Monanthotaxis filamentosa (Diels) Verdc. — Plate, 1971

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 : 155

28. Monanthotaxis filamentosa (Diels) Verdc. — Plate 3c; Map 19

Monanthotaxis filamentosa (Diels) Verdc. (1971b) 31. — Popowia filamentosa Diels (1907) 478. — Type: G.A. Zenker 2985 (holo B not seen; iso BR0000008804297 , E00624352 , GOET005686 ,HBG-502505, K000198988 , L 0038042 , M0107931 , P00362600 ,S, WAG0071434 , WU0025872 ), Cameroon, South Region, Bipinde, Apr. 1904.

Popowia malchairii De Wild. (1911) 309. — Type: L. Malchair 295 (holo divided over 2 sheets: BR0000008804624 , BR0000008804952 ), Democratic Republic of the Congo, Equateur, Budjala,environs a Likimi, 25 Apr. 1910.

Popowia setosa Diels (1915) 442,syn. nov. — Lectotype (designated here): G.W.J. Mildbraed 5989 (lectotype B ( B100154095 ); iso HBG502503 ), Cameroon, South Region , 58 km E of Kribi, Fenda, 1911.

Liana, to 10 m long; young branches densely covered with erect, reddish brown hairs 0.7–1.4 mm long, becoming glabrous; old branches black to blackish brown. Leaves: petiole 2.5– 6 mm long, 1–2.5 mm diam, slightly grooved, indument as on branches; lamina oblong-elliptic, obovate or oblanceolate, 12.5–28.6 by 4.1–12.5 cm, 1.8–3.1 times longer than wide, subcoriaceous, not punctate, dark green above, glaucous below, above sparsely covered with ascending to erect, whitish hairs 0.5–1 mm long, on primary vein indument more dense and composed of yellow hairs, below sparsely covered with erect, yellowish hairs 0.5–1.4 mm long, more densely so on primary vein, base rounded to subcordate, with slightly thickened black margin, apex acute to acuminate, acumen 5–10 mm long, secondary veins 12–19 per side, curving or straight and halfway curving upwards, tertiary venation percurrent. Inflorescences axillary or terminal, composed of solitary flowers or 2–10-flowered, raceme-like rhipidia; sympodial rachis absent or to 10 cm long, densely covered with erect, reddish brown hairs; pedicels 1–18 mm long, 0.6–1 mm diam, fruiting pedicels 9–31 mm long, 0.6–2.1 mm diam, covered with erect, reddish brown hairs 0.5–1 mm long; lower bract absent or narrowly ovate, c. 2.1 by 0.5 mm, indument as on pedicel; upper bract absent or very large, sepal-like, just below the flower, ovate, 1.1–8 by 0.5–4.1 mm, indument as on pedicel; flower buds ovoid. Flowers bisexual; sepals free, covering flower in bud, ovate, 4.5–10 by 3.2–5.5 mm, apex acute, densely covered with appressed to ascending hairs, not persistent in fruit; receptacle c. 2 mm diam, flat; petals colour in vivo unknown, 6, in two whorls, outer petals ovate to narrowly ovate, 8–22 by 4.7–8.5 mm, outside and inside (except for the glabrous base) densely covered with appressed, yellow hairs, inner petals ovate to elliptic, 6.5–14 by 3–5 mm, indument as on outer petals; stamens 17–46, in two to four whorls, free or connate at the base, linear, 1.8–2.3 mm long, filaments 1.3–1.9 mm long, thecae introrse, convergent apically, hiding connective, glabrous, staminodes absent; carpels 8–14, subcylindric, 2.3– 2.5 by 0.5–0.6 mm, dense hairy, ovules 7–9, lateral, stigma elongate, c. 0.7 mm long, glabrous. Monocarps 1–7, yellow to red, subcylindric, 110–175 by 6.5–8 mm, slightly verrucose, densely to sparsely covered with erect, reddish brown hairs, apex apiculate, apiculum 1–3 mm long, stipes 8–15 mm long. Seeds 1–7, subcylindric, 17–25 by 4–5 mm, ochre-brown.

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

Habitat & Ecology — In primary forest, secondary forest, submontane forest and gallery forest, on rocky soil. Altitude: 120–1700 m. Flowering: October to July; fruiting: February, March, June, September, November.

Vernacular names — Democratic Republic of the Congo: Lisis (Kibila name) (Nasanga 45), Amapapasia (Bila name) (F. Amsini 283), Nginko e Likebe e Tokembe (L. Toussaint 858).

Preliminary IUCN conservation status — Least concern (LC). EOO: 2 090 176 km 2, AOO: 108 km 2. This species has a large extent of occupancy and occurs in quite some locations and protected areas. Furthermore, it has in recent years been collected relatively often, including in several new locations.

Note — Monanthotaxis filamentosa is easily recognizable by the dense indument of erect, reddish brown hairs on the young branches and the leaves, and by the large, ovoid flower buds. Specimens from the western part of the distribution area generally have oblong-elliptic or sometimes obovate leaves, while some specimens from the eastern part of the distribution area have more obovate to oblanceolate leaves. The monocarps appeared more densely hairy in the eastern part of the distribution. More flowering and fruiting material, especially from the Democratic Republic of the Congo, is needed to verify if those populations belong to the same species.

Figures

Plate 3 a. Monanthotaxis discrepantinervia Verdc. Flowering branch. — b. Monanthotaxis enghiana (Diels) P.H.Hoekstra. Leaves. — c. Monanthotaxis filamentosa (Diels) Verdc. Flower. — d. Monanthotaxis foliosa (Engl. & Diels) Verdc. Flowering branch. — e. Monanthotaxis glabra P.H.Hoekstra.Leaves and fruit. — f. Monanthotaxis hirsuta (Benth.) P.H.Hoekstra. Flowers (a: Couvreur 94; b: not collected; c: Letouzey 14591; d: Couvreur 601; e: Jongkind 7965; f: Jongkind 8836). — Photos: a, d: T.L.P. Couvreur; b, e–f: C.C.H. Jongkind; c: P.H. Hoekstra.

Map 19 Distribution of Monanthotaxis filamentosa (Diels) Verdc.(●, Omeans uncertain dets).