Sabicea sanguinosa subsp. sanguinosa

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 : 138-140

7a. Sabicea sanguinosa subsp. sanguinosa

( Fig. 2E–F , 12E ).

Distribution, ecology and phenology. – This subspecies is endemic to coastal Gabon, occurring in the Wonga-Wongué reserve and slightly further north (Nyonié) ( Fig. 10 ) and grows in forest edges on coastal sandy soils, up to 150 m in elevation.

Flowers collected in January (buds), February, and from May to July; fruits in January-February and August.

Conservation status. – The extent of occurrence (EOO) of S. sanguinosa subsp. sanguinosa is estimated to be 860 km ², and its area of occupancy (AOO) to be 32 km ²; both values fall within the limit for “Endangered” status under subcriteria B1 and B2. The taxon is endemic to coastal Gabon, and is known from nine specimens, representing five subpopulations, all but one of which occur in the Wonga-Wongué Presidential Reserve. Its situation is rather comparable to that of the species as a whole, and it is assessed as “Least Concern” [LC] for the same reasons using the IUCN Red List Categories and Criteria ( IUCN, 2012).

Additional material studied. – GABON. Estuaire: Savane Boyam , 25.I.1997, fl.b., Delègue 1.Trs ( LBV); Oyane , X.1990, st., Minkoue 55 ( LBV); Réserve de Wonga Wongué , 23.I.1986, fr., A.M. Louis & J.M. Reitsma 2004 ( LBV, WAG); Nyonyie survey , sondage W , 28.VI.1990, fl., Wilks 2028 ( WAG); Nyonyie , Transect M2 , 15.VII.1990, fl., Wilks 2252 ( WAG). Moyen-Ogooué : Eastern part of the Presidential Reserve Wonga-Wongué , c. 100 km S of Libreville, 28.II.1983, fl. & fr., J.J.F.E. de Wilde et al. 815 ( BR, K, LBV, WAG). OgoouéMaritime : à ± 10km au SSE de Batanga, 21.V.2001, fl., Sosef 1613 ( K, LBV, P); ca 10 km à l’Est de Batanga, 26.V.2001, fl., Sosef 1745 ( K, LBV, P).

Figures

Fig. 2. – Seeds of Sabicea spp. viewed in electron microscopy. Sabicea proselyta (N. Hallé) Razafim. et al.: A. Entire seed; B. Detail of seed surface. Sabicea rubiginosa O. Lachenaud, Zemagho & Sonké: C. Entire seed; D. Detail of seed surface. Sabicea sanguinosa subsp. sanguinosa: E. Entire seed; F. Detail of seed surface. Sabicea segregata Hiern: G. Entire seed; H. Detail of seed surface. [A–B: van Valkenburg et al. 3140; C–D: Lachenaud et al. 2105; E–F: A. M. Louis & Reitsma 2004; G–H: J.J.F.E. de Wilde et al. 9485] [Photos: I. van der Beeten]

Fig. 12. – Sabicea rubiginosa O. Lachenaud, Zemagho & Sonké: A. Plant with flowers and fruits; B. Lower side of leaf; C. Inflorescence; D. Infructescence with mature (white) and immature fruits (green). Sabicea sanguinosa subsp. sanguinosa: E. Apex of flowering stem. Sabicea sanguinosa subsp. viridis O. Lachenaud, Zemagho & Sonké: F. Stem with flowers and fruits, note bullate leaves. [A: Sonké & Ikabanga 6155; B, D: Lachenaud et al. 2105; C: Bidault et al. 1329; F: Bidault et al. 1691] [Photos: A: B. Sonké; B, D: O. Lachenaud; C, F: E. Bidault; E: J.-P. Vande weghe]

Fig. 10. – Distribution map of Sabicea proselyta (N. Hallé) Razafim. et al. (circles), S. rubiginosa O. Lachenaud, Zemagho & Sonké (stars) and S. sanguinosa (N. Hallé) Razafim. et al. (triangles: subsp. sanguinosa; squares: subsp. viridis O. Lachenaud, Zemagho & Sonké).