Chamaecrista serpens (L.) Greene var. serpens
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Authors
Howard S. Irwin, Rupert C. Barneby
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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.
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Family
Caesalpiniaceae
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Scientific Name
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Type
Holotypus, acquired by Linnaeus from Patrick Brown in 1758, LINN 528/241— Ophiocaulon serpens (Linnaeus) Rafinesque, Sylva Tell. 129. 1838.
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Synonyms
Cassia serpens L., Ophiocaulon serpens (L.) Raf., Cassia prostrata Humb.
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Description
Variety Description - Stems usually very slender, glabrous, puberulent, or setose; lvs mostly 1-3 cm, with up to 5-7(-8) pairs of lfts, these varying from glabrous to thinly, rarely densely setose dorsally; fl small, the cucullus 5-7 mm, the longer anthers 2.5-4 mm, the style 2-3.6(-4) mm; pod usually both puberulent and weakly long-pilose, mostly 1.4—3.2 cm, 5-9-seeded.—Collections: 134. [Key: "Fl small, the asymmetric long petal 5-7 mm, the longer anthers to 2.5-4 mm, the style 2-3.6(-4) mm; s.-centr. Mexico (Michoacan, Guerrero, Mexico, Oaxaca) and w. Cuba s. to Argentina. Lfts of larger lvs 4-7(-8) pairs, but these either glabrous or thinly setose."]
Distribution and Ecology - Savannas, campos, roadsides and waste places, becoming weedy in parks, fallow fields and lawns, mostly on light or sandy soils, near sea level up to 800 m on the Brazilian Planalto, 1200 m in Central America, 1300 m in n. Venezuela, and 1600 m in Colombia, widely but discontinuously dispersed through the Neotropics: around the w. and s. periphery of the Caribbean (Jamaica, w. Cuba, Isthmus of Tehuantepec in Mexico, Belize, Honduras, Guatemala, Nicaragua, Colombia, and Venezuela n. of the Orinoco R.) extending w. to the Pacific slope in Nicaragua and n.-w. to coastal Guerrero, Mexico, in Colombia s. up the Magdalena Valley to Huila; disjunct on the margins of Guayana Highland in interior Guyana and adjacent Terr. do Roraima, Brazil; in s. hemisphere reappearing on Rio Tocantins near 4°30'-8°S in Pará and Maranhão; in Rio Grande do Norte; in s. Pernambuco and w. and coastal Bahia; over the s. Planalto from w. Minas Gerais to n. São Paulo and s. Mato Grosso; not recorded from Goiás, Brazil or from Paraguay but again locally frequent in Corrientes, Argentina; introduced in peninsular Florida (Hillsboro Co.); and in s. Mexico (Michoacán and s.-w. Mexico) represented by forms intermediate in foliage to var. delicata.—Fl. nearly throughout the year, except where inhibited by seasonal drought.
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Discussion
The range of var. serpens is, on present evidence, puzzlingly discontinuous. The plants are, however, inconspicuous at best and easily passed over, and the herbarium record is probably not an accurate reflection of the full dispersal. On the other hand, the ability of Ch. serpens to thrive in disturbed places may well have encouraged its spread by artificial means. Variation in pubescence is in this case clearly correlated with dispersal. In North America, and in South America s.-ward to Bahia, the leaflets are glabrous except for minutely ciliolate margins; but from Minas Gerais s.-ward setae become more abundant on the stems and petioles and extend outward, few or many, to the margins and sometimes to the dorsal face of some or all leaflets. A notable collection from the lower Orinoco valley in Venezuela (Cd. Bolívar, Holt & Gehriger 53, US) suggests a hybrid between var. serpens and Ch. pilosa or possibly a distinct entity coincidentally sharing some aspects of the latter, for neither parent is known from the immediate region. This plant has the hispid stem and few (2-3) pairs of leaflets expected in Ch. pilosa; but the floral morphology, including ample oblique cucullus and decandrous androecium, are typical of var. serpens. The protologue of Cassia serpens is somewhat ambiguous, Linnaeus having described seven pairs of leaflets and a pentandrous androecium. The latter character agrees with Ch. pilosa, also native to Jamaica, but not to the species traditionally known as C. serpens, which has always a full set of ten stamens. On the other hand the leaflets are only 4-5 pairs in Jamaican Ch. pilosa. Both species are represented in the Linnaean herbarium by specimens acquired from Patrick Browne, and by simply accepting these as the types the difficulties inherent in the description of Ch. serpens can be passed over.
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Distribution
Guerrero Mexico North America| Huila Colombia South America| Pará Brazil South America| Maranhão Brazil South America| Rio Grande do Norte Brazil South America| Pernambuco Brazil South America| Bahia Brazil South America| Minas Gerais Brazil South America| São Paulo Brazil South America| Mato Grosso Brazil South America| Goiás Brazil South America| Florida United States of America North America| Michoacán Mexico North America| México Mexico North America| Jamaica South America| Cuba South America| Belize Central America| Honduras Central America| Guatemala Central America| Nicaragua Central America| Colombia South America| Venezuela South America|