Monanthotaxis montana (Engl. & Diels) P.H.Hoekstra

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 : 179-181

50. Monanthotaxis montana (Engl. & Diels) P.H.Hoekstra — Fig. 10h–o ; Plate 5c; Map 32

Monanthotaxis montana (Engl. & Diels) P.H.Hoekstra in Guo et al. (2017) 15. — Unona montana Engl. & Diels (1899) 296. — Oxymitra montana (Engl. & Diels) Sprague & Hutch. (1916) 155. — Richella montana (Engl.& Diels) R.E.Fr. (1959) 139. — Friesodielsia montana (Engl.& Diels) Steenis (1964) 360. — Type: G.A. Zenker & A. Staudt 431a (holo B100153061), Cameroon, Central Province, Yaúnde-station, 11 Jan. 1894.

Unona glauca Engl. & Diels (1899) 296, p.p. — Oxymitra soyauxii Sprague & Hutch. (1916) 155, non O. glauca Hook.f. & Thomson (1855: 146) . — Richella soyauxii (Sprague & Hutch.) R.E.Fr. (1959) 139, non R. glauca (Hook.f.& Thomson) R.E.Fr.(1959) 139. — Friesodielsia soyauxii (Sprague & Hutch.) Steenis (1964) 361, non F. glauca (Hook.f. & Thomson) Steenis (1964) 359. — Lectotype (designated by Guo et al. 2017): H. Soyaux 203 (lecto B100153059;isolecto K000198946), Gabon, Estuaire,Sibange farm, 6 Feb. 1881.

Oxymitra mortehanii De Wild.(1922) 472.— Type: M.G. Mortehan 512 (holo consisting of 3 sheets: BR000008800459 , BR000008800060 , BR000008800787 ), Democratic Republic of the Congo, Equateur, Dundusana, Sept. 1913.

Liana, to 7 m long, to 1 cm diam; young branches blackish brown, densely covered with appressed to ascending, reddish brown hairs 0.2–0.3 mm long,becoming glabrous;old branches blackish brown to dark grey. Leaves: petiole 2.5–6 mm long, 0.8– 1.5 mm diam, slightly grooved, indument as on branches; lamina elliptic to obovate or narrowly so, 5.5–20 by 2.8–6.7 cm, (1.3–)1.8–2.6(–3.3) times longer than wide, subcoriaceous, not punctate, glossy dark green above, drying dark grey, pale glaucous below, above glabrous, but primary vein densely covered with ascending, yellow hairs, becoming glabrous, below covered with appressed, yellow-brown hairs 0.2–0.4 mm long, more densely so on the primary vein, base subcordate, with thickened black margin, apex acute to acuminate, acumen to 15 mm long, secondary veins 7–13 per side, slightly curving, tertiary venation percurrent, not visible above. Inflorescences extra-axillary, composed of solitary flowers or sometimes to 4-flowered fascicle-like rhipidia; sympodial rachis 0.5–5 mm long, indument as on young branches; pedicels 13–33 mm long, 0.4–0.5 mm diam, fruiting pedicels 28–38 mm long, 0.4–0.9 mm diam, sparsely covered with ascending, reddish brown hairs c. 0.2 mm long; lower bract ovate, 1–1.1 by 0.4– 0.6 mm, densely covered with appressed, yellowish hairs; upper bract absent or very close to the base of the pedicel, ovate, 0.6–0.9 by 0.4–0.5 mm, densely covered with appressed, yellowish hairs; flower buds ovoid. Flowers bisexual; sepals free, ovate, 1.2–2 by 0.8–1.5 mm, reflexed at anthesis, apex acute, densely covered with hairs, not persistent in fruit; receptacle 1.7–2.7 mm diam, convex to torus-like, 1.1–1.3 mm high; petals yellow to green on the outside, purple-black on the inside, 6, in two whorls, reflexed at anthesis, outer petals ovate to spathulate, 6–15 by 5.4–6.7 mm, outside and the upper half of the inside sparsely covered with yellow hairs, inner petals cordate, 5.8–7.5 by 4.5–9 mm, glabrous; stamens 36–48, in three to five whorls, free, linear-oblong, 0.8–0.9 mm long, filaments c. 0.1 mm long, thecae extrorse, connective truncate, hiding thecae, glabrous, staminodes absent; carpels 11–14, narrowly ellipsoid, 1.1–1.9 by 0.5–0.6 mm, dense hairy, ovules 1–3, lateral, stigma globose, c. 0.2 mm diam, glabrous. Monocarps 4 –11, yellow with red stripes or dull red, moniliform, each part ellipsoid, 12–33 by 4–9 mm, slightly verrucose, densely covered with appressed hairs, becoming glabrous, apex rounded to apiculate, apiculum to 1.5 mm long, stipes 3–8 mm long. Seeds 1–3, ellipsoid, 10.5–12 by 5–6 mm, ochre-brown, apex rounded or flattened, raphe hardly visible.

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

Habitat & Ecology — In primary evergreen forest, secondary forest, swamp forest, gallery forest, terra firme forest and low spiny forest, on rocky soil and on river banks. Altitude: 5–1030 m. Flowering and fruiting all year round.

Vernacular names — Democratic Republic of the Congo: Biembré (M.G. Mortehan 512), Kitsaka tsamba (L. Pauwels 3490).

Preliminary IUCN conservation status — Least concern (LC). EOO: 2 218 732 km 2, AOO: 188 km 2. This species has a wide distribution from many locations.

Note — Monanthotaxis montana can be recognised by the combination of small, reflexed, ovate sepals, many stamens in multiple whorls, and a grey upper leaf side in sicco.

Figures

Map 32 Distribution of Monanthotaxis montana (Engl.& Diels) P.H.Hoekstra (●, O means uncertain dets).

Fig. 10 a–g. Monanthotaxis congoensis Baill. a. Flowering branch; b. petal inner and outside view; c. flower with three petals removed; d. stamen front view and seen from above; e. staminodes; f. carpel and longitudinal section of carpel; g. longitudinal section of seed. — h–o. Monanthotaxis montana (Engl. & Diels) P.H.Hoekstra. h. Flowering branch; i. outer petal; j. inner petal; k. flower with petals removed; l. stamen, front and side view; m. carpel and longitudinal section of carpel; n. fruiting branch; o. transverse section of seed (a–g: Thollon 813; h–m: Le Testu 4364; n–o: Tisserant 1362). — Modified from Le Thomas (1969) plates 42 and 45.