Uvaria obanensis Baker f., Cat. Pl. Oban: 1, 1913

Couvreur, Thomas L. P., Dagallier, Leo-Paul M. J., Crozier, Francoise, Ghogue, Jean-Paul, Hoekstra, Paul H., Kamdem, Narcisse G., Johnson, David M., Murray, Nancy A. & Sonke, Bonaventure, 2022, Flora of Cameroon - Annonaceae Vol 45, PhytoKeys 207, pp. 1-532 : 363-366

Uvaria obanensis Baker f., Cat. Pl. Oban: 1, 1913

Fig. 113 ; Map 14D

≡ Richella obanensis (Baker f.) R.E.Fr. Nat. Pflanzenfam., ed. 2, 17a(2): 139, 1959.

= Uvaria marginata Diels, Bot. Jahrb. Syst. 53. 437, 1915. Type. Cameroon. South-West Region, Johann Albrechtshöhe, Büsgen M. 191, 1 Dec 1908: holotype: B[B 10 0153104].

Type.

Type. Nigeria. Cross River State; Oban, Talbot P.A. 1603, 1912: lectotype, sheet here designated: K[K000198779]; isotypes: BM[BM000554066]; K[K000198780, K000198781] .

Description.

Liana, 3-10 m tall, d.b.h. unknown. Indumentum of simple or fasciculate hairs, but overall glabrous; old leafless branches glabrous, young foliate branches sparsely pubescent becoming quickly glabrous. Leaves: petiole 4-5 mm long, 2 mm in diameter, glabrous, slightly grooved, blade inserted on top of the petiole; blade 15-26 cm long, 5-10 cm wide, oblong, apex acuminate to acute, acumen 1.5-2 cm long, base rounded to subcordate, coriaceous, below very sparsely pubescent to glabrous when young, glabrous when old, above glabrous when young and old; midrib sunken or flat, above glabrous when young and old, below glabrous when young and old; secondary veins 7 to 12 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young foliate branches, extra axillary. Flowers with 9 perianth parts in 3 whorls; 1 to 3(9) per inflorescence; pedicel 6-8 mm long, 2-3 mm in diameter, sparsely pubescent to glabrous; bracts 2, one basal and one towards the lower half of pedicel, basal bract 2-4 mm long, 3-4 mm wide; upper bract 2-3 mm long, 3-5 mm wide; sepals 3, valvate, free, 4-7 mm long, 6-8 mm wide, ovate to semiorbicular, apex obtuse, base truncate, green, tomentose outside, pubescent inside, margins flat; petals free, sub equal; outer petals 3, 20-30 mm long, 17-25 mm wide, ovate to suborbicular, apex rounded, base truncate, green to light yellow, margins flat, tomentose outside, glabrous inside; inner petals 3, imbricate, 20-30 mm long, 17-25 mm wide, ovate to suborbicular, apex rounded, base unguiculate, green to light yellow, margins flat, tomentose outside, glabrous inside; stamens 120 to 150, in 8 to 10 rows, 2-3 mm long, oblong to cuneiform; connective discoid, glabrous; staminodes absent; carpels free, 15 to 20, ovary ca. 3 mm long, stigma coiled, glabrous. Monocarps sessile, monocarps possibly 5 to ca. 8 (but only one seen in McPherson 15524 (LBV)), ca. 40 mm long, ca. 25 mm in diameter, glabrescent to glabrous, ellipsoid, apex rounded, smooth, green when ripe; seeds not seen.

Distribution.

Known from Nigeria to Cameroon, and more recently from Gabon (see below); in Cameroon known from South and South West regions.

Habitat.

A fairly rare species in Cameroon; in lowland secondary or primary rain forests. Altitude 0-300 m a.s.l.

Local and common names known in Cameroon.

None recorded.

IUCN conservation status.

Not evaluated.

Uses in Cameroon.

None reported.

Notes.

Uvaria obanensis belongs to a group of species that are almost glabrous on the branches and leaves. It is characterized by its large and shiny (in herbarium material) oblong coriaceous leaves with few secondary veins (less than 13) and a broadly cordate base. The flowers have free sepals not enclosing the petals in bud. The monocarps are sessile, a character only found in one other Uvaria species from Cameroon. U. scabrida . Uvaria obanensis closely resembles U. cabrae De Wild from the Democratic Republic of the Congo in the shape and size of its leaves with a cordate leaf base and being overall glabrous, but differs in its monocarps which are stipitate, ribbed and densely pubescent brown in the latter (versus sessile, smooth and glabrescent to glabrous in U. obanensis ).

We recently collected Uvaria obanensis in Gabon (near Koulamoutou, Ogooué-Lolo, Couvreur 1098), extending its distribution range south of the equator.

The monocarps are here described for the first time (but we did not see the seeds) based on a collection from Gabon (McPherson 15524 (LBV)).

Specimens examined.

South Region: 9 km N of Kribi, 3°N, 9.933°E, 30 October 1969, Bos J.J. 5555 (BR,C,K,LD,P,WAG,YA); Ebom, 3.1°N, 10.73°E, 24 February 1997, Elad M. 564 (KRIBI,WAG). South-West Region : Ekombe-Mofako Mokoko Forest Reserve, 4.47°N, 9.092°E, 23 April 1994, Acworth J.M. 182 (K,YA); Kumba, 4.63°N, 9.433°E, 01 December 1908, Büsgen M. 191 (B, K); West bank of the Onge River, 4.28°N, 8.966°E, 07 November 1993, Thomas D.W. 9802 (K,YA) .

Figures

Map 14. A Uvaria klaineana B Uvaria mollis C Uvaria muricata var. yalingensis D Uvaria obanensis E Uvaria osmantha F Uvaria poggei G Uvaria scabrida H Uvariastrum insculptum I Uvariastrum pierreanum. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 113. Uvaria muricata var. muricata (not in Cameroon) A habit B leaf base, upper side C fruit D leaf base, lower side E leaf base, upper side F flower bud. Uvaria obanensis G leaf base, lower side H leaf base, upper side I flower bud A-C Couvreur 571, Gabon D-F Couvreur 892, Gabon G-I Couvreur 1098, Gabon. Photos Thomas L. P. Couvreur.