Cassia fasciculata Michx.

Authority

Isley, Duane. 1975. Leguminosae of the United States: II. Subfamily Caesalpinioideae. Mem. New York Bot. Gard. 25 (2): 1-228.

Family

Caesalpiniaceae

Scientific Name

Cassia fasciculata Michx.

Description

Species Description - Glabrate to hirsute, erect to prostrate, simple to much branched annual. Stems puberulent to conspicuously hirsute (with an underlayer of puberulence). Leafstalk 3-6 cm with a depressed to stalked, medial to distal petiolar gland .5 to 1.5 mm diam or length; leaflets .5-16(-18) pairs (fewer on lower leaves) oblong, .5-1.5 mm, 3-6 r, asymmetrically nerved, mucronate, glabrous to strigose or puberulent. Stipules persistent, subulate-lanceolate, striate. Flowers 1-3 in axillary bracteate fascicles on pedicels 8-15 mm. Sepals equal, lanceolate-acuminate, 9-12 mm; corolla yellow, rarely nearly white, 2.5-4 cm diam, somewhat irregular, 4 of the petals red-marked at base, the largest usually ventral; functional stamens 10, nearly sessile, anthers of 2 lengths, yellow or bicolored to red. Legume elastically dehiscent, oblong, flat, 3-5.7(-8) cm long, 3-5(-10) mm wide; valves thick-papery, black at maturity, glabrate to hirsute, obliquely transverse-lined between seeds. Seeds few.

Discussion

CN n = 8 (Irwin and Turner, 1960; determinations on all varieties except var. brachiata); Pullen (1963; determinations on all varieties). And others. The wide ranging Cassiafasciculata, reasonably consistent through most of its range, is phenotypically diverse across the southern coastal plain. Here, variational patterning is not amenable to hierarchical classification, and interpretations become so subjective that one individual’s structuring will likely not satisfy others. Several of the past treatments of Cassia fasciculata sens lat. (Pollard, 1894; Pennell, 1917; Britton 8c Rose, 1930; Isely, 1958; Pullen, 1963) take up several sympatrie species or varieties. My observations and to some extent the data presented by Pullen (1963) suggest this premise is not sound. Within a given region, populations vary in pubescence, gland and habit characters, and often in anther color. It is unfortunately just these characters that have been used most often as markers for taxonomic groups. Undoubtedly habitat changes and seed dispersal by man have rendered the species more panmictic than 200 years ago. Perhaps much local variance between and among populations is due to this disturbance, or is circumstantial and random, and from the evolutionary standpoint, “noise.” On the other hand, the frequency of given phenotypic characters and the manner in which they are combined differ from place to place, and I suspect that both are independent of the hand of man and have evolutionary and taxonomic significance. A given ecotypic expression in coastal Mississippi may closely resemble another in southern Texas, but each seems more closely related to the contiguous populations from whence they spring than to each other. Thus, to the extent the species can be defined in conventional taxonomic form, it seems more rational to do so on a largely geographic basis. Turner (1959) and Irwin (1970), treating Texas forms of C. fasciculata, have to some degree substituted a regional interpretation for morphological literalism. Herein I follow this method except in the instance of var. brachiata. Cassia fasciculata is divided into 4 geographic varieties. Within the two major varieties (fasciculata and puberula) regional variants are characterized.

Distribution

E and c U.S.: s New England, se South Dakota, w Texas, Florida (reported from New Mexico and Colorado but no material seen). Of diverse habitats, frequently ruderal, in disturbed places or open woodland. Common and conspicuous in most of range. Planted to limited extent. Phenology various. Partridge pea.

United States of America North America|