Monanthotaxis pynaertii (De Wild.) P.H.Hoekstra, 2021

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 : 191-193

61. Monanthotaxis pynaertii (De Wild.) P.H.Hoekstra , comb. nov. — Fig. 25 ; Map 38

Popowia pynaertii De Wild.,Bull.Jard.Bot.État Bruxelles 4(1914) 382. — Lectotype (designated here): L.A. Pynaert 852 (lecto consisting of 2 sheets: BR0000008805348 , BR0000008805355 ), Democratic Republic of the Congo, Equateur, Mbandaka, Eala, 20 Dec. 1908.

Liana, to 20 m long, 2 cm diam; young branches covered with erect, reddish brown hairs 0.6–1.2 mm long, becoming glabrous; old branches dark brown. Leaves: petiole 5–7 mm long, 1.1–1.5 mm diam, grooved, indument as on branches; lamina oblong-elliptic to obovate, mostly narrowly so, 9.5–23.2 by 2.9– 7 cm, 2.4–4.1 times longer than wide, chartaceous to subcoriaceous, not punctate, glaucous below, above sparsely covered with erect, yellow hairs 0.4–1 mm long, becoming glabrous, primary vein densely covered with erect and long-persisting yellow hairs, below covered with erect, yellow hairs 0.5–1 mm long, base rounded to subcordate, with thickened black margin, apex acute to acuminate, acumen to 15 mm long, secondary veins 11–17 per side, straight to curving upwards, tertiary venation percurrent. Flowers unisexual. ♂ Inflorescences axillary, flowers solitary or in up to 10-flowered fascicles; sympodial rachis 4–8 mm long, covered with erect hairs 0.3–0.6 mm long; flowering pedicels 2.5–3.5 by c. 0.3 mm, indument as on rachis; bracts ovate, 0.6–0.7 by c. 0.3 mm, indument as on pedicels; flower buds depressed globose; sepals broadly triangular to ovate, 0.7–1 by 0.6–0.7 mm, covered with appressed, short hairs; receptacle 1.1–1.3 mm diam, flat; petals colour in vivo unknown, 6, in two whorls, outer petals broadly ovate, c. 2.7 by 3 mm, outside covered with appressed, yellowish, short hairs, inside densely covered with yellowish, very short hairs, inner petals elliptic, c. 0.8 by 0.4 mm, outside and inside densely covered with yellowish, very short hairs; stamens 6(–9), in one whorl, in pairs, oblong, free, c. 1 mm long, filaments c. 0.2 mm long, thecae latrorse, connective truncate, glabrous, staminodes 12–16, in one whorl, 0.2–0.5 mm long, sparsely hairy or glabrous. ♀ Inflorescences cauliflorous, condensed many-flowered panicles; sympodial rachis 3.5–5 cm long, densely covered with erect hairs 0.5–1 mm long; pedicels 20–33 mm long, 0.6–0.8 mm diam, fruiting pedicels to 2 mm diam, covered with erect, yellowish brown hairs; bracts lanceolate to ovate, 2.3–2.4 by c. 0.7 mm, indument as on rachis; flower buds ovoid; sepals depressed ovate to broadly ovate, 1–2 by 1.5–2 mm, densely covered with appressed hairs, persistent in fruit; receptacle 1.8–1.9 mm diam, convex; petals colour in vivo unknown 6, in two whorls, outer petals broadly ovate, 5–6.3 by 5–6.5 mm, outside densely covered with appressed, reddish brown hairs, inside covered with yellowish, very short hairs, inner petals ovate, 1.7–1.8 by 0.7–0.8, outside and inside covered with yellowish, very short hairs; carpels 95–150, subcylindric to ellipsoid, 1.5–1.7 by 0.4–0.5 mm, densely hairy, ovules 4–6, lateral, stigma globose to ellipsoid, 0.3–0.4 mm long, grooved, glabrous. Monocarps up to 20, colour in vivo unknown, ellipsoid to subcylindric, 20–60 by 7–8 mm, constricted between the seeds, slightly verrucose, rather densely covered with erect hairs 0.2–0.4 mm long, apex apiculate, apiculum 1–2 mm long, stipes 9–12 mm long, slightly grooved. Seeds 1– 6, ellipsoid, 11–13 by 6.5–7.5 mm, reddish brown, ends slightly apiculate, raphe not visible.

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

Habitat & Ecology — In swamp forest and gallery forest. Altitude: c. 362 m. Flowering: October to February; fruiting: March, June.

Vernacular names — Central African Republic: Mindowali (Sango name) (C. Tisserant Équipe 2035). Democratic Republic of the Congo: Babua (Embai name) (P. Gérard 5534), Pome (M.G. Mortehan 617), Bodzingo kodzi (Nkundo name) (B.I. Fruth 332).

Preliminary IUCN conservation status — Vulnerable (VU): B2ab(iii). EOO: 518 446 km 2, AOO: 60 km 2. This species is only known from 9 locations and has only been collected twice in recent years.

Note — Monanthotaxis pynaertii is quite easily distinguished from other caulescent species by the 0.6–1.2 mm long, erect hairs on the young branches and leaves. Monanthotaxis pynaertii was previously placed in the synonymy of M. diclina , but it differs besides the erect indument in having larger flowers, and more carpels in the pistillate flowers.

Figures

Map 38 Distribution of Monanthotaxis pynaertii (De Wild.) P.H.Hoekstra (■) and M. scamnopetala (Exell) P.H.Hoekstra (●, O means uncertain det).

Fig. 25 Monanthotaxis pynaertii (De Wild.) P.H.Hoekstra. a. Branch with staminate inflorescences;b. pistillate inflorescence;c. pistillate flower bud; d. pistillate flower with two outer petals removed; e. outer petal of pistillate flower, inside view; f. inner petal of pistillate flower, inside view; g. carpel; h. staminate flower bud; i. staminate flower with two outer petals removed; j. outer petal of staminate flower, inside view; k. inner petal of staminate flower, inside view; l. stamen, front and side view; m–n. staminodes; o. fruit (a, h–n: Evrard 5198; b–g: Pynaert 852, BR; o: Tisserant 2035). — Drawing by E. Winkel.