Senna gardneri (Benth.) H.S.Irwin & Barneby
-
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 1: 1-454.
-
Family
Caesalpiniaceae
-
Scientific Name
-
Type
Lectoholotypus, Gardner 2123, collected IV.1829 (fl), K (hb. Hook.)! = IPA Neg. 978 = NY Neg. 1461; isotypus, BM! paratypi, Blanchet 2890, BM, FI, K = NY Neg. 979, NY, P!
-
Synonyms
Cassia gardneri Benth.
-
Description
Species Description - Lvs (3-)3.5-7 cm; petiole including livid swollen pulvinus (9-) 12-24 mm, at middle 0.5-0.6 mm diam subterete; rachis 3-8 mm, obscurely sulcate ventrally; gland between proximal pair plumply obovoid-pyriform or clavate, in profile 1.2-2.5 mm tall, the livid lustrous body 0.5-1.2 mm diam; lfts 2 pairs, the distal ones broadly obovate obtuse or emarginate (18-)22-38 x (13-)15-20 mm, 1.2-2 times as long as wide, at base very slightly or obscurely asymmetrical, the centric midrib with 6-11 major (and some intercalary) secondary veins either prominulous on both faces or subimmersed above, the major secondary ones widely ascending to margin and there anastomosing with a prominently raised marginal or subintramarginal nerve, the tertiary connecting venules prominulous at least beneath to form an open coarse reticulum, the proximal pair of lfts similar but shorter and proportionately wider, sometimes suborbicular. Racemes few from axils of distal lvs (often reduced to glanduliferous lf-stalk) 1-4-fld, the peduncle 0.5-1.5 cm, the axis almost 0; bracts subulate ±1-1.5 mm, caducous; pedicels 1.7-2.5 cm; buds plumply obovoid glabrous; sepals (apparently reddish pallid-margined) broadly oblong-obovate obtuse unequal, the inner ±10-12 mm, the outermost ±1/2 shorter; petals (little known) yellow glabrous up to ±23 mm; androecium glabrous, the filaments of 4 median stamens ±2 mm, of 3 abaxial ones 5-9 mm, the anthers of 4 median stamens 4.5-5.5 mm nearly straight up to the abruptly divaricate 2-porose beak ±0.5 mm, those of 3 abaxial ones lunately incurved, the body 7-9 mm contracted into a subulate erect, slightly incurved 2-porose beak 1-1.5 mm; ovary glabrous or strigulose; style ±2.5 mm, little dilated distally, ±0.4-0.6 mm diam below the stigma, the stigmatic aperture 0.2-0.45 mm diam; ovules ±80-90. Pod (little known) spreading-recurved, the stipe ±0.8 cm, the narrowly cylindric body ±14 x 0.6 cm, when ripe apparently resembling that of C. splendida, the ventral suture 1.5-2 mm wide, the valves castaneous smooth or faintly venulose, the biseriate seeds (not seen) reportedly (Sucre 10254, RB) embedded in sweet pulp sought by ants.—Collections: 7.
Distribution and Ecology - Caatinga thickets below 700 m, known only from scattered stations in n. Piaui (Lagoa do Potinho), centr. Piauf (Oeiras) and Chapada Diamantina in centr. Bahia (Sa. d’Agurua).—Fl. IX-X, II, IV, the full season unknown.
-
Discussion
Bentham described Cassia gardneri from two flowering specimens and provisionally referred it, along with C. corifolia, to a ser. Coriaceae of sect. Prososperma, some members of which have similar flowers and androecium. The flower, however, is also essentially that of S. splendida and S. georgica and the pod, collected recently for the first time in northern Piaui, turns out to be the tubular one of sect. Chamaefistula ser. Bacillares, with seeds lying across the long axis of the valves in a bed of pulp. Among east Brasilian Bacillares with strongly dimorphic stamens S. gardneri now emerges as closest to the two species just mentioned, differing from S. georgica in the much smaller leaflets, from S. splendida in the obovate-suborbicular, proportionately much broader leaflets, and from both (as indeed from all members of the series) in the strong marginal nerve which forms an elevated rim around the leaflets connected to the midrib by straight, widely ascending secondary venation.
-
Distribution
Piauí Brazil South America| Bahia Brazil South America|