Toussaintia hallei Le Thomas, Adansonia ser . 2, 7: 99, 1967

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 : 325-327

Toussaintia hallei Le Thomas, Adansonia ser. 2, 7: 99, 1967

Fig. 101 ; Map 12H

Type.

Gabon. Ogooué-Ivindo; Belinga, Hallé N. 4189, 2 Jul 1966: lectotype, sheet here designated: P[P00046762]; isotypes: P[P00046760, P00046761] .

Description.

Liana, 10-15 m tall, d.b.h. 4 cm. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches tomentose. Leaves: petiole 4-7 mm long, ca. 1 mm in diameter, pubescent, grooved, blade inserted on top of the petiole; blade 5-14 cm long, 3.5-5 cm wide, oblong to elliptic, apex acuminate, acumen ca. 1 cm long, base rounded, subcoriaceous, below pubescent when young and old, above glabrous when young and old, concolorous; midrib impressed, above glabrous when young and old, below sparsely pubescent when young, glabrous when old; secondary veins 7 to 10 pairs, glabrous above; tertiary venation reticulate, very dense and tight. Individuals bisexual; inflorescences ramiflorous on young foliate branches, axillary. Flowers with 12 to 14 perianth parts in 3 to 4 whorls, 1 to 2 per inflorescence; peduncle short, ca. 2 mm long; pedicel 10-17 mm long, 1-2 mm in diameter, tomentose; one large bract at the base of the inflorescence, 7-13 mm long, 5-7 mm wide, elliptic; floral bracts 2 to 4, one basal and several upper towards the lower half of pedicel, basal bract 5-9 mm long, 4-7 mm wide, elliptic; upper bracts 5-8 mm long, 4-6 mm wide, elliptic; sepals 3, valvate, free, 10-18 mm long, 5-7 mm wide, elliptic to ovate, apex acute, base truncate, green, tomentose outside, glabrous inside, margins flat, slightly reflexed in bud; petals free, valvate, sub equal; petals 15-30 mm long, 5-9 mm wide, narrowly obovate, apex rounded, base truncate, greenish-yellow, streaked with red-brown, base shading into bright white, margins flat, pubescent outside, glabrous inside; staminodes absent; stamens 300 to 350, in 20 to 30 rows arranged on a long conical receptacle (androgynophore), ca.1 mm long, linear; connective discoid, glabrous, yellow; carpels free, 20 to 22, ovary 4-5 mm long, stigma shortly bilobed, glabrous. Fruits unknown.

Distribution.

A central African species, known from Gabon, Cameroon and Republic of Congo. In Cameroon known from the East region (one collection).

Habitat.

A very rare species across its range. In primary rain forests. Altitude ca. 400 m a.s.l.

Local and common names known in Cameroon.

None recorded.

IUCN conservation status.

Not evaluated.

Uses in Cameroon.

None reported.

Notes.

Toussaintia hallei is characterized by leaves that are shiny above and have a reticulate and very dense tertiary venation. The flowers have 9 to 10 petals inserted in 2 to 3 whorls and numerous stamens inserted horizontally on a very strongly convex receptacle referred to as an androgynophore, all unusual and unique features among Cameroonian Annonaceae ( Le Thomas 1967b, 1969b; Luke and Deroin 2005). This species is rarely collected and is known from a single collection in Cameroon.

Specimen examined.

East Region: ca 30 km NW of Moloundou, 2.25°N, 15.08°E, 07 December 1982, de Kruif A.P.M. 871 (WAG,YA).

Figures

Map 12. A Piptostigma pilosum B Piptostigma submontanum C Polyceratocarpus microtrichus D Polyceratocarpus parviflorus E Polyceratocarpus pellegrinii F Sirdavidia solannona G Sphaerocoryne gracilipes H Toussaintia hallei I Uvaria afzelii. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 101. Toussaintia hallei A flowering branch, note the dense network of tertiary veins on levaes B detail of pubescence lower leaf side C inflorescence diagram with large prophyl at the base D flower bud, top view E detail of opened flower, note the androgynophore part of receptacle F longitudinal cut of flowering receptacle G details of stamens, side and front views H details of carpels front view, and latitudinal cut I floral diagram (black. sepals; dashed petals) J, K floral diagrams showing the variable number of petals; Toussaintia congolensis Boutique (not in Cameroon) L flower bud M flower bud top view A-K Halle 4189, based on living material L, M Wagemans 1677. Drawings by Helene Lamourdedieu, Publications Scientifiques du Museum national d'Histoire naturelle, Paris; modified from Le Thomas (1969 b; pl. 3, p. 31).