Monographs Details: Senna birostris var. campiana 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.
Description:Variety Description - Bushy shrubs 1-2 m, pilosulous with straight ascending or spreading pallid hairs to 0.5-0.8 mm, the lfts glabrous above, the racemes at first axillary and lateral, becoming terminally paniculate; stipules ±4.5-8 x 0.8-1.2 mm, linear- lance-attenuate; lvs 7-14 cm; lfts 9-14 pairs, ovate- or oblong-elliptic obtuse or subemarginate, the longest 9-15 x 3-7 mm, 1.9-3.1 times as long as wide; racemes 10-35-fld; sepals graduated, the firm, dorsally puberulent outer ones 3-4 mm, the subpetaloid, finely fuscous-reticulate, dorsally glabrous inner ones up to 5-6.3 mm; petals 8-10 x 4-7 mm, filaments of 2 latero-abaxial stamens 2.2-3 mm, of the centric abaxial one 1.8-2.5 mm, the anthers of all 3.4-4.5 mm, when dry chocolate-brown paler at tip; ovary white-pilosulous; ovules 16-22; stipe of pod 3-4 mm, the body linear straight 5-6.5 x 0.6-0.7 cm, the seminal locules 3-3.5 mm long, as wide as the cavity.—Collections: 6. [Key: "Anthers of 3 abaxial stamens all fertile, of ± equal length (4-7.8 mm) and girth even though the centric one is raised on a shorter filament than its neighbors; style 1.2-2.7(-3.4) mm. Lfts glabrous on upper, often nearly so on lower face, the margins and the midrib on dorsal face ciliolate; widespread along the Andes from Ecuador to Argentina. Plants of Ecuador; filaments of 3 abaxial stamens 2-3 mm; pod 0.6-0.7 cm wide."]

Distribution and Ecology - Dry brushy slopes, 2300-3000 m, known only from the sources of Rio Paute in s. Canar and n.-e. Azuay (lat. 2°45'-3°S) in the Andes of s.-centr. Ecuador.— Fl. I-IV.

Discussion:The one flowering collection of var. campiana ("Colombia, Lobb s.n., K) known to Bentham was tentatively identified by him with the remotely allopatric Cassia arequipensis. This, treated herein as a coordinate variety of S. birostris, much resembles var. campiana in general aspect, but differs in the denser vesture of the leaflets, in the longer abaxial filaments and consequently exserted anthers, and particularly in the longer-stipitate and much broader pods. In the same characters, vesture excepted, it differs equally from var. helveola and var. birostris, the forms of S. birostris geographically nearest (even though still some 700 kilometers distant southward along the Cordillera) and further from var. helveola, the more similar in ecology and vesture, in the short glabrate inner sepals. The general facies and small calyx of var. campiana forcibly recall Bolivian var. totorae, different in the slightly fewer (6-9, not 9-14) pairs of leaflets, in the abbreviated style, in the loss or reduction to sterility of the central abaxial stamen, in the yet smaller anthers, and in the at least slightly broader, fewer-ovulate pod.
Distribution:Cañar Ecuador South America| Azuay Ecuador South America|