Sabicea mildbraedii var. glabrescens Wernham (1914: 53)

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

10a. Sabicea mildbraedii var. glabrescens Wernham (1914: 53) ( Fig. 20 )

Type:— DR CONGO. Environs de Kisantu , s.d., J. Gillet 3520 (holotype BR [ BR0000008851956 ]!) .

Stems densely white-felted, sometimes also with appressed to patent long stiff hairs. Leaves sometimes sparsely white-felted above when young, glabrous to sparsely villose when mature; densely felted below, without any stiff hairs. Stipules glabrescent to densely white-felted outside, sometimes villose on the margin. Calyx tube erect, densely white-felted outside; lobes shortly elliptic, 1–1.8 x 0.7–1.2 mm, acute to rounded at apex, erect or usually bending outwards, densely white-felted outside, sometimes shortly villose (stiff hairs ca. 0.3 mm long) on the margin, glabrous or sparsely villose inside with short appressed hairs near the apex. Corolla lobes densely white-felted outside, sometimes villose near the apex. Hypanthium and fruit densely white-felted.

Distribution: —Lower Guinea and Congolia Domains. This variety occurs in central Gabon, Republic of Congo and south-western DR Congo ( Fig. 21 ). Its range partly overlaps with that of var. mildbraedii in the two latter countries.

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Habitat and ecology: —Forest-savanna boundaries and young stages of forest regrowth, especially on roadsides; at 230–700 m altitude.

Phenology: —Flowers in March–April, July and November–December; fruits in January, April and November.

Discussion: —A collection from the Lastoursville area in Gabon, Van der Maesen et al. 5726 (BR, P, WAG) resembles this taxon but is unusually robust (1.5 m tall, according to label data) and has a remarkably dense white indumentum on the upper side of young leaves. More collections from the same area are necessary to decide its status.

Conservation status:— IUCN Red List Category: Least Concern [LC]. The extent of occurrence is estimated as 281,278.242 km 2 and the area of occupancy as 120 km 2, the latter value being within the limit for Endangered under criterion B2. However, the taxon is known from more than 10 locations (sensu IUCN 2012) including three national parks (Odzala in Republic of Congo, Lopé and Ivindo in Gabon), occurs mostly in sparsely populated areas, is locally common, and is likely to benefit from forest degradation due to its preference for open habitats. It is not therefore threatened.

Additional specimens examined:— DR CONGO. Mpese , 1 June 1947, H. Callens 8 ( BR) ; Mpese , December 1949, H. Callens 2152 ( BR) ; Kimuenza , 10 October 2010, J. Mildbraed 3664 ( HBG) . GABON. Lopé Reserve , 4 July 1986, M.P.T. Alers & A. Blom LOPE 86 ( MO, WAG) ; 1–5 km E of Lambaréné airstrip along road to Mouila , 10 Mars 1999, L. Andersson & A. Nilsson 2344 ( BR) ; Sud de Lambaréné , entre 5 et 10 km depuis la ville, entre l’Ogooué et la route de Fougamou, 0°45’4.3’’ S 10°15’43’’ E, 10 April 2015, E. Bidault, E.Akouangou & Sylvafrica 1900 ( MO) ; Aschouka (Lopé), île Nzangui, 28 January 1998, A. Binot & J. Lejoly 147 ( BRLU) ; 40–50 km SEE of Lastoursville , 4 May 1992, F.J. Breteler, C.C.H. Jongkind & J.J. Wieringa 11287 ( WAG) ; near Okondja , Route de Falaise, 6 October 1997, F.J. Breteler & M.E. Leal 14221 ( WAG) ; Makande surroundings, ca. 65 km SSW of Booué, Makande Camp, 22 February 1999, F.J. Breteler, G. Caballé, Y. Azizet Issembé, J.-M. Moussavou & O. Pascal 15174 ( LBV, WAG) ; South of the Ogooué River, 0°06.6’S 11°45.1’E, 24 December 1996, J.J.F.E. de Wilde & R.W. de Wilde-Bakhuizen 11813 ( BR, LBV, SEGC, WAG) ; Lopé , près de la station Ecofac, 9

