Baissea congensis (R.D. Good) Jongkind, 2022

Jongkind, Carel C. H. & Lachenaud, Olivier, 2022, Novelties in African Apocynaceae, Candollea 77 (1), pp. 17-51 : 22

Baissea congensis (R.D. Good) Jongkind , comb. nov. ( Fig. 4A).

 Zygodia congensis R.D. Good in J. Bot. 67 (Suppl. 2): 89. 1929.

Holotypus: ANGOLA. Cabinda: Lufo River , near Belize, 29.III.1919, fl., Gossweiler 7959 (K [K000233966]!; iso-: BM [ BM000925816 ]!, COI [ COI00070733 ] image!, MO- 1302577 image!) .

Distribution and ecology. – Restricted to Gabon (Ngounié and Nyanga provinces) and Angola ( Cabinda), and probably Republic of Congo (where not collected yet); occurs in forest edges, often along rivers, at elevations of 10– 640 m.

Notes. – This species, previously treated as a synonym of Baissea campanulata (see comments under the latter species) is resurrected here. Since it was originally described in Zygodia Benth. , a genus synonymised with Baissea by PICHON (1948), the new combination is required.

Additional specimens examined. – GABON. Ngounié: 40 km E. of Mouila, along the road to Yeno , 28.XI.1984, fl., Arends et al.501 ( WAG, LBV) ; Sindara, 27.IX.1917, fl., Le Testu 2227 ( BM, BR, P); ibid. loco, 22.III.1926, fl., Le Testu 5867 ( BM, BR, P); Mbigou, 3.V.1925, fl., Le Testu 5415 ( BM, BR, P); ibid. loco, 17.IV.1930, fl., Le Testu 8032 ( BM, BR, P); Epambwa, 18.III.1927, fl., Le Testu 6427 ( BM, BR, P); 50 km along Mouila-Yeno road, 31.III.1988, fl., de Wilde & Jongkind 9639 ( BR, LBV, WAG) . Nyanga: sur la route entre Mabanda et Ndendé, 9.IV.2018, fl., Bidault et al. 4363 ( BR, G, MO, WAG); along Nyanga river, upstream from Mayonami , 16.III.1994, fl., Wieringa et al. 2495 ( BR, G, K, LBV, P, WAG) .

Baissea lane-poolei Stapf in Bull. Misc. Inform. Kew 1915: 46. 1915.

Holotypus: SIERRA LEONE. Western Area: York Pass , 7.VII.1914, fl., Lane-Poole 322 (K [K000233866]!; iso-: GB) .

Distribution and ecology. – A West African endemic, widespread in the hill ranges of Guinea, Sierra Leone (north and Freetown Peninsula), northern Liberia (Nimba area) and western Côte d’Ivoire (around Man) ( Fig. 3 ); occurring in semideciduous or gallery forests up to elevations of 1400 m.

Notes. – This species is here considered in its narrow sense, excluding Baissea concinna , which is treated as a distinct species (see comments under it).

Baissea subsessilis (K. Schum.) Stapf ex Hutch. & Dalziel, Fl. West Trop. Afr. 2: 46. 1931.

 Oncinotis subsessilis K. Schum., Bot. Jahrb. Syst. 33: 321. 1903.

Lectotypus (designated by VAN DILST, 1995: 102 ): NIGERIA. Lagos State: Ishagama (Jorubaland), III.1899, fl., Schlechter 12310 (K [K000234015]!; isolecto-: AMD [AMD.25157] image!, BM [ BM000925815 ]!, BR [ BR0000008825087 ]!, G [G00009017, G00009018] images!, L [L0004439, L0004438] images!, P [P00413270, P00413271] images!, WAG [ WAG0003984 ]!, Z) .

Distribution and ecology. – Restricted to southern Nigeria and adjacent south-western Cameroon, occurring in lowland rainforest edges up to elevations of 250 m.

Notes. – This species, like Baissea congensis , was included in the synonymy of B. campanulata by VAN DILST (1995) ; see additional comments under the latter species. It can be separated from both B. congensis and B. campanulata by its much hairier stems and leaves (see Table 1). Its distribution locally overlaps with that of B. campanulata in Cameroon, but is widely separated from that of B. congensis .

Additional specimens examined. – NIGERIA. Cross River State: Eko-Esai , 18.III.1977, fl., Ariwaodo 699 FHI 88762 ( WAG) ; Iyamoyong Forest Reserve , 12.V.1959, fl., Binuyo FHI 41294 ( BR, WAG) . Ogun State: Ijebu Igbo , 24.IV.1949, fl., Ejiofor FHI 26114 ( BR, K) . Oyo State: Gambari , 9.V.1966, fl., van Eijnatten 1475 ( WAG) ; Gambari , 15.V.1974, fl., Gbile FHI 73085 (P) .

CAMEROON. South-West Region: S of Baro Village , 31.III.1988, fl., D.W. Thomas et al. 7468 ( MO, WAG) .

Figures

Fig. 3. – Distribution map of Baissea concinna Stapf ex Hutch.