Abarema barbouriana (Standl.) Barneby & J.W.Grimes var. barbouriana

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 barbouriana (Standl.) Barneby & J.W.Grimes var. barbouriana

Type

"Panama: Zetek Trail, Barro Colorado Island, Canal Zone, October 27. 1931, Otis Shattuck 237" — Holotypus, F!; isotypus, MO!. — Erroneously interpreted in the protologue as related to genus Cojoba Britton & Rose.

Synonyms

Pithecellobium fanshawei Sandwith

Description

Variety Description - Lf-formula vi—xii/12—19; lfts almost always finely and often densely silky-villosulous dorsally, sometimes only barbellate in anterior basal angle of midrib and along the midrib, the largest ones at most 11.5 x 5 mm (to 15x6 mm on juvenile branches), the venation (as given in key) relatively simple; pods either strigulose or pilosulous. [Key] "Lf-formula vi-xii/12-19; larger lfts (excluding terminal pair) on fertile branches 4.5-11.5 x 2-5 mm; secondary veins of hypophyllum 2-6 on each side of midrib;"

Distribution and Ecology - In non-inundated forest, from near sea level in Panama and W Colombia to 950 m in Panama (C. Jefe), 1850 m in Antioquia, Colombia, and 1080 m in Aragua, Venezuela, locally plentiful from centr. Panama (Colón, Panamá, canal zone) to NW Colombia (Chocó, Antioquia, Valle de Cauca); in mountainous N Venezuela (Aragua, Miranda); and far disjunct in lowland Guyana (Mazaruni and Potaro valleys) and interior French Guiana. — Map 16. — Fl. VIII—II. [Key] "Panama and N Colombia, interruptedly E to the Guianas........14a. var. barbouriana"

Local Names and Uses - Dormilón, palo paloma (Colombia).

Discussion

The var. barbouriana is known in Panama and Colombia both from near sea level and from upland forest; there is much variation in form and size of the leaf-nectaries, but we find no correlation between these and elevation of habitat. The pod varies in this same region from strigulose to golden-pilosulous; when pilosulous, it is indistinguishable from that of the remotely allopatric Pithecellobium fanshawei, which we here reduce to synonymy. A few individual specimens here referred to var. barbouriana deserve brief mention:

a. Albert de Escobar 5054, 7708 and Daly 5959 (all NY) from Guatapé, Antioquia, Colombia, at the upper known limit of the species at 1850 m, have exceptionally small lfts, up to 4.5 mm, rather than the usual range of 7-11 mm.

b. F. Tamayo 2038 (US) from cloud forest in state of Miranda, Venezuela, at unrecorded elevation, has dorsally glabrate lfts coinciding with unusually numerous filaments (48 in one dissected flower), a number observed once also in var. arenaria, but not elsewhere in var. barbouriana.

Here again the lfts are small in the context of the species. The specimen was annotated by Pittier as a new species of Calliandra.

c. Weitzman & Boom 110 (NY), from Parque National Pittier, the only other collection of var. barbouriana known to us from northern Venezuela, has lfts nearly as small as those of the last mentioned, but they are pubescent dorsally as usual in A. barbouriana.

d. The specimens from Guyana on which Pithecellobium fanshawei was based have the aspect and lf-formula of var. barbouriana, but the lfts tend toward a rhombic-oblong rather than elliptic outline and in this respect resemble var. arenaria.  In the protologue of P. fanshawei, Sandwith likened it to the then poorly known P. arenaria Ducke. At that time genuine P. barbourianum was not represented at Kew. The very similar populations in French Guiana have almost plane lfts reminiscent of A. jupunba but slenderly stipitate lf-nectaries and loose yellowish indumentum of A. barbouriana.

The only collection known from Ecuador (K. Thomsen 58828, NY) differs from all others by its peripheral fls on a pedicel to 2.5 mm long; otherwise the plant fits neatly within barbouriana var. barbouriana. Should the fruit, when it becomes known, present variation yet undocumented in barbouriana, the plants may represent a new variety.

Common Names

dormilón, palo paloma

Distribution

Colón Panama Central America| Panamá Panama Central America| Antioquia Colombia South America| Chocó Colombia South America| Valle del Cauca Colombia South America| Aragua Venezuela South America| Miranda Venezuela South America| Mazaruni Guyana South America| Potaro-Siparuni Guyana South America| French Guiana South America|