Monanthotaxis barteri (Baill.) Verdc.

Hoekstra, P. H., Wieringa, J. J., Maas, P. J. M. & Chatrou, L. W., 2021, Revision of the African species of Monanthotaxis (Annonaceae), Blumea 66 (2), pp. 107-221 : 128-129

5. Monanthotaxis barteri (Baill.) Verdc. — Fig. 5a–d ; Map 4

Monanthotaxis barteri (Baill.) Verdc. (1971b) 21. — Popowia barteri Baill. (1868) 324. — Enneastemon barteri (Baill.) Keay (1953) 72. — Type: C. Barter s.n. (holo P00362783; iso K000198913, K000198914), Sierra Leone, Western Area, Sugarloaf mountain, 8 May 1857.

Popowia heudelotii Baill. (1868) 321. — Clathrospermum heudelotii (Baill.) Scott Elliot (1894) 71. — Lectotype (designated here): J. Heudelot 878 (lecto P ( P00362765 ); iso P00362764 ), Guinea, Boké , Senegambia, Karkandy, 1837.

Popowia nigritana Baker f. (1913) 4. — Enneastemon nigritanus (Baker f.) Exell (1934) 281. — Type: P.A. Talbot 1550 (holo BM000547357 ; iso K000198912 ), Nigeria, Cross River State, Oban , 1912.

Shrub, scandent shrub or liana, to 12 m long; young branches densely covered with appressed, yellowish brown hairs 0.2– 0.3 mm long, becoming glabrous; old branches dark brown to blackish brown. Leaves: petiole 2.5–6 mm long, 0.6–1.3 mm diam, terete, indument as on branches; lamina oblong-elliptic, elliptic, obovate to oblanceolate, 4.8–12.1(–14.2) by 2.4–5.1 cm, 2–4.3 times longer than wide, subcoriaceous to chartaceous, not punctate, glossy above, glaucous below, above glabrous, but primary vein sparsely covered with appressed, white-yellow hairs 0.1–0.3 mm long, becoming glabrous, below sparsely covered with appressed, yellow hairs 0.1–0.3 mm long, base attenuate to cuneate, sometimes rounded, with thickened black margins, apex acute to acuminate, acumen to 10 mm long, secondary veins 6–10 per side, curving upwards, tertiary venation percurrent, not or hardly visible above. Inflorescences axillary, composed of solitary flowers to a 2- (or 3-) flowered fascicle-like rhipidia; sympodial rachis absent; pedicels (8–) 10–25 mm long, 0.2–0.4 mm diam, fruiting pedicels 17–32 mm long, 0.6–1.5 mm diam, densely covered with appressed, yellowish brown hairs; lower bracts absent; upper bract in the upper half of the pedicel, halfway or sometimes in lower half of pedicel, ovate to lanceolate, 0.9–1.3 by 0.4–0.7 mm, indument as on pedicel; flower buds globose. Flowers bisexual; sepals connate at the base, depressed ovate, 0.8–1.5 by 1.4–1.8 mm, apex obtuse to slightly acute, densely covered with appressed hairs, persistent in fruit; receptacle 1.5–1.8 mm diam, flat; petals colour in vivo unknown, 6, in two whorls, base of inner petals visible in bud, outer petals ovate, 3.2–3.6(–5) by 2.2–2.6(–3.4) mm, outside and apical part and margins of inside densely covered with appressed, yellow-brown hairs, inner petals elliptic to rhombic, 2.7–3.1(–4.5) by 1.5–2.3 mm, densely hairy outside and near the apex on the inside; stamens 9, in one whorl, free, clavate, 1.2–1.4 mm long, filaments 0.8–0.9 mm long, thecae extrorse, connective truncate, prolonged inward and slightly outward, glabrous, but hairy on the inside, staminodes absent; carpels 6, ellipsoid, c. 1.4 by 0.6 mm, densely hairy, ovules 4 (or 5), lateral, stigma elongate, c. 0.4 mm long, glabrous. Monocarps 1–6, colour unknown in vivo, moniliform with each part ellipsoid to narrowly ellipsoid, 13–55 by 7–8 mm, verrucose, densely covered with appressed, yellowish brown hairs, becoming glabrous, apiculate, apiculum 0.5–1.5 mm long, stipes 2–5 mm long. Seeds 1–5, ellipsoid, 11–19 by 6–7 mm, ochre-brown, apex rounded or slightly apiculate, raphe visible.

Distribution — Senegal, Guinea-Bissau, Guinea, Sierra Leone, Liberia, Ivory Coast, Ghana, Nigeria.

Habitat & Ecology — In primary rain forests, gallery forests, forest edges, swamp forests and wooded savannahs. Altitude: 0–1000 m. Flowering: March to August; fruiting: all year round.

Vernacular name — Guinea: Setinan Lanhtè (Balantè name) (CA Couch 478).

Preliminary IUCN conservation status — Least concern (LC). EOO: 1 017 067 km 2, AOO: 260 km 2. This species is known from many localities and nature reserves and therefore is currently not under threat of extinction.

Notes — 1. Monanthotaxis barteri is the only species of Monanthotaxis in West Africa that is densely covered with appressed yellow-brown hairs on the young branches and cuneate to attenuate leaf bases.

2. Some specimens of Monanthotaxis barteri can be similar to M. schweinfurthii from Central Africa, but differ by having the upper bract generally in the upper half of the pedicel, by having smaller leaves with more cuneate to even attenuate leaf base with only 6–10 secondary veins per side, while M. schweinfurthii has larger leaves with cuneate to rounded leaf base with 9–13 secondary veins per side and the upper bract generally in the lower half of the pedicel. Furthermore, the pericarp thickness is less than 1 mm in ripe fruits of M. barteri and more than 1 mm in ripe fruits of M. schweinfurthii .

3. The single specimen from Nigeria ( PA Talbot 1550), has longer leaves, shorter pedicels and larger flowers than specimens of M. barteri from West-Africa. Two specimens from an elevation of 2000 m in the Atewa Range ( DK Abbiw 275 and JM Lock GC43945 ) differ in having shorter leaves, shorter pedicels and a more reddish brown indument .

Figures

Map 4 Distribution of Monanthotaxis barteri (Baill.) Verdc. (●, O means uncertain dets or aberrant specimens).

Fig. 5 a–d. Monanthotaxis barteri (Baill.) Verdc. a. Flower; b. flower with petals removed; c. stamens; d. longitudinal section of flower. — e–i. Monanthotaxis buchananii (Engl.) Verdc. e. Flowering branch and fruiting inflorescence; f. flower; g. petal, inside view; h. stamens; i. carpel and longitudinal section of carpel. — j–p. Monanthotaxis elegans (Engl. & Diels) Verdc. j. Flowering branch; k. flower bud; l. stamens and carpels; m. stamens, front and side view; n. carpel; o. carpel longitudinal section; p. fruiting inflorescence. — q–v. Monanthotaxis fornicata (Baill.) Verdc. q. Flowering branch; r. outer petal, inside view; s. inner petal, inside view; t. stamens and carpels; u. stamens, front and side view; v. carpel. — w. Monanthotaxis trichocarpa (Engl. & Diels) Verdc. Fruiting branch. — x. Monanthotaxis vogelii (Hook.f.) Verdc. Stamen. — Modified from Engler & Diels (1901) table 18 and 19.