Monanthotaxis capea (E.G.Camus & A.Camus) 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 : 138-139

12. Monanthotaxis capea (E.G.Camus & A.Camus) Verdc. — Fig. 6b–h ; Map 9

Monanthotaxis capea (E.G.Camus &A.Camus) Verdc.(1971b) 21. — Popowia capea E.G.Camus & A. Camus (1913) 5. — Enneastemon capeus (E.G. Camus & A.Camus) Ghesq. (1939) 141. — Lectotype (designated here): G.­L. Angoulvant s.n. (lecto P (P00362786); isolecto BM001125039, E00624344, K000041008, P00362784, P00362785), Ivory Coast, de l’est du pays d’Attié, 1910.

Enneastemon seretii (De Wild.) Robyns & Ghesq.var. tisserantii Le Thomas (1963) 292,syn.nov. — Enneastemon schweinfurthii (Engl.& Diels) Robyns & Ghesq. var. tisserantii (Le Thomas) Le Thomas (1969) 254. — Monanthotaxis schweinfurthii (Engl. & Diels) Verdc. var. tisserantii (Le Thomas) Verdc.(1971b) 21. — Type: C. Tisserant (Équipe) 1710 (holo P01982418), Central African Republic, Lobaye, Boukoko, 10 Apr. 1950.

Shrub or liana, several meters long; young branches densely covered with ascending to erect, reddish brown hairs 0.2– 0.3 mm long, becoming glabrous; old branches dark brown to grey-brown. Leaves: petiole 4.5–8 mm long, 1.4–2.6 mm diam, slightly grooved, indument as on branches; lamina oblong-elliptic, obovate to oblanceolate, (7.4–)11.7–19.7 by 3.4–7.7 cm, 1.7–3.1 times longer than wide, subcoriaceous, not punctate, medium green above, glaucous below, above sparsely covered with appressed, whitish hairs 0.3–0.5 mm long, soon becoming glabrous, primary vein more densely covered with erect, reddish brown, below sparsely covered with appressed, yellow-brown 0.1–0.2 mm long hairs, primary vein more densely covered with ascending hairs 0.2–0.3 mm long, base cuneate to rounded, with thickened black margins or thick, globose, black glands, apex acute to acuminate, acumen to 15 mm long, secondary veins 7–12 per side, slightly curving upwards, tertiary venation percurrent, hardly visible above. Inflorescences axillary, composed of solitary flowers to 4-flowered fascicle-like rhipidia; sympodial rachis absent or as a cushion up to 1 mm long, densely covered with reddish brown hairs; pedicels 6–9 mm long, 0.3–0.7 mm diam, fruiting pedicels 11–16 mm long, 1.1–1.9 mm diam, densely covered with ascending to erect, reddish brown hairs; lower bracts absent; upper bract in the lower half of the pedicel, broadly ovate or represented by a tuft of hairs, c. 0.6 by 0.7–0.8 mm, indument as on pedicel; flower buds globose. Flowers bisexual; sepals connate at the base to almost entirely fused, depressed ovate, c. 0.7 by 1.2 mm, apex obtuse, densely covered with hairs, persistent in fruit; receptacle 1.5–2 mm diam, flat; petals colour in vivo unknown, 6, in two whorls, base of inner petals visible in bud, outer petals ovate, 3.5–5 by 2–3.8 mm, outside and upper half of the inside densely covered with appressed to ascending, yellowish brown hairs, inner petals rhombic to slightly obovate, 2.5–3.5 by 1.5–2.4 mm, outside and apical part of the inside densely covered with yellowish brown hairs; stamens (8 or) 9 (or 10), in one whorl, free, clavate, 1.4–1.5 mm long, filaments 0.8–0.9 mm long, thecae extrorse, connective truncate, slightly prolonged inward and outward, glabrous, but hairy on the inside, staminodes absent; carpels 6–9, subcylindric, c. 1.8 by 0.5 mm, densely hairy, ovules 4–6, lateral, stigma elongate, 0.2–0.6 mm long, glabrous. Monocarps 1–6, colour in vivo unknown, moniliform with each part narrowly ellipsoid to elipsoid, 20–79 by 8–10 mm, strongly tuberculate-rugulose, densely covered with ascending, white to brown hairs, apex apiculate, apiculum 2–4 mm long, stipes 3–6 mm long. Seeds 1–6, ellipsoid, c. 12 by 7–8 mm, ochre-brown, apex rounded, raphe visible.

