Cassia apoucouita

  • Title

    Cassia apoucouita

  • Authors

    Howard S. Irwin, David J. Rogers

  • Scientific Name

    Cassia apoucouita Aubl.

  • Description

    9. Cassia apoucouita Aubl., Hist. Pl. Guiana 379. 1775. Photos of isotype examined (NY): French Guiana, "Cayenne." M. Fusee Aublet s.n. Fig. 51. We wish to thank the keeper of BM for providing certain detailed information about their isotype as well as some most useful photographs. The holotype collection, presumably at P, could not be located.

    Cassia acuminata Willd., Sp. Pl. 2: 517. 1799.

    Tree 10-30 m tall, 13-36 cm in diameter, the trunk sulcate, the heartwood dark. Branchlets striate, glabrous or finely puberulent, with longitudinally directed lenticels; axillary buds solitary or in files of 3 or more, tomentose. Stipules absent. Petiole canaliculate, more or less marginate, 5-10 cm long (including rachis). terminating with a bristle 1-2 mm long, puberulent at base and or at points of leaflet attachment, otherwise glabrous: petiolar glands between petiolules of opposite leaflets, urceolate, the lowest largest, subsessile. the stipe not more than 0.5 mm high. Leaflets 2-4 pairs, successively larger distally, the largest 6-10 cm long, sessile or nearly so. narrowly ovate to ovate, the base cuneate, the apex acute to acuminate, glabrous or more or less puberulent on midrib, or secondary veins, or margin. Racemes 1-2 (—3) per node, the peduncle puberulent; peduncular glands urceolate, 0.5—1.0 mm in diameter, subsessile; bracts caducous; pedicels 1.5—3.0 cm long, puberulent; bracteoles triangular, mostly subopposite, 2-5 mm below hypanthium. Calyx (including hypanthium) 6-10 (-13) mm in diameter, sepals 2—3 (—4) mm long, glabrous; petals 10—18 mm long, glabrous or finely puberulent at base without; filaments 0.25—0.5 mm long; anthers 4—7 (—9) mm long, glabrous or finely puberulent along slits; pistil 10-15 mm long, glabrous. Pod 10-14 cm long, 1.25-1.75 cm wide, nitid, marginate. Seed lenticular, 8-10 mm in diameter.

    Distribution (Fig. 50): Coastal region of French Guiana and the Potaro- Mazaruni district of British Guiana.

    Aublet's application of C. apoucouita was much narrower than that later adopted by Bentham (1870), the latter including virtually everything known to that time outside of C. hymenaeifolia and C. adiantifolia. However, as has been shown, a number of distinct taxa lay hidden in this expanded C. apoucouita, resulting in taxonomic confusion which has led to increasing difficulty of interpretation. C. apoucouita, in the present sense, is a well defined taxon, most closely resembling C. solimoesensis, and is entirely extra-Brazilian.

    Curiously, Aublet's citation "Guyane, R. Sinnamary" in Hist. Pl. Guiana occurs on the label of a Cassia referable to section Chamaefistula, very likely C. quinquangulata or C. viminea, and not on the label of his collection of C. apoucouita. Aublet's reference to R. Sinnamary in the published work may be supplemental or qualifying information to be added to "Cayenne,'' or may result from subsequent confusion between specimen and data. For the present, the former alternative will be taken as likely, but the fact that C. apoucouita has never been recollected in French Guiana tends to raise questions about the verity of the original data.

    BRITISH GUIANA: Essequibo, Bartica-Potaro Road, 2 January 1949, D. J. Atkinson 97 (BM. IAN); Essequibo, Mazaruni-Kuribrung divide, 28 October 1926, Forest Dept. of British Guiana 892 (K): Essequibo. Bartica-Potaro Road, 20 January 1931, Forest Dept. of British Guiana 2040 (F, K): Essequibo, Mahdia R., mile 107 on Bartica-Potaro Road, 1 September 1943, Forest Dept. of British Guiana 3730 (NY); Essequibo, Bartica-Potaro Road, mile 107, 8 January 1943, Forest Dept. of British Guiana 3778 (IAN, U); Essequibo, Mazaruni R., Autumn 1898, R. V. McConnell & J. J. Quelch 716 (K); Essequibo, Potaro Gorge, Tukeit, 28 April 1944, B. Maguire & D. B. Fanshawe 26170 (BR, F, G, GH, MO, NY, U, UC, US).