Mischogyne gabonensis (Pellegr. ex Le Thomas) Gosline, Kew Bull. 74(2)-28: 13, 2019

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 : 163-165

Mischogyne gabonensis (Pellegr. ex Le Thomas) Gosline, Kew Bull. 74(2)-28: 13, 2019

Fig. 45 ; Map 6C

≡ Mischogyne elliotiana (Engl. & Diels) Le Thomas var. gabonensis Pellegr. ex Le Thomas, Flore du Gabon 16: 291, 1969.

Type.

Gabon. Nyanga; Mayumba, Le Testu G.M.P.C. 1768, 26 Aug 1914: lectotype, designated by Gosline et al. (2018), p. 28 [P00315820]; isolectotypes BM[BM000547338]; BR[BR0000008801661, BR0000008802330]; LISC[LISC000379]; P[P00315817, P00315818]; WAG[WAG0175098, WAG0175099, WAG0247284, WAG0247285, WAG0247286] .

Description.

Tree, 3-25 m tall, d.b.h. up to 25 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches shortly pubescent. Leaves: petiole 5-10 mm long, ca. 2 mm in diameter, sparsely pubescent to glabrous, cylindrical, blade inserted on the side of the petiole; blade 8-16 cm long, 4-7 cm wide, obovate, apex acuminate, acumen 1-3 cm long, base cuneate, papyraceous to subcoriaceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib impressed, above glabrous when young and old, below glabrous when young and old; secondary veins 6 to 9 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on old or young foliate branches, extra-axillary. Flowers with 9 perianth parts in 3 whorls, 1 per inflorescence; pedicel 5-12 mm long, 0.5-1 mm in diameter, pubescent; in fruit 7-15 mm long, 2-3 mm in diameter, glabrous; bracts few, reduced to a tuff of hairs, all basal; sepals, valvate, completely fused in bud, tearing at anthesis into 2 or 3 parts, 7-13 mm long, 3-5 mm wide, triangular, apex acute, base truncate, green, tomentose on both sides, margins flat; petals free, equal; outer petals 3, valvate, 14-16 mm long, 3-5 mm wide, narrowly elliptic, apex acute, base truncate, bright white, margins flat, densely pubescent outside, tomentose inside; inner petals 3, valvate, 14-16 mm long, 3-5 mm wide, narrowly elliptic, apex acute, base truncate, bright white, margins flat, densely pubescent outside, tomentose inside; stamens 50 to 60, in 3 to 4 rows, 1-3 mm long, elongated; connective tongue shaped, pubescent, cream; staminodes absent; carpels free, 3-7, ovary 5-6 mm long, stigma bilobed, densely pubescent. Monocarps sessile, 1 to 3, 60-65 mm long, 28-32 mm in diameter, cylindrical, apex rounded, glabrous, smooth, 1-ribbed, yellow when ripe; seeds 6 per monocarp, ca. 20 mm long, ca. 15 mm in diameter, ellipsoid, covered with an indumentum of fine white hairs; aril absent.

Distribution.

Cameroon, Gabon and Bioko island (Equatorial Guinea); in Cameroon known from the South and South-West regions.

Habitat.

A rare species in Cameroon (or at least uncommonly collected); in lowland primary or old secondary rain forests. Altitude 0-500 m a.s.l.

Local and common names known in Cameroon.

None recorded.

IUCN conservation status.

Endangered (EN) ( Texier and Stévart 2021a).

Uses in Cameroon.

None reported.

Notes.

Mischogyne gabonensis is morphologically similar to the West African endemic M. elliotiana (of which it was formerly regarded as a variety) in the shape and size of its flowers and monocarps ( Gosline et al. 2018). However, M. gabonensis is a large tree up to 25 m tall and 25 cm in d.b.h. with sepals completely fused and tearing at anthesis and has 3-7 carpels, whereas M. elliotiana is a smaller tree or shrub 3-10 m tall, with 3 sepals that are free with reduplicate-valvate margins, and 7-12 carpels.

Specimens examined.

South Region: Environs de Nko'olong 30 km E Campo, 2.40°N, 10.03°E, 21 November 1992, Satabié B. 978 (YA) . South-West Region: Mount Cameroon National Park Bakinguili trail above Bakinguili village, 4.09°N, 9.054°E, 02 April 2016, Couvreur T.L.P. 1033 (WAG,YA); Fako Njonji Njonji along path to the lake Low canal forest, 4.15°N, 9.066°E, 26 September 2001, Kenfack D. 1545 (MO) .

Figures

Map 6. A Letestudoxa lanuginosa B Meiocarpidium oliverianum C Mischogyne gabonensis D Monanthotaxis bicornis E Monanthotaxis bokoli F Monanthotaxis capea G Monanthotaxis cauliflora H Monanthotaxis congoensis I Monanthotaxis couvreurii. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 45. Meiocarpidium oliverianum A detail of lower side of leaf showing lepidote (scale-like) hairs; white bow zoomed in) B flowering branch C fruiting branch. Mischogyne gabonensis D base of trunk E base of leaf blade, upper side F base of leaf bade, lower side G flower bud, note sepals tearing H detail of flower, top view I detail of flower, all petals and sepals fallen, note elongated carpels J longitudinal section of monocarp, note hairy seeds A-C Sosef 2317 D-I Couvreur 1033, Mt Cameroon, Cameroon J Kenfack 1545; Mt Cameroon, Cameroon. Photos A-H Thomas L. P. Couvreur I David Kenfack, Tropicos. org, Missouri Botanical Garden.