Piptostigma macranthum Mildbr. & Diels, Bot. Jahrb. Syst. 53(1-2): 142, 1915

Couvreur, Thomas L. P., Dagallier, Leo-Paul M. J., Crozier, Francoise, Ghogue, Jean-Paul, Hoekstra, Paul H., Kamdem, Narcisse G., Johnson, David M., Murray, Nancy A. & Sonke, Bonaventure, 2022, Flora of Cameroon - Annonaceae Vol 45, PhytoKeys 207, pp. 1-532 : 291-293

Piptostigma macranthum Mildbr. & Diels, Bot. Jahrb. Syst. 53(1-2): 142, 1915

Figs 88 , 89 ; Map 11D

= Piptostigma mayumbense Exell, J. Bot. 64 (Suppl. 1): 10, 1926. Type. Angola. Cabinda, M’bulu hills, Mayumbe, Gossweiler J. 7807, 15 Feb 1919: holotype: B[B100460898].

Type.

Cameroon. South Region; Mimfia (Bipindi), Zenker G.A. 2528, 1902: holotype: B[B100154080]; isotypes:[BR0000013174743]; G[G00442261]; K[K000199001]; P[P00363281, P00363282, P00363283]; S[S07-13471].

Description.

Tree, 6-18 m tall, d.b.h. 15-21 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches pubescent. Leaves: petiole 2-3 mm long, 2-3 mm in diameter, pubescent, cylindrical, blade inserted on top of the petiole; blade 14-31 cm long, 7-9 cm wide, ovate to oblong, apex acuminate, acumen 0.5 cm long, base rounded to cordate, subcoriaceous, below pubescent when young and old, above glabrous when young and old, discolorous, whitish below; midrib impressed, above pubescent when young and old, below densely pubescent when young, densely pubescent when old; secondary veins 16 to 30 pairs, glabrous above; tertiary venation percurrent. Individuals bisexual; inflorescence cauliflorous, pubescent all over, peduncle like base 6-25 mm long, axial internodes 10-20 mm long, compact to sub-lax, sympodial rachis 10-70 mm long. Flowers with 9 perianth parts in 3 whorls, 2 to 4 per inflorescence; pedicel 5-20 mm long, 3-5 mm in diameter, tomentose; in fruit 20-25 mm long, ca. 6 mm in diameter, pubescent; basal bract ca. 10 mm long, ca. 10 mm wide; upper bract ca. 10 mm long, ca. 10 mm wide; sepals 3, valvate, free, ca. 9 mm long, ca. 8 mm wide, triangular, apex acute, base truncate, brown, pubescent outside, glabrous inside, margins flat; petals free, outer petals shorter than inner; outer petals 3, 12-28 mm long, 9-11 mm wide, obovate, apex acute, base truncate, wine-brown, margins flat, pubescent outside, glabrous inside; inner petals 3, valvate, 40-55 mm long, 10-20 mm wide, elliptic, apex acute, base truncate, cream, margins wavy, pubescent outside, pubescent inside; stamens 280 to 320, in 10 to 11 rows, 1-2 mm long, broad; connective discoid, glabrous, red; staminodes absent; carpels free, 9 to 12, ovary ca. 2 mm long, stigma globose, pubescent. Monocarps sessile, 3 to 6, 30-40 mm long, 25-40 mm in diameter, obovoid, apex acute, pubescent, muricate with projections up to 10 mm long, not ribbed, projections brown otherwise reddish when mature; seeds 2 to 6 per monocarp, ca. 10 mm long, ca. 5 mm in diameter, ellipsoid; aril absent.

Distribution.

From Cameroon to the Republic of Congo; in Cameroon known from the South and Central regions.

Habitat.

A rare species in Cameroon; in forest edges or in closed forests along rivers. Altitude 50-500 m a.s.l.

Local and common names known in Cameroon.

Nom-owé (Dial. Yaoundé, Letouzey s.n.).

IUCN conservation status.

Least Concern (LC) ( Cosiaux et al. 2019a k).

Uses in Cameroon.

None reported.

Notes.

Piptostigma macranthum is easily distinguished from other species of Piptostigma by its characteristic narrowly oblong to oblong leaf blade shape, shiny upper side of leaf blade, rounded and cordate leaf blade base and thick compact inflorescences.

Specimens examined.

Central Region: Ca 50 km S of Badjob ca 60 km SW of Eséka, 3.46°N, 10.5°E, 19 March 1964, de Wilde W.J.J.O 2132 (BR,P,WAG); Akomimbang (Mbalmayo), 3.52°N, 11.5°E, 13 November 1957, Letouzey R. 1937 (P); Akomimbang Mbalmayo, 3.52°N, 11.5°E, 13 November 1957, Letouzey R. s.n. (P,YA) . South Region: 10 km From Kribi Lolodorf road, 2.98°N, 9.966°E, 27 May 1969, Bos J.J. 4647 (BR,K,MO,P,U,WAG,YA); Bezirk Kribi Vorland mit einzeln Hügeln bei Adjab 25 km Grand batanga near Eduma and Bidue, 2.93°N, 9.92°E, 25 July 1911, Mildbraed G.W.J. 6118 (HBG); 51 SE de Campo Nkolmenbegue, 2.39°N, 10.3°E, 24 November 1992, Satabié B. 1037 (YA); Efoulan, 2.74°N, 10.54°E, 04 December 2000, Tchouto Mbatchou G.P. 3100 (KRIBI,WAG,YA); Bipindi, 3.08°N, 10.42°E, 01 January 1903, Zenker G.A. 2528 (B,BR,G,L,P,WAG); Bipindi, 3.08°N, 10.42°E, 01 May 1902, Zenker G.A. s.n. (P) .

Figures

Map 11. A Piptostigma glabrescens B Piptostigma goslineanum C Piptostigma longepilosum D Piptostigma macranthum E Piptostigma macrophyllum F Piptostigma mayndongtsaeanum G Piptostigma mortehanii H Piptostigma multinervium I Piptostigma oyemense. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 88. Piptostigma macranthum A leaf B inflorescence C receptacle, inner petals removed. Piptostigma longepilosum D leaf, note long pubescence E inflorescence F receptacle, outer petals removed A-C from Letouzey 1937 D-F from Annet 420. Drawings by Helene Lamourdedieu, Publications Scientifiques du Museum national d'Histoire naturelle, Paris.

Figure 89. Piptostigma macranthum A habit with cauliflorous flowers B base of leaf blade, upper side C base of leaf blade, lower side D compact inflorescence with a single flower E detail of receptacle, outer petals removed F fruit, note brown muricate monocarps. Piptostigma macrophyllum G leaf, upper side H fruit; note smallish red-pink muricate monocarps A, D-F Couvreur 1135, Gabon B, C Couvreur 1125, Gabon G, H Couvreur 1034, Mt Cameroon, Cameroon. Photos Thomas L. P. Couvreur.