Tuesday, 24 March 2009

Acokanthera oblongifolia

Acokanthera spectabilis Benth. in Gen. Plant, vol II p. 696
Curtis's Botanical Magazine Vol CIV Nº 6359 (1878)

Acokanthera oblongifolia (Hochst.) Codd
Bothalia 7: 449. 1961

Basionym: Carissa oblongifolia Hochst. Flora 27(2): 827. 1844.

Synonym: Acokanthera spectabilis (Sond.) Hook. f.

FZ, Vol 7 Part 2 Author: A. J. M. Leeuwenberg and F. K. Kupicha et al.
Evergreen shrub or small tree up to 6 m. high. Young branches glabrous, conspicuously angled and ribbed. Leaves coriaceous, glabrous, smooth; petiole 4–9 mm. long; lamina 6–8·4 x 1·5–4·5 cm., ± elliptic, the apex obtuse to acute, mucronate, the base cuneate or rounded; upper surface glossy, with midrib shallowly impressed and lateral veins slightly raised but usually inconspicuous; lower surface mat, midrib and lateral veins raised but the latter inconspicuous; lateral veins looped to join their neighbours. Inflorescences dense contracted many-flowered axillary cymes; flowers fragrant, white tinged pink. Calyx c. 3 mm. long, lobes lanceolate, weakly imbricate, puberulous and ciliate. Corolla tube 14–20 mm. long, glabrous or pubescent on external surface, pilose within in upper half, faintly wrinkled below; corolla lobes broadly ovate with rounded apex, 3–7 mm. long, glabrous to pubescent, ciliate or not. Stamens inserted near the top of the corolla tube so that the anthers reach to within 1 mm. of the mouth and are not visible at anthesis; anthers 1·5–1·7 mm. long. Ovary c. 1 mm. long, cylindrical, longitudinally ribbed. Fruit 2–2·5 cm. long, ellipsoid or subglobose, purplish-black, 2(l)-seeded. Seeds up to 1·5 cm. long.

Aspecto general y detalle de flores y frutos

Tab. 6359
Acokanthera spectabilis
Curtis’s Botanical Magazine
May 1st 1878

Native of South Africa

Genus Acokanthera, Don; (Benth. Et Hook. F. Gen. Plant, vol. ii p. 696)

A. spectabilis
Toxicophlaea spectabilis, Sonder in Linnaea, vol. xxiii. P. 79;

The genus Acokanthera was founded by G. Don in the ‘Gardener’s Dictionary’ (vol. iv. P. 485) on Thunberg’s Cestrum veneatum (and other South African plants having no relation thereto), a native of Western South Africa. Subsequently, Harvey, overlooking Don’s genus, established Toxicophlaea on the same Cestrum venenatum, and his name is taken up by A. De Candolle in the Prodomus, and has consequently been current for that plant ever since ; subsequently, a congener was found in Abyssinia, the Carissa Schimperi, A.D.C. (C. Mepte Hochst., and Strychnos abyssinica, Hochst.), and finally the present plant was sent from South East Africa, and published as Toxicophlaea spectabilis by Sonder. The three known species are probably all of them very poisonous. A. veneata (Toxicophaea Thunbergii), Harvey, is the “Gift-boom,” or poison-tree of the Dutch and English colonists. According to Thunberg, a decoction of the bark reduced to a jelly was used by the Aborigines for poisoning their arrows ; and of the A. spectabilis, Mrs Barber writes that the seeds are intensely bitter, and the whole plant considered by the natives to be a deadly poisonous one. The genus is, as Mr. Dyer has remarked (Gard. Chron. l.c.), too closely allied to Carissa, differing chiefly, if not solely, in the want of thorns.

A. spectabilis is a native of the Western districts of South Africa, from Port Albany to Port Natal, where it forms a large shrub, with masses of white very fragrant flowers, on woody sand-hills near the sea. It was introduced by Mr. B S. Williams, and exhibited by him in 1872. Our specimen flowered at Kew in February of the present year.

DESCR. A large shrub, quite glabrous, except the inflorescence, which is slightly hairy or almost glabrous ; branches stout, green, obscurly angled. Leaves three to five inches long, narrowed into a very short thick petiole, coriaceous, elliptic- or oblong-lanceolate, acute, acuminate, or apiculate, shining above with very obscure spreading nerves, paler and opaque beneath. Flowers in dense fasiculated axillary branched short cymes, sometimes forming a globose head towards the top of the branch, pure white, very sweet scented ; peduncles and pedicels very short ; bracts minute, broadly ovate. Calyx-lobes ovate-lanceolate, green, subacute, hairy. Corolla-tube three quarters of an inch long, slender, slightly enlarged upwards, sparsly hairy in the throat ; lobes spreading, ovate-oblong, acute. Stamens included, inserted near the mouth of the corolla, filaments very short ; anthers braodly ovate, with a pubescent terminal claw. Stigma conical, hairy, emarginate. Ovules attached towards the base of the septum. --- J. D. H.

Fig. 1, Flower ; 2 calyx ; 3, vertical, and 4, transverse section of ovary ; 5, top of style and stigma; 6, stamens : - all enlarged.

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