Cassia ramosa var. ramosa

Cassia uniflora Spreng. var. parvifolia Benth., Trans. Linn. Soc. 27: 568. 1871.

Cassia tetraphylla Desv. var. ramosa (Vog.) Amsh., On S. Am. Papilionaceae: 26. 1939.

Cassia uniflora Spreng. var. utiarityi Hoehne, Comm. Linh. Tel., Annex 5, Bot. pt. VIII: 47. 1919. Accompanying photograph of holotype examined: Brazil, Mato Grosso, "Rio Papagaio, near Salto Utiariti." Hoehne 2075. June 1909.

Cassia savannensis Miq., Ann. Nat. Hist., p. 15. 1843. Holotype examined (U): "Surinam, Joden savanna.’' Focke 454. w/o date (collected in Surinam 1835-1850). Amshoff's selection of the type of C. savannensis as that for C. tetraphylla var. ramosa. is quite untenable, for Vogel's name, C. ramosa, based on a Sellowian specimen from Brazil, was not only proposed before Miquel’s C. savannensis but probably before Focke’s Surinam materials had reached Europe.

Chamaecrista ramulosa Killip R: Pittier, Bol. Soc. Venezolana Cienc. Nat. 7: 146. 1941. Type not seen: "Lomas de los Caños, valle del río Carí, al sur de El Tigre. Diciembre 15, 1940." H. Pittier 14476. Material (e.g. L. H. & E. Z. Bailey 1378) annotated by Britton as Ch. rusbyi Britt. & Rose was examined (NY). This latter name, while evidently not validly published, was treated by Killip and Pittier as a synonym of Ch. ramulosa. Characters given in the type description of Ch. ramulosa and material annotated as Ch. rusbyi clearly fall within the presently recognized range of variability of Cassia ramosa.

Erect shrub or subshrub, usually freely and often intricately branched, to 1.5 m tall. Stipules ovate-cordate, acuminate, 2.5-6.4 mm long, 1.5-3.4 mm broad, glabrous, occasionally puberulent or infrequently glaucous. Petiole 1.3-2.6 mm long, entirely glabrous or puberulent, the abaxial surface sometimes sparingly pilose; rachis about as long as petiole. Gland 1, rarely 2, usually urceolate but varying from scutellate to globular, 0.4-0.7 mm broad, elevated on a slender stipe 0.5-1.2 mm long. Leaflets bijugate, the pairs equal or the superior pair somewhat longer, joined to rachis by a small arcuate black or brown pulvinule 0.4-0.7 mm long, oblanceolate to obovate, often somewhat falcate, glabrous or sometimes puberulent, less commonly glaucous, firmly membranaceous, 0.3-1.2 cm long, 0.20.7 cm broad; apex obtuse or rounded. Flowers solitary or rarely in pairs, produced more or less continuously but most prolifically after rains; pedicels straight, glabrous, or unilaterally or completely puberulent, 1.4-2.3 cm long and ca. 0.4 mm thick in flower, up to 3.3 cm long and 0.8 mm thick in fruit; bracts 2, broadly ovate to orbicular, 0.6-1.1 mm long, 0.5-1.1 mm broad; bracteoles subopposite, lanceolate or narrowly ovate, glabrous or sometimes puberulent, 2.2-2.8 mm long, 0.8-1.4 mm broad; sepals lanceolate, mostly glabrous, 1.0-1.7 cm long, 0.3-0.5 cm broad; petals 1.7-2.6 cm long, 1.3-2.3 cm broad; ovary gray-sericeous. Pod narrowly oblong, 2.64.2 cm long, 0.4-0.6 cm broad, faces usually slightly sulcate between the seeds, sparsely pubescent to puberulent or glabrous. Seeds 15-22, somewhat compressed, 3.7-5.0 mm long, 1.0-1.7 mm broad.

Chromosome number: n = 7.

Distribution: southern Venezuela, eastward through British Guiana and Surinam to French Guiana, southward in Brazil through eastern Pará, Pernambuco, and Bahia to Minas Gerais, Goiás, and Mato Grosso. Occurring in savannas and open woods, chiefly on sandy soils, from sea level to 3500 feet (up to 5000 feet in the vicinity of Mount Roraima) .

Although the distribution map of C. ramosa var. ramosa would seem to indicate a high degree of localization, it is probable that future collections from the Rio Branco area of Brazil, Rupununi district of British Guiana, Amapá, much of the southern drainage of the Amazon, and the northeastern states of Brazil, will include material of this taxon. Despite its already known wide dispersal, a remarkable degree of morphological stability is shown. However, material from littoral areas is distinctive in habit as well as in foliar details, and, because of the likelihood of maritime selection having had influence in the expression of these characters, this material has been segregated as var. maritima Irwin.

Another variable character, that of vesture of pedicels and leaflets, shows as yet, little correlation with geography, and hence, puberulent or pubescent specimens are not given nomenclatural recognition. While glabrous plants are common over the entire range, in Surinam and British Guiana approximately one-third of the collections which have been examined display puberulent or pubescent pedicels. However, this character also appears, rather less commonly, not only in adjacent Venezuela but far to the south in Pernambuco, Bahia, and Minas Gerais. Puberulent or pubescent leaflets, a condition always accompanied by similar vesture of pedicels, occurs in the Gran Sabana of Venezuela and in inland areas of Bahia. Conspicuous glaucescence of leaflets is found in the Gran Sabana and in central Minas Gerais, but, as far as is known, nowhere in between. Until the savannahs in the north and south drainage of the lower Amazon become better known botanically, it would seem best to regard these variants as unnamed local forms. In the present treatment, the conception of C. ramosa includes the vestural and dimensional extremes elucidated by Miquel (1850).

Bentham’s transfer of C. ramosa to varietal status under C. uniflora Spreng. (= C. chartacea Irwin) was plausible at the time of his work, but in view of the presently known wide dispersal of this taxon, its relative stability, and its clear distinction from C. chartacea, on the basis of the stipitate glands, small bracteoles, and large corolla, its reinstatement at specific rank seems more consistent with the treatment accorded other taxa in the section. The varietal epithet, parvifolia, was an arbitrary name change by Bentham, presumably made in the interest of etymological clarity (C. chartacea itself is also quite ramose), but lacking legitimacy under the present code (Lanjouw et al., 1956).

Amshoff’s transfer of C. ramosa to varietal rank under C. tetraphylla Desv. was an expression of her opinion that all bijugate taxa in the section Xerocalyx were probably varieties of a single variable species. As will be shown, variability in C. tetraphylla is indeed considerable, but does not tend in the direction of characters displayed by C. ramosa.

C. uniflora var. utiarityi is, as Hoehne states, distinct only in its erect habit and general pubescence. However, neither character is sufficiently stable to warrant recognition, at least until this presumed segregate and the area from which it was taken become better known.