Uvariastrum germainii Boutique, Bull. Jard. Bot. Etat Bruxelles 21: 120. 1951.

Couvreur, Thomas L. P., 2014, Revision of the African genus Uvariastrum (Annonaceae), PhytoKeys 33, pp. 1-40 : 6-10

1. Uvariastrum germainii Boutique, Bull. Jard. Bot. Etat Bruxelles 21: 120. 1951. Figure 5

Type.

Democratic Republic of Congo. Orientale: Yangambi, 29 Feb 1910, R.G.A. Germain 213 (lectotype, designated here: BR! [BR8824400]; isolectotypes: BR! [BR8824417], FT! [FT001090], K! [K000198809], P! [P00315823, P00315825], US! [accession number US00104141]).

Description.

Tree, up to 25 m tall, up to 50 cm in diameter, stem cylindrical; old branches glabrous; young branches glabrous to sparsely pubescent quickly becoming glabrous, hairs ca. 0.1 mm long, erect to appressed, brown. Petioles 4-7 mm long, ca. 1 mm in diameter, glabrous or sparsely pubescent, quickly becoming glabrous, leaf lamina inserted on top, weakly grooved adaxially. Leaf lamina 6-10 cm long, 2-3 cm wide, length:width ratio 2.5-4, narrowly elliptic to elliptic, coriaceous, glabrous on both sides, base cuneate, apex cuneate to acuminate, acumen ca. 1 cm long; midrib glabrous on both sides; secondary veins 10-12, glabrous, hardly visible adaxially, slightly raised abaxially, curving upwards and anastomizing near margin; margins wavy. Raphidia 1(-2), on leafy or older branches, no report of cauliflory. Flower buds up to 1 cm long, 1 cm in diameter, margins clearly folded outwards. Bracts soon falling, not seen. Flowering pedicel 0.7-1.5 cm long, ca. 1 mm in diameter, densely pubescent, hairs ca. 0.5 mm long, appressed, light brown. Sepals 1-1.5 cm long, 0.5-1 cm wide, length:width ratio 1-1.5, very broadly ovate to broadly ovate, base truncate, apex acute, densely pubescent outside, same as on pedicel, tomentose inside, glabrous towards the center; outside light brown, inside light brown along margins, black in center in herbarium material. Outer petals 1.3-3 cm long, 0.5-1.2 cm wide, length:width ratio 1.8-3, elliptic to broadly elliptic, base truncate, apex acute, densely pubescent outside, more so along central vein, hairs ca. 0.3 mm long, appressed, light brown, tomentose inside. Inner petals 1-2 cm long, 0.5-1 cm wide, length:width ratio 1.7-2, elliptic, base truncate, apex acute, pubescence same as outer petals; petals light brown in herbarium material, yellow on fresh material. Stamens ca. 4 mm long, connective ca. 0.6 mm long, tongue shaped. Carpels ca. 9, 4 mm long, 1 mm in diameter, densely pubescent, hairs ca. 0.7 mm long, appressed upwards, stigma bilobed, ca. 1 mm in diameter, glabrous. Fruiting pedicel 1-4 cm long, 3-4 mm in diameter, glabrous, woody. Monocarps 3-8, 2.5-7 cm long, 1.5-2 cm in diameter, ellipsoid, straight to curving, glabrous or very sparsely pubescent, many to few irregularly longitudinal ribs, resembling a peanut; stipe 3-8 mm long, ca. 5 mm in diameter; rostre ca. 5 mm long. Seeds 3-5 per monocarp, 0.7-1.4 cm long, ca. 1 cm in diameter, broadly ellipsoid, not flattened, testa bark brown on herbarium material, raphe raised, hilum ca. 4 mm long, ca. 1 mm wide, narrowly elliptic.

Distribution.

Gabon, Central African Republic, Republic of Congo and Democratic Republic of Congo, mainly in the Congo basin. ( Figure 6 ).

Habitat and ecology.

This species is found in Gilbertiodendron J. Léonard forests as well as in semi-deciduous forests. One collection indicates a habitat on white sand on a river bank (Germain 412); 400-900 m.

Phenology.

Mature flowers collected from Feb to Mar, Jun, Aug and Oct. Mature fruits collected in Jan, May to Jun and Oct.

