Monanthotaxis hirsuta (Benth.) P.H.Hoekstra, Taxon 66: 14, 2017

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 : 212-213

Monanthotaxis hirsuta (Benth.) P.H.Hoekstra, Taxon 66: 14, 2017

Figs 58 , 59 ; Map 8B

≡ Unona hirsuta Benth., Trans. Linn. Soc. London 23(3): 469, 1862; Oxymitra hirsuta (Benth.) Sprague & Hutch., Bull. Misc. Inform. Kew: 155, 1916; Richella hirsuta (Benth.) R.E.Fr., Nat. Pflanzenfam., ed. 2, 17 a(2): 139, 1959.

= Uvaria caillei A.Chev. ex Hutch. & Dalziel, Fl. W. Trop. Afr. 1: 49, 1927. Type. Guinea. Mamou, Timbou, Kouria, Chevalier A.J.B. 14817, 28 Nov 1905: lectotype, chosen by Hoekstra et al. (2021), p. 165: P[P00363329]; isolectotypes: G[G00308375]; L[L.1765233]; P[P00363319, P00363320, P01954813].

Type.

Equatorial Guinea. Bioko Norte ; Fernando Poo, Mann G. 559, 1860: holotype: K[K000198950]; isotypes: P[P00363313; P00363314] .

Description.

Shrub to liana, up to 3 m tall, d.b.h. unknown. Indumentum of simple hairs; old leafless branches glabrescent, young foliate branches densely pubescent with erect reddish brown 1.2-1.7 mm long hairs. Leaves: petiole 5-6 mm long, 2-3 mm in diameter, densely pubescent with erect reddish brown hairs, slightly grooved, blade inserted on top of the petiole; blade 8.3-28.5 cm long, 4.9-7.5 cm wide, oblong to obovate, apex acuminate to acute, acumen 0.5-2 cm long, base cordate or subcordate, subcoriaceous to membranous, below pubescent when young and old, above densely pubescent with yellowish hairs when young, sparsely pubescent with yellowish hairs to glabrous when old, discolorous, whitish below; midrib sunken or flat, above sparsely pubescent with erect reddish brown hairs when young, sparsely pubescent with erect reddish brown hairs when old, below densely pubescent when young, pubescent when old; secondary veins 9 to 23 pairs, glabrous above; tertiary venation percurrent. Individuals bisexual; inflorescences ramiflorous on old leafless branches, leaf opposed. Flowers with 9 perianth parts in 3 whorls, 1 to 2 per inflorescence; pedicel 7-12 mm long, 1-3 mm in diameter, densely pubescent with yellow erect hairs; in fruit 13-31 mm long, ca. 2 mm in diameter, pubescent; basal bract ca. 5 mm long, ca. 3 mm wide; upper bract ca. 5 mm long, ca. 5 mm wide; sepals 3, valvate, free, 6-9 mm long, 5-7 mm wide, triangular to ovate, apex acute to obtuse, 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, 21-50 mm long, 9-17 mm wide, elliptic to ovate, apex acute, base truncate, red to cream, margins flat, densely pubescent outside, pubescent with a glabrous base inside; inner petals 3, valvate, 16-25 mm long, 6-8 mm wide, linear to elliptic, apex acute, base truncate, margins flat, densely pubescent outside, pubescent inside; stamens 100 to 120, in 4 to 5 rows, 1-2 mm long, cylindrical to obconic; connective truncate, glabrous; staminodes absent; carpels free, 22 to 24, ovary ca. 2 mm long, stigma elongate, glabrous. Monocarps stipitate, stipes 7-11 mm long, 2-3 mm in diameter; monocarps 2 to 9, 23-52 mm long, 9-13 mm in diameter, moniliform, ellipsoid to cylindrical, apex rounded to apiculate, pubescent, densely pubescent with erect hairs, slightly constricted around seeds when more than 1, orange when ripe; seeds 1 to 3, 17-27 mm long, 9-10 mm in diameter, ellipsoid; aril absent.

Distribution.

A mainly west African species from Guinea to Ivory Coast, and eastern Nigeria to Equatorial Guinea; in Cameroon known from the Central, Littoral, South and South-West regions.

Habitat.

A fairly uncommon species in Cameroon; in primary and secondary rain forest, in swamp forests, gallery forests. Altitude 50-200 m a.s.l.

Local and common names known in Cameroon.

None recorded.

Preliminary IUCN conservation status.

Least Concern (LC) ( Hoekstra et al. 2021).

Uses in Cameroon.

None reported.

Notes.

Monanthotaxis hirsuta is distinguished by its branches and petioles with long (> 1 mm) erect reddish brown hairs and when in flower by its long petals (> 20 mm) and its monocarps with dense long erect hairs. This species is morphologically close to M. enghiana and M. velutina (the latter not present in Cameroon), but the former generally has narrowly obovate or oblanceolate leaves with a narrow subcordate base and acuminate leaf apex, while the latter generally has more obovate leaves with a broader subcordate base and obtuse to acute leaf apex.

Throughout its range, M. hirsuta is quite variable when sterile ( Hoekstra et al. 2021) and can be hard to distinguish from M. enghiana . In Cameroon, however, M. hirsuta has broadly oblong or obovate leaves versus narrowly obovate leaves in M. enghiana .

Specimens examined.

Central Region: Chantier forestier au sud de Song Bong, 3.41°N, 10.5°E, 08 December 1967, Bamps P.R.J. 1381 (BR,P,YA). Littoral Region : Mapubi 30 km before Edea on Yaoundé-Edea road On forestry road 5 km direction to Sanaga river, 3.84°N, 10.39°E, 28 February 2018, Couvreur T.L.P. 1175 (K,MPU,P,WAG,YA) .

Figures

Map 8. A Monanthotaxis hexamera B Monanthotaxis hirsuta C Monanthotaxis klainei D Monanthotaxis laurentii E Monanthotaxis letouzeyi F Monanthotaxis montana G Monanthotaxis paniculata H Monanthotaxis pellegrinii I Monanthotaxis pynaertii. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 58. Monanthotaxis foliosa A leaf, upper view B base of leaf blade, lower view, note two small lobes at base C base of leaf blade, upper view D flower, petals removed, top view E detail of stamens, side view; not clearly unguiculate stamens. Monanthotaxis hirsuta F leaves, upper view G base of leaf blades, lower view H Base of leaf blade, upper view A-E Couvreur 601, Gabon F-H Couvreur 1175, Mapubi, Cameroon. Photos Thomas L. P. Couvreur.

Figure 59. Monanthotaxis gracilis A Flowering branch B flower, side view C sepal, inner view D outer petal, inner view E inner petal; inner view F stamens, side and front views G carpel, side view and detail of ovules H fruit, note persistent sepals. Monanthotaxis montana I flowering branch J flower, side view K inner petal, inner view L flower, all petals removed, side view M stamen, front view N carpel, side view and details of ovules O fruiting branch P seed, side view. Monanthotaxis hirsuta Q flowering branch R inner petal, inner view S stamen, front view T fruiting branch A from Meikle 956 B, C from Akpabla 1106 D-G from Dalziel 1096 H from FHI 28906 I-P unknown Q-S from Chevalier 14817 T from FHI 19738. Drawings by Helene Lamourdedieu, Publications Scientifiques du Museum national d'Histoire naturelle, Paris.