Abarema barbouriana var. arenaria (Ducke) 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 barbouriana var. arenaria (Ducke) Barneby & J.W.Grimes

  • Type

    "Habitat prope Manáos . . . circa Ponte do Mindú . . . 14-3-1932 leg. A. Ducke, H[erb.] J[ard.] B[ot.] R[io de Janeiro] n° 23.233." — Holotypus, RB!; isotypi, P!, US!

  • Description

    Variety Description - Lf-formula (ii—)iii—v/(7—)8—11; lfts either pilosulous overall on dorsal face, glabrate except for pilosulous midrib, or (locally) glabrous, the largest ones 9-21 x 5-10 (locally only 3-7) mm, the venation (as given in key) commonly better developed than in var. barbouriana; pods loosely strigulose with hairs up to 0.5 mm. [Key] "Lf-formula ii-v(-vi)/(7-)8-11(-13); larger lfts (excluding terminal pair) on fertile branches (9-)10-18 x (3-)5-10 mm; secondary veins of hypophyllum (5-)6-9 on each side of midrib;"

    Distribution and Ecology - In savanna and forest-margin habitats at low and montane elevations in Venezuelan Guayana, W-centr. Guyana, and the Río Negro basin in T. F. Amazonas, Venezuela, and state of Amazonas, Brazil: N slope of Mt. Roraima, 800 m, Guyana and on Gran Sabana and emergent tepuis, at 1250-1900 m, in Bolívar, Venezuela; on cliffs and rocks at 1500-2000 m of tepuis of T. F. Amazonas, Venezuela; in sandy, sometimes inundated savanna and along streams at 120-150 m on the Negro-Orinoco divide in T. F. Amazonas, Venezuela; and collected frequently in moist sandy, non-inundated, pristine and disturbed woodland in vicinity of Manaus, state of Amazonas, Brazil; and disjunct in sandy campo cerrado at ±200 m near Pôrto Velho in N Rondônia, Brazil, and (see discussion below) at 200 m on Río Caquetá, 75°W, in Amazonian Colombia. — Map 16. — Fl. in upland X-II, in lowland nearly throughout the year. [Key] "Venezuelan Guayana and the Río Negro basin in Amazonas, Brazil.........14b. var. arenaria"

    Local Names and Uses - Guamito (T. F. Amazonas); mese-yek (Bolívar; the bark yields saponins for washing); angico bravo, faveira (Manaus).

  • Discussion

    The var. arenaria differs from var. barbouriana principally in lower leaf-formula, and, for the most part, var. arenaria has larger leaflets with more numerous secondary nerves, and locally it has larger flowers. It is racially complex, however, and the number of pinnae, at most 4 or near Manaus occasionally 5 (not 5-12) pairs, is the only dependable criterion. Six groups of populations are feebly distinguished by combinations of habitat, dispersal, and minor features of the indumentum and flower-size, two of them found in lowland white-savannas of the Río Negro basin, two at montane or upland elevations in Venezuelan Guayana, one in Amazonian Colombia, and one in campo of middle Río Madeira basin in N Rondônia:

    a. Around Manaus, at 30-40 m: lf-formula (ii-)iii-v/8—11 (—13), the largest lfts 11-18 x 5-8 mm; lfts densely pilosulous beneath; peripheral fls small, the calyx 3.2-4 mm, the corolla 5.3-6.5 mm.

    b. Headwaters of Río Negro in Venezuela and adjacent Brazil, not over 150 m: lf-formula iii— iv(-v)/10-14, the largest lfts only 9-13 x 3-7 mm, pilosulous overall beneath; peripheral fls of the preceding. In its small, ventrally convex lfts this simulates var. barbouriana.

    c. In sandy campo near Porto Velho, Rondônia: lf-formula iii—iv/7—8, the lfts to 20-24 x 6-7 mm, glabrous dorsally except for pilosulous midrib; fls of the preceding.

    d. Tepuis of T. F. Amazonas, Venezuela, 1500-2000 m: lf-formula ii-iv/8-11, the largest lfts 12-16 x 5-7 mm; lfts glabrous beneath or almost so; peripheral fls of the two preceding.

    e. Gran Sabana and tepuis of state of Bolívar, Venezuela, eastward from Río Paragua, 1250-1900 m: lf-formula ii-iv/8-11 (—12), the largest lfts (10-) 14-21 x (5—)7—10, usually pilosulous beneath but rarely glabrous except for ciliolate midrib; peripheral fls larger, the calyx 4.2-6 mm, the corolla 8-9.5 mm.

    f. Solano, on Río Caquetá, 200 m: lf-formula ±iv/8—10, the lfts to 18x9 mm; peripheral fls small, the calyx 2.5-4 mm, the corolla 4.5-5 mm.

  • Common Names

    Guamito, mese-yek , angico bravo, Faveira

  • Distribution

    Amazonas Venezuela South America| Amazonas Brazil South America| Guyana South America| Bolívar Venezuela South America| Rondônia Brazil South America|