Monanthotaxis pynaertii (De Wild.) P.H.Hoekstra, Blumea 66 (1): 191, 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 : 228-230

Monanthotaxis pynaertii (De Wild.) P.H.Hoekstra, Blumea 66 (1): 191, 2021

Fig. 67 ; Map 8I

≡ Popowia pynaertii De Wild., Bull. Jard. Bot. État Bruxelles 4: 382, 1914.

Type.

Democratic Republic of the Congo. Equateur; Mbandaka, Eala, Pynaert L.A.E.J. 852, 20 Dec 1908: lectotype, designated by Hoekstra et al. (2021), p. 191: BR[BR0000008805348, BR0000008805355] .

Description.

Liana, 20 m tall, d.b.h. up to 2 cm. Indumentum of simple hairs; old leafless branches glabrescent, young foliate branches pubescent with erect reddish brown hairs 0.6-1.5 mm long. Leaves: petiole 5-7 mm long, 1-2 mm in diameter, pubescent with long erect reddish brown hairs, weakly grooved adaxially, blade inserted on top of the petiole; blade 9.5-23.2 cm long, 2.9-7 cm wide, ovate to oblanceolate, apex acuminate to acute, acumen 0.5-1 cm long, base rounded to subcordate, papyraceous to subcoriaceous, below pubescent with erect yellow hairs 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 pubescent when young and old; secondary veins 11 to 17 pairs, glabrous above; tertiary venation percurrent. Individuals unisexual, dioecieous, male and female inflorescences dimorphic, male inflorescences axillary, composed of a solitary flower to a few-flowered fascicle with up to 10 flowers; peduncle 4-8 mm long with erect hairs, female inflorescences cauliflorous, a condensed panicle with many flowers; peduncle 35-50 mm long, densely pubescent with erect hairs; Flowers with 9 perianth parts in 3 whorls, male and female flowers dimorphic. Male flowers: flowering pedicel 2-3 mm long, ca. 1 mm in diameter, 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, c. 1 mm long, ca. 1 mm wide, triangular to ovate, apex acute, base truncate, pubescent outside, glabrous inside, margins flat; petals free, outer petals longer than inner, inner petals entirely covered in bud; outer petals 3, ca. 3 mm long, 3 mm wide, circular to broadly ovate, apex rounded to obtuse, base truncate, margins flat, densely pubescent outside, pubescent inside; inner petals 3, valvate, ca. 1 mm long, ca. 0.5 mm wide, ovate, apex rounded, base truncate, margins flat, pubescent outside, pubescent inside; stamens 6 (9), in 1 row, ca. 1 mm long, oblong; connective truncate, glabrous; staminodes 12 to 16, in one whorl externally to the stamens, very short, very sparsely pubescent or glabrous. Female flowers: flowering pedicel 20-30 mm long, ca. 1.5 mm in diameter, densely pubescent with erect hairs; in fruit ca. 33 mm long, ca. 2 mm in diameter; basal bract ca. 2-3 mm long, 1.5-2 mm wide; upper bract ca. 1 mm long, ca. 1 mm wide; sepals 3, valvate, basally fused, 1-2 mm long, 1.5-2 mm wide, ovate to broadly ovate, apex acute, base truncate, pubescent outside, glabrous inside, margins flat; petals free, outer petals longer than inner; outer petals 3, 5-6.3 mm long, 5-6.3 mm wide, circular to broadly ovate, apex rounded to obtuse, base truncate, margins flat, densely pubescent outside, pubescent inside; inner petals 3, valvate, 1.7-1.8 mm long, 0.7-0.8 mm wide, ovate, apex rounded, base truncate, margins flat, pubescent outside, pubescent inside; carpels free, 95 to 150, ovary ca. 2 mm long, stigma globose to ellipsoid, glabrous. Monocarps stipitate, stipes 9-12 mm long, ca. 2 mm in diameter; monocarps up to 20, 20-60 mm long, 7-8 mm in diameter, moniliform, ellipsoid to cylindrical, apex apiculate, pubescent, verrucose, constricted around seeds when more than 1, color unknown; seeds 1 to 6 per monocarp, 11-13 mm long, 7-8 mm in diameter, ellipsoid; aril absent.

Distribution.

A central African species, from Cameroon to the Democratic Republic of the Congo and the Central African Republic; in Cameroon known from the East region.

Habitat.

Very frequent when present (Letouzey 5049) but only known in Cameroon from a single collection to date; in swamp forests and gallery forests. Altitude ~500 m a.s.l.

Local and common names known in Cameroon.

None recorded.

Preliminary IUCN conservation status.

Vulnerable (VU) ( Hoekstra et al. 2021).

Uses in Cameroon.

None reported.

Notes.

Monanthotaxis pynaertii is distinguished from the other species in the genus with cauliflorous inflorescences by the long (up to 1.5 mm long) erect hairs on the young foliate branches, petioles and leaves. It was previously placed in synonymy of M. diclina , but Hoekstra et al. (2021) reinstated its species status, as it differs by its erect pubescence, larger flowers, and more numerous carpels in the female flowers (95 to 150 versus 80 to 100 in M. diclina ).

Specimen.

East Region: A 25 km au Sud de Mboy I (45 km à l’Est de Yokadouma), 3.38°N, 15.13°E, 15 May 1963, Letouzey R. 5049 (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 67. Monanthotaxis pynaertii A branch with male inflorescences B female inflorescence C female flower bud D female flower with two outer petals removed E outer petal of female flower, inner view F inner petal of female flower, inner view G carpel H male flower bud I male flower with two outer petals removed J outer petal of male flower, inner view K inner petal of male flower, inner view L stamen front and side views M, N staminodes O fruit A, H-N from Evrard 5198 B-G from Pynaert 852 O from Tisserant 2035). Drawings by Esmee Winkel (Hoekstra et al. 2021, fig. 25, p. 190).