Distribution — Ivory Coast, Cameroon, Gabon, Central African Republic, Democratic Republic of the Congo.

Habitat & Ecology — In gallery forests, swamp forests, evergreen forest and old secondary forest. Altitude: 350– 530 m. Flowering: April to August, November; fruiting: May, July to November.

Vernacular name — Central African Republic: Nolo tsanga (Lissongo name) (R. Sillans s.n.).

Preliminary IUCN conservation status — Vulnerable ( VU): B2 ab(iii). EOO: 1 004 525 km 2, AOO: 56 km 2. This species has a wide distribution range, however, it has only been collected a few times recently and occurs in 9 localities of which only one is in a nature reserve. For these reasons the category ‘vulnerable’ is assigned to this species. There is, however, quite some variation in morphological characters within Central Africa, especially the 2 specimens from central Cameroon are different. Therefore, each population separately has a much higher extinction risk and requires protection .

Notes — 1. Monanthotaxis capea is the only species of Monanthotaxis with strongly tuberculate-rugulose monocarps. Flowering material is difficult to distinguish from other species of the M. schweinfurthii complex ( Fig. 1 , clade B). It can be distinguished by the combination of ascending to erect reddish brown 0.2–0.3 mm long hairs on the young branches, the cuneate to rounded leaf bases and 4–6 ovules per carpel. There is quite some variation in the vegetative characters over the distribution. The specimens from Ivory Coast have more oblong-elliptic leaves, while in Central Africa the specimens have more obovate leaves and these were previously assigned to M. schweinfurthii var. tisserantii . However, no other distinguishable characters have been found between those populations and no different base-pairs were found in the few DNA-markers that could be sequenced for a specimen from Ivory Coast compared to one from Gabon ( Fig. 1 , clade B), therefore these names are here synonymised.

2. Two specimens from the Adamawa region in central Cameroon ( R. G. Letouzey 7570 and 8738) have narrowly obovate leaves and smaller monocarps than specimens from other regions, more material, especially flowering, is needed to verify if this should be a different taxon .

3. Some flowering specimens from the Central African Republic are hardly distinguishable from M. seretii , because fruits are lacking and more material especially from the north of the Democratic Republic of the Congo and the Republic of the Congo is needed to assess the exact status of M. capea and M. seretii .

Figures

Map 9 Distribution of Monanthotaxis capea (E.G.Camus & A.Camus) Verdc. (■) and M. cauliflora Chipp (●, O means uncertain dets).

Fig. 6 a. Monanthotaxis seretii (De Wild.) P.H.Hoekstra. Fruiting branch. — b–h. Monanthotaxis capea (E.G.Camus & A.Camus) Verdc. b. Flower bud, seen from above; c. flower bud, side view; d. stamen, outer, inner and side view; e. carpel; f. fruiting branch; g. fruiting branch; h. seed. — i. Monanthotaxis biglandulosa (Boutique) P.H.Hoekstra. Fruiting branch. — j–m. Monanthotaxis foliosa (Engl. & Diels) Verdc. j. Flowering branch; k. flower bud, seen from above; l. stamen,outer and side view; m.carpel (a: J.L.P. Louis 11405; b–h: Hallé 3561; i: Bamps 600; j–m: Le Testu 2108). — Modified from Le Thomas (1969) plate 44.

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.