Monographs Details: Senna pallida var. tuerckheimiana 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 2: 455-918.
Description:Variety Description - Weak, sometimes subsarmentose shrubs 1.5-3 m, densely pilosulous with sordid or lutescent hairs to 0.4-0.6 mm, the leaflets densely pilosulous beneath, at least puberulent above, the 2-fld racemes both axillary and forming a small terminal panicle. Stipules erect setiform 2-6 x 0.2-0.3 mm. Major cauline lvs 10-15 cm (those near and in the inflorescence, not further described, smaller and simpler); petiole 6-13(-15) mm, at middle 0.6-1.3 mm, ± 1.2-1.8(-2.1) times longer than first segment of rachis; rachis 7-11 cm; gland between proximal pair 2-2.6 mm, sessile or stipitate, the stipe pilosulous, the body strongly compressed, in profile 0.7-1.2 mm wide; lfts up to 10-13 pairs, not or scarcely accrescent upward, in outline elliptic, elliptic-oblanceolate or oblanceolate, obtuse-mucronulate or deltately acute (1.8-)2.2-3.7 x 0.7-1 mm, (2.2-)3-4.2 times as long as wide, the margins strongly revolute, the venation of 5-8(-9) pairs of camptodrome and some faint intercalary secondary veins either immersed or prominulous above, finely prominulous beneath, tertiary venulation imperceptible. Peduncles 18-36 mm; pedicels 15-19 mm; long sepals 11-13 mm; long petals 22-32 mm; filaments glabrous or pilosulous, of 4 median stamens commonly united at base, 1.5-2.1 mm, of 3 abaxial ones free, 3.5-5 mm, the anthers of 4 median stamens 4.5-5.5 mm, sharply truncate, the lateral beak 0.3-0.5 mm, dehiscent by parallel slits, those of 3 abaxial ones 7-8.5 mm, the tubular beak 2.5-3.8 mm; style 1.5-1.8 mm. Stipe of pod 5-7 mm, the body 8-13 x 0.7-0.8 cm, the interseminal septa 2.5-3.5 mm apart; seeds (few seen) obovate ±4 x 2.8 mm, the areole 1.8-2 x 1.1 mm.-Collections: 7. [Key: "Appendage terminal of lf-stalk subulate or setiform, not modified and dilated into a gland; range of whole species.Continental N. and S. America and Lesser Antilles, s. Windward Is. and Swan Is. in s. Caribbean; anthers nearly always stouter (1.2-)1.3-2 mm diam, abruptly truncate at apex and the tubules there commonly umbonate at the angle opposed to the laterally divaricate, often slightly infra-terminal beak, if whole anther less than 1.25 mm diam and umbo pronounced. Reticulate tertiary venulation imperceptible or almost so on both faces of lfts, these superficially either penninerved or veinless. Lfts of primary lvs 9+ pairs, at least in larger lvs (caveat: deciduous, and absent from some specimens with ample panicle which may be accompanied by only diminished distal lvs), the pairs not or scarcely accrescent upward, the terminal pair not obviously the largest; areole of seeds mostly 1.1-2.4(-3.5) mm in greatest diam. Lfts of largest lvs 9-15(-17) pairs (if led hither by plants of lowland s.-e. Mexico, cf. 177b. var. isthmica). Lf-stalk either sharply or bluntly carinate dorsally but only narrowly winged latero-ventrally, the wings not constricted at insertion of lfts. Petiole of major lvs 6-13(-15) mm, 1-2 times as long as first interfoliar segment; local in Guatemala."]

Distribution and Ecology - Cool humid forest, 1300-1700 m, local, known only from the highlands of Que- zaltenango (Volcanes Zunil and Santa Maria) and Santa Rosa (Sta. Rosa; Salama), Guatemala.-Fl. IX-I.

Discussion:This variety is closely related to var. quiedondilla, with which it has in common relatively many, simply penniveined leaflets (in larger leaves up to 10-13 pairs) not accrescent upward along the rachis, and a broad, large-seeded pod, but is readily distinguished by the short petioles, only 1-2, not 3-5 times longer than the first interfoliolar segment of the leaf-stalk. The dense yellowish or sordid pilose pubescence seems further characteristic, but in the context of ser. Interglandulosae it would be imprudent to put diagnostic emphasis on this feature. The also related var. longirostrata is similar in ecology and in the simply veined leaflets, but these are fewer (up to 6-9 pairs) and strongly accrescent distally, and the narrow, small-seeded pod is only 4-5.2 (not 7-8) mm wide. Donnell Smith distributed the type-collection of var. tuerckheimiana as Cassia biflora, but later determined the holotypus (US) as C. viciifolia. The latter (distantly allopatric in Venezuela) is superficially similar in ample foliage, large flowers, and width of pod, but the median anthers dehisce by one U-shaped slit and the pod becomes fragile when ripe, breaking along transverse lines of interseminal septa.
Distribution:Quezaltenango Guatemala Central America| Santa Rosa Guatemala Central America|