Senna pallida var. delgadoana

  • Title

    Senna pallida var. delgadoana

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Senna pallida var. delgadoana H.S.Irwin & Barneby

  • Description

    177s. Senna pallida (Vahl) var. delgadoana Irwin & Barneby, var. nov., foliorum seta terminali glandula obsita cum vars. macdougalliana et lemniscata comparanda, ab ambabus foliolis numerosis (14-24, nec 6-12-jugis), ovulisque paucis (16-22, nec 30-52), patriaque montana diversa.- MEXICO. Oaxaca, distr. Juxtlahuaca: a 2 km al SE. de Copala, 1700 m, 3.II. 1977 (fl, fr jun), M. Sousa et al. 6978.-Holotypus, MEXU (2 sheets).

    Subarborescent, the annotinous branchlets gray lenticellate, the young ones and the foliage loosely strigulose, the lfts bicolored, dull olivaceous above, pale beneath, the inflorescence composed of solitary or paired axillary 1-2-flowered racemes.

    Stipules erect linear-setiform deciduous.

    Lvs 6-10 cm; petiole 11-15 mm; rachis 3-8 cm, the longer interpetiolular segments 3-6 mm; gland between proximal pair 2-2.3 mm, oblanceolate compressed acute, and a gland at tip of rachis collateral with the seta; lfts (7-)9-24 pairs, narrowly elliptic or elliptic-oblanceolate, the longer ones (near middle of rachis) 14-20 x 3-6 mm, 3-4 times as long as wide, the margin revolute, the upper face veinless, the midrib prominent beneath and 5-8 pairs of secondary veins discolored but immersed.

    Peduncles 5-9 mm; fruiting pedicels ±1 cm; stipe of pod 5-6 mm; body linear (4.5-6-11 x 0.6-0.9 cm, the valves a little elevated over the seeds but not decussately ridged; seeds 16-22, paddle-shaped 3.5-4.5 x 3-4 mm, the areole 1.3-2 x 1 mm.-Collections: 3.

    Oakwoods, 1530-1700 m, locally plentiful but known only from the vicinity of Copala, distr. Juxtlahuaca, Oaxaca.-Fl. I-II, fr. VIII.

    The var. delgadoana, marked by the combination of many pairs of relatively small, revolute, simply penniveined leaflets, a gland between the distal pair collateral with the seta, and a short few-seeded pod, has a notably distinct facies and perhaps deserves specific status. We dedicate it to Dr. A. Delgado S., a perceptive student of Cassieae and Mexican legumes in general.