Senna pallida var. longirostrata (Britton & Rose) 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.

Family

Caesalpiniaceae

Scientific Name

Senna pallida var. longirostrata (Britton & Rose) H.S.Irwin & Barneby

Type

Holotypus, US! clas to typus (fragm) + phototypus, NY!-Cassia longirostrata (Britton & Rose) Lundell, Phytologia 1: 214. 1937.

Synonyms

Peiranisia longirostrata Britton & Rose, Cassia longirostrata (Britton & Rose) Lundell

Description

Variety Description - Shrubs 1-3 m with deeply sulcate hornotinous branchlets, varying from glabrous below the always strigulose-pilosulous ovary to densely pilosulous up to the glabrous fl-buds, the vesture of stems and lf-stalks composed of stiff, spreading-ascending hairs up to 0.4-0.8 mm but the lfts either pubescent on both faces or only beneath, the mature inflorescence corymbosely or virgately paniculate. Stipules linear-attenuate or narrowly linear-oblanceolate 5-15 x 0.4-1 mm. Major lvs 6-13 cm; petiole 2-3.4(-4) cm, at middle (0.5-)0.6-1(-1.1) mm diam, (2-)2.3-5 times as long as first segment of rachis; gland between proximal pair of lfts sessile or stipitate (1-) 1.4-3(-3.5) mm, the stipe when present either glabrous or pilosulous, the body 0.4-1 mm wide; lfts up to 6-9 pairs, accrescent upward along rachis, the distal pair largest, obovate, oblong-obovate or oblanceolate obtuse or deltately subacute 18-35 x (7-)8-14 mm, 1.8-3 times as long as wide, the simply pinnate venation of (4-)5-7(-8) pairs of camptodrome and some few faint intercalary secondary veins immersed and scarcely or not perceptible above, beneath either finely prominulous or immersed and discolored, tertiary venulation essentially 0. Peduncles (4-)8-22 mm; racemes 2(-4)-fld, the axis 0-1.5(-4) mm; pedicels 10-21 mm; long sepals (6-)6.5-9 mm; long petals (16-) 18-21 mm; filaments glabrous or pilosulous, free to base, those of 4 median stamens 0.9-1.8 mm, those of 3 abaxial ones 3-5.5 mm; anthers of 4 median stamens 3.2-5.3 mm, bluntly truncate, the lateral beak not over 0.4 mm, dehiscent by parallel pores, those of 3 abaxial ones 5-7 mm, contracted into beak 1.6-2.8 mm; style 1.7-2.5 mm. Stipe of pod 3-5 mm, the body 6.5-9.5 x 0.4-0.5 cm, the valves simply mounded over the seeds, the interseminal septa 1.5-2 mm apart; seeds not seen ripe, but the areole small, <1 mm diam.-Collections: 24. [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 or larger primary cauline lvs 2-8(-9) pairs, perceptibly and usually conspicuously accrescent distally, the terminal pair longest; areole of seeds 0.4-0.9 mm in greatest diam. Scattered over s. Mexico and Guatemala. Plants of Pacific Mexico to Chiapas and highland Guatemala. Pod 4-5.5 mm wide; either Sonora-Sinaloa, or Oaxaca-Guatemala. Habitat and dispersal differesnt, in Oaxaca, Chiapas and Guatemala, if below 1000 m the valves of pod raised over each seed into a sharply defined decussate pyamid. Pine-oak forest at 1200-2150 m; valves of ripe pod plane or weakly bullate over each seed. Primary lvs 6-13 cm, their rachis 6-13 cm and lfts 6-9 pairs, the longest 18-35 mm; Guatemala."]

Distribution and Ecology - Thickets and brushy hillsides in oak-pine, cypress- and mixed forest, (1200-) 1400-2000 m, scattered through the mountains of Guatemala from s. Huehuetenango s.-e. to Jalapa (±89o30'-91°30').-FI. XI-II.

Discussion

Due to great superficial variation in pubescence and in outline of leaflets var. longirostrata is difficult to characterize neatly. It is closely related to vicariant and partly sympatric var. quiedondilla and resembles it in the relatively long petioles, but differs in the fewer leaflets accrescent upward along the rachis, the distal pair largest, and in the narrow pod and (presumably) smaller seed with smaller areole. Both leaflets and pods of var. longirostrata resemble those of lowland var. pallida except that the leaflets are simply penniveined, as in other highland varieties, and not reticulate; and the petiole is actually and relatively longer, 2-5, not ±1-2 times as long as the first segment of the rachis. The rarer var. tuerckheimiana, the third form of S. pallida found in the Guatemalan highlands at the same elevations and in the same latitudes, resembles pubescent var. longirostrata at anthesis, but has the broad pod, large seeds and numerous (10-13-jugate) leaflets of var. quiedondilla combined with the short petiole of var. pallida. The species Peiranisia longirostrata was described by Britton & Rose from a fragmentary specimen and contrasted in North American Flora with P. oxyadena, P. shaferi and P. robiniifolia, all distantly allied. The report in the protologue from Veracruz was based on a specimen of pubescent var. quiedondilla (Purpus 2342), mentioned under the latter heading. Despite the epithet, the beak of the long anthers is not exceptionally long in the context of either S. pallida, sens, lat., or of the whole series Interglandulosae.

Distribution

Huehuetenango Guatemala Central America| Jalapa Guatemala Central America|