Senna orcuttii (Britton & Rose) H. S. Irwin & Barneby

Peiranisia orcuttii Britton & Rose, sp. nov
Stem glabrate or puberulent, 3 dm. high or higher. Stipules linear, 6-8 mm. long, persistent; gland slender, elongated, 2.5 mm. long, brownish, borne between the lower pair of leaflets; leaflets 4 or 5 pairs, narrowly lanceolate, 1.5-2.5 cm. long, 5-7 mm. wide, acute or acuminate, appressed-pubescent on both sides, or becoming glabrate above; inflorescence racemose, axillary, longer than the subtending leaf, several-flowered; bracts lanceolate, acute, deciduous; pedicels slender, about 1 cm. long; sepals oblong, 6 mm. long, obtuse; petals 8-10 mm. long; none of the anthers beaked; legume flat, about 10 cm. long, 3-4 mm. wide, glabrous.
Near Sanderson, Texas, June 26, 1924, C. R. Orcutt 653.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Stems erect or ascending, Stems less than 1 m tall, Stems solid, Stems or young twigs sparsely to densely hairy, Leaves alternate, Leaves petiolate, Extrafloral nectary glands on petiole, Stipules inconspicuous, absent, or caducous, Stipules setiform, subulate or acicular, Stipules deciduous, Stipules free, Leaves compound, Leaves even pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 5-9, Leaflets 10-many, Leaves glandular punctate or gland-dotted, Leaves hairy on one or both surfaces, Inflorescences racemes, Inflorescence axillary, Bracts very small, absent or caducous, Flowers actinomorphic or somewhat irregular, Calyx 5-lobed, Calyx glabrous, Petals separate, Petals orange or yellow, Stamens 9-10, Stamens heteromorphic, graded in size, Stamens completely free, separate, Filaments glabrous, Anthers opening by basal or terminal pores or slits, Style terete, Fruit a legume, Fruit stipitate, Fruit unilocular, Fruit freely dehiscent, Fruit elongate, straight, Fruit oblong or ellipsoidal, Fruit exserted from calyx, Fruit compressed between seeds, Fruit glabrous or glabrate, Fruit 11-many seeded, Seed with elliptical line or depression, pleurogram, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black.

Senna orcuttii là một loài thực vật có hoa trong họ Đậu. Loài này được (Britton & Rose) H.S.Irwin & Ba miêu tả khoa học đầu tiên.