Sabicea sciaphilantha subsp. sciaphilantha

Zemagho, Lise A., Liede-Schumann, Sigrid, Lachenaud, Olivier, Dessein, Steven & Sonke, Bonaventure, 2017, Taxonomic revision of Sabicea subgenus Anisophyllae (Ixoroideae, Rubiaceae) from Tropical Africa, with four new species, Phytotaxa 293 (1), pp. 448-450 : 448-450

13b. Sabicea sciaphilantha subsp. sciaphilantha ( Fig. 28 A–K )

Stems and petioles sometimes glabrous, or usually appressed-pubescent with stiff hairs ca. 1.5 mm long intermingled with a dense felt of woolly hairs. Hypantium glabrous to very sparsely villose. Calyx tube glabrous or very sparsely villose outside. Corolla glabrous outside or sparsely villose on the lobes and distal half of the tube.

Distribution: —Lower Guinea Domain. Endemic to Gabon and apparently restricted to the lower Ngounié basin, where it is locally common ( Fig. 29 ).

Habitat and ecology: —Half-shaded areas along forest streams, small forest gaps on slopes, and also frequently on the banks of forest tracks; 40–100 m in altitude.

58 • Phytotaxa 293 (1) © 2017 Magnolia Press

ZEMAGHO ET AL. TAXONOMIC REVISION OF SABICEA SUBGENUS ANISOPHYLLAE

Phytotaxa 293 (1) © 2017 Magnolia Press • 59

Phenology:— Flowering in May–June and October–November; fruits in February.

Discussion: —The specim ens Sonké & Ikabanga 5980 and Thomas & Wilks 6440 differ from the other collections of this species in having glabrous stems, in which character they resemble S. aurifodinae . Their calyces, however, are typical for S. sciaphilantha .

Conservation status:— IUCN Red List Category: Endangered [EN B1ab(i,ii,iii,iv,v)+2ab (i,ii,iii,iv,v)]. The extent of occurrence is estimated as 202.568 km 2 and the area of occupancy as 40 km 2, both within the limit for Endangered under criteria B1 and B2 respectively. The taxon is known from 10 subpopulations representing two locations (sensu IUCN 2012), none of which is protected. The Mabounié region, where all but one subpopulation occur, is potentially at risk from a mining project. A decline in the extent of occurrence, area of occupancy, extent and quality of habitat, number of locations and number of individuals can therefore be expected, and the taxon qualifies for Endangered status under the conditions B1ab(i,ii,iii,iv,v) and B2ab(i,ii,iii,iv,v).

Additional specimens examined (Paratypes):— GABON. Mabounié, 45 km SE de Lambaréné , près de la rivière Ngounié, 9 October 2012 , E. Bidault, J.- Y. Serein & S. Griffith 722 ( BRLU, MO), Zone de Mabounié , à 45 km au SW de Lambaréné, rive nord de la rivière Ngounié, 14 November 2013 , E. Bidault, E. Akouangou & J.- Y. Serein 1303 ( BRLU, MO), Zone de Mabounié , à 45 km au SE de Lambaréné, rive nord de la rivière Ngounié, 16 November 2013 , E. Bidault, E. Akouangou & J.- Y. Serein 1328 ( BRLU, MO); Zone de Mabounié , à 45 km au SE de Lambaréné, rive nord de la rivière Ngounié, 21 June 2014 , E. Bidault, E. Akouangou, T. Stévart & A. Boupoya 1642 ( BRLU, MO); Mabounié , entre camp et débarcadère, 10 November 2013 , O. Lachenaud, T. Stévart, D. Ikabanga, Y. Issembé, A. Boupoya & J.D. Kaparidi 1272 ( BRLU, LBV, MO); Mabounié, Golgotha , 11 November 2013 , O. Lachenaud, T. Stévart, D. Ikabanga, Y. Issembé, A. Boupoya & J.D. Kaparidi 1289 ( BRLU, LBV, MO); Mabounié , entre camp et débarcadère, 14 November 2013 , O. Lachenaud, T. Stévart, D. Ikabanga, Y. Issembé, A. Boupoya & J.D. Kaparidi 1375 ( BRLU); Mabounié , 11 October 2012 , B. Sonké & D. Ikabanga 5962 ( BR, BRLU, MO); Mabounié , le long de la rivière Ngounié, 12 October 2012 , B. Sonké & D. Ikabanga 5980 ( BR, BRLU, MO); Mabounié , 13 October 2012 , B. Sonké & D. Ikabanga 6002 ( BR, BRLU, MO); Mabounié , 14 October 2012 , B.

60 • Phytotaxa 293 (1) © 2017 Magnolia Press

ZEMAGHO ET AL.

Sonké & D. Ikabanga 6020 (BR, BRLU, MO); Mabounié, Golgotha, 3 February 2013, B. Sonké, E. Bidault, E. Akouangou, D. Ikabanga & J.-N. Boussiengui 6182 ( BR, BRLU, MO) ; Komi, near Sindara, 17 June 1986, D.W. Thomas & C. Wilks 6460 ( MO, P) .

Figures

FIGURE 28. Sabicea sciaphilantha subsp. sciaphilantha (A–K) & subsp. hirsuta (L). A, flowering stem; B, node with stipules, reduced leaf and base of normal leaf; C, detail of inflorescence with one short-styled flower; D, detail of a hair from the corolla mouth; E, flower bud; F, section of short-styled flower; G, flower bud; H, long-styled flower; I, section of long-styled flower; J, section of calyx and ovary; K, fruit; L, node with stipules, reduced leaf and base of normal leaf. From Sonké & Ikabanga 5957 (A), Lachenaud et al. 1375 (B), Lachenaud et al. 1272 (C–F), Bidault et al. 1303 (G–I), Lachenaud et al. 1289 (J–K), Breteler et al. 14850 (L). Drawing by Hans De Vries.

FIGURE 29. Distribution of Sabicea sciaphilantha subsp. sciaphilantha and S. sciaphilantha subsp. hirsuta.