Uvariopsis etugeana Dagallier & Couvreur, PhytoKeys 207: 423 (2022)

Dagallier, Leo-Paul M. J., Mbago, Frank M., Couderc, Marie, Gaudeul, Myriam, Grall, Aurelie, Loup, Caroline, Wieringa, Jan J., Sonke, Bonaventure & Couvreur, Thomas L. P., 2023, Phylogenomic inference of the African tribe Monodoreae (Annonaceae) and taxonomic revision of Dennettia, Uvariodendron and Uvariopsis, PhytoKeys 233, pp. 1-200 : 1

Uvariopsis etugeana Dagallier & Couvreur, PhytoKeys 207: 423 (2022)

Figs 63 , 64

Type.

Cameroon - North-West Region • R.G. Letouzey 13414 (holotype: P! (P01982826)), Rive droite de la Metchum, près Obang (18 km S of Wum ); 6°15'N, 10°01'59.99"E; alt. 600 m; 03 Dec. 1974 .

Description.

Tree 3-6 m tall, D.B.H unknown; young branches slightly pubescent, old branches glabrous. Leaves with minute pelucid punctuations. Petiole 3.5-4 mm long, 2.5-3.5 mm wide, glabrous. Leaf lamina 190-235 mm long, 70-85 mm wide, length:width ratio ca. 2.7, elliptic, coriaceous, base acute to slightly decurrent, apex attenuate to acuminate, acumen ca. 10 mm long, surface above glabrous, surface below glabrous; midrib impressed above, raised below, glabrous above, glabrous below; secondary veins 8-10 pairs, brochidodromous, impressed above, raised below; tertiary veins reticulate. Flowers unisexual, male and female flowers dimorphic, on same individuals (plant monoecious). Flower buds ovoid to pyramidal. Male inflorescences borne on trunk, composed of 1 to 2 flowers. Peduncle inconspicuous. Flower pedicel 8-10 mm long, 1-1.5 mm in diameter, glabrate to glabrous. Bracts 1 at base and 1 towards the middle or lower half of the pedicel, upper bract 1-1.5 mm long, 1-2.5 mm wide, broadly ovate, adpressed, semi clasping the pedicel, pubescent outside, glabrous inside. Sepals 2, ca. 2 mm long, ca. 4 mm wide, broadly ovate, basally fused, sparsely pubescent to glabrous outside, glabrous inside, color unknown. Petals 4, 6-11.5 mm long, 3.5-7 mm wide, length:width ratio 1.6-2.5, elliptic to ovate, sparsely pubescent to glabrous outside, glabrous inside, color unknown. Stamens numerous (exact number unknown), 0.5-1 mm long, ca. 0.2 mm wide, anthers linear, connective prolongation truncate. Female inflorescences borne on trunk, composed of 1 to 2 flowers. Flower pedicel ca. 4 mm long, ca. 2 mm in diameter, glabrate to glabrous. Bracts 1 at base and 1 towards the middle or lower half of the pedicel, upper bract ca. 1.5 mm long, ca. 2.5 mm wide, broadly ovate, adpressed, semi clasping the pedicel, pubescent outside, glabrous inside. Sepals 2, 1-1.5 mm long, 2-3.5 mm wide, broadly ovate, basally fused, sparsely pubescent to glabrous outside, glabrous inside, color unknown. Petals 4, ca. 14 mm long, ca. 8 mm wide, length:width ratio 1.6-2.5, elliptic, glabrous outside, glabrous inside, color unknown. Stamens ca. 5, ca. 1 mm long, sterile, seen on one female flower. Carpels ca. 20, ca. 3 mm long, ca. 1 mm wide, glabrate at base to glabrous, free; stigma coiled. Fruits unknown.

Distribution.

Endemic to Lower Guinean Domain of the Guineo-Congolian Region. Known from only two localities in the North-West and South-West Regions in Cameron.

Habitat and ecology.

Lowland mature rain forests or semi-deciduous forests. 170-600 m asl.

Phenology.

Flowers collected in March and December.

Notes.

Up. etugeana resembles Up. pedunculosa in the shape of the leaves, and Up. solheidii in the shape of its flowers. However, Up. etugeana has a short flowering pedicel (4-10 mm vs. 14-325 mm in Up. pedunculosa and 9-198 mm in Up. solheidii ) and petals which are glabrous outside (vs. pubescent in both Up. pedunculosa and Up. solheidii ).

Preliminary conservation status.

This species is known from only two specimens from two different locations in western Cameroon. Its EOO is estimated less than 1,000 km2 and its AOO is estimated at 8 km2. The two specimens were collected more than 30 years ago, and only one occurs in a protected area, in the Takamanda National Park. This species is thus likely to have undergone, or to undergo in the future, a decline in its AOO. Following IUCN criterion B, it is thus assigned a preliminary conservation status of Endangered EN B1ab(i,ii)+2ab(i,ii).

Additional specimens examined.

Cameroon - South-West Region • D.W. Thomas 4544 (MO), Takamanda Forest Reserve ; 6°14'N, 9°19'E; alt. 170 m; 21 Mar. 1985 .

Figures

Figure 63. Uvariopsis etugeana Dagallier & Couvreur A branch with leaves B flower, semi-bottom view C inflorescence with two flowers D female flower, transversal cut, three petals removed E male flower, transversal cut of the receptacle. A-C Letouzey 13414 D, E Thomas 4544. Photos Leo-Paul Dagallier.

Figure 64. Distribution map of Uvariopsis etugeana. Shades of grey represent elevation, from white (sea level) to darker grey (higher elevation). The inset shows the extent of the map over Africa.