Hexalobus salicifolius Engl., Monogr. Afrik. Pflanzen.-Fam. 6: 57, 1901

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 : 128-129

Hexalobus salicifolius Engl., Monogr. Afrik. Pflanzen.-Fam. 6: 57, 1901

Fig. 31 ; Map 4H

Type.

Cameroon. South Region; Bipindi, Zenker G.A. 2268, 1900: holotype: B[B 10 0154199]; isotypes: BM[BM000546383]; COI[COI00033180]; G[G00011622, G00011623]; GEOT[GOET005680]; HBG[HBG518921]; K[K000582046]; L[L 0049299]; M[M0089219]; MO n.v.; P[P00363369, P00363367]; S[S12-22767]; WAG[WAG0053744]; WU[WU0025889]; Z[Z-000034502] .

Description.

Tree, up to 35 m tall, d.b.h. up to 100 cm; stilt roots or buttresses absent, trunk fluted. Indumentum of simple hairs; old leafless branches glabrous, young foliate branches densely pubescent. Leaves: petiole 1-3 mm long, 1-2 mm in diameter, sparsely pubescent, slightly grooved, blade inserted on top of the petiole; blade 5-10 cm long, 1.5-3.5 cm wide, elliptic, apex acuminate, acumen 0.5-1 cm long, base cuneate, coriaceous, above glabrous when young and old, above sparsely pubescent when young, sparsely pubescent when old, concolorous; midrib sunken or flat, below pubescent when young and old, below pubescent when young and old; secondary veins 5 to 12 pairs; tertiary venation reticulate. Individuals bisexual; inflorescences ramiflorous on young foliate branches, axillary. Flowers with 9 perianth parts in 3 whorls, 1 to 3 per inflorescence; pedicel 8-15 mm long, 1-2 mm in diameter, densely pubescent; in fruit 10-13 mm long, 2-3 mm in diameter, glabrous; bracts 5 to 6, several basal and two (sometimes fused) towards the upper half of pedicel, basal bracts 5 mm long, 3 mm wide; upper bracts 5 mm long, 3 mm wide; sepals 3, valvate, free, 7-11 mm long, 4-7 mm wide, ovate, apex acute, base truncate, brown, pubescent outside, densely pubescent inside, margins flat; petals basally fused, tube 2-4 mm long, purple, inner and outer whorl not differentiated, equal; lobes 17-30 mm long, 4-8 mm wide, elliptic, apex rounded, cream to yellow, margins wavy, pubescent outside, pubescent inside, plicate; stamens numerous, in 11 to 13 rows, ca. 2 mm long, elongated; connective discoid, glabrous, cream; staminodes absent; carpels free, 3 to 4, ovary 2-3 mm long, stigma divided into two lobes with margins coiled inwards, pubescent. Monocarps stipitate, 1-2 mm long, ca. 3 mm in diameter; monocarps 2 to 4, 60-93 mm long, 40-55 mm in diameter, ovoid to oblong, apex rounded, pubescent to glabrous, verrucose, rusty-brown when ripe; seeds 15 to 15 per monocarp, 22-31 mm long, 11-18 mm in diameter, flattened; aril absent.

Distribution.

Known from Cameroon, Gabon and the Republic of Congo (one specimen); in Cameroon known from the East, South and Central regions.

Habitat.

A fairly scarce species, in primary and secondary lowland and pre-montane rain forest, occasionally in semi-deciduous forests, in periodically inundated forests and on river banks. Altitude 50-900 m a.s.l.

Local and common names known in Cameroon.

Ooué (dial. Jaundi, Hédin 1663); Owoé (dial. Yetbou, Médou 1703).

IUCN conservation status.

Least Concern (LC) ( Cosiaux et al. 2019o).

Uses in Cameroon.

None recorded.

Notes.

Hexalobus salicifolius is morphologically close to H. crispiflorus from which it is distinguished by its smaller leaves, fewer carpels (2 to 4 versus 7 to 16 in H. crispiflorus ) and verrucose monocarps (versus smooth in H. crispiflorus ).

Specimens examined.

South Region: South Province 15 km from Kribi, 2.96°N, 9.933°E, 28 August 1970, Bos J.J. s.n. (WAG[WAG0162941]); Campakok (Camp Akok), 2.65°N, 9.9°E, 30 October 1991, Hallé F. 4181 (WAG); Colline près Mezese à 17 km ENE de Sangméli 2.95°N, 12.14°E, 19 October 1966, Letouzey R. 8122 (BR,P,YA); Bidou, 2.85°N, 9.991°E, 28 May 1954, Médou J. SRFK 1703 (P,YA); 22 km NE of Kribi Kribi-Bipindi road Bidou I cultivated fields NE of village, 3.00°N, 10.09°E, 04 June 2006, van Velzen R. 98 (WAG); 26 km N of Kribi SE of the toll post for Kribi-Edéa road forest at Bebamboue II, 3.05°N, 9.987°E, 26 May 2006, van Velzen R. 99 (WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1900, Zenker G.A. 2268 (COI,G,G,K,L,M,MO,P,S,WAG); Bipindi, 3.08°N, 10.42°E, 01 January 1907, Zenker G.A. 3330 (BR,G,UPS) .

Figures

Map 4. A Duguetia dilabens B Duguetia staudtii C Greenwayodendron glabrum D Greenwayodendron suaveolens E Hexalobus bussei F Hexalobus crispiflorus G Hexalobus monopetalus H Hexalobus salicifolius I Isolona campanulata. White borders represent region limits in Cameroon; green patches represent protected areas (see methods and Suppl. material 1: Fig. S 1).

Figure 31. Hexalobus crispiflorus A flowering branch B flower bud C receptacle, petals removed D stamen, front view E three carpels different views, one with longitudinal section showing ovules F pedicel with one monocarp, note smooth surface G longitudinal section of monocarp showing seeds. Hexalobus salicifolius H branch I a single detached monocarp, note verrucose surface A, C-F from Le Testu 8838 B from Le Testu 693 G, H from Chevalier 7471 I from Le Testu 6387 J from Zenker 2268. Drawings by Helene Lamourdedieu, Publications Scientifiques du Museum national d'Histoire naturelle, Paris; modified from Le Thomas (1969 b, pl. 14, p. 85).