Sabicea floribunda var. floribunda

Lachenaud, Olivier, Zemagho, Lise & Sonké, Bonaventure, 2020, A synopsis of the Sabicea floribunda group (Rubiaceae) from Central Africa, including three new species, Candollea 75 (1), pp. 115-143 : 126-129

3a. Sabicea floribunda var. floribunda

( Fig. 7A ).

Distribution, ecology and phenology. – This taxon occurs in Atlantic Central Africa, mostly from southern Cameroon to east-central Gabon with a disjunct occurrence in southeastern Nigeria and adjacent western Cameroon ( Fig. 8 ). Its distribution marginally overlaps with those of var. paucinervis in the west of its range and of var. anisostegia in the east. It occurs in forest edges and regrowth, often along roads, 0–510 m in elevation, and is locally abundant.

Flowers probably all year (recorded from all months except March, June and September); fruits from February to June.

Conservation status. – The extent of occurrence (EOO) of S. floribunda var. floribunda is calculated to be 187,299 km ², well above the limit for “Vulnerable” status under subcriterion B1. Its area of occupancy (AOO) is estimated to be 84 km ², which falls within the limit for “Endangered” status under subcriterion B2, but is an obvious underestimation, given the low collecting density in most of its range. The taxon occurs in Central Africa from Nigeria to Gabon, and is known from 26 specimens. It is a locally common plant of secondary forest habitats, and not in any way threatened; consequently it is here assessed as “Least Concern” [LC] using the IUCN Red List Categories and Criteria ( IUCN, 2012).

Notes. – This taxon is morphologically (and also geographically) intermediate between S. floribunda var. paludosa and var. paucinervis , differing from the former in the shape and indumentum of its bracts, and from the latter by its stems and leaves being more hairy, the latter with more numerous secondary veins.

Additional material studied. – CAMEROON. Reg. South: au S de Zingui, 20.I.1962, fl., Letouzey 4043 ( BR, K, P, WAG, YA); Ebemwok (55 km W Ebolowa), 13.III.1963, imm.fr., J. & A. Raynal 10435 ( P, YA); Bebai, Campogebiet , 14.XII.1908, buds, Tessmann 716 ( K); Bipindi, 1898, buds, Zenker 1820 ( BM, G, K, P, WAG); Bipindi, 1904, fl., Zenker 3232 ( BM, BR, K). Reg. Southwest: Abonando , 5.V.1902, buds, Rudatis 52 ( K) .

EQUATORIAL GUINEA. Centro-Sur: Monte Mitra, 28.XI.1997, fl., Obama 315 ( BRLU, WAG); SE of Bata c. 50 km, Oborobikó , 25.II.1969, fl. (fallen), Sanford 6034 ( K); Ayaguening ( Akonangui ), 11.VIII.2001, buds, Sonké 2518 ( BR, BRLU); 8 km N de Mitong, 13.XII.2003, buds, Sonké 3157 ( BR, BRLU, K). Litoral: rte d’exploitation chantier SEMGE vers le 1er pont sur Mitemelé , 13.VI.1988, fr., Dibata 451 ( BR, K, WAG); de Sendje à Ongamnsok , 19.II.2001, imm.fr., Lejoly 01/08 ( BRLU); rte de Nco vers Misobong au niveau de la grande cascade , 9.I.1998, fl., N. Nguema & Lejoly 206 ( BRLU) .

GABON. Estuaire: Forêt de Mondah on road Libreville-Cap Esterias , 26.II.1999, imm.fr., Andersson & Nilsson 2277 ( BR); c. 20 km NNE of Libreville, 11.III.1987, fr., J.M. Reitsma & B. Reitsma 3142 ( LBV, WAG); Crystal Mountains N.P. , 8 km on road from Kinguélé to Tchimbélé, 26.III.2013, imm.fr., Wieringa et al. 7801 ( WAG). Moyen-Ogooué: Mboumi. 0°18–0°30S/10°45–10°48E, 16.I.2000, fl., Champluvier 6019 ( BR, K, WAG). Ogooué-Lolo: Chantier Bambidie, c. 52 km on the road to Okondja-Lelama, along Sebe river , 31.X.2005, fl., Sosef et al. 2122 ( BR, LBV, WAG). OgoouéMaritime: Région du Lac Alombié , ± 7 km au N de Mpaga, 18.X.2014, buds, Lachenaud et al. 2007 ( BRLU, LBV, MO). Woleu-Ntem: SEEG road near Tchimbélé , pylone 7, 6.II.2008, buds, Dessein et al. 1724 ( BR, LBV, WAG); Angoum, 28.VII.1933, fl., Le Testu 9198 ( BM, P); Monts de Crystal, Tchimbélé , 14.IV.2006, imm.fr., Leal et al. 1109 ( BR, LBV).

NIGERIA. Cross River State: Oban, 1911, buds, Talbot 228 ( BM, K); New Ndebiji , 30.IV.1952, fl., Ejiofor FHI 21883 ( FHI, K).

Figures

Fig. 7. – Sabicea floribunda var. floribunda: A. Inflorescence. Sabicea floribunda var. paucinervis Wernham: B. Fruits. Sabicea nobilis R.D. Good: C. Lower side of leaf; D. Stem with mature infructescence. Sabicea proselyta (N. Hallé) Razafim. et al.: E. Fruiting stem; F. Mature infructescence. [A: near Tchimbélé, Gabon, plant not collected; B: Sonké 5915; C–D: Texier et al. 706; E: Sonké & Zemagho 6329; F: van Valkenburg et al. 3140] [Photos: A: S. Dessein; B: B. Sonké; C–D: N. Texier; E: B. Sonké; F: J. Degreef]

Fig. 8. – Distribution map of Sabicea floribunda K. Schum. (squares: var. anisostegia O. Lachenaud, Zemagho & Sonké; stars: var. floribunda; triangles: var. paludosa O. Lachenaud, Zemagho & Sonké; circles: var. paucinervis Wernham).