Abarema laeta

Title

Abarema laeta

Author(s)

Rupert C. Barneby

Scientific Name

Abarema laeta (Benth.) Barneby & J.W.Grimes

Description

19. Abarema laeta (Bentham) Barneby & Grimes, comb. nov. Pithecolobium laetum Bentham, London J. Bot. 3: 203. 1844. — "Maynas in Brazil, Poeppig." — Inga laeta (Bentham) Poeppig ex Poeppig & Endlicher, Nov. Gen. Sp. Pl. 3: 80. 1845. -"Crescit cum praecedente [in sylvis provinciae Maynas circum Yurimaguas]." — Holotypus, Poppig D.2367, W(herb. poeppig.)! = NY Neg. 12572; isotypi, = F Neg. 1204, F (fragm.)!, OXF!, W(herb. endlicher.)!. — Feuilleea laeta (Bentham) O. Kuntze, Revis. Gen. Pl. 1: 188. 1891. Klugiodendron laetum (Bentham) Britton & Killip, Ann. New York Acad. Sci. 35: 125. 1936.

?Pithecolobium polycarpum Poeppig & Endlicher, Nov. Gen. Sp. Pl. 3: 81. 1845. — "Crescit in sylvis maynensibus ad Yurimaguas [Alto Amazonas, Loreto, Peru]. Februario [1831] cum fructu maturo lectum." — Equated with P. laetum by Bentham, 1875: 582, but no acceptable typus found at W. A candidate for typus, Poeppig 2245, W(herb. endlicher.)! disagrees with the protologue in lacking "stipulae . . . spinescentes minutae," in pod valves much less than "sesquipedem longis" [unless sesquipedem is a mistake for semipedem], and the seeds are well over 6 in number. No Abarema is known to have pods 1½ feet (i.e., ±45 cm) long. Perhaps based on mixed materials.

Klugiodendron umbrianum Britton & Killip, Ann. New York Acad. Sci. 35: 126. 1936. — "Comisario del Putumayo, Umbria, Colombia, in forest at 325 m altitude, December, 1930, G. Klug 1865." — Holotypus, NY!; isotypi, A!, GH!, IAN (fragm.)!, US 1456622!.

Pithecolobium laetum sensu Bentham, 1875: 582; 1876; 434; Ducke, 1949: 37.

Klugiodendron laetum sensu Nielsen, 1981: 190, fig. 5(4a-4c).

