Monanthotaxis klainei (Engl.) 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 : 167

40. Monanthotaxis klainei (Engl.) Verdc. — Fig. 18a–i ; Map 26

Monanthotaxis klainei (Engl.) Verdc.(1971b) 30. — Popowia klainei Engl. in Engl. & Diels (1901) 52 (‘ klainii ’). — Atopostema klainei (Engl.) Boutique (1951b) 122 (‘ klainii ’). — Lectotype (designated by Le Thomas 1969:220): T.­J. Klaine 1539 (lecto P00362628;isolecto P00362629), Gabon, Estuaire, environs de Libreville, 25 Mar. 1899.

Liana to 7 m tall, 1–4 cm diam; young branches dark brown to blackish covered with reddish brown hairs 0.1 mm long, soon becoming glabrous; old branches dark brown to blackish. Leaves: petiole 3–7(–11) mm long, 0.9–2.9 mm diam, grooved, indument as on branches; lamina obovate, 9.8–26.8 by 4.6– 10.8 cm, 1.6–2.7 times longer than wide, chartaceous to subcoriaceous, not punctate, glaucous below, primary vein red-brown in sicco, only slightly contrasting with petiole, above glabrous, below sparsely covered with appressed, reddish brown hairs c. 0.1 mm long, base subcordate, glands hardly visible, apex acute to shortly acuminate, acumen to 15 mm long, secondary veins 7–12 per side, straight to curving upwards, tertiary venation percurrent. Inflorescences cauliflorous, composed of solitary flowers or many-flowered fascicles; sympodial rachis 0–4 mm long; pedicels 0–20 mm long, 0.5–0.6 mm diam, fruiting pedicels 1–24 mm long, 0.8–1.9 mm diam, densely covered with appressed, very short hairs to glabrous; lower bracts absent or broadly triangular, c. 0.5 by 0.5 mm, indument as on pedicels; upper bract in the lower half of the pedicel or near the base, ovate to narrowly triangular, small, 0.5–1.4 by c. 0.5 mm, indument as on pedicels; flower buds ovoid. Flowers bisexual; sepals connate at the base, depressed ovate, 0.5–0.8 by 1–1.4 mm, sparsely covered with appressed, very short hairs, persistent in fruit; receptacle 1.5–2.2 mm diam, flat; petals creamy pink to red-pink, 6, in two whorls, base of inner petals visible in bud, outer petals ovate, 3.3–4.5 by 2.5–3.4 mm, outside covered with appressed, yellowish to reddish brown, very short hairs, inside glabrous except for a few hairs at the apex; inner petals elliptic, 3.2–3.7 by 1.2–2.1, outside covered with short hairs on the midline, inside glabrous; stamens 9, in one whorl, connate at the base, oblong to slightly ellipsoid, 0.8–1 mm long, filaments 0.2–0.3 mm long, thecae placed on top of each other at the lateral inside of the stamen, transversally dehiscent, connective truncate, glabrous, staminodes 9, in one whorl alternating with the stamens, 0.3–0.4 mm long, ellipsoid to spathulate, glabrous; carpels 16–26, subcylindric to narrowly ellipsoid, 1.1–1.5 by 0.3–0.5 mm, densely hairy, ovules 1 or 2, basal or lateral, stigma subsessile, square or globose, c. 0.2 mm diam, glabrous. Monocarps up to 10, yellow to red when ripe, ellipsoid to narrowly ellipsoid, 14 –27 by 7–10 mm, slightly verrucose, sparsely covered with appressed, yellowish, short hairs, becoming glabrous but longer persistent at stipe and top, apex rounded to apiculate, apiculum to 1 mm long, stipes 1–4 mm long, grooved to round. Seeds 1 or 2, globose to ellipsoid, 8–12 by 6–9 mm, ochre-brown to reddish brown, both ends rounded, raphe visible as a longitudinal furrow from base to apex.

Notes — 1. Monanthotaxis klainei can be distinguished from other species of Monanthotaxis by having 9 stamens, with transversally dehiscent thecae. It has more carpels (16–26) than closely related species, such as M. vogelii (8–12) and M. aquila (12–13) and it has more staminodes (9 vs 6).

2. Monanthotaxis klainei was named after T.-J. Klaine, therefore, the epithet klainii has been corrected to klainei according to ICBN article 60.7 ( Turland et al. 2018).

Figures

Map 26 Distribution of Monanthotaxis klainei (Engl.) Verdc. var. klainei (●, O means uncertain dets), M. klainei (Engl.) Verdc. var. lastoursvillensis (Pellegr.) Verdc. (■).

Fig. 18 a–i. Monanthotaxis klainei (Engl.) Verdc. a. Leaves; b. flower bud seen from above; c. outer petal, inside view; d. inner petal, inside view; e. flower with petals removed; f. stamen, inside view and outside view; g. staminode; h. carpel and longitudinal section of carpel; i. fruits. — j–o. Monanthotaxis laurentii (De Wild.) Verdc. j. Flowering branch; k. outer petal, inside view; l. inner petal, inside view; m. flower with petals removed; n. stamen, outside and inside view; o. carpel and longitudinal section of carpel (a–h: Klaine 2662; i: Klaine 1539; j–o: Le Testu 4512). — Modified from Le Thomas (1969) plate 39.