Monanthotaxis faulknerae 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 : 152

26. Monanthotaxis faulknerae Verdc. — Map 14

Monanthotaxis faulknerae Verdc. (1971b) 25. — Type: H.G. Faulkner 1624 (holo K000198979 ;iso B100153028 , BR0000008802002 ), Tanzania, Tanga, Tanga-Mombasa road, 16 km from Tanga, 60 m, 28 May 1955.

Scandent shrub or liana, to 3 m long; young branches reddish brown, covered with erect, yellowish hairs 0.2–0.5 mm long, becoming glabrous; old branches dark brown, grey-black to blackish. Leaves: petiole 1.5–3 mm long, 0.4–0.7 mm diam, terete, indument as on branches; lamina oblong-elliptic or sometimes obovate to narrowly so, 1.4–5.5(–6.7) by 0.7–2.6 cm, 1.5–2.8 times longer than wide, subcoriaceous, punctate, discolorous, olive-green above, dull greenish white below, young leaves above sparsely covered with ascending, white hairs 0.4–0.6 mm long, becoming glabrous, primary vein more densely hairy, below sparsely covered with ascending to erect, white hairs 0.3–0.6 mm long, base rounded or sometimes slightly subcordate, glands hardly visible, apex rounded to acute, secondary veins 7–10 per side, from base curving upwards, tertiary venation percurrent, slightly raised and reticulate above. Inflorescences terminal or extra-axillary, mostly leaf-opposed, composed of solitary flowers; sympodial rachis absent; pedicels 4–22 mm long, 0.4–0.6 mm diam, fruiting pedicels 0.7–1.1 mm diam, sparsely covered with erect hairs 0.3–0.5 mm long; lower bracts absent; upper bract in the lower half of the pedicel or absent, ovate, 1.2–2.4 by 0.7–1.7 mm, indument as on pedicel; flower buds globose. Flowers bisexual; sepals free, depressed ovate to orbicular, 1.8–3.7 by 2.8–4.2 mm, apex rounded, densely covered with ascending, white, short hairs, punctate, persistent in fruit, slightly accrescent; receptacle 2.2–2.7 mm diam, flat; petals colour in vivo unknown, 6, in two whorls, outer petals broadly ovate to ovate, 4.2–8.8 by 4.8–7.5 mm, outside and apex and margins on the inside covered with ascending, white-yellow, short hairs, inner petals elliptic, 3.8–5.2 by 2.3–4.6 mm, outside and apex of the inside covered with short hairs; stamens 23–27, in two whorls, free, linear-obovoid, c. 1.2 mm long, filaments c. 0.4 mm long, thecae latrorse to extrorse, connective truncate, prolonged outward and inward, not hiding thecae, glabrous, staminodes absent; carpels 8–10, subcylindric, c. 1.7 by 0.5 mm, densely hairy, ovules 2 or 3, lateral, stigma elongate, c. 0.8 mm long, glabrous. Monocarps up to 9, orange, narrowly ellipsoid, 14–23 by 4.8–5.5 mm, constricted between the seeds, slightly verrucose, densely covered with erect, yellowish white hairs, apiculate, apiculum 1–2 mm long, stipes 3.2–5.5 mm long. Seeds 1–3, subglobose to ellipsoid, 6.2–9.8 by 3.8–4.7 mm, ochre-brown, apex flattened, rounded or apiculate, raphe hardly visible as a longitudinal furrow from base to apex.

Distribution — Kenya (Coast), Tanzania (Tanga).

Habitat & Ecology — In lowland forest, Brachystegia woodland, coastal thicket on tan sand.Altitude: 20– 370 m. Flowering: May, June; fruiting: February, July, December.

Preliminary IUCN conservation status — Vulnerable (VU): B2ab(iii). EOO: 12 700 km 2, AOO: 40 km 2. This species is known from 10 collections from 7 locations along the coast of Kenya and north-east of Tanzania of which only three are in protected areas.

Note — Monanthotaxis faulknerae is morphologically closely resembling M. suffruticosa and M. trichocarpa . All three species have punctate leaves in sicco and have extra-axillary inflorescences, c. 25 stamens and erect hairs on the monocarps. Monanthotaxis faulknerae can be distinguished from M. suffruticosa in the lower number of carpels (8–10 vs 14–16) and a different growth form (shrub or liana vs a subshrub). Monanthotaxis faulknerae is difficuilt to distinguish from M. trichocarpa , but generally has oblong-elliptic leaves, which are much smaller than those of M. trichocarpa , which has generally obovate leaves that are normally double the size of those of M. faulknerae . Further M. faulknerae has 8–10 carpels per flower, while M. trichocarpa normally has around 12 carpels per flower.There is some overlap in the characters and generally a combination of characters has to be used when a specimen has leaves in the length of 4.5–6 cm. More material of M. faulknerae and field and DNA-studies are needed to assess if it merely is an extreme form of M. trichocarpa or a good species.

Figures

Map 14 Distribution of Monanthotaxis dictyoneura Diels (■) and M. faulknerae Verdc. (●, O means uncertain det).