Uvaria buchholzii Engl. & Diels, Notizbl. Konigl . Bot. Gart. Berlin 2: 295, 1899

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 : 358-348

Uvaria buchholzii Engl. & Diels, Notizbl. Konigl. Bot. Gart. Berlin 2: 295, 1899

Fig. 107 ; Map 13F

≡ Uva buchholzii (Engl. & Diels) Kuntze, Kuntze, Deutsche Bot. Monatsschr. 21: 173, 1903; Balonga buchholzii (Engl. & Diels) Le Thomas, Adansonia ser. 2, 8, 1: 108, 1968.

Type.

Cameroon. West Region; Balong, Buchholz R.W. 103, 26 Jun 1874: holotype: B[B 10 0154065] .

Description.

Scrambling shrub or liana, height unknown, d.b.h. to 25 cm in diameter. Indumentum of simple or fasciculate hairs; old leafless branches glabrous, young foliate branches pubescent becoming quickly glabrous. Leaves: petiole 5-9 mm long, ca. 1 mm in diameter, glabrous, grooved, blade inserted on top of the petiole; blade 10-24 cm long, 3.5-9 cm wide, obovate to oblong, apex acuminate, acumen ca. 1 cm long, base obtuse to subcordate, papyraceous, below sparsely pubescent when young, sparsely pubescent to glabrous when old, above glabrous when young and old; midrib sunken or flat, above glabrous when young and old, below sparsely pubescent when young, glabrous when old; secondary veins 10 to 14 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old leafless branches, leaf opposed or extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 per inflorescence; pedicel 20-25 mm long, 1-2 mm in diameter, pubescent; in fruit 25-27 mm long, 2-3 mm in diameter, glabrous; bracts 2, one basal and one upper towards the upper half of pedicel, basal bract 1-2 mm long, 1 mm wide; upper bract 4-6 mm long, 3-5 mm wide; sepals 3, imbricate, free, 6-8 mm long, 6-8 mm wide, suborbicular, apex rounded, base truncate, pubescent outside, glabrous inside, margins flat; petals free, inner slight longer than outer; outer petals 3, 10-15 mm long, 7-10 mm wide, ovate to oblong, apex acute, base truncate, margins revolute, pubescent outside, pubescent inside; inner petals 3, imbricate, 20-22 mm long, 14-17 mm wide, obovate, apex rounded, base ungulate, margins flat, pubescent outside, glabrous inside; stamens numerous, in 10 rows, 1-2 mm long, narrowly oblong; connective discoid, glabrous; staminodes absent; carpels free, numerous, ovary ca. 3 mm long, stigma obpyramidal, glabrous. Monocarps stipitate, stipes 20-30 mm long, laterally inserted, 1-2 mm in diameter; monocarps 30 to 40, 12-15 mm long, 10-15 mm in diameter, ellipsoid, apex apiculate or rounded, pubescent, smooth, irregularly ribbed with two main prominent ribs, greyish green turning orange when ripe; seed 1 (more rarely 2) per monocarp, 8-10 mm long, 5-6 mm in diameter, flattened ellipsoid; aril absent.

Distribution.

A central African species, from Cameroon to Gabon; in Cameroon known from the East, South, South West and West regions.

Habitat.

An uncommon and rarely collected species but is suggested to be frequent when present; in rain forests near rocky outcrops. Altitude 100-800(1000) 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 buchholzii is mainly distinguished by its imbricate sepals and its 2-ribbed monocarps with few seeds (1 to 2) and laterally inserted stipes. Uvaria buchholzii superficially resembles U. welwitschii Engl. & Diels (not present in Cameroon to date) in the overall leaf morphology, but the latter has smooth monocarps with centrally inserted stipes.

The imbricate aestivation of the sepals led Le Thomas (1968a) to place this species into a new genus, Balonga Le Thomas. However, recent molecular data found this species nested within Uvaria and so the name was transferred back into Uvaria ( Zhou et al. 2010).

Le Thomas suggested that this species might be a small tree or a shrub ( Le Thomas 1968a, 1969b) which would be unusual for Uvaria (generally lianas). However, a collection by Letouzey (12190, P) indicates it is a scrambling shrub ("arbuste sarmenteux") which is a more common habit state for Uvaria .

Specimens examined.

East Region: Rocher Ekok Edanbawa à 110 km au SW de Yokadouma 2.81°N, 14.48°E, 29 March 1973, Letouzey R. 12190 (P,WAG,YA). South Region : Bipindi, 3.08°N, 10.42°E, 01 January 1913, Zenker G.A. 4926 (L,P); Bipindi, 3.08°N, 10.41°E, 01 April 1914, Zenker G.A. 597 (U,WAG). South-West Region: Limbe Mt Etinde above Mpanja, 4.08°N, 9.174°E, 11 July 1990, Cheek M. 3014 (K) .

Figures

Map 13. A Uvaria angolensis B Uvaria anisotricha C Uvaria anonoides D Uvaria baumannii E Uvaria bipindensis F Uvaria buchholzii G Uvaria chamae H Uvaria comperei I Uvaria heterotricha. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 107. Uvaria buchholzii A flowering branch B detail of lower side of flower, showing imbricate sepals and upper bract C outer petal, inner view D inner petal, inner view E longitudinal section of flower (petals removed) showing strongly convex receptacle F stamen G pollen grain H longitudinal section in carpel showing ovule I flower diagram J fruit K detail of stipitate monocarp showing ridges L detail of monocarp showing ridges M detail of monocarp showing different structure N longitudinal section of seed; longitudinal section of monocarp A-H from Zenker 4926 J-N from Klaine 2658 bis O from Bulchholz 103. Drawings by Helene Lamourdedieu, Publications Scientifiques du Museum national d'Histoire naturelle, Paris; modified from Le Thomas (1969 b, pl. 4, p. 35).