Sirdavidia solannona Couvreur & Sauquet, PhytoKeys 46: 4, 2015

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 : 317-320

Sirdavidia solannona Couvreur & Sauquet, PhytoKeys 46: 4, 2015

Figs 97 , 98 ; Map 12F

Type.

Gabon. Estuaire; Monts de Cristal , near first bridge after Kinguele, Couvreur T.L.P. 596, 15 Nov 2013: holotype: WAG[WAG0392343]; isotypes: LBV; P[P04022675]; YA; WAG[WAG0392342] .

Description.

Tree, 4-6 m tall, d.b.h. 2-4 cm; stilt roots or buttresses absent. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches sparsely pubescent. Leaves: petiole 3-4 mm long, 2-3 mm in diameter, sparsely pubescent to glabrous, slightly grooved, blade inserted on top of the petiole; blade 20-26 cm long, 4.5-9 cm wide, ovate to elliptic or obovate, apex long acuminate, acumen 2-3 cm long, base obtuse, coriaceous, below glabrous when young and old, above sparsely pubescent to glabrous when young, glabrous when old, concolorous; midrib sunken or flat, above glabrous when young and old, below sparsely pubescent when young, glabrous when old; secondary veins 9 to 12 pairs, glabrous above; tertiary venation reticulate. Individuals bisexual [possibly androdioecious], inflorescences cauliflorous or ramiflorous on young foliate or old leafless branches, axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 3 per inflorescence; pedicel 2-10 mm long, densely pubescent; in fruit 8-15 mm long, diameter unknown, glabrous; bracts several basal and one upper towards the lower half of pedicel, bracts ca. 1 mm long, ca. 1 mm wide; sepals 3, valvate, free, 2-3 mm long, ca. 2 mm wide, ovate, apex acute, base truncate, pink to light red, densely pubescent outside, glabrous inside, margins flat; petals free, valvate, sub equal; outer petals 3, 4-10 mm long, 2.5-5 mm wide, elliptic, apex acute, base truncate, red, margins flat, densely pubescent outside, pubescent inside, reflexed; inner petals 3, valvate, 4-9 mm long, 2-4 mm wide, elliptic, apex acute, base truncate, pink to light red, margins flat, densely pubescent outside, pubescent at least towards margins inside, reflexed; stamens 16 to 19, in 2 to 3 rows, 3-4 mm long, linear; connective tongue shaped, glabrous, bright yellow; staminodes absent; carpel 1, ovary 4-5 mm long, stigma cylindrical to coiled, sparsely pubescent. Monocarp sessile, 1, 50-70 mm long, 15-18 mm in diameter, oblong, apex apiculate, sparsely pubescent to glabrous (pubescent when young), smooth, longitudinally 4 to 6 ribbed; seeds not counted, biseriate, 12-16 mm long, 6-7 mm in diameter, ellipsoid; aril absent.

Distribution.

Cameroon and Gabon; in Cameroon known from the Littoral region.

Habitat.

A rare species, only collected once in 1973 in Cameroon, but it is common in the forest understory when present (e.g. Monts de Cristal, Gabon); in lowland primary or old secondary rain forests on non-inundated soils. Altitude 100-600 m a.s.l.

Local and common names known in Cameroon.

None recorded.

IUCN conservation status.

Vulnerable (VU) ( Cosiaux et al. 2019a s).

Uses in Cameroon.

None reported.

Notes.

Sirdavidia solannona is easily distinguished by its long acuminate leaves (acumen 2-3 cm long), flowers with bright yellow stamens and small red reflexed petals, resembling the flower of a Solanaceae nor even Ardisia ( Primulaceae ) (Olivier Lachenaud, pers. com), its single carpel and thus single monocarp with 6 to 8 ribs. The androdioecious nature [flowers unisexual staminate or bisexual] of this species needs to be confirmed. We observed male and bisexual flowers in Gabon. Letouzey 12405 suggests that male flowers are cauliflorous and hermaphrodite ones are ramiflorous, which needs to be confirmed.

Sirdavidia solannona , the only species of the genus, was thought to be endemic to Gabon ( Couvreur et al. 2015). However, after its description, a herbarium collection from Cameroon, Letouzey 12405 was identified (dating from 1973). We returned to this same locality in 2018, but unfortunately could not locate the species.

In the original description, we didn’t have access to a fruiting specimen. Here, we provide a description of the fruit (Moungazi 1544, LBV).

Specimen examined.

Littoral Region: near Nkak Ndjok (ca Mapubi) 30 km ENE Ed 3.83°N, 10.43°E, 17 December 1973, Letouzey R. 12405 (K,P).

Figures

Map 12. A Piptostigma pilosum B Piptostigma submontanum C Polyceratocarpus microtrichus D Polyceratocarpus parviflorus E Polyceratocarpus pellegrinii F Sirdavidia solannona G Sphaerocoryne gracilipes H Toussaintia hallei I Uvaria afzelii. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 97. Sirdavidia solannona A flowering branch B flower C sepal, outer side view D sepal, inner view E flower bud F outer petal, outer view G detail of pubescence of outer petal, outer side H outer petal, inner view I inner petal, outer view J detail of pubescence of inner petal, outer side K inner petal, inner view L detail of pubescence of inner petal, inner side M stamen from inner whorl N stamen from outer whorl O longitudinal section of carpel showing uniseriate row of ovules (stigma missing) P detail of young fruit A-P from Couvreur 596, 597. Drawing by Hans de Vries (Couvreur et al. 2015, fig. 3, p. 8).

Figure 98. Sirdavidia solannona A habit B base of leaf blade, upper side C base of leaf base, lower side D flower E flower, top view F flower G detail of receptacle, petals and 1 sepal removed H young cauliflorous fruit A Couvreur, no voucher B-H Couvreur 597, 596, Gabon. Photos Thomas L. P. Couvreur.