Monanthotaxis elegans (Engl. & Diels) Verdc., Kew Bull. 25(1): 25, 1971

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 : 191-192

Monanthotaxis elegans (Engl. & Diels) Verdc., Kew Bull. 25(1): 25, 1971

Fig. 49 ; Map 7C

≡ Popowia elegans Engl. & Diels, Monogr. Afrik. Pflanzen.-Fam. 6: 45, 1901.

Type.

Cameroon. South Region; Bipindi, Zenker G.A. 1321, 23 Mar 1897: holotype: B[B100153023]; isotypes: BM[BM000553832, BM000553833]; E[E00181437]; G[G00308366]; HBG[HBG-502506]; K[K000198990, K000198991]; M[M-0198713]; P[P00362605, P00362606] .

Description.

Liana, up to 4 m tall, d.b.h. unknown. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches densely pubescent with dense appressed to ascending reddish brown hairs 0.1-0.2 mm long. Leaves: petiole 3-5 mm long, ca. 1 mm in diameter, densely pubescent, slightly grooved, blade inserted on top of the petiole; blade 4.6-15.4 cm long, 2.3-4.6 cm wide, narrowly oblong-elliptic to oblong-oblanceolate (to obovate), apex acute to acuminate, acumen ca. 3 cm long, base rounded to subcordate, papyraceous, below sparsely pubescent when young and old, above sparsely pubescent when young and old, discolorous, whitish below; midrib impressed, above glabrous when young and old, below sparsely pubescent when young and old; secondary veins 11 to 14 pairs, glabrous above; tertiary venation percurrent. Individuals bisexual; inflorescences ramiflorous on foliate branches, leaf opposed to extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 8 per inflorescence, glomerule-like; pedicel 1-2 mm long, ca. 1 mm in diameter, densely pubescent with appressed yellowish brown hairs; in fruit 4-5 mm long, ca. 1 mm in diameter; basal bract ca. 1 mm long, ca. 0.5 mm wide; upper bract ca.1 mm long, ca. 0.5 mm wide; sepals 3, valvate, free, ca. 1 mm long, 1-2 mm wide, triangular to ovate, apex acute, base truncate, densely pubescent outside, glabrous inside, margins flat; petals free, outer petals longer than inner, inner petals entirely covered in bud; outer petals 3, 2.6-4.3 mm long, 2.6-3.5 mm wide, ovate, apex acute, base truncate, yellow to cream, margins flat, densely pubescent outside, glabrous, pubescent towards margins inside; inner petals 3, valvate, ca. 3.5 mm long, ca. 2 mm wide, rhombic, apex acute, base truncate, yellow to cream, margins flat, pubescent towards base outside, pubescent inside; stamens 9, in 1 row, ca. 1 mm long, linear to oblong; connective truncate, glabrous; staminodes 6, alternating with the stamens, minute, glabrous; carpels free, 12 to 20, ovary ca. 1 mm long, stigma globose, glabrous. Monocarps stipitate, stipes ca. 2 mm long, ca. 2 mm in diameter; monocarps 2 to 8, 9-16 mm long, 5-6 mm in diameter, ellipsoid, apex apiculate, glabrous, verrucose, constricted around seeds when more than 1, color unknown; seeds 1 to 2 per monocarp, 7-9 mm long, 5-6 mm in diameter, ellipsoid; aril absent.

Distribution.

endemic to Cameroon, known from the Central and South regions.

Habitat.

In primary lowland rain forests and gallery forests, open rocky spot on sandy soil. Altitude 50-500 m a.s.l.

Local and common names known in Cameroon.

None recorded.

Preliminary IUCN conservation status.

Endangered (EN) ( Hoekstra et al. 2021).

Uses in Cameroon.

None reported.

Notes.

Monanthotaxis elegans is generally distinguished by its oblong-lanceolate leaves and extra-axillary or terminal glomerule-like inflorescences with yellow-brown pubescence.

The specimen Annet 348 [P01960095] has obovate instead of oblong-lanceolate leaves, but the inflorescence and flowers are typical for M. elegans .

Specimens examined.

Central Region: Riverine forest bank Nyong river near the new bridge ca 65 km SSW of Eseka, 3.46°N, 10.5°E, 16 June 1964, de Wilde W.J.J.O 2709 (B,BR,K,MO,P,WAG,YA); Natchigal ca 20 km N of Obala, 4.35°N, 11.63°E, 01 July 1964, de Wilde W.J.J.O 2787 (B,BR,K,MO,P,WAG,YA). South Region : Bipinde, 3.26°N, 10.20°E, 20 June 1918, Annet E. 348 (BR,K,P); Campo Ma'an National Park 11 km on trail from Ebinanemeyong village on road 7 km from Nyabessan to Campo town, 2.48°N, 10.33°E, 13 February 2015, Couvreur T.L.P. 704 (WAG,YA); Bipindi, 3.08°N, 10.41°E, 1897, Zenker G.A. 132 (L); Bipindi, 3.08°N, 10.41°E, 1897, Zenker G.A. 1321 (E,M,P); Lokoundjé, 3.08°N, 10.41°E, 01 January 1913, Zenker G.A. 199 (U,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1904, Zenker G.A. 2693 (E,L,M,P,WAG); Bipindi, 3.08°N, 10.41°E, 01 January 1911, Zenker G.A. 4000 (E,L,M,P); Bipindi, 3.08°N, 10.41°E, 01 January 1912, Zenker G.A. 4477 (E,L,M); Bipindi, 3.05°N, 10.25°E, Zenker G.A. s.n. (P) .

Figures

Map 7. A Monanthotaxis diclina B Monanthotaxis dielsiana C Monanthotaxis elegans D Monanthotaxis enghiana E Monanthotaxis ferruginea F Monanthotaxis filamentosa G Monanthotaxis foliosa H Monanthotaxis glaucifolia I Monanthotaxis gracilis. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 49. Monanthotaxis cauliflora A habit B base of leaf blade, upper side C base of leaf blade, lower side. Monanthotaxis congoensis D leaf, lower side E base of leaf blade, upper side F base of leaf blade, lower side. Monanthotaxis elegans G leaves, upper side H base of leaf blade, upper side, not subcordate base I base of leaf blade, lower side A-C Couvreur 676, Campo, Cameroon D-F Couvreur 626, Ebo, Cameroon G-I Couvreur 704, Campo, Cameroon. Photos Thomas L. P. Couvreur.