Monanthotaxis mannii (Baill.) Verdc. — Plate, 1971

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 : 176

47. Monanthotaxis mannii (Baill.) Verdc. — Plate 4e–f; Map 31

Monanthotaxis mannii (Baill.) Verdc. (1971b) 21. — Popowia mannii Baill. (1868) 320. — Clathrospermum baillonii Scott Elliot (1894) 70,non C.mannii Oliv. — Popowia baillonii (Scott Elliot) Engl.& Diels (1901) 48,nom. superfl. — Lectotype (designated here): G.Mann 809 (lecto P (P00362639);isolecto GH, K000041018), Sierra Leone, Southern Province, Moyamba, Bagroo River, Apr. 1861.

Shrub or liana, to 3 m long; young branches densely covered with appressed, reddish brown hairs c. 0.1 mm long, becoming glabrous; old branches blackish brown to dark brown. Leaves: petiole 2–3.5 mm long, 0.6–1.1 mm diam, slightly grooved, indument as on branches; lamina oblong-elliptic to slightly obovate, 5.4–13 by 2–5 cm, 1.9–2.8 times longer than wide, chartaceous, not punctate, glaucous below, above glabrous, but primary vein glabrous or sparsely covered with white-yellow hairs 0.1–0.2 mm long, below sparsely covered with hardly visible appressed, white to yellow hairs 0.3–0.5 mm long, slightly more densely so on primary vein, becoming glabrous, base rounded to slightly cuneate, with slightly thickened black margin, apex acute to acuminate, acumen 5–10 mm long, secondary veins 5–9(–13) per side, curving, tertiary venation percurrent, not visible above and indistinct below. Inflorescences axillary, composed of solitary flowers or 2- or 3-flowered rhipidia; sympodial rachis 1.5–10(–13) mm long, densely covered with appressed to ascending, yellow hairs; pedicels 7–11 mm long, 0.2–0.3 mm diam, fruiting pedicels 5–15 mm long, 0.6–0.9 mm diam, indument as on rachis; lower bract ovate, 0.7–0.9 by 0.3–0.4 mm, indument as on rachis; upper bract in the lower half of the pedicel, ovate, c. 0.6 by 0.3–0.4 mm, indument as on rachis; flower buds globose or slightly ovoid. Flowers bisexual; sepals free, depressed ovate, 0.6–0.9 by 0.9–1.3 mm, apex acute, densely covered with appressed hairs, persistent in fruit or not; receptacle 1.2–1.8 mm diam, flat; petals yellow, 6, in two whorls, outer petals broadly ovate, 3.1–3.3 by 2.8–3.5 mm, outside densely covered with yellow, short hairs, base of the inside glabrous, inner petals broadly ovate to rhombic, 2.1–3.1 by 2–2.3 mm, indument as on outer petals; stamens 9 or 10, in one whorl, free, linear-oblong, 0.5–0.9 mm long, filaments 0.1–0.3 mm long, thecae introrse to latrorse, connective truncate, prolonged inward and outward, not hiding thecae, glabrous, staminodes 9–15, in one or two whorls, inner whorl alternating with the stamens, c. 0.5 mm long, outer whorl if present c. 0.2 mm long, glabrous; carpels 12–14(–18), ellipsoid, 0.8–1 by c. 0.4 mm, densely hairy, ovules 1 (or 2), basal, stigma subsessile, globose, 0.1–0.2 mm diam, glabrous. Monocarps 1–10, orange, ellipsoid, 8–12 by 5–7 mm, slightly verrucose, densely covered with appressed, yellow hairs, becoming glabrous, apex rounded, stipes 1–2.5 mm long. Seeds 1 (or 2), ellipsoid to subglobose, 5.5–9 by 4.7–5.5 mm, ochre-brown, apex rounded, raphe visible.

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

Habitat & Ecology — In gallery forest, primary forest and secondary forest on sandy clay and brown clay. Altitude: 30–957 m. Flowering: March to July; fruiting: April, June, July, September to December.

Vernacular names — Sierra Leone: Kongan (N.W. Thomas 2993), T’Cobwe (N.W. Thomas 6182), Egbor (Temne name) (N.W. Thomas 2136), Bowonkingime (Susu name) (N.W. Thomas 2136), Nomai (Limba name) (N.W. Thomas 2136).

Preliminary IUCN conservation status — Least concern (LC). EOO: 161 503 km 2, AOO: 168 km 2. There are many recent collections from different localities.

Notes — 1. Monanthotaxis mannii is together with M. nimbana the only species with oblong-elliptic leaves and rounded leaf base in Upper Guinea. Sterile and fruiting specimens can look very similar to M. nimbana , but the majority of the fruits generally have more than 3 monocarps. The flowers of M. mannii , however, are very different from M. nimbana , and the phylogeny reconstruction shows that they are not related ( Fig. 1 , clade C and F). The flowers of M. mannii consist of one whorl of stamens and one or two whorls of staminodes, while M. nimbana has two whorls of stamens. Also M. mannii has more carpels than M. nimbana (12–14 vs 2–5).

2. Most specimens of M. mannii have one whorl of staminodes and a few specimens have an additional whorl of 6 staminodes. There is one specimen from Guinea that has 15 staminodes in one whorl .

Figures

Plate 4 a–c. Monanthotaxis latistamina P.H.Hoekstra.a.Leaves;b. inflorescence;c.flowers. — d.Monanthotaxis letouzeyi (Le Thomas) Verdc.Leaves. — e–f. Monanthotaxis mannii (Baill.) Verdc. e. Leaves; f. leaves and flower (a–c: Couvreur 565; d: Couvreur 752; e–f: Jongkind 11848). — Photos: a–d: T.L.P. Couvreur; e–f: C.C.H. Jongkind.

Map 31 Distribution of Monanthotaxis mannii (Baill.) Verdc.(■) and M. nimbana (Schnell) Verdc. (●).

Fig. 1 Bayesian 50 % majority rule consensus tree of the genus Monanthotaxis. Asterisks at nodes indicate node support, i.e., *** Strong node support, ** moderate node support, * weak node support, see Hoekstra et al. (2018). The letters A to K with adjacent black bars indicate the clades. The triangles, circles and squares represent morphological characters of the species which are of some use to distinguis the clades. Green triangles = staminodes absent, red triangles = staminodes present. Green circles = petals in one whorl, red circles = petals in two whorls, yellow circles = petals in bud basally in one whorl, at the top outer petals overlapping the inner ones. Green squares = inflorescences extra-axillary or if cauliflorous also extra-axillary inflorescences present, red squares = inflorescences axillary, supra-axillary or cauliflorous, red and green squares = both extra-axillary and axillary inflorescences present.