Description originale
Irwin, H. S. & Barneby, R. C. 1982. The American Cassiinae: a synoptical revision of Leguminosae tribe Cassieae subtribe Cassiinae in the New World. Memoirs of the New York Botanical Garden, 35(1-2): 1-918.

 

Statut pour la Guyane française
Irwin, H. S. & Barneby, R. C. 1982. The American Cassiinae: a synoptical revision of Leguminosae tribe Cassieae subtribe Cassiinae in the New World. Memoirs of the New York Botanical Garden, 35(1-2): 1-918. [GF = D]

 

Date de publication : Mem. New York Bot. Gard., 35(2): 874. 1982 [17/12/1982, fide p. de titre].

Description : "When adult erect, bushy-branched distally, up to 7-12 dm, the purplish-castaneous stems pilosulous when young, the olivaceous lfts either glabrous or glabrous-ciliolate; stipules submembranous, lance-oblong, obtuse or abruptly acute, up to 6.5-14 X 2.5-6.5 mm, all deciduous before the associated If; lf-stalk 5-11(-12) mm, the petiole 3-7 mm, the rachis 1-2 mm; petiolar gland 0.5-1.1 mm diam, sessile or elevated on a low mounded stipe as wide or slightly wider than head; lfts oblanceolate or narrowly obovate-elliptic obtuse or subacute, the larger of larger lvs 20-42 x 5-12(-14) mm, the distal pair often much longer than the proximal one and often a trifle arched backward; pedicel, fl and pod of var. mollissima." (Irwin & Barneby, Mem. New York Bot. Gard., 35(2): 874. 17/12/1982).

Distribution : "Campo or savanna, on white sand, quartzite, or sandstone, ±250-500 m, interruptedly dispersed around the n. w. and s. periphery of the Amazon Basin: sources of Río Vaupés (ríos Kubiyu and Kuduyarí) in Vaupés, Colombia; middle Orinoco valley in n.-w. Amazonas, Venezuela; Guayana Highland in Bolívar, Venezuela (Gran Sabana near Uriman); Sa. Tumucumaque and vicinity, along the frontier in Surinam, Brazil (Pará, Amapá) and probably French Guiana; and on middle and upper Rios Xingú and Araguaia in s.-e. Pará and n.-e. Mato Grosso (Parque Nacional do Xingú; Sa. do Roncador)." (Irwin & Barneby, Mem. New York Bot. Gard., 35(2): 874. 17/12/1982). Voir aussi GBIF.

Statut biogéographique : Taxon signalé à sa description comme probablement présent en Guyane française, en raison de sa présence dans les Tumuc Humac côté Suriname (et Amapá?). Malheureusement le protologue ne livre pas les détails sur la ou les collecte(s) concernée(s), et nous n'avons pas été en mesure de les tracer. Sa présence dans les Tumuc Humac nécessite donc d'être formellement confirmée.

Taxonomie : "Readily distinguished from glabrous forms of var. mollissima, which it otherwise closely resembles, by early loss of the membranous stipules, the year-old stems in consequence naked and not clothed in gray marcescent tatters. Like other discontinuously dispersed forms of Ch. desvauxii, the var. piptostegia consists of major geographic populations that are minutely different and technically separable, possibly indeed independent but parallel modifications of the protean ancestral stock of tetraphyllous Xerocalyx. The Colombian plants (holotypus; Garcia Barriga et al. 16043; Schultes & Cabrera 18321) have glabrous leaflets, sessile glands, and relatively long petioles; those from northeastern Brazil and adjoining countries (Steyermark 75288; Oldenburger ON-166; Fittkau & Coelho in INPA 12835; Cavalcante 2512; Pires & Cavalcante 52023) have ciliolate leaflets, glands raised on a mounded pediment, and proportionately very long distal leaflets bent backward in the style of the narrow-leaved form of Ch. diphylla that has been known as C. cultrifolia; while the Xingú-Araguaia populations (D. Coelho in INPA 15877; Froes 29821; Argent et al. 6640; Santos et al. in Ratter 1496) combine ciliolate but ampler leaflets with sessile glands." (Irwin & Barneby, Mem. New York Bot. Gard., 35(2): 874. 17/12/1982).

Type : Colombie, Vaupés, Cerro Yapobodá, río Kuduyarí, sabanas sobre piedras areniscas, ±450 m , 05-06/10/1951, fleurs, R.E. Schultes & I. Cabrera 74562 (HT: NY00004172; IT: US00372843).