Monanthotaxis vogelii (Hook.f.) 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 : 208

75. Monanthotaxis vogelii (Hook.f.) Verdc. — Fig. 5x ; Map 46

Monanthotaxis vogelii (Hook.f.) Verdc. (1971b) 23. — Uvaria vogelii Hook.f. in Hook. (1848) 767. — Clathrospermum vogelii (Hook.f.) Benth. in Benth. & Hook.f.(1862) 29. — Popowia vogelii (Hook.f.) Baill.(1868) 324. — Type: E. de Vogel 203 (holo consisting of 2 sheets: K000198915, K000198916), Nigeria, Quorra, opposite Stirling, Sept. 1841.

Monanthotaxis angustifolia (Exell) Verdc.(1971b) 21,syn.nov.— Enneastemon angustifolius Exell (1937) 163. — Type: P.W. Richards 3469 (holo consisting of 3 sheets: BM000547356 , BM001125040 , BM001125041 ; iso MO-1889425), Nigeria, Ogun State, Ijebu, Shasha Forest reserve , 17 May 1935.

Popowia dalzielii Hutch. in Hutch. & Dalziel (1927a) 55. — Lectotype (designated here): J.M. Dalziel 712 (lecto consisting of 2 sheets: K000198917 , K000913659 ; isolecto BM001125037 , MO 2 sheets, P00362644 , P00362645 ), Nigeria, Benue State, north Nigeria, Abinsi , 13 Sept. 1972.

Shrub, scandent shrub or liana, to 3 m long; young branches sparsely covered with appressed, reddish brown hairs 0.1– 0.2 mm long, becoming glabrous; old branches blackish brown to dark brown. Leaves: petiole 2–5 mm long, 1.1–1.5 mm diam, slightly grooved to terete, indument as on branches; lamina narrowly obovate, 9.7–17.5 by 2.5–5.6 cm, 2.4–4.1 times longer than wide, chartaceous, not punctate, dark green above, greyish green below, above glabrous, but primary vein sparsely covered with appressed, whitish hairs 0.1–0.2 mm long, below sparsely covered with appressed, yellowish hairs 0.1–0.2 mm long, base cuneate to rounded, with slightly thickened black margin, apex acute to acuminate, acumen to 15 mm long, secondary veins 7–12 per side, forming an acute angle with primary vein, straight, but curving halfway, tertiary venation percurrent, not visible above and slightly visible below. Inflorescences axillary, composed of solitary flowers or 2- or 3- (or 4-)flowered fascicle-like rhipidia; sympodial rachis 0.5–1.5 mm long, densely covered with appressed, yellow-brown hairs 0.1–0.2 mm long; pedicels 6–14 mm long, 0.4–0.5 mm diam, fruiting pedicels 0.7–1 mm diam, sparsely covered with appressed, yellowish hairs 0.1–0.2 mm long; lower bract ovate, 1–1.5 by c. 1 mm, indument as on rachis; upper bract absent or sometimes present near the base of the pedicel, lanceolate, c. 2 by 0.7 mm, densely covered with appressed, yellowish hairs; flower buds ovoid. Flowers bisexual; sepals connate at the base, depressed ovate to shallowly triangular, 0.5–0.7 by 1.3–1.5 mm, apex acute to rounded, sparsely covered with appressed hairs, persistent in fruit; receptacle c. 2 mm diam, flat; petals colour in vivo unknown, 6, in two whorls, base of inner petals visible in bud, pinkish yellow, outer petals broadly ovate to ovate-elliptic, 2.4–3.3 by 2–2.1 mm, outside sparsely covered with yellow hairs, inside glabrous except for some very short hairs near the apex, inner petals elliptic, 2–2.7 by c. 1.3 mm, base and centre outside sparsely covered with yellow hairs, inside glabrous except for a few hairs at the apex; stamens 8 or 9, in one whorl, free, linear-oblong, 0.7–0.8 mm long, filaments c. 0.3 mm long, thecae extrorse to latrorse, connective truncate, slightly prolonged inward and outward, not hiding the thecae, glabrous, staminodes 6, alternating with the stamens, but not in front of the inner petals, c. 0.3 mm long, glabrous; carpels 8–12, narrowly ellipsoid, 0.9–1.3 by 0.2–0.3 mm, densely hairy, ovule 1, basal, stigma elongate, c. 0.4 mm long, glabrous or covered with few papillae. Monocarps 2–9, red, narrowly ellipsoid, 11–15 by 4.5–5.5 mm, slightly verrucose, densely covered with appressed, yellow-brown, very short hairs, apex apiculate, apiculum to 0.3 mm long, stipes 2–4 mm long. Seed 1, ellipsoid, c. 10.3 by 4–4.7 mm, ochre-brown, apex rounded, raphe visible.

Distribution — Ivory Coast, Ghana, Benin, Nigeria, Cameroon.

Habitat & Ecology — In gallery forest, swamp forest, savannah open woodland and open high forest; growing in cracks of schist rocks, on rocky islands, on loamy soil and on black clay. Flowering: March, April, June, July, September; fruiting: April, June, September, November, December.

Vernacular name — Ghana: Jmada Adanine (F.R. Irvine 2887).

Preliminary IUCN conservation status — Least concern (LC). EOO: 386 040 km 2, AOO: 84 km 2. This species has a wide distribution and occurs in several reserves.

Notes — 1. Monanthotaxis vogelii can be recognised by the combination of narrowly obovate leaves, ovoid flower buds and flowers with 9 stamens and 6 staminodes. Furthermore, the inflorescences are often ramiflorous and each monocarp has 1 ellipsoid seed.

2. Monanthotaxis angustifolia is synonymised as it was only distinguished from M. vogelii by leaf shape, but the leaf shape is quite variable with intermediate forms present, although the narrowest obovate leaves occur in Cameroon and East Nigeria. However, no other distinguishing characters could be found and the DNA sequences are highly similar ( Fig. 1 , clade C).

Figures

Map 46 Distribution of Monanthotaxis velutina (Sprague & Hutch.) P.H. Hoekstra (●) and M. vogelii (Hook.f.) Verdc. (■).

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.

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.