Uvariopsis solheidii (De Wild.) Robyns & Ghesq., Ann. Soc. Sci. Bruxelles, Ser. B liii. 321 (1933)

Dagallier, Leo-Paul M. J., Mbago, Frank M., Couderc, Marie, Gaudeul, Myriam, Grall, Aurelie, Loup, Caroline, Wieringa, Jan J., Sonke, Bonaventure & Couvreur, Thomas L. P., 2023, Phylogenomic inference of the African tribe Monodoreae (Annonaceae) and taxonomic revision of Dennettia, Uvariodendron and Uvariopsis, PhytoKeys 233, pp. 1-200 : 1

Uvariopsis solheidii (De Wild.) Robyns & Ghesq., Ann. Soc. Sci. Bruxelles, Ser. B liii. 321 (1933)

Figs 79 , 80A-O , 81

≡ Tetrastemma solheidii De Wild., Ann. Mus. Congo Belge, Bot. sér. 5, 3(1): 85 (1909). Type. Democratic Republic of the Congo - Orientale • A.F. Solheid 96 (holotype: BR! (BR0000008824240)); Banalia, Env. de Yambuya; 1°16'N, 24°33'E; 1906.

= Uvariopsis batesii Robyns & Ghesq., Ann. Soc. Sci. Bruxelles, Ser. B liii. 320 (1933). Type. Cameroon - South Region • G.L. Bates 1367 (holotype: BM! (BM000554077)), Bitye; 3°00'41.45"N, 12°21'04.18"E; 1919.

= Uvariopsis letestui Pellegr.; syn. nov. concerning Uvariopsis letestui var letestui (see details under this variety).

Description.

Shrub to tree 1.5-8 m tall, D.B.H 2-6 cm; young branches tomentose to shortly tomentose, old branches glabrous. Petiole 2-5 mm long, 1.5-3 mm wide, tomentose to glabrous. Leaf lamina 131-260 (285) mm long, 40-93 mm wide, length:width ratio 2.1-3.9, elliptic to obovate, coriaceous, base acute to rounded to subcordate, apex attenuate to narrowly acuminate, acumen 4-20 mm long, surface above glabrous, surface below glabrous; midrib impressed above, raised below, glabrous above, tomentose to glabrous below; secondary veins 7-13 pairs, brochidodromous to weakly brochidodromous, impressed above, raised below; tertiary veins reticulate. Flowers unisexual, male and female flowers dimorphic, on same individuals (plant monoecious, but individuals with only pistillate flowers were also reported; e.g. Le Testu 8458). Flower buds long ovoid to conical. Male inflorescences borne on small thickenings of the trunk, mainly between the base towards 50 cm, up to ca. 2.50 m, above the female inflorescence, composed of 1 to 2 flowers. Peduncle inconspicuous. Flower pedicel 9-30 mm long, 0.5-1 mm in diameter, pubescent to sparsely pubescent. Bracts 1 to 2 at base and none to 1 towards the lower half of the pedicel, upper bract 1-2 mm long, 1.5-3 mm wide, broadly ovate, adpressed, semi clasping the pedicel, pubescent outside, glabrous inside. Sepals 2, 1.5-2 mm long, 1.5-2 mm wide, broadly ovate, free, pubescent outside, glabrous inside, brown to red. Petals 4, 5-10 mm long, 2.5-3.5 mm wide, length:width ratio 2-3.2, ovate to narrowly ovate, free, straight to curving outward at anthesis, pubescent to sparsely pubescent outside, glabrous inside, brown to light red outside, dull pink to dark purplish red inside. Stamens ca. 300, 0.2-0.5 mm long, 0.2-0.3 mm wide, anthers linear, connective prolongation truncate. Female inflorescences borne on small thickenings of the trunk, mainly between the base towards ca. 50 cm, up to ca. 2.50 m, below the male inflorescence, composed of 1 to 2 flowers. Flower pedicel 30-198 mm long, 1-1.5 mm in diameter, pubescent to glabrous. Bracts 1 to 2 at base and none to 1 towards the lower 30% of the pedicel, upper bract 1-2 mm long, 1.5-3 mm wide, broadly ovate, adpressed, semi clasping the pedicel, pubescent outside, glabrous inside. Sepals 2, 1.5-4 mm long, 2-5 mm wide, broadly ovate, free, pubescent outside, glabrous inside, brown to red. Petals 4, 7.5-17 mm long, 3.5-7 mm wide, length:width ratio 1.3-3.6, ovate to narrowly ovate, free, straight to curving outward at anthesis, pubescent outside, glabrous inside, brown to light red outside, dull pink to dark purplish red inside. Carpels 30 to 65, 1-3.5 mm long, 1-1.5 mm wide, velutinous, free; stigma globose. Fruiting pedicel 30-176 mm long, 1-2 mm in diameter, pubescent to glabrous. Monocarps, 1-5, 21-70 mm long, 12-30 mm wide, length:width ratio 1.8-3 (measures taken from both dried fruits and their associated specimen label, note that monocarps seem to sink when drying), cylindrical, with 4-6 longitudinal ridges and several transversal ridges or wrinkles, sparsely pubescent to glabrous, bright red, subsessile; stipe 0-4 mm long, 4-5 mm wide, pubescent to glabrous. Seeds 2-10 per monocarp, uniseriate to biseriate, 11-18 mm long, 10-12 mm wide, ellipsoid.

Distribution.

Element of the Lower Guinean Domain and Congolia Domain of the Guineo-Congolian Region: Cameroon, Central African Republic, Democratic Republic of the Congo, Gabon, Republic of the Congo.

Habitat and ecology.