TAXONOMIC REVISION OF SABICEA SUBGENUS ANISOPHYLLAE

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November 1993, M.M. Dhetchuvi 1169 ( BRLU); Chantier CGPPO, 80 km de Ndjolé, vers Lalara , 13 June 1971, G. Gilles 401 (P); Ogooué , Booué , 30 July 1966, N. Hallé & Le Thomas 213 (P); 10 km SW de Ndjolé , 14 April 1963, N. Hallé 1661 ( BR, P); Ayem , 10 km SW de Ndjolé , 16 April 1963, N. Hallé 1662 (P); Ayem , SW de Ndjolé , 27 April 1963, N. Hallé 1896 (P); Alembe-Ayem Road, km 23, near Ogooue River , right bank , 1 November 1982, A.J.M. Leeuwenberg & A.M. Louis 12415 ( BR, MO, WAG); Forêt des Abeilles. Station de la Makandé , 11 July 1993, J. Lejoly 93/67 ( BRLU) ; 12 July 1993, J. Lejoly 93/88 ( BRLU); Dibouka , 21 November 2004, A.C. Ley & J. Yedy 75 ( WAG); Ogooué-Ivindo : Near Achouka , 10 November 1983, A.M. Louis, F.J. Breteler & J. de Bruijn 577 ( BR, WAG); Ivindo National Park : route Langoué , 8 April 2004, A. Moungazi 1536 ( BR, MO, P, WAG); Mont de Casque ca. 20 km Km. NW of Booué , 16 May 1987, J.M. Reitsma, B. Reitsma, C.M. Wilks & T. Nzabi 3394 ( MO, WAG, NY); sud de Lambaréné , zone entre l’Ogooué , le lac Ezanga , et la route de Lambaréné à Fougamou, 0°45’04”S, 10°15’43”E , 12 April 2015, Sylvafrica 10 ( MO); Lopé-Okanda Reserve , Grand-Débardage Trail , 2 November 2000, G.M. Walters, J.R. Stone, B. Nziengui & J.-M. Moussavou, 499A ( BR, LBV, MO); Lope reserve , 14 January 1993, L.J.T. White 692 ( MO, WAG); Lopé-Okanda Reserve , 26 September 1990, L.J.T White [series 2] 141 ( MO). REPUBLIC OF CONGO. Mayombe , gorge de la Loukoula, à 5/ 6 km de Les Saras , 1 February 1965, A. Bouquet 1907 (P); forêt du cirque de Diosso , 28 January 1966, C. Farron 4830 (P); Parc National d’Odzala, transect Tombi km 14.9 , 17 January 1996, J. Lejoly 96/50 ( BRLU); Parc National d’Odzala , de Mbanza vers Edibabanza , 28 January 1996, J. Lejoly 96/316 ( BRLU); Mayombe , Mvouti, forêt de Masseka vers le col du Bamba , 22 November 1986, J. Lejoly 96/366 ( BR); Kouilou , Kakamoeka , 11 October 1990, S. Lisowski B-8011 ( BR); Littoral congolais , 20 November 1962, L. Makany 452 ( BR) .

Figures

FIGURE 20. Sabicea mildbraedii var. glabrescens. 1, flowering stem; 2, section of a flower bud; 3, inflorescence; 4, section of longstyled flower; 5, anthers; 6, stigma viewed from outside; 7, cross section of the ovary; 8; portion of fruiting stem; 9, fruit; 10, seed. From N. Hallé 1896 (1), N. Hallé 1661 and 1662 (2–10). Drawing by N. Hallé, reprinted with from Hallé (1966: 207)

FIGURE 21. Distribution of Sabicea mildbraedii var. glabrescens and S. mildbraedii var. letestui.