Monanthotaxis glomerulata (Le Thomas) 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 : 161-162

35. Monanthotaxis glomerulata (Le Thomas) Verdc. — Fig. 9o–s ; Map 23

Monanthotaxis glomerulata (Le Thomas) Verdc.(1971b) 31. — Popowia glomerulata Le Thomas (1963) 288. — Type: G.M.P.C. Le Testu 8700 (holo consisting of 2 sheets: P00362634 , P00362635 ; iso BM000553849 , BR0000008823755 , BR0000008823762 , BR0000008823854 ), Gabon, Ogooué-Lolo, region de Lastoursville, Lastoursville , 13 Mar. 1931.

Liana; young branches blackish brown, densely covered with appressed, reddish brown hairs 0.1–0.2 mm long, becoming glabrous; old branches blackish brown. Leaves: petiole 5 – 6.5 mm long, 1.1–1.9 mm diam, terete, indument as on branches; lamina obovate to oblanceolate, 9.6–24.1 by 4.3–8.1 cm, 2.2–3 times longer than wide, chartaceous, not punctate, glabrous above, primary vein sparsely covered with ascending yellow-brown hairs 0.2–0.3 mm long, below sparsely covered with appressed, yellowish hairs 0.1–0.2 mm long, base cuneate to rounded, with thickened black margin, apex acute to slightly acuminate, acumen to 5 mm long, secondary veins 12–17 per side, slightly curving, tertiary venation percurrent. ♂ Inflorescences unknown. ♀ Inflorescences cauliflorous, consisting of glomerule-like rhipidia; sympodial rachis to 5 mm long, densely covered with appressed, reddish brown hairs; flowering pedicels 5–10 mm long, 1.1–1.5 mm diam, densely covered with appressed, reddish brown hairs; lower bracts ovate, c. 1.4 by 0.7 mm, indument as on sympodial rachis; upper bract in lower half of the pedicel, depressed ovate, 1–1.2 by 1.3–1.7 mm; ♀ flowers; sepals free to slightly connate, broadly to depressed

Map 23 Distribution of Monanthotaxis glomerulata (Le Thomas) Verdc. (■), M. hexamera P.H.Hoekstra (▲) and M. latistamina P.H.Hoekstra (●).

ovate, 1.7–2 by 1.8–2.5 mm, apex acute, densely covered with hairs; receptacle c. 1.5 mm diam, convex; petals colour in vivo unknown, 6, in two whorls, outer petals depressed ovate, 4–6 by 5.5–7.5 mm, outside and inside densely covered with yellow-brown hairs; inner petals elliptic, 1.5–2 by 0.5–1 mm, indument as on outer petals; staminodes absent; carpels 80–95, subcylindric, 1.7–1.9 by 0.4–0.5 mm, densely hairy, ovules 6 or 7, lateral, stigma elongate, 0.3–0.4 mm long, glabrous. Monocarps and seeds not seen.

Distribution — Gabon (Ogooué-Lolo).

Habitat & Ecology — Flowering: March.

Preliminary IUCN conservation status — Critically endangered ( CR): B2 ab(iii). AOO: 4 km 2. This species is only known from the type collection, which was collected more than 80 years ago and is outside a protected area. This species is possibly already extinct .

Note — Monanthotaxis glomerulata can be distinguished from other cauliflorous Monanthotaxis species by the glomerule-like inflorescences. Monanthotaxis bidaultii has few-flowered glomerule-like inflorescences, but differs in having c. 50 carpels, with 2 – 4 ovules and M. bidaultii has a denser indument of ascending to erect hairs on the lower leafside.

Figures

Fig. 9 a–e. Monanthotaxis confusa P.H.Hoekstra. a. Staminate flowering branch; b. staminate flower,outer petal,inside view; c. staminate flower, inner petal, inside view; d. staminate flower with petals removed; e. stamen, outer and side view. — f–n. Monanthotaxis diclina (Sprague) Verdc. f. Staminate flowering branch; g. staminate flower with one outer petal removed; h. staminate flower inner petal, inside view; i. stamen, outside and inside view; j. staminate flower staminode; k. pistillate flower, outer petal, inside view; l. pistillate flower, inner petal, inside view; m. carpel and longitudinal section of carpel; n. fruits. — o–s. Monanthotaxis glomerulata (Le Thomas) Verdc.o. Pistillate inflorescence; p. pistillate flower with one outer petal removed;q. pistillate flower, outer petal,inside view; r. pistillate flower, inner petal, inside view; s. carpel and longitudinal section carpel (a–e: Lebrun 6134; f–j: Klaine 2881; k–m: Klaine 1382; n: Klaine 404; o–s: Le Testu 8700). — Modified from Le Thomas (1969) plate 38.