Monanthotaxis filipes 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 : 155-157

29. Monanthotaxis filipes P.H.Hoekstra — Fig. 13; Map 20

Monanthotaxis filipes P.H.Hoekstra in P.H. Hoekstra et al. (2016) 82. — Type: G.S. Bidgood 1402 (holo K 2 sheets; iso BR0000013186036 , C, EA, MO4027188 , P01967237 , UPS, WAG0071696 ), Tanzania, Lindi district, Rondo plateau, Rondo forest Reserve , S10°07' E39°13', 700 m, 7 Feb.1991.

Shrub, c. 1 m tall; young branches yellow-brown, densely covered with appressed to ascending, yellowish hairs 0.3–0.7 mm long, becoming glabrous; old branches dark brown to greyish brown. Leaves: petiole 3–5 mm long, 0.7–1 mm diam, slightly grooved, indument as on branches; lamina oblong-elliptic to narrowly obovate, 3.7–10.7 by 1.5–4.4 cm, 1.6–3.3 times longer than wide, chartaceous, not punctate, discolorous, pale bluish green below, above sparsely covered with whitish appressed hairs when young, soon becoming glabrous, below densely covered with ascending, yellowish white hairs 0.3–0.5 mm long, base rounded, truncate or slightly subcordate, with thickened margin at the base, apex acute, secondary veins 7–10 per side, first straight, halfway curving upwards, tertiary venation percurrent. Inflorescences supra-axillary, 2–6 mm above leaf axil, 1- or 2-flowered rhipidia; sympodial rachis 0–1 mm long; flowering pedicels 18–55 mm long, c. 0.2 mm diam, sparsely covered with ascending to erect hairs; lower bracts strongly reduced or absent; upper bract halfway up the pedicel, ovate, c. 0.3 by 0.1 mm or just a dense tuft of hairs or absent, indument as on pedicels; flower buds globose. Flowers bisexual, pendulous; sepals connate at the base, depressed ovate to almost cup-shaped, c. 0.5 by 1.1–1.2 mm, apex obtuse to rounded, densely covered with appressed, yellow hairs; receptacle 1.5–2 mm diam, flat; petals creamy white, 6, in two whorls, outer petals broadly ovate, 2.5–2.7 by 2.8–3.6 mm, outside and apex of the inside densely covered with yellowish, short hairs, base of inside glabrous; inner petals ovate to rhombic, 1.9–2 by 1.2–1.4 mm, indument as on in outer petals; stamens (13?–)15, in 1 or 2 whorls, free, obovoid, 1.1–1.3 mm long, filaments 0.3–0.4 mm long, thecae extrorse, connective truncate, not hiding thecae, glabrous, staminodes absent; carpels 9, subcylindric, c. 1.2 by 0.2–0.3 mm, densely hairy, but glabrous near the apex, ovules 2, lateral, stigma elongate, c. 0.4 mm long, grooved, glabrous. Monocarps and seeds not seen.

Distribution — Tanzania (Lindi).

Habitat & Ecology — In steep escarpment densely covered with thickets; stony-gravelly soil. Altitude: c. 700 m. Flowering: February.

Preliminary IUCN conservation status — Critically endanger- ed (CR): B2a(ii,iii). AOO: 8 km 2. This species is only known from the Rondo Forest Reserve. Although it is a reserve, a major part of the forest in the reserve has been cleared in recent years as can be seen in satellite images provided by Google Earth (assessed April 2017).

Note — Monanthotaxis filipes is easily recognisable by the long and filiform pedicels and a dense indument of appressed to ascending, yellow hairs on the young branches and lower side of the leaves. In East Africa M. trichantha has a similar yellow indument, but that species has extra-axillary inflorescences, shorter pedicels and the flowers are very different. Filiform pedicels also occur in some Monanthotaxis species on Madagascar (e.g., M. heterantha ). The phylogenetic analyses place M. filipes as sister to the Malagasy species.

Figures

Map 20 Distribution of Monanthotaxis filipes P.H.Hoekstra (■) and M. fornicata (Baill.) Verdc. (●).