Rhaphiostylis minima Jongkind, 2015

Jongkind, Carel C. H., 2015, Rhaphiostylis minima Jongkind (Icacinaceae), a new liana species from Ivory Coast & Liberia, European Journal of Taxonomy 138, pp. 1-8 : 3-6

Rhaphiostylis minima Jongkind sp. nov.

urn:lsid:ipni.org:names:77150009-1 Table 1 , Figs 1 D–G, 2

Diagnosis

Slender woody liana up to 4 m high, resembling R. elegans Engl. from Cameroon in leafshape. Differing from R. elegans in the first place by its shorter and more hairy ovary, 2.5–3 mm versus 3.5–4 mm.

Type

IVORY COAST. ca. 140 km N of Tabou, crossing Hana River, on the way to Taï, fl., 10 Oct. 1963, W. de Wilde 1061 (holo-: WAG; iso-: BR, K n.v.)

Description

Slender woody liana going up to 3–4 m high. Leaves alternate, glabrous; slender petiole 2–3 mm long; blade ovate to lanceolate, 5–10 cm long and 1.5–3.5 cm wide, papery, midrib impressed above, 3 or 4 pairs of main laterals of which the first are often long and ascending, margin entire, base rounded, apex long acuminate, up to 3 cm long with a spathulate tip. Inflorescences fasciculate, supra-axillary with 1–3 flowers. Flowers bisexual; pedicel 2–4 mm long; calyx 5 lobed, lobes about 1 mm long, puberulous; petals 5, ca. 5 mm long, valvate, free, glabrous. Stamens 5, glabrous; filaments subulate, gradually narrowing to filiform above, about 4 mm long, alternipetalous; anthers ca. 1 mm long. Ovary 2.5–3 mm high, hairy on the lower ½ and at the top, almost glabrous on the narrow part in between; style 3.5–4 mm long, excentric but erect. Fruit 2-lobed, flattened through the longitudinal axis, fleshy with thin exocarp, smooth and glabrous, but conspicuously hairy on and around the base of the persistent style; endocarp woody, reticulate, about 1.5 cm wide and 1 cm high.

Distribution and habitat

South-east Liberia and south-west Ivory Coast below 250 m altitude. In the shade of evergreen forest with a rainfall of more than 2200 mm a year and a weak dry season.

Additional material examined

IVORY COAST. Entre Niebe et Bihoué, fl., 9 Aug. 1962, Jangoux 401 (BR).

LIBERIA. East of Greenville-Zwedru road, fl., fr., 23 Sep. 2013, Jongkind 12109 (BR, MO, P); West of Sapo National Park, 15 Sep. 2013, Jongkind 12321 (BR), Jongkind 12322 (WAG); West of Greenville, 18 Sep. 2013, Jongkind 12323 (BR); North of Sapo National Park, 27 Sep. 2013, Jongkind 12324 (BR); Ca. 50 km east of Greenville, 10 Mar. 2014, Jongkind 12361 (BR), 11 Mar. 2014, Jongkind 12381 (WAG).

Conservation status

The “Extent of Occurrence” (EOO) is 6,056 km 2 and the “Area of Occupancy” (AOO) is 32 km 2, the EOO counts as “Vulnerable” and the EOO counts as “Endangered”. The AOO is based on a cell width of 2 km. None of the 9 specimens was collected in a protected area, but it is very likely that the species occurs in Sapo National Park in Liberia, as this protected area is completely included in the species EOO. The plant and its flowers are not conspicuous, so it is probably more common than what the few collections suggest. However, looking at all the economical development planned and in progress in this part of Liberia, and while it is not sure that the species grows in a protected area, “Vulnerable” should be the correct status for the moment (B1 & B2 ab(iii), IUCN 2015).

Remarks

All specimens cited under the new species were collected after the publication of the Icacinaceae in the Flora of West Tropical Africa ( Hepper 1958).

The leaves of seedlings of Rhaphiostylis beninensis and R. preussii may resemble those of mature R. minima sp. nov.

Figures

Fig. 1. A–C. Rhaphiostylis elegans Engl. A. Flower B. Flower without petals and stamens. C. Leaf. D–G. Rhaphiostylis minima sp. nov. D. Branch with flowers. E. Flower. F. Flower without petals and stamens. G. Leaf. H–M. Rhaphiostylis preussii Engl. H. Flower. I. Flower without petals and stamens. J. Leaf. K. Flower. L. Flower without petals and stamens. M. Leaf. All flowers are on the same scale (scale bar with B) and all single leaves too (scale bar with G). A–C from Tchouto & Elad 3310 (WAG), D–G from W.de Wilde 1061 (WAG), H–J from Beentje 1353 B from Ivory Coast (WAG), K–M from Breteler 14204 from Gabon (WAG). Drawn by Hans de Vries.