Preliminary IUCN conservation status.

VUB2ab(iii): Uvariastrum germainii is moderately represented in herbaria, and has an Area of Occupancy less than 60 km² with just nine localities. Although it is found in several protected areas (Dzanga-Sangha, Central African Republic; Nouablé-Ndoki National Park, Republic of Congo) it is highly fragmented in distribution (although this might be linked to collecting effort). The vulnerable category thus seems applicable.

Vernacular names.

Democratic Republic of Congo: Loopa lo nénu (Turumbu people Lombo language, Germain 213, 412); Mosangui (Gambe language, Leontovitch 113).

Uses.

None recorded.

Notes.

This species somewhat resembles Uvariastrum pierreanum in the small size of its leaves, but can be distinguished by the longer petioles (4-7 mm vs 2-4 mm), long acuminate leaf apex and tongue-shaped connectives of the stamens. In addition, the fruits of Uvariastrum germainii are clearly ribbed and glabrous, compared to the smooth and pubescent fruits of Uvariastrum pierreanum .

Specimens examined.

Central African Republic. Sangha-Mbaere: Kongana research camp, 25 km SE of Bayanga. 31 May 1994, Harris, D.J. 5002 (E); Kongana research camp, 25 km SE of Bayanga. 7 Feb 1994, Harris, D.J. 4505 (E); Madibwé, close to St. Francois road, c. 12 km NE of Bayanga. 3 May 2001, Harris, D.J. 7526 (E); Bai Hoku, 25 km E of Bayanga. 17 Aug 1995, Remis, M. 101-95 (E).

Democratic Republic of Congo. Equateur: Djoa, 17 Oct 1958, Evrard, C.M. 5064 (BR); Dua-Ebola, 28 Aug 1938, Leontovitch, C. 113 (BR); Dundusana, Feb 1913, Reygaert, F.J. 53 (BR); Bokome/Tushuapa, 22 Jan 1959, Evrard, C.M. 5594 (K); Kasai-Oriental: lotissement de Shinga II, Jun 1952, Germain, R.G.A. 7648 (BR, EA); Maniema: entre Nyangwe-Malela, Aug 1932, Lebrun, J.-.P.A. 5977 (BR, K, P); Orientale: Yangambi, Réserve forestière, vallée de la Luweo, 29 Feb 1940, Germain, R.G.A. 213 (BR, FT, K, P, US); Yangambi, 1948, Gilbert, G.C.C. 9375 (P); 1 May 1948, Germain, R.G.A. 936 (P); Yangambi, RFI, vallée de Luweo, 1 Mar 1943, Germain, R.G.A. 412 (BR, P); Yangambi, 2 Oct 1952, Madoux, E. 453 (BR); 1950, Gilbert, G.C.C. 9347 (BR, S); Yangambi, vallée de la Luweo, May 1952, Toussaint, L. 929 (BR).

Gabon. Ogooué-Ivindo: Boka-Boka, piste menant au Mt Bengoué, 4 Mar 1979, Florence, J. 1723 (P).

Republic of Congo. Niari: chantier à 4 km de Moukoudi, sur route de Mougala, 27 Oct 1975, Sita, P. 3939 (BR, P); Sangha: Nouablé-Ndoki National Park, Goualougo Study Site, 36.62 km E de Bomassa, 375m, 27 Mar 2008, Ndolo Ebika, S.T. 311 (E, IEC, WAG); Nouablé-Ndoki National Park, Goualougo Study Site, 38.33 km E-SE de Bomassa, 391m, 15 Sep 2008, Ndolo Ebika, S.T. 387 (E, IEC, WAG); Likouala: North side of Sombo stream, 8 km N of Makao, 150 km NW of Impfondo. 22 Apr 1995 Harris, D.J. 5268 (E).

Figures

Figure 5. Uvariastrum germainii. A Flowering branch B Flower C Transversal cut of flower showing carpels and stamens D detail of sepals E detail of carpels and ovule placentation F stamen G detail of a monocarp. Drawings by Fadia, EPHE in MNHN-Palynotheque (Paris).

Figure 6. Distribution of Uvariastrum germainii.