Senna macrophylla var. gigantifolia

  • Title

    Senna macrophylla var. gigantifolia

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Senna macrophylla var. gigantifolia (Britton & Killip) H.S.Irwin & Barneby

  • Description

    17a. Senna macrophylla (Kunth) var. gigantifolia (Britton & Killip) Irwin & Barneby, stat. nov. Chamaefistula gigantifolia Britton & Killip, Ann. N.Y. Acad. Sci. 25(3): 171. 1936.—. . Rio Putumayo, Peru-Colom- bia Boundary, September 26, 1930, G. Klug 1622 . . . Mishuyacu, Loreto, Peru, G. Klug 279. "—Holotypus, Klug 1622, NY! = NY Neg. 4956; isotypi F, MICH, MO, US; paratypi, Klug 279, F, NY! —Cassia gigantifolia (Britton & Killip) Cowan ap. R. E. Schultes, Bot. Mus. Leaf!. Harvard Univ. 18: 146. 1958.

    Chamaefistula barbinervis Pittier, Bol. Soc. Venezol. Ci. Nat. 10: 111. 1945.—"VENEZUELA. Aragua: Entre Guamita y Rancho Grande, 900 m. Parque Nacional, Aragua, . . . Julio 8, 1938 (Ll. Williams 10254, tipo). Distrito Federal: Las Conchitas, 800 m, valle de Puerto la Cruz, Mayo 1926 (A. Jahn 477)."—Holotypus, Williams 10254, VEN! = NY Neg. 6331; isotypi, F, US! paratypi, Jahn 477, NY, US, VEN = NY Neg. 6330.

    Variably pubescent, the hornotinous branchlets, lf-stalks, lower face of lfts and axes of inflorescence varying from minutely subappressed strigulose to villosulous-pilose, the hairs up to 0.1-0.6(-1.2) mm, the vesture either pallid or rufescent; stipules highly variable, either setiform and 9-12 mm, less than 1 mm diam, or oblanceolate acute up to 20 x 2 mm, or greatly enlarged and foliaceous, resembling the leaflets and up to 12 x 5 cm; lvs 3-7.5 dm, the petiole including pulvinus (6-)7-28 cm, at middle 2-4.5 mm diam; rachis mostly 5.5-12(-15) cm, shorter than petiole; gland 2-5(-6) mm; distal lfts 18-44 x 7.5-18(-24) cm, the major camptodrome secondary veins 11-18; inflorescence either axillary to living lvs or cauliflorous, consisting either of a condensed leafless branchlet or reduced to 1(-2) shortly pedunculate racemes; sepals of var. macrophylla, but sometimes thinly pilosulous dorsally; petals (11-) 12-25(-34) mm.—Collections: 106.

    Primary and disturbed Hylaean forest of the upper Amazon and Orinoco basins, commonly on terra firme but occasional in varzea, on a variety of clay and sand soils (sometimes in caatinga), from ±130 up to 400-1300 m on the e. slope of the Andes in Venezuela, Ecuador and Peru, to 800 m on Guayana Highland (Sa. de Parima) and to 800-1400 m in cloud-forest of Cordillera Costanera in n. Venezuela, widespread as scattered individual trees or shrubs over n.-w. Brazil (Terr, do Roraima, Amazonas, Acre, Rondonia) and adjacent Peru (Cuzco, Huanuco, Loreto, San Martin, Amazonas), Ecuador (Napo-Pastaza), Colombia (Caqueta, Putumayo, Vaupes) and Venezuela (Amazonas), n. in Venezuela round the Andean sources of Rio Orinoco in Apure, Barinas and Merida and reappearing near crest of the coastal cordillera in e. Lara, Aragua and Distrito Federal.—Fl. nearly throughout the year.—Matarro (Peru).

    Two collections from the Rio Negro-Orinoco divide in Vaupes, Colombia, are notable for elongate pedicels (up to 5.5-6.5 cm) and large flowers (longest petal 2.6-3.4 cm). One of them (Schultes et al 17964, US) was particularly cited by Cowan when he transferred Chamaefistula gigantifolia to Cassia. Following Cowan, we regard this, with Fernandez 2126 (US), as remarkable but taxonomically insignificant individual variants.