Monanthotaxis vulcanica P.H.Hoekstra, Blumea 66 (1): 208, 2021

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 : 240-242

Monanthotaxis vulcanica P.H.Hoekstra, Blumea 66 (1): 208, 2021

Figs 71 , 72 ; Map 9E

Type.

Cameroon. South-West Region; NW du Mt Cameroon, Letouzey R.G. 15050, 1 Jun 1976: holotype: P[P01982551]; isotypes: K[K001322493]; WAG[WAG.1576469]; YA[YA0003005] .

Description.

Liana, to 20 m tall, d.b.h. unknown. Indumentum of simple hairs; old leafless branches glabrescent, young foliate branches sparsely pubescent with appressed yellowish hairs 0.2 mm long to almost glabrous. Leaves: petiole 3-6 mm long, ca. 1 mm in diameter, sparsely pubescent with appressed yellowish hairs, slightly grooved, blade inserted on top of the petiole; blade 5.6-11.8 cm long, 2.3-3.9 cm wide, oblong elliptic, apex acuminate to acute, acumen up to 2 cm long, base rounded to narrowly cuneate or cordate, papyraceous, below sparsely pubescent when young, glabrous when old, above glabrous when young and old, discolorous, whitish below; midrib impressed, above sparsely pubescent when young and old, below sparsely pubescent when young and old; secondary veins 8 to 12 pairs, glabrous above; tertiary venation percurrent. Individuals bisexual; inflorescences ramiflorous on old leafless branches, leaf opposed or extra axillary. Flowers with 9 perianth parts in 3 whorls, 1 per inflorescence; pedicel 19-25 mm long, 0.5-1 mm in diameter, sparsely pubescent; in fruit 20-37 mm long, ca. 1 mm in diameter; basal bract ca. 1 mm long, ca. 1 mm wide; upper bract, leaf-like, 7-15 mm long, 5-10 mm wide; sepals 3, valvate, basally fused, ca. 2 mm long, ca. 3 mm wide, ovate, apex acute, base truncate, densely pubescent outside, glabrous inside, margins flat; petals free, outer petals longer than inner, inner petals entirely covered in bud; outer petals 3, 6.4-8 mm long, ca. 6 mm wide, ovate, apex obtuse, base truncate, pale orange, margins flat, sparsely pubescent outside, sparsely pubescent inside; inner petals 3, valvate, 5.3-5.7 mm long, ca. 4 mm wide, broadly elliptic, apex acute, base truncate, pale orange, margins flat, pubescent outside, sparsely pubescent inside; stamens 15, in 2 rows, ca. 2 mm long, clavate; connective truncate, larger than base, glabrous; staminodes absent; carpels free, ca. 14, ovary ca. 2 mm long, stigma elongate, flattened at top, glabrous. Monocarps stipitate, stipes 6-10 mm long, ca. 2 mm in diameter; monocarps 2 to 13, 12-50 mm long, 5-7 mm in diameter, moniliform, ellipsoid to cylindrical, apex apiculate, very sparsely pubescent, verrucose, constricted around seeds when more than 1, orange when ripe; seeds 1 to 4 per monocarp, 8-15 mm long, 5-6 mm in diameter, ellipsoid; aril absent.

Distribution.

From Nigeria to Cameroon; in Cameroon known from the North-West, South-West and West regions.

Habitat.

In sub-montane rain forest and on forest edges. Altitude 800-2600 m a.s.l.

Local and common names known in Cameroon.

None recorded.

Preliminary IUCN conservation status.

Endangered (EN) ( Hoekstra et al. 2021).

Uses in Cameroon.

None reported.

Notes.

Monanthotaxis vulcanica is distinguished by its large leaf-like (7-15 mm long and 5-10 mm wide) upper bract on the flowering pedicel (this leafy bract is also found in a few other species such as M. obovata (Benth.) P.H.Hoekstra and M. orophila (Boutique) Verdc., none found in Cameroon however), 15 stamens and ca. 14 pubescent carpels per flower and the monocarps with long stipes (6 to 10 mm long).

In the check list to the plants of Mt Oku ( Cheek et al. 2000, p. 114) and in the Flora of West Tropical Africa ( Keay 1952), collection Maitland 1618 was identified as Monanthotaxis (Popowia) littoralis (Bagsh. & Baker f.) Verdc. but is in fact M. vulcanica . In addition, in the check list to the plants of Bali Ngemba reserve ( Harvey et al. 2004), the collection under " Monanthotaxis sp. of Bali Ngemba" (Etuge 4810) is now identified as M. vulcanica . Finally, specimen Chapman & Chapman 3675 was label as Friesodielsia sp. ( Chapman and Chapman 2001), and is also identified here as M. vulcanica .

Specimens examined.

North-West Region: Mantum , 5.82°N, 10.08°E, 17 November 2000, Etuge M. 4810 (K,YA) . South-West Region: Mount Cameroon National Park on the Bomona trail behind Bomona village 10 km NW from Idenau , 4.29°N, 9.086°E, 03 April 2016, Couvreur T.L.P. 1049 (WAG,YA); Pentes NW du Mont vers Efolofo 30 km W, 4.21°N, 9.05°E, 01 June 1976, Letouzey R. 15050 (K,P,YA); Bamenda Distr at Bambui, 6.02°N, 10.21°E, 01 June 1931, Maitland T.D. 1618 (K) . West Region: Megom , 5.43°N, 10.42°E, 01 February 1939, Jacques-Félix H. 3078 (P); Massif du Nkogam (2263 m) 25 km W de Foumban, 5.73°N, 10.67°E, 28 October 1974, Letouzey R. 13046 (P,P,YA) .

Figures

Map 9. A Monanthotaxis sterilis B Monanthotaxis submontana C Monanthotaxis tripetala D Monanthotaxis vogelii E Monanthotaxis vulcanica F Monanthotaxis whytei G Monanthotaxis zenkeri H Monodora angolensis I Monodora crispata. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 71. Monanthotaxis tripetala A habit, juvenile B leaf, lower side C base of leaf blade, upper side D base of leaf blade, lower side. Monanthotaxis vulcanica E base of leaf blade, lower side F habit, juvenile G base of leaf blade, upper side A-D Couvreur 870, Gabon E-G Couvreur 1049, Mt Cameroon, Cameroon. Photos Thomas L. P. Couvreur.

Figure 72. Monanthotaxis vulcanica A fruiting branch B inflorescence with flower bud C flower bud with one outer and one inner petal removed D stamen, outer view E stamen, side view D carpel G longitudinal section of carpel A from Chapman 3675 B-F from Letouzey 15050. Drawings by Esmee Winkel (Hoekstra et al. 2021, fig. 33, p. 209).