Monodora zenkeri Engl., Notizbl. Konigl . Bot. Gart. Berlin 2: 301, 1899

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 : 262-264

Monodora zenkeri Engl., Notizbl. Konigl. Bot. Gart. Berlin 2: 301, 1899

Fig. 79 ; Map 10D

Type.

Cameroon. Central Region ; Yaoundé, Zenker G.A. 776, 1896: holotype: B[B 10 015406]; isotypes: COI[COI00077202]; G[G00011721]; K[K000199027]; NY[NY00026141]; P[P00363263] .

Description.

Leaning tree [or liana?], to 6 m tall, d.b.h. up to 6 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches sparsely pubescent to glabrous. Leaves: petiole 2-4 mm long, 1 mm in diameter, glabrous, grooved, blade inserted on the side of the petiole; blade 10-15 cm long, 8-14 cm wide, elliptic to obovate, apex acuminate, acumen 3-6 cm long, base rounded to obtuse, coriaceous to papyraceous, below glabrous when young and old, above glabrous when young and old, concolorous; midrib raised above, above glabrous when young and old, below glabrous when young and old; secondary veins 10 to 13 pairs, glabrous below; tertiary venation intermediate. Individuals bisexual; inflorescences ramiflorous on young foliate branches, leaf opposed or extra axillary. Flowers bisexual with 9 perianth parts in 3 whorls, 1 per inflorescence; pedicel 28-50 mm long, 1 mm in diameter, sparsely pubescent; in fruit unknown; bracts 1, towards the upper half or middle of pedicel, 11-20 mm long, 10-13 mm wide; sepals 3, valvate, free, 2-5 mm long, 2-4 mm wide, ovate, apex acute, base truncate, green to brown-red, glabrous outside, glabrous inside, margins flat; petals basally fused, tube 4-7 mm long, inner and outer whorl differentiated, outer petals longer than inner; outer petals 3, 35-45 mm long, 20-28 mm wide, ovate, apex acute to obtuse, base truncate flanked by two small lobes, speckled and streaked yellow-purple, base creamy-white, margins flat, sparsely pubescent outside, sparsely pubescent to glabrous inside; inner petals 3, valvate, 9-13 mm long, 13-16 mm wide, triangular, apex acute, base narrowed into a claw, claw 4.0-7 mm long, pale green with red spots, margins flat, folded outwards, glabrous inside, pubescent outside; receptacle convex to flat; stamens numerous, in 9 to 10 rows, 1 mm long, broad; connective discoid, glabrous; staminodes absent; carpels fused into a single structure, 1 mm long, stigma bilobed, slightly capitate. Fruits unknown.

Distribution.

endemic to Cameroon; known from Central, East, South regions.

Habitat.

A rare species, not collected recently; in secondary and disturbed lowland rain forests. Altitude 600-700 m a.s.l.

Local and common names known in Cameroon.

None recorded.

IUCN conservation status.

Not evaluated (certainly threatened).

Uses in Cameroon.

None reported.

Notes.

Monodora zenkeri is easily distinguished by the presence of two small lobes at the base of the outer petals. Some labels indicate that it is a liana, probably a strongly leaning tree, mainly near large rocks. In this sense it resembles M. crispata in its lianescent habit.

Specimens examined.

Central Region: ca. 4 km NE of Otélé near the road to Yaoundé, 3.58°N, 11.25°E, 28 March 1964, de Wilde J.J.F.E 2249 (BR,P,WAG,YA); Etwa 195 km NO Jaunde, 5.21°N, 12.9°E, 01 January 1914, Mildbraed G.W.J. 8476 (K); Mt Ngoro à 38 km au N de Bafia (piedmont), 4.93°N, 11.38°E, 01 May 1978, Ngameni B.K. 113 (P,YA); Yaoundé, 3.87°N, 11.52°E, 1896, Zenker G.A. 776 (B,COI,G,K,P). East Region : Bertoua, 4.58°N, 13.73°E, 27 April 1961, Breteler F.J. 1319 (WAG); 6 km along road south to Doumé, 4.38°N, 12.91°E, 10 April 1962, Breteler F.J. 2747 (BR,K,P,WAG,YA); Deng Deng, 5.16°N, 13.58°E, 01 April 1914, Mildbraed G.W.J. 8850 (K); Bertoua, 4.58°N, 13.68°E, 27 May 1955, Nana P. 98 (P,YA). South Region : Nkoldjobe dans le massif du Mbam-Minkom 18 km Nord-Ouest de Yaoundé, 3.93°N, 11.35°E, 16 April 1984, Achoundong G. 1056 (YA); Bitye river, 3.02°N, 12.37°E, 01 January 1920, Bates G.L. 1244 (COI); Near village Oveng 27 km from Sangmélima along road to Yaoundé, 3.09°N, 11.90°E, 21 March 1962, Breteler F.J. 2683 (BR,K,P,U,WAG,YA) .

Figures

Map 10. A Monodora myristica B Monodora tenuifolia C Monodora undulata D Monodora zenkeri E Neostenanthera myristicifolia F Neostenanthera neurosericea G Neostenanthera robsonii H Piptostigma calophyllum I Piptostigma fugax. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 79. Monodora zenkeri A flowering branch B outer petal, inside view C inner petal, inside view D androecium with missing stigma E stamen, front view. Monodora undulata F leaf G flower H outer petal, inside view I inner petal, inside view J androecium and stigma A from Zenker 776 B-E from Breteler 2747 F-I from Preuss 1314 J from Bos 3227. Drawings by Helene Lamourdedieu, Publications Scientifiques du Museum national d'Histoire naturelle, Paris; Drawings B, C and J Hans de Vries (Couvreur 2009, fig. 69, p. 129).