Cassia polystachya

  • Title

    Cassia polystachya

  • Author(s)

    Howard S. Irwin, David J. Rogers

  • Scientific Name

    Cassia polystachya Benth.

  • Description

    12. Cassia polystachya Benth., Hook. Jour. Bot. 2: 77. 1840. Holotype examined (K): British Guiana. 1839. Robt. Schomburgk 621. Isotype: (BM). Photos of holotype: (NY, US). Photos of isotype: (F). Fig. 52.

    [NOTE from Jackie Kallunki: This species is called "Cassia ulei Benth." in the key to species on page 89 and in the numerical list of taxa on page 118.  This name is simply an error.  Cassia polystachya is recognized as Chamaecrista polystachya in the Irwin & Barneby treatment of the Cassiinae in 1982.]

    Tree or shrub 5-10 m tall. Branchlets striate, glabrous, with longitudinally directed lenticels; axillary buds 1-2 per node, tomentose; stipules absent. Petiole terete, 6-8 cm long, terminating with a bristle 0.5-1.0 mm long, puberulent; petiolar glands ovoid- or oblong-scutellate, sessile, 2 or 3, the lowest largest, occurring below leaflet attachment; pulvinus cylindrical, rugose, glabrous, 1.25-2.5 mm long. Leaflets 2-4 pairs, 5-6 cm long, ovate, the base rounded or truncate, the apex obtuse, glabrous and nitid above, glabrous and paler below; pulvinules 0.75-1.5 mm long. Racemes 1-2 per node (frequently those of the season), the peduncle velutinous; peduncular glands scutellate, 0.25-0.5 mm in diameter, on stipes 0.5-1.0 mm high; bracts deciduous; pedicels 1.5-2.0 cm long, velutinous; bracteoles triangular, velutinous, subopposite (not more than 0.5 mm distant from each other), 3-4 mm below hypanthium. Calyx (including hypanthium) 13-15 mm in diameter; sepals 3-5 mm long, puberulent without; petals 11-14 mm long, puberulent at base without and along veins; anthers 4-5 mm long, puberulent along fissures. Pistil glabrous, not exceeding anthers. Pod 6-9 cm long, 6-10 mm wide, nitid, smooth, strongly marginate, somewhat broader at apical end.

    Distribution (Fig. 53): Forested slopes in the vicinity of Mount Roraima and southwestward in the Serra Pacaraima on the Brazil-Venezuela frontier.

    Bentham mistakenly placed this species in section Absus, regarding it a close relative of C. crenulata. He no doubt rejected it from inclusion in the present section because of the apparent absence of the very diagnostic cauliflory. However, as is indicated by the description above, characters of the flowers, glands, and fruit clearly ally C. polystachya with the more westerly C. hymenaeifolia.

    BRAZIL, TERR. RORAIMA: Serra de Pacaraima, Parime, November 1909, E. Ule 8145 (G, K, MG, NY, UC); Abhany der Serra de Mairary, 600m, November 1909, E. Ule 8397 (G, UC). BRITISH GUIANA: Roraima, 1842-1843, Robt. Schomburgk 514 (= Rich. Schomburgk 811) (BM, F, G, K, NY).