Senna pallida var. goldmaniana 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 2: 455-918.

  • Family

    Caesalpiniaceae

  • Scientific Name

    Senna pallida var. goldmaniana H.S.Irwin & Barneby

  • Type

    Holotypus, US = NY Neg. 10493.

  • Description

    Variety Description - Slender shrubs, in habit and resinously dotted foliage resembling var. bahamensis, with terete branchlets, glabrous except for minutely puberulent ovary, the mature foliage pallid-glaucescent beneath, the 2-fld racemes borne on depauperately leafy branchlets axillary to coeval lvs. Stipules subulate or setaceous 1-5 x 0.2-0.3 mm. Primary cauline lvs 4.5-7.5 cm; petiole 12-20 x 0.5-0.6 mm, 1-1.5 times as long as first (or only) interfoliolar segment of lf-stalk; rachis 1-4.2 cm; gland between proximal pair, shortly stipitate, 1.1-2 mm, the head 0.4-0.8 mm diam; lfts 2-4 pairs, accrescent distally, the terminal pair broadly obovate obtuse 2-2.8 x 1-2 cm, 1.3-2 times as long as wide, the venation of 5-6 pairs of camptodrome secondary nerves weakly prominulous on both faces, reticular venulation 0; lvs of branchlets shorter, the lfts always 2-jugate. Peduncles 12-17 mm; pedicels 1-2.2 cm; long sepals ±6 mm; long petals ±13-17 mm; filaments glabrous, of 4 median stamens ±1 mm, of 3 abaxial ones ±2.5 mm, the anthers of 4 median stamens abruptly truncate 4.5-4.8 x 1.5 mm, of 3 abaxial ones 5-5.5 mm, with beak ±1.5 mm; style 1.5 mm. Stipe of pod 5-7 mm, the body 5.5-9 x 0.55-0.7 cm, the valves simply mounded over seeds; seed 3 x 1.7-2.8 mm, the castaneous testa densely finely pitted overall, the areole 0.7-0.9 x 0.6-0.7 mm.-Collections: 5. [Key: "Appendage terminal of lf-stalk subulate or setiform, not modified and dilated into a gland; range of whole species. Continental N. and S. America and Lesser Antilles, s. Windward Is. and Swan Is. in s. Caribbean; anthers nearly always stouter (1.2-)1.3-2 mm diam, abruptly truncate at apex and the tubules there commonly umbonate at the angle opposed to the laterally divaricate, often slightly infra-terminal beak, if whole anther less than 1.25 mm diam and umbo pronounced. Reticulate tertiary venulation imperceptible or almost so on both faces of lfts, these superficially either penninerved or veinless. Lfts or larger primary cauline lvs 2-8(-9) pairs, perceptibly and usually conspicuously accrescent distally, the terminal pair longest; areole of seeds 0.4-0.9 mm in greatest diam. Scattered over s. Mexico and Guatemala. Plants of Yucatan Peninsula, Mexico. Lfts of primary lvs 2-4, of brachyblast lvs exactly 2 pairs; local in Quintana Roo; seeds pitted."]

    Distribution and Ecology - Habitat not recorded, known only from the n.-e. shoulder of Yucatan Peninsula, Terr. Quintana Roo, Mexico.-FI. II-IV, probably later.

  • Discussion

    A remarkable plant, clearly distinct from var. gaumeri, vicariant immediately to the east, in its few large leaflets, those of primary leaves two to four (not 4-6), those of leaves associated with flowering brachyblasts exactly two (not 3-4) pairs; and unique among known forms of S. pallida in its pitted seeds. The same characters distinguish it from var. bahamensis, which has in addition characteristically slender anthers; and from var. pallida, of which the nearest known stations lie some 800 km south westward in Veracruz and 500 km southeastward on Swan Islands in the western Carribean. In general aspect var. goldmaniana is reminiscent of S. holwayana var. absoidea which has leaves similarly simplified down to two pairs of leaflets, but differs, inter alia, in the proportionately very long and slender petiole, 5-9 (not 1-1.5) times as long as the rachis proper.

  • Distribution

    Quintana Roo Mexico North America|