Monanthotaxis tripetala P.H.Hoekstra, PhytoKeys 69: 96, 2016

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 : 236-238

Monanthotaxis tripetala P.H.Hoekstra, PhytoKeys 69: 96, 2016

Figs 70 , 71 ; Map 9C

Type.

Cameroon. East Region; 15 km E of Dimako , village halfway Bertoua-Doumé, Leeuwenberg A.J.M. 5828, 11 Jun 1965: holotype: WAG [WAG0110801, WAG0110802]; isotypes: B[B100190273]; BR[BR0000014126253]; C; EA; K; LISC; MO; P[P01967268]; PRE; YA .

Description.

Liana, 3 m tall, d.b.h. to 11 cm. Indumentum of simple hairs; old leafless branches glabrescent, young foliate branches pubescent with very short appressed reddish brown hairs 0.1 mm long. Leaves: petiole 2-8 mm long, 1-2 mm in diameter, pubescent, blade inserted on the side of the petiole; blade 4.2-16.2 cm long, 1.8-5.3 cm wide, oblong to elliptic, apex acuminate to acute, acumen 0.5-1 cm long, base rounded, subcoriaceous, below sparsely pubescent when young, glabrous when old, above sparsely pubescent to glabrous when young and old, discolorous, whitish below; midrib impressed, above sparsely pubescent when young, glabrous when old, below pubescent when young, sparsely pubescent when old; secondary veins 7 to 10 pairs, glabrous above; tertiary venation percurrent. Individuals bisexual; inflorescences ramiflorous on old leafless branches, axillary. Flowers with 6 to 7 perianth parts in 2 to 3 whorls, 1 to 2 per inflorescence, peduncle 0-6 mm long, pubescent; pedicel 12-20 mm long, 0.5 mm in diameter, pubescent; in fruit 16-29 mm long, ca. 2 mm in diameter; basal bract not seen; upper bracts ca. 1 mm long, ca. 0.5 mm wide; sepals 3, valvate, free, ca. 1 mm long, ca. 1 mm wide, ovate, apex obtuse, base truncate, densely pubescent outside, glabrous inside, margins flat; petals free, outer petals longer than inner (when present), inner petals entirely covered in bud; outer petals 3, 2-2.2 mm long, ca. 2.2 mm wide, broadly ovate to circular, apex rounded to obtuse, base truncate, margins flat, pubescent outside, pubescent inside; inner petals absent or more rarely 1 minute, ca. 1.5 mm long, ca. 0.5-0.6 mm wide, elliptic, apex acute, base truncate, margins flat, pubescent outside, pubescent and glabrous towards the base inside; stamens 9 to 12, in 1 row, ca. 1 mm long, linear to clavate; connective reduced, slightly acute, glabrous; staminodes absent; carpels free, 9, ovary ca. 1 mm long, stigma flat, glabrous. Monocarps stipitate, stipes 7-22 mm long, ca. 2 mm in diameter; monocarps up to 7, 110-130 mm long, 8-9 mm in diameter, moniliform, ellipsoid, apex apiculate, sparsely pubescent to glabrous, verrucose, constricted around seeds when more than 1, yellow when ripe; seeds 1 to 4 per monocarp, ca. 17 mm long, ca. 7 mm in diameter, ellipsoid; aril absent.

Distribution.

A Central African species, from Cameroon to Gabon, in Cameroon known from the East region.

Habitat.

A rare species, known from a single collection in Cameroon; in lowland primary or secondary rain forests, on hillsides. Altitude ~650 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 tripetala is distinguished by the small axillary bisexual flowers, of which the inner petals are highly reduced or absent. The latter character also occurs in the male flowers of Monanthotaxis cauliflora and M. diclina , but those have unisexual flowers.

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 70. Monanthotaxis tripetala A flowering branch B leaf base abaxially C leaf base and inflorescence D flower with one petal removed E petal inner side view F flower with petals removed G stamen outer side view H stamen inner side view I stamen side view J carpel A-J from Leeuwenberg 5828. Drawings by Hans de Vries (Hoekstra et al. 2021, fig. 30, p. 201).

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.