Abarema zolleriana (Standl. & Steyerm.) Barneby & J.W.Grimes

Authors

Rupert C. Barneby

Authority

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.

Family

Mimosaceae

Scientific Name

Abarema zolleriana (Standl. & Steyerm.) Barneby & J.W.Grimes

Type

"Guatemala: Dept. San Marcos: Above Finca El Porvenir . . . lower south-facing slopes of Volcán de Tajumulco, alt. 1,300-1,500 meters, March 9, 1940, Julian A. Steyermark 37440 ..." — Holotypus, F!; isotypus, A!; paratypus, Steyermark 33295, F!

Description

Species Description - Amply microphyllidious trees 5-18 m with smooth trunk, the young branchlets and all axes of lvs and inflorescence densely brown-, bronze- or sordid-puberulent or -tomentulose, the thin-textured lvs strongly bicolored, the lfts above deep green and glabrous except for thinly ciliolate midrib, beneath pale bright green and remotely minutely strigulose overall, the solitary or paired capituliform racemes axillary to coeval or immediately hysteranthous lvs, sometimes at first forming a small efoliate panicle but the fruits immersed in foliage. Stipules linear-lanceolate 2-4 mm, very early caducous. Lf-formula (iii-)iv- x(—"xiii"; protologue)/ll-16(-18); lf-stks (5-)6-20 cm, the stout petiole 2-4.5 cm, the longer interpinnal segments 1.2-2.5 cm; petiolar nectaries sessile, round or elliptic, shallowly cupular with thick wrinkled rim, the first situated shortly below insertion of first pair of pinnae 0.9-3 mm diam, others at some distal pinna- and lft-pairs similar but progressively smaller upward; pinnae accrescent distally but the penultimate pair often longest, their rachis 6-13 cm, the longer interfoliolar segments 5—10(—11) mm; lft-pulvinules in dorsal view 0.5-1 x 0.4-0.8 mm; lfts decrescent proximally, those near and above midrachis, except for the obovate furthest pair (no further mentioned) subequiform, the blades obtusely rhombic-oblong around a diagonal, straight or slightly retroarcuate midrib, at base inequilaterally broad-cuneate, very obtuse or emarginate at broadly rounded apex, the larger ones 12-20 x 5-9 mm, 2-3 times as long as wide; the midrib giving rise on each side to ±6-8 pairs of major (and few weaker intercalary) secondary nerves brochidodrome well within the weakly revolute margin, the tertiary venules few, weak and random, all venation finely prominulous on both faces. Peduncles 3-12 cm; racemes ±26-45-fld, the obovoid or scarcely thickened linear axis becoming 3-15 mm; bracts (few seen) very early caducous, linear-spatulate ±1 mm; fls dimorphic, the peripheral ones distinctly pedicellate (but pedicels shorter upward), the terminal one or two subsessile, broader, and with enlarged androecium, the perianth of all 5-merous, finely minutely silky-puberulent either overall or sometimes glabrate proximally; PERIPHERAL FLS: pedicel 0.9-4 mm; calyx turbinate-campanulate 2-2.3 mm, the depressed-deltate teeth 0.3-0.5 mm; corolla 6-6.4 mm, the ovate lobes 2-2.8 x 1.3-1.7 mm; androecium 22-26-merous, 2.3-2.6 cm long, the stemonozone ±1.5 mm, the tube 2.5-3.5 mm; ovary ellipsoid, conical at apex, glabrous; stigma poriform ±0.1 mm diam; TERMINAL FL(S): pedicel 0.2-0.5 x 1 mm; calyx broadly campanulate 2.5-3 x 1.6-3 mm; corolla 6.5-8 mm, the lobes 2-3.5 mm; androecial tube about as long as corolla, dilated at separation of the 23-45, 2-3-seriate whitish filaments. Pods 1 per capitulum, sessile, in profile broad-linear, evenly recurved through 1/4-3/4- circle, 5.5-12.5 x 1.3-1.6 cm, constricted only where ovules abort, the glabrous valves at first plane, framed by thickened sutures, becoming stiffly coriaceous, fuscous, rugulose but externally veinless, the crustaceous mesocarp ±0.4 mm thick, the fully ripe endocarp dull-maroon (in age castaneous) overall, smooth lustrous in the seed-cavities and papillate between them; dehiscence downward through both sutures, the valves recurved but not or little twisted; seeds plumply obovoid or lentiform, at least a trifle compressed, in broad view 7.5-8.5 x 6-7.5 mm, the translucent white testa ±0.2 mm thick, when fresh transmitting the aniline blue color of the homy embryo but when dry dull whitish nearly overall, bearing on each face a complete or hippocrepiform, delicately incised pleurogram 3.5-4 x 2.5-4 mm.

Distribution and Ecology - In pine-oak woodland, 1100-1800 m, apparently local in Sa Madre del Sur of S Mexico and adjacent Guatemala, between 91° and 98°W latitude: in district Juquila of SW Oaxaca; and in depts. San Marcos and Quetzaltenango, Guatemala. — Map 18. Fl. in Mexico V-VII, fr. X-II.

Discussion

In the context of its dispersal A. zollerana is likely to be mistaken only for A. idiopoda, which differs, however, in more numerous (to 18-40, not 11—18 pairs in longer pinnae) and narrower (to 2.5—3.5, not 5-9 mm wide) leaflets, in longer peripheral pedicels (the lowest mostly more, not less than 4 mm long) and in the technical character of apically conic, not truncate ovary. The perhaps closely related, though distantly allopatric, A. jupunba var. jupunba has leaflets emphatically accrescent upward along the pinna rachis, with terminal pair to 1-2 cm (not 5-9 mm) wide, and a more densely silky perianth. The separation between them is weak, and the specific status of A. zollerana somewhat precarious.

The epithet preserves the memory of Erich Zoller, proprietor of Finca El Porvenir, who assisted Steyermark in his exploration of Cerro Tajumulco.

Common Names

coralillo, plumillo

Distribution

Oaxaca Mexico North America| San Marcos Guatemala Central America| Quezaltenango Guatemala Central America| Chiapas Mexico North America|