Monanthotaxis letouzeyi (Le Thomas) Verdc., Kew Bull. 25(1): 31, 1971

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 : 218-221

Monanthotaxis letouzeyi (Le Thomas) Verdc., Kew Bull. 25(1): 31, 1971

Figs 63 , 64 ; Map 8E

≡ Popowia letouzeyi Le Thomas, Adansonia sér. 2, 8: 241, 1968.

Type.

Cameroon. East Region; Nkoum, Letouzey R.G. 3066, 19 Feb 1960: holotype P[P00362617]; isotype: YA[YA0002635] .

Description.

Liana, 30 m tall, d.b.h. unknown. Indumentum of simple hairs; old leafless branches glabrescent, young foliate branches pubescent completely covered with dense erect reddish brown hairs 0.4 mm lon g. Leaves: petiole 6-15 mm long, 2-3 mm in diameter, densely pubescent with erect reddish brown hairs, weakly grooved adaxially, blade inserted on top of the petiole; blade 6-23 cm long, 6-12.2 cm wide, oblong to oblanceolate, apex rounded to emarginate, acumen ca. 1 cm long, base cordate (to rounded), papyraceous, below pubescent when young and old, above sparsely pubescent when young, glabrous when old, discolorous, whitish below; midrib sunken or flat, above densely pubescent when young and old, below densely pubescent when young and old; secondary veins 14 to 19 pairs, sparsely pubescent above; tertiary venation percurrent. Individuals unisexual, dioecious, male and female inflorescences dimorphic, male inflorescences cauliflorous with 3 to 50 flowers, in a fascicle or glomerule, peduncle 5-25 mm long; female inflorescences cauliflorous, in a condensed panicle with many flowers, peduncle 25-40 mm long. Flowers with 9 perianth parts in 3 whorls, male and female flowers dimorphic, male flowers: pedicel 6-10 mm long, ca. 1 mm in diameter, densely pubescent; basal bract ca. 1 mm long, ca. 1 mm wide; upper bract ca. 1 mm long, ca. 1 mm wide; sepals 3, valvate, basally fused, ca. 1 mm long, ca. 1 mm wide, broadly ovate, apex rounded, base truncate, brown, densely pubescent outside, glabrous inside, margins flat; petals shortly connate basally, outer petals longer than inner; outer petals 3, ca. 3 mm long, ca. 5 mm wide, ovate, apex acute, base truncate, margins flat, densely pubescent outside, papillose and sparsely pubescent with a few very short hairs inside; inner petals 3, valvate, 1.5-2 mm long, ca. 1 mm wide, elliptic to ovate, apex acute, base truncate, margins flat, papillose, sparsely pubescent towards the apex outside, papillose, sparsely pubescent towards the apex outside inside; stamens 31 to 40, in ca. 4 rows, ca. 1 mm long, oblong; connective truncate, pubescent; staminodes absent. Female flowers: pedicel 8-15 mm long, 1-2 mm in diameter, densely pubescent; in fruit 10-30 mm long, 2 mm in diameter; bracts 2, one basal and one upper towards the lower half of pedicel, basal bract 1-1.5 mm long, ca. 1 mm wide; upper bract ca. 1 mm long, ca. 1 mm wide; sepals 3, valvate, basally fused, 1-2 mm long, ca. 1-2 mm wide, broadly ovate, apex acuminate, base truncate, densely pubescent outside, densely pubescent inside, margins flat; petals free, outer petals longer than inner, inner petals entirely covered in bud; outer petals 3, 5-6 mm long, 4.8-6 mm wide, broadly ovate, apex obtuse, base truncate, margins flat, densely pubescent with short papillose hairs outside, pubescent with short papillose hairs inside; inner petals 3, valvate, ca. 2 mm long, 1.2-1.4 mm wide, spathulate, apex obtuse, base truncate, margins flat, pubescent with short papillose hairs outside, pubescent with short papillose hairs inside; carpels free, 120, ovary ca. 1 mm long, stigma ellipsoid to globose, glabrous. Monocarps stipitate, stipes 7-10 mm long, 2-3 mm in diameter; monocarps at least 3 (but potentially with many more, up to 100), 20-80 mm long, 9-10 mm in diameter, moniliform, globose, apex rounded, densely pubescent, smooth, constricted around seeds when more than 1, blackish green when ripe; seeds 1 to 6 per monocarp, ca. 9 mm long, c. 9 mm in diameter, ellipsoid; aril absent.

Distribution.

A central African species, from Cameroon to the Republic of the Congo; in Cameroon known from the East and South regions.

Habitat.

An uncommon species; in primary and old secondary rain forests, gallery forests and swamp forests, on sandy clay. Altitude 300-750 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 letouzeyi is distinguished by the dense erect reddish brown hairs on the young foliate branches and petioles, the generally cordate leaf base, unisexual flowers with male and female inflorescences both being cauliflorous. This species is morphologically close to M. diclina , but this latter has yellow-brown hairs, male inflorescences that are axillary (not cauliflorous) and 6 stamens with 12 staminodes (versus 31 to 40 stamens and no staminodes in Monanthotaxis letouzeyi ).

Specimens.

East Region: Bertoua, 4.56°N, 13.65°E, 05 September 1961, Breteler F.J. 1874 (P,U,WAG,YA); Palisco forest consession 15 km along main road into consession, 3.52°N, 13.54°E, 27 March 2015, Couvreur T.L.P. 752 (WAG,YA); Nkoum, 4.1°N, 13.17°E, 19 February 1960, Letouzey R. 3066 (P,YA); A 23 km à l’W de Masea (village situé à 50 km au SSW de Yokadouma), 3.15°N, 14.87°E, 04 July 1963, Letouzey R. 5403 (P,YA); Eden 48 km from Lomie, 3.25°N, 13.28°E, 15 April 1996, Nzooh Dongmo Z. L. 578 (MO). South Region: 16 km east from Lélé village, 2.28°N, 13.32°E, 07 September 2013, Couvreur T.L.P. 458 (WAG,YA); Piste Meyo Ntem-Evouzok 75 km W Ambam Entre 1er et 3e bras du Ntem, 2.17°N, 10.37°E, 28 November 1979, Letouzey R. 15270 (P,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 63. Monanthotaxis letouzeyi A leaf, upper side B detail of leaf pubescence, loer side C male flowers, cauliflorous D outer petal, inner view E inner petal, inner view F stamen, front view G flower, all petals removed, and a few stamens too H fruit, cauliflorous. Monanthotaxis cauliflora I female inflorescence J female flower, all petals removed K carpel, side view and detail of oules A-G from Letouzey 3066 H from Letouzey 5403 I-K from Zenker 356. Drawings by Helene Lamourdedieu, Publications Scientifiques du Museum national d'Histoire naturelle, Paris. (This drawing originally had sketches from Lebrun 6134 of a flowering branch with male flowers and detailed drawings of a male flower, however Hoekstra et al. (2021) indicated that Lebrun 6134 is in fact Monanthotaxis confusa Hoekstra, and so was removed from the drawing).

Figure 64. Monanthotaxis letouzeyi A base of leaf blade, upper view B cauliflorous inflorescence C leaf, upper view D base of leaf blade, lower view. Monanthotaxis montana E flower, basal view, note small sepals F flower, side view G leaves, top view H base of leaf blade, upper side I base of leaf blade, lower side A-D Couvreur 458, Lele, Cameroon E-I Couvreur 891, Gabon. Photos Thomas L. P. Couvreur.