Uvariopsis citrata Couvreur & Niang., PhytoKeys 68: 3 (2016)

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 citrata Couvreur & Niang., PhytoKeys 68: 3 (2016)

Figs 53 , 54

Type.

Gabon - Estuaire • T.L.P. Couvreur 1143 (holotype: WAG! (no barcode); isotypes: LBV, P!), Monts de Cristal National Park , Mbé sector, 800 m from Kinguélé ANPN camp, near bridge; 0°27'50.18'N, 10°16'42.82'E ; 14 Jun. 2016.

Description.

Tree 4-10 m tall, D.B.H 3-10 cm; young branches pubescent, old branches glabrous. Leaves strong lemon scent when crushed. Petiole 4-8 mm long, 3-5 mm wide, pubescent to glabrous. Leaf lamina 312-500 mm long, 88-120 mm wide, length:width ratio 3.5-4.3, elliptic to obovate, coriaceous, base subcordate, apex acuminate, acumen 20-30 mm long, surface above glabrous, surface below glabrous; midrib impressed above, raised below, glabrous above, sparsely pubescent to glabrous below; secondary veins 17-19 pairs, brochidodromous to weakly brochidodromous, impressed above, raised below; tertiary veins reticulate. Flowers unisexual, male and female flowers similar, on same individuals (plant monoecious). Flower buds ovoid to conical. Male and female inflorescences borne on trunk, sparsely spaced mostly towards the lower half of the trunk, composed of 1 to 2 sessile flowers. Peduncle inconspicuous. Flower pedicel 0-2 mm long, 1-2 mm in diameter, densely pubescent. Bracts up to 3 at base, upper bract 1-2 mm long, ca. 4 mm wide, broadly ovate, pubescent outside, glabrous inside. Sepals 2, 9-15 mm long, 4-6 mm wide, narrowly ovate, basally fused, enclosing the petals in bud, densely pubescent outside, densely pubescent to glabrous toward base inside, brown. Petals 4, 7-15 mm long, 5-8 mm wide, length:width ratio ca. 3.5, ovate, pubescent outside, glabrous inside, brownish to greenish yellow outside, greenish yellow inside. Male flowers: stamens number unknown, ca. 0.5 mm long, anthers linear, connective prolongation truncate. Female flowers: carpels 60, 4-5 mm long, ca. 0.5 mm wide, densely pubescent, free; stigma coiled. Fruits unknown.

Distribution.

Endemic to Lower Guinean Domain of the Guineo-Congolian Region: Cameroon, Gabon.

Habitat and ecology.

Lowland mature or old secondary rain forests, near streams or in periodically inundated forest. Altitude: 60-300 m asl.

Phenology.

Flowers collected from March to June.

Uses.

Young leaves are used to wrap fish while cooking to give it an aromatic taste (Letouzey 9017).

Notes.

This species resembles Up. bakeriana , Up. korupensis and Up. submontana in having large obovate leaves (more than 31 cm long), with rounded to subcordate bases. Up. citrata is unique within the genus by its leaves emitting a strong lemon scent when crushed (Table 5 ). It also differs from all the other Uvariopsis species (except Up. zenkeri ) in having subsessile flowers, with pedicel less than 2 mm. It differs from Up. zenkeri in having larger leaves (31-50 cm vs. less than 16 cm in Up. zenkeri ).

Conservation status.

This species is known from one locality in Gabon situated in the Monts de Cristal National Park, and two localities in Cameroon both situated in the Campo-Ma’an National Park. It has been previously assessed as Data Deficient based on the Gabonese population ( Cosiaux et al. 2019c). Here, its EOO is estimated at 3,392 km2 and its AOO at 12 km2. Given it is close to a road, the future of the Gabonese population is uncertain ( Couvreur and Niangadouma 2016). Following IUCN criterion B it is thus assigned an updated preliminary conservation status of Endangered EN B1ab(iii)+2ab(iii).

Additional specimens examined.

Cameroon - South Region • G.P. Tchouto Mbatchou 2869 (KRIBI, WAG, YA), Campo-Ma'an area, Bibabimvoto ; 2°12'48'N, 10°00'51'E; alt. 60 m; 13 May. 2000 • R.G. Letouzey 9017 (P), 15 km au SSE de Zingui (soit à 50 km au SE de Kribi), feuille IGN 1/200000 Nyabessan; 2°37'52.24'N, 10°15'58.54'E; 14 Mar. 1968 . Gabon - Estuaire • T.L.P. Couvreur 1126 (LBV, WAG), Monts de Cristal National Park , 800 m from Kinguélé ANPN camp, near bridge; 0°27'50.18'N, 10°16'42.82'E; 11 Jun. 2016 .

Figures

Figure 53. Uvariopsis citrata Couvreur & Niang A trunk with flower buds B leaves, upper side C leaf base, lower side D lear apex, upper side E leaf base, upper side F female flower bud, two petals removed, side view G male flower bud, one petal removed, side view H flower buds on trunk. A-E, H Couvreur 1143 (type) F, G Couvreur 1126. Photos Thomas Couvreur.

Figure 54. Distribution map of Uvariopsis citrata. Shades of grey represent elevation, from white (sea level) to darker grey (higher elevation). The inset shows the extent of the map over Africa.