Uvariopsis citrata Couvreur & Niangadouma, PhytoKeys 68: 1-8, 2016

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 : 409-411

Uvariopsis citrata Couvreur & Niangadouma, PhytoKeys 68: 1-8, 2016

Fig. 129 ; Map 15I

Type.

Gabon. Estuaire; Monts de Cristal, near first bridge after Kinguele village , 0°46'66"N, 10°27'81"E, Couvreur T.L.P 1143, 14 Jun 2016: holotype: WAG; isotypes: LBV, P .

Description.

Tree, 4-10 m tall, d.b.h. 3-10 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent. Leaves: petiole 4-8 mm long, 3-5 mm in diameter, pubescent when young, pubescent to glabrous when old, grooved on top, blade inserted on top of the petiole, strong lemon scent when crushed; blade 31.2-50 cm long, 8.8-12 cm wide, elliptic to obovate, apex acuminate, acumen 2-3 cm long, base subcordate to cordate, coriaceous, below glabrous when young and 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 17 to 19 pairs per side, glabrous above; tertiary venation reticulate. Individuals unisexual, monoecious; inflorescences cauliflorous, sparsely spaced along the trunk mostly towards the lower half of the trunk. Flowers with 6 perianth parts in 2 whorls, ovoid to conical in bud, 1 to 2 per inflorescence, male and female inflorescences similar; pedicel 0-2 mm long, 1-2 mm in diameter, densely pubescent; in fruit unknown; bracts up to 3, all basal, 1-2 mm long, 4 mm wide; sepals 2, valvate, basally fused, enclosing the petals in bud, 9-15 mm long, 4-6 mm wide, narrowly ovate, apex acute, base truncate, densely pubescent with hairs appressed outside, densely pubescent or glabrous towards base inside, margins flat; petals 4, 7-15 mm long, 5-8 mm wide, ovate, apex acute, base truncate, brownish-greenish-yellow, margins flat, pubescent outside, glabrous inside; male flowers: stamen number unknown, 0.5 mm long, oblong, connective truncate, glabrous, pale yellow; female flowers: carpels free, ca. 60, ovary 4-5 mm long, ca. 0.5 mm wide, densely pubescent with long appressed hairs, stigma cylindrical coiled. Fruits unknown.

Distribution.

A species only known from southern Cameroon and two localities in Gabon (Monts de Cristal National Park, Mbé sector); in Cameroon known from the South Region.

Habitat.

A rare species; in mature or old secondary forests near rivers in periodically flooded soils, in flat valley bottoms or in well-drained forests on slope. Altitude 60-300 m a.s.l.

Local and common names known in Cameroon.

Ntala ( Yaoundé, Letouzey 9017); Kakangula (Bagielli Pygmies, Letouzey 9017).

IUCN conservation status.

Data deficient (DD) ( Cosiaux et al. 2019a x), but this assessment didn’t take in account the two specimens cited here form Cameroon.

Uses in Cameroon.

None reported.

Notes.

Uvariopsis citrata resembles U. sessiliflora by its (sub)sessile flowers (pedicels 0-2 mm long), but is easily distinguished by its strong lemon scent, longer leaves (31-50 vs 12-18 cm) and (sub)cordate leaf base (vs acute). The strong lemon scent is unique in the genus. This character has also been reported in Uvariodendron angustifolium and in U. molundense var. citrata (endemic to Gabon).

This species was suggested to be endemic to Gabon ( Couvreur and Niangadouma 2016), however we identified two specimens from southern Cameroon that fit this species morphologically (young foliate branches pubescent; leaves ca. 35 cm long and sessile ovoid flowers). Neither specimen mentions the citrus scent of the leaves. Letouzey 9017 however does mention that the leaves emit a strong smell when crushed, and the leaves are used to prepare fish dishes which gives them an "aromatic taste" (translated from French, “goût aromatique").

Specimens examined.

South Region: A 15 km au SSE de Zingui (soit à 50 km au SE de Kribi ), 2.82°N, 10.97°E, 14 March 1968, Letouzey R. 9017 (P,YA); Campo-Ma’an area Bibabimvoto, 2.21°N, 10.01°E, 13 May 2000, Tchouto Mbatchou G.P. 2869 (KRIBI,WAG,YA) .

Figures

Map 15. A Uvariastrum zenkeri B Uvariodendron angustifolium C Uvariodendron calophyllum D Uvariodendron conniven s E Uvariodendron fuscum F Uvariodendron fuscum var. giganteum G Uvariodendron molundense H Uvariopsis bakeriana I Uvariopsis citrata. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 129. Uvariopsis citrata A trunk with slash (Couvreur 1126) B entire leaf C leaf base upper side D leaf apex, upper side E pre anthetic flower buds on trunk, 1. female flower, 2. male flower F leaf base, lower side A-F Couvreur 1143, Gabon. Photos A-F Thomas L. P. Couvreur.