Macrophyllidious arborescent shrubs, fertile at (1.5—)2 m but becoming 6(-?) m tall with trunks to 2(—?) cm diam and yellow wood, the hornotinous branchlets, lf-stks, and peduncles pilosulous or sub- appressed- or incurved-puberulent with rufous or sordid-yellowish trichomes to 0.2-0.7(-0.8) mm, the permanently pale green and subconcolorous, thinly papery lfts lustrous above, dull beneath, either glabrous overall, or minutely ciliolate on margin and on midrib beneath, or (locally in Peru) pilosulous dorsally overall, the loosely capitate or subracemose capitula of dimorphic fls borne singly or in pairs in a few distal lf-axils, or rarely, in default of these lvs, forming a short terminal pseudoraceme. Stipules herbaceous, narrowly lanceolate 1.5—5(—7) mm, 1-3- nerved dorsally, thickened at base and early deciduous from a small, sometimes elevated whitish scar. Lf-formula i-ii/1, the lfts either exactly 4 or exactly 8 per lf; lf-stks (1.5—)2—14 cm, narrowly shallowly grooved ventrally, the petiole proper (1.5—)2—10(—12) cm, the one interpinnal segment, when present, (2.5-)3-7 cm, ordinarily a little longer than the petiole, sometimes as long or a trifle shorter; first petiolar nectary situated usually somewhat below midpetiole, less often at or above it, rarely near the lf-pulvinus, always sessile, low-convex, in outline narrowly elliptic, 1.5-5 mm in long diameter, without obvious aperture, similar but smaller nectaries immediately below each pair of lfts; pinna-rachises (4-)6- 20(-31) mm, widely shallowly grooved ventrally; pulvinule of lfts, seen from dorsal side, (1-) 1.5-3 mm; lft-blades of distal (or only) pair of pinnae sub-symmetrically elliptic or (ob)ovate-elliptic from cuneate base, caudately acuminate, the larger ones (including acumen) 10-18(-20) x 3-7(-7.7) cm, (2-)2.1-2.5(-3.9) times as long as wide, the anterior one of each pair a little longer than its fellow, all cuneate and usually revolute at very base, the acumen 1- 2.5(-3) cm; midrib either straight or very gently an- trorsely curved, prominulous on both faces but above less so and sunk into a groove, the secondary nerves from costa numerous, ascending at wide angle, brochidodrome well within the plane or subundulate margin and giving rise to a dorsally prominulous reticulum of veinlets. Peduncles 3-7 cm, naked or bearing under the capitulum one or more empty bracts, occasionally with a flower distant from the rest; capitula 12-28-fld, the subglobose or clavate receptacle 2-7 mm long; floral bracts thinly herbaceous, linear-lanceolate 2.5-8 x 0.4-1.5 mm (rarely abbreviated, ovate and only 1.5 mm), tardily deciduous from a small spur; fls sessile or almost so, dimorphic, one or rarely two terminal ones a little larger and with long-exserted stamen-tube, all greenish; perianth (4)5-merous, externally either rufescent-pilosulous overall or glabrate except for minutely barbellate or puberulent calyx- and corolla-lobes; PERIPHERAL FLS: calyx turbinate 2-4 mm, the tube 1.5-2.5 mm, the triangular or depressed-deltate lobes 0.5-1 mm; corolla (4.2-)4.7-7 mm, the ascending, ovate lobes 1.6-2.7 x 1.2-1.9 mm, finely 1-nerved; androecium white, fading orange, 20-34-merous, the filaments united into a tube 1.7-4(-4.5) mm, this shortly coherent to base of corolla, the longer filaments (13-) 18-34 mm; TERMINAL FL(S): slightly wider and coarser than the peripheral ones, scarcely longer (to 6-8 mm), but the staminal sheath 7-16 mm long, at least 1 mm longer than corolla-lobes; ovary of all fls glabrous, truncate; ovules 8-14. Pods usually one per capitulum, subsessile but abruptly narrowed into a short neck at base, in broad profile oblong or broad-linear (5-)5.5- 13(—16) x 1.4-2.2 cm, 2.5-7(-10) times as long as wide, when short nearly straight but when longer evenly recurved through to 3/4 circle, at first piano-compressed and framed by the scarcely undulate sutures, becoming umbonate over developing seeds, the stiffly papery valves green turning tan-brown, densely cross-venulose, the venules subcontiguous; dehiscence through both sutures, the valves elastically recurved and coiling, on inner face crimson and densely microscopically papillate (appearing velvety); funicles ribbonlike, coiled but not at all dilated; seeds plumply ellipsoid 10-11 x 6-8 x 5 mm, the translucent testa either colorless (hyaline) or yellowish, pleurogram 0; the horny, plano-convex cotyledons blue or blackish indigo, visible through the testa, their cordate base concealing the plumule.

In the understory of wet, virgin and disturbed equatorial forest, on terra firme, mostly between 100 and 600 m but on Sa Macarena in Colombia attaining 1100 m, in French Guiana 780 m, fairly frequent in W-centr. Amazonia, in SE Colombia, E Peru, extreme SW Venezuela, and Brazil (lat. 3°N-11°S), and outside this range known from remote stations in W Venezuela (sources of Río Apure), in SE Surinam and adjacent French Guiana, and on Sa do Cachimbo in SW Pará, Brazil. — Map 21. — Found in fl. in all months, collected in fr. II, VII-IX. — Pacay shimbillo, shimbillo, (Maynas, Peru); tu ku (also Maynas; furnishes soap).

Permanently bright green foliage, widely divergent and crowded secondary venation of the obligately geminate, acuminate leaflets, and orange coloration of the dried (or faded) androecia characterize A. laeta at anthesis. The densely cross-venulose valves of the pod, green turning light brown externally and velvety-crimson inside, are quintessential abaremoid, as are the blue exareolate seeds.