Senna pilifera var. subglabra (S.Moore) H.S.Irwin & Barneby

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Authority

    Irwin, Howard S. & Barneby, Rupert C. 1982. The American Cassiinae. A synoptical revision of Leguminosae tribe Cassieae subtrib Cassiinae in the New World. Mem. New York Bot. Gard. 35, part 1: 1-454.

  • Family

    Caesalpiniaceae

  • Scientific Name

    Senna pilifera var. subglabra (S.Moore) H.S.Irwin & Barneby

  • Type

    Holotypus, BM! = IPA Neg. 1439 = MO Neg. 2067 = NY Neg. 158.

  • Synonyms

    Cassia pilifera var. subglabra S.Moore, Cassia maritima Willd. ex Vogel, Cassia mattogrossensis Malme, Emelista pilifera (Vogel) Pittier

  • Description

    Variety Description - Herbaceous from fibrous roots, sometimes appearing monocarpic, sometimes suffruticose in age, normally much taller and more erect than var. pilifera, the foliage thinner-textured, usually glaucescent beneath, usually finely puberulent on both faces, exceptionally glabrous; petioles 2-6 cm, mostly 0.5-1.2 mm diam; distal lfts 3-6(-7.5) x 1.5-3.4 cm, the tertiary and reticular venulation scarcely or not visible above, faintly raised beneath; pedicels 1.5-2.6 cm; style of var. pilifera; areole of seeds 2-2.5 x 0.3-0.6 mm.—Collections: 52. [Key: "Stems erect or strongly assurgent (0.6-) 1-2.4 m; lf-rachis 3-6(-9) mm; fls smaller, either the long sepals 4.5-7.5(-8.5) mm or the longest petal (12-) 13-23(-26) mm, or both; anthers of 3 abaxial stamens 4.5-10 mm; seeds 3-5 mm long, the testa castaneous; allopatric, except for emphatically smaller-fld var. tubata. Style only slightly dilated distally, widest shortly below apex, there 0.3-0.6 mm diam and thence contracted to a narrower, introrsely directed stigmatic cavity; lfts membranous, puberulent on both faces, obscurely reticulate dorsally; anthers of 3 abaxial stamens 6.5-10 mm; Mexico to Panama, n. Colombia, the Pacific slope in Ecuador, n. Peru; Cuba; disjunctly in n. & e. Venezuela and in e. Brazil from the Amazon delta s. to centr. Mato Grosso, Distrito Federal, s. Minas Gerais and e. S. Paulo."]

    Distribution and Ecology - Thickets, open or disturbed woodland, riverbanks and shores, southward along gallery margins in cerrado, becoming locally weedy in hedges and pastures, near sea-level up to 1400 m in Mexico, 1450 m in Peru, 1050 m on the Brazilian Planalto, widespread but highly scattered through parts of tropical N. and S. America: w. and s. Mexico (Sinaloa, near 25°N, to Oaxaca, Chiapas and Veracruz); e. Cuba (Oriente); centr. Panama (Panama and Canal Zone); Cordillera Oriental in n. Colombia (Santander); lowland Pacific Ecuador (Guayas); sources of R. Huancabamba in s.-e. Piura and Cajamarca, Peru; remotely disjunct in the Orinoco valley in Bolivar and Guarico, Venezuela and in lower Amazonian and e. Brazil, from the delta region in Para s. to the headwaters Rio Araguaia in Mato Grosso, of Rio Tocantins in Goias, the Sao Francisco-Doce watershed in s. Minas Gerais, and e. Sao Paulo (Bocaina)—Fl. in Mexico IX-II, Cuba and Panama IX-II, in n. S. America IV-V, in Brazil III-VII.

  • Discussion

    There can be little question that the Mexican, Cuban, Panamanian and Amazonian plants referred by Bentham and by Britton & Rose to Cassia (or Emelista) pilifera are distinct from genuine S. pilifera of tropical Argentina and adjoining states, for they differ in habit, probably in duration of the root, in size of all flower parts and, most importantly, in the shape of the seed-locules as determined by the smaller size of the differently colored seeds. Collectively they might well be construed as an independent species, but the populations known from Maranhao, Goias and Minas Gerais, while for the most part firmly linked to the northern ones by their seeds and habit of growth, have larger flowers, the measurements of all organs independently overlapping, if only a little, those of typical S. pilifera; and a few of these are ambiguous as to growth-habit, taller certainly than var. pilifera of extreme southeastern Brazil and Argentina but described as diffuse. A line drawn along the Amazon-Parana watershed through the Federal District effectively separates the ranges of the varieties but as they approach this line, from either direction, the more obvious differences become muted. Unfortunately we have as yet too few examples of seeds from the Planalto, which might prove critical in the case of ambiguous specimens. Unlike var. pilifera, the present variety is rather uniform in pubescence of the foliage, the leaflets being almost always puberulent on both faces; but the ovary may be either strigulose or pilose, its vesture varying independently of that of the stems or of geography. The holotypus of var. subglabra and Irwin et al. 15267 from Sa. do Morcego on the Goias-Minas border near 15°S are notable for the complete loss of the long lustrous setae usually thought characteristic of C. pilifera, but are not otherwise different from compatriot populations. The epithet sub glabra is for the most part inappropriate and misleading.

  • Common Names

    Acahualera

  • Distribution

    Sinaloa Mexico North America| Oaxaca Mexico North America| Chiapas Mexico North America| Veracruz Mexico North America| Oriente Cuba South America| Panamá Panama Central America| Canal Zone Panamá Central America| Santander Colombia South America| Guayas Ecuador South America| Piura Peru South America| Cajamarca Peru South America| Bolívar Venezuela South America| Guárico Venezuela South America| Pará Brazil South America| Mato Grosso Brazil South America| Goiás Brazil South America| Minas Gerais Brazil South America| São Paulo Brazil South America|