Mendoncia camerounensis Breteler & Wieringa, 2018

Breteler, F. J. & Wieringa, J. J., 2018, A synopsis of Mendoncia (Acanthaceae) in continental Africa including the description of two new species from western Central Africa and a new subspecies from West Africa, Blumea 63 (2), pp. 109-119 : 110-113

1. Mendoncia camerounensis Breteler & Wieringa , sp. nov. — Fig. 1; Plate 1 ; Map 1

Resembling most Mendoncia iodioides (Moore) Heine , differing from this species by the longer pedicels, the larger, pinnately veined bracteoles, and the stellate-hairy calyx. — Type: J.J. Wieringa, Mackinder & Nana 5855 (holo WAG 2 sheets,WAG0237438 & WAG0237439;iso K, YA), Cameroon, Littoral Region, in the proposed Ebo F.R., N4°21.53' E10°25.07', alt. 910 m, 9 Mar. 2007.

Liana, climbing to canopy. Branchlets, leaves, inflorescences (bracteoles outside) hispid-hairy mixed with shorter, stellate and/or branched hairs. Leaves opposite: petiole ± terete, slightly grooved above, 25–40(–50) mm long; lamina broadly ovate-elliptic, 1.2–1.5 times as long as wide, 5.5–16 by 4–12 cm, rounded to subcordate at base, rounded to acute at apex, glabrescent, more rapidly so above; main lateral nerves 5–6(–7) pairs. Inflorescence axillary, fasciculate, (1–)3–4-flowered. Pedicel 20–40(–50) mm long. Bracteoles ovate, 25–30 by 15–20 mm, pinnately, reddish purple veined, obtuse at base, 2–3 mm apiculate at the apex, minutely pustulate inside. Flowers only partly known; calyx shallowly lobed, 1.5–2.5 mm long, stellately hairy outside; corolla (not seen by us) white-yellow (Cable et al. 3884); disc cupular, c. twice as long as the calyx, glabrous; ovary ellipsoid, c. 9 mm long, appressed-pubescent. Fruits ellipsoid, c. 2 cm long, velutinous, black at maturity.

Habitat & Distribution — Tropical submontane rain forest in Cameroon, Littoral and SW Regions. Altitude 700–910 m.

Additional specimens studied. CAMEROON, South-West Region, Cable et al. 3884 ( BR, K, P, WAG), Kupe Mt, SW Kupe village , 17 July 1996 ; Etuge 2769 ( BR, K, P, WAG), ibid., 12 July 1996 ; SchÖnenberger et al. 50 ( BR, K, WAG), Kupe Mt, SW slope, N4°45' E9°41', 8 Nov. 1995 . Littoral Region, Osborne & Beheng 118 ( K), Ebo Forest proposed National Park, near research station, 2006; Van der Burgt & Ngansop 1700 ( BR, K, MO *, P, SCA *, WAG, YA *), Ebo proposed National Park, trail to Iboti, 2 Dec. 2013 .

Conservation status — Both the EOO (271 km 2) and AOO (16 km 2) indicate Endangered. Since none of the localities is currently protected while there is extensive logging in Cameroon, and the number of subpopulations is only two which could be considered, depending on a likely difference in logging pressure, as either 1–2 locations, we assess this species as Endangered (EN B1ab(i-v) & 2a, b(i-v)). In case the areas where this species occurs would be protected as National Parks, its status should be reconsidered to become Vulnerable (VU D2).

Note — SchÖnenberger 50 was used in the phylogenetic study of the Thunbergioideae by Borg et al. (2008), identified as M. phytocrenoides . Magnaghi & Daniel (2017) have also identified specimens of this consistently as M. phytocrenoides . However, the distinct venation of the bracteoles and general indumentum distinguish this species from both M. iodioides and M. phytocrenoides .

Figures

Plate 1 Mendoncia camerounensis Breteler & Wieringa. Node with leaf and young fruit hidden by bracteoles. — Photo by Xander van der Burgt of X.M. v.d. Burgt 1700.

Map 1 Distribution of Mendoncia camerounensis Breteler & Wieringa.