Monographs Details: Chamaecrista nictitans subsp. patellaria var. praetexta
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:Fabaceae
Synonyms:Cassia praetexta Vogel, Chamaecrista lucesiae Pittier, Chamaecrista nelsonii Britton & Rose, Cassia praetexta Vogel
Description:Species Description - Monocarpic herbs (1.5—)4—10 dm, with usually 1 erect stem strictly few- branched from near or beyond middle, or less often branched from near root- crown and the lateral stems incurved-ascending, appearing glabrous below the coarsely ciliolate pod but the young internodes and pedicels minutely or thinly puberulent with incurved hairs, the concolorous foliage brown when dry, the lft- margins either glabrous or minutely ciliolate. Stipules erect, submembranous, lance-acuminate 4-10 x 1.1-2 mm, from base striately 7-13-nerved, persistent. Adult lvs 3-9 cm, shortly petiolate, the expanded blades lance-elliptic in outline; petiole including pulvinus 3-8 mm, at middle 0.25-0.8 mm diam, very narrowly margined; gland 1, situated near or above middle of petiole proper, sessile, in profile tub- or drum-shaped, rarely turbinate, slightly wider than high, 0.25-0.9 mm tall, the round or elliptic head 0.35-1.2 mm diam; lfts 10-21 pairs, in outline narrowly oblong to broadly linear, obtuse and mucronate or acuminulate, straight or slightly falcate, 5-16 x 1-2.7 mm, at base cordate on proximal and cuneate on distal side, the moderately excentric costa dividing the blade ±1:2, from base (3-)4-5-nerved, the lateral nerves all short, 3 on broad and 0-1 on narrow side, the costa remotely 3-6-penninerved, the venulation above immersed, beneath finely prominulous. Peduncles adnate to stem through 4-15 mm; racemes l-4(-5)-fld, the axis 0-4 mm; pedicels at anthesis 1.5—4.5 mm, in fruit 3.5—6.5 mm, bracteolate 0.5—2 mm below calyx; buds ovoid-acuminate, glabrous or almost so; sepals lance-acuminate, 5-6.5 mm; petals yellow, the 3 adaxial broadly oblanceolate to obovate- cuneate 5-6.5 x 2.5-3.5 mm, the 2 abaxial longer or broader, one broadly obovate 6.5-8 X ±6 mm, the cucullus obliquely reniform ±6 mm long, 7 mm wide; stamens 10, the long anthers 3.6-4.4 mm; ovary glabrous on sides, densely pilosulous along sutures; style straight linear ±1.5 mm; ovules 8-13. Pod erect, linear slightly curved outward, 2.5-4.5(-5.1) cm long, the thin-textured glabrous valves 3-4 mm wide, the thick sutures winged lengthwise on either side, the thinly herbaceous, commonly reddish wings coarsely ciliolate, becoming 0.75-1.6 mm wide; seeds 2.6—3.2 mm, the testa atrofuscous above the fulvous base, dull, sharply lineolate-pitted.—Collections: 28.

Distribution and Ecology - Savannas, mostly below 500 m, apparently rare and nowhere abundant, scattered around the n.-e. shoulder of S. America, from the lower Amazon valley (downstream from near mouth of Rio Trombetas) in Pará, through coastal French Guiana and Guyana (not yet recorded from Surinam) to Trinidad (Piarco Savanna) and the lower Orinoco valley in Venezuela (Guárico and Anzoátegui); one record, perhaps adventive, from suburban Manaus in Amazonas; disjunctly in Cuba (Oriente and Camaguey) and the Pacific lowlands of Isthmus of Tehuantepec in s.-e. Oaxaca, Mexico.—Fl. mostly X-IV, but along the Amazon River perhaps irregularly through the year.

Discussion:

Until the characteristic sutural wings develop with the maturing pod, the plant body of var. praetexta is virtually identical with that of those glabrescent or glabrous Cuban forms of var. glabrata which Britton & Rose (1930) described as Ch. glaberrima; and except for smaller, shorter-styled flowers and laterally glabrous ovary mimics in exact detail the glabrescent forms of subsp. disadena var. disadena encountered on savannas of the central Amazon valley and interior Guyana. In both of these forms, moreover, the sutures of the ripe pod sometimes carry obscure but definite herbaceous flanges up to 0.4 mm wide, narrower, it is true, than those of var. praetexta, which become up to 0.8-1.6 mm wide, but of precisely the same essential structure. We interpret var. praetexta as a derivative of the Ch. nictitans stock inhabiting northeastern South America and the southern Caribbean region in which one single vegetative feature, already present in facultative form, has become exaggerated. In the absence of supporting differential characters we confidently reduce C. praetexta to varietal status. Exaggerated sutural wings appear to have developed in parallel style in the genus Senna, the local and rare S. pentagonia (P. Miller) hardly differing otherwise from widespread and variable S. obtusifolia (Linnaeus) Irwin & Barneby.

Distribution:Pará Brazil South America| French Guiana South America| Guyana South America| Trinidad and Tobago South America| Venezuela South America| Guárico Venezuela South America| Anzoátegui Venezuela South America| Cuba South America| Oriente Cuba South America| Camagüey Cuba South America| Oaxaca Mexico North America| Mexico North America|

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