to the Usumacinta valley in SE Tabasco and N Chiapas, Mexico, S into Alta Verapaz, Guatemala. — Map 12. — Fl. VII—III. — Pricklewood (Belize); motilla (Guatemala).

In an absent-minded moment Rico (1991: 519) called P. macrandrium endemic to Belize, even though it was described from Alta Verapaz in Guatemala.

Pithecellobium macrandrium resembles P. lanceolatum, P. johansenii, P. winzerlingii, and P. hymenaeifolium in inflorescence, individual flowers, and fruits; it differs only in elaborately decompound (not quadrifoliate) leaves. Pithecellobium peckii and P. bipinnatum resemble P. macrandrium in the relatively high leaf-formula, but differ from it (as well as from Pp. lanceolatum, johansenii, winzerlingii, and hymenaeifolium) in short sessile spikes of smaller flowers.