Piptostigma macrophyllum Ghogue, Sonke & Couvreur, Pl. Ecol. Evol. 150 (2): 199 2017

Piptostigma macrophyllum Ghogue, Sonké & Couvreur, Pl. Ecol. Evol. 150 (2): 199, 2017 Fig. 89; Map 11E Type. Cameroon. South-West Region; above small Koto village (Mt. Cameroon), Thomas D.W. 4493, 6 Mar 1985: holotype: YA[YA0002852]; isotypes: MO[MO3282523]; P[P00284016]. Description. Tree, 5-10 m tall, d.b.h. 10-20 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent. Leaves: petiole 6-7 mm long, 3-4 mm in diameter, pubescent, cylindrical, blade inserted on top of the petiole; blade 25-41 cm long, 9-16 cm wide, obovate, apex acuminate, acumen ca. 2.5 cm long, base acute, papyraceous, below glabrous when young and old, above sparsely pubescent when young, sparsely pubescent when old, discolorous, whitish below; midrib impressed, above glabrous when young and old, below sparsely pubescent when young and old; secondary veins 21 to 28 pairs, glabrous above; tertiary venation percurrent. Individuals bisexual; inflorescence cauliflorous or ramiflorous on old leafless branches, axillary, pubescent all over, peduncle like base 5-10 mm long, axial internodes 5-15 mm long, compact to sub-lax, sympodial rachis up to 70 mm long. Flowers with 9 perianth parts in 3 whorls, 3 to 6 per inflorescence; pedicel 8-10 mm long, ca. 2 mm in diameter, tomentose; in fruit 10-12 mm long, ca. 4 mm in diameter, glabrous; basal bract ca. 12 mm long, ca. 3 mm wide; upper bract ca. 12 mm long, ca. 3 mm wide; sepals 3, valvate, free, ca. 9 mm long, ca. 3 mm wide, ovate, apex acute, base truncate, brown, pubescent outside, glabrous inside, margins flat; petals free, outer petals shorter than inner; outer petals 3, 9-15 mm long, 2.5-3 mm wide, narrowly elliptic, apex acute, base truncate, margins flat, pubescent outside, glabrous inside; inner petals 3, valvate, 25-35 mm long, 4-5 mm wide, ovate, apex acute, base truncate, margins wavy, pubescent outside, pubescent inside; stamens numerous, in 6 to 8 rows, 1-2 mm long, broad; connective discoid, glabrous, red; staminodes absent; carpels free, ca. 5, ovary ca. 3 mm long, stigma globose, densely pubescent. Monocarps sessile, 1 to 3, ca. 33 mm long, ca. 35 mm in diameter, globose, apex rounded, glabrous, verrucose to muricate with short projections, not ribbed, light red pink when ripe; seeds 2 to 4 per monocarp, 10-15 mm long, ca. 12 mm in diameter, ellipsoid; aril absent. Distribution. endemic to Cameroon, known from the South, Littoral and South-West regions. Habitat. A rare species; in primary or secondary lowland or premontane rain forests on black volcanic soils, sometimes in plantations. Altitude 550-1000 m a.s.l. Local and common names known in Cameroon. None recorded. IUCN conservation status. Vulnerable B2ab(iii,iv) (Cosiaux et al. 2019a l). Uses in Cameroon. None reported. Notes. Piptostigma macrophyllum is morphologically close to P. pilosum by the large size and papery consistency of its leaf blade. However, the leaf blades of P. pilosum are mostly oblong or elliptic and only exceptionally narrowly obovate like those of P. macrophyllum. The inflorescences of P. pilosum are also less compact and less pubescent than those of P. macrophyllum. The monocarps of P. macrophyllum strongly resemble those of P. multinervium and P. macranthum being muricate to verrucose in texture with short projections. Piptostigma macrophyllum is distinguished from P. multinervium by its larger size of the leaf blades (25-41 cm long versus 13-21 cm long in P. multinervium), the lower side of the leaf blades being glabrous between the veins in P. macrophyllum and pubescent in P. multinervium; finally the sepals are narrowly ovate in P. macrophyllum while broadly triangular in P. multinervium. From P. macranthum it is distinguished by the leaves being obovate (versus narrowly oblong to oblong). Specimens examined. Littoral Region: Ebo Forest Reserve Djuma permanent camp on transect 5, 4.33°N, 10.23°E, 16 February 2013, Couvreur T.L.P. 637 (WAG,YA). South Region: Bord de la Lobé 25 km E Campo, 2.37°N, 9.82°E, 01 January 1968, Letouzey R. 9156 (P,YA). South-West Region: Mount Cameroon National Park Bakinguili trail above Bakinguili village, 4.09°N, 9.054°E, 02 April 2016, Couvreur T.L.P. 1034 (WAG,YA); on trail through palm oil plantation 3 km before lava flow and Seme Beach hotel when coming from Limbe, 4.06°N, 9.079°E, 18 October 2013, Couvreur T.L.P. 518 (WAG,YA); Entre DikomeBalue (1200 m) et Ifanga Nalende (650 m) 35 km NNW-Kumba, 4.9°N, 9.29°E, 25 March 1976, Letouzey R. 14590 (P,YA); Etinde forest reserve Njonji lake, 4.13°N, 9.033°E, 25 January 1993, Tchouto Mbatchou G.P. 1053 (K); Disturbed forest Bomana and Koto II, 4.3°N, 9.05°E, 26 April 1996, Tchouto Mbatchou G.P. 1378 (K,YA); Mount Cameroon above small Koto village, 4.3°N, 9.1°E, 06 March 1985, Thomas D.W. 4493 (YA); Between Ikenge and Esukutang ca 6 kms West of Ikenge, 5.28°N, 9.083°E, 03 April 1988, Thomas D.W. 7645 (YA); Cameroon Mountain, 4.12°N, 9.029°E, 20 June 2001, van Andel T.R. 3728 (U,WAG).