Lowland to submontane mature or old secondary rain forests. Altitude: 0-1200 m asl.

Phenology.

Flowers collected from January to May, in November and December. Fruits collected in February, from April to August, in October and December.

Vernacular names.

Central African Republic: ‘Molo-Mobay’ in Bissongo (Tisserant 2422), 'Ita ti ngaingai’ in Bambindjere (Fay 8384). Gabon: ‘Héli’ in Bakota ( Hallé 3029).

Notes.

Up. solheidii resembles Up. dioica , Up. guineensis , and Up. pedunculosa in having elliptic to obovate leaves, with acute to rounded base and attenuate to acuminate apex. Leaf base of Up. solheidii can also be subcordate, and differs from these species in having young branches and petioles tomentose to shortly tomentose (vs. pubescent to glabrous) and in having cylindrical monocarps with longitudinal and transversal ridges (vs. smooth in Up. dioica , with a single longitudinal ridge in Up. guineensis and verrucose in Up. pedunculosa ).

Here we make the two names Uvariopsis solheidii (De Wild.) Robyns & Ghesq. and Uvariopsis letestui Pellegr. synonyms. They have usually been distinguished based on the shape of their petals (narrowly ovate petals in Ud. solheidii vs. elliptic-ovate petals in Ud. letestui ), the position of the bracts along the flowering pedicel, and the length of the flower pedicels (longer in Ud. solheidii than in Ud. letestui , but with an overlap) ( Robyns and Ghesquière 1933a; Pellegrin 1948; Le Thomas 1965, 1969). Our observations indicate a high overlap between these supposedly distinctive characters, and difficulties to place some specimens in one or the other group. Our molecular phylogenies retrieve the specimens of Ud. solheidii as paraphyletic with the specimens of Ud. letestui . Together, they form a strongly supported monophyletic group (Fig. 1 , Suppl. materials 1, 2), justifying further the two names actually represent the same species. Given the priority rule ( Turland et al. 2018), the name Uvariopsis solheidii prevails. We make Ud. letestui as the variety Ud. solheidii var. letestui , to recognize the existence of this morphotype in spite of overlap of some characters with the type variety (see notes under the Ud. solheidii var. letestui ).

Conservation status.

This species is widespread in central Africa. It has been assessed as Least Concern LC (Botanic Gardens Conservation International and IUCN SSC Global Tree Specialist Group 2019b). Here its EOO is estimated at 1,429,739 km2 and its AOO at 132 km2.

Figures

Figure 1. Phylogenetic trees of the Monodoreae inferred with ASTRAL, based on 334 nuclear genes trees. The branch support is given as local posterior probability (LPP) in three shades of greys. For the details on the specimens see Suppl. material 3. Insets: flowers of A Ophrypetalum odoratum (Couvreur 82) B Sanrafaelia ruffonammari (Dagallier 31) C Asteranthe asterias (Dagallier 10) D Hexalobus crispiflorus (no specimen associated) E Uvariastrum zenkeri (no specimen associated) F Isolona hexaloba (no specimen associated) G I. cauliflora (Dagallier 44) H Monodora grandidieri (Dagallier 26) I M. myristica (living specimen at NY conservatory) J M. tenuifolia (Couvreur 1019) K Mischogyne elliotana (no specimen associated) L Uvariodendron gorgonis (Dagallier 38) M Ud. molundense (Bidault 2222) N Ud. connivens (Couvreur 1016) O Ud. var. fuscum (Couvreur 990) P Uvariopsis congensis (Lachenaud 1384) Q Up. lovettiana (Couvreur 97 b) R Up. bakeriana (Couvreur 1000) S Up. submontana (Couvreur 627) T Up. pedunculosa (Couvreur 878). Photos CC BY-NC 4.0 A, D-F, J, N, O, Q-T Thomas Couvreur B, C, G-I, L Leo-Paul Dagallier K Carel Jongkind M Ehoarn Bidault P Olivier Lachenaud.

Figure 79. Uvariopsis solheidii (De Wild.) Robyns & Ghesq A leaf, upper side B leaf base, upper side C leaf base, lower side D flower buds, side view, var. Uvariodendron fuscum solheidii (top), var. Uvariodendron fuscum letestui (bottom) E inflorescence, side view F male flowers, top view G drawing of: flowers with details (left), young fruits (top right), young monocarp (bottom right). A-C, D (bottom) Couveur 550 D (top), E, F Couvreur 855 G Halle 3474. Photos Thomas Couvreur. Drawing Nicolas Halle, part of specimen Halle 3474 (P).

Figure 80. Uvariopsis solheidii (De Wild.) Robyns & Ghesq. - var. solheidii A male inflorescence B female flower, one petal removed, side view C petal of female flower, inner view D carpel, side and front views, detail of ovules E male flower, one petal removed, side view F petal of male flower, inner view G stamen, front and side views - var. Uvariodendron fuscum letestui (Pellegr.) Dagallier & Couvreur H flower bud I petal of female flower, inner view J female flower, all four petals removed, side view K carpel, front view and detail of ovules L male flower, one petal removed, side view M stamen, front view N fruit O longitudinal section of A monocarp Uvariopsis pedunculosa (Diels) Robyns & Ghesq P female inflorescence Q female flower, one petal removed, side view R petal of female flower, inner view S carpel, side view and detail of ovules. A from Tisserant 2422 B-G from Tisserant 804 H-M from Halle 3060 N, O from Halle 2975 P-S from Le Testu 8525. Drawings by Helene Lamourdedieu, from Le Thomas (1969; pl. 54, p. 299), Publications Scientifiques du Museum national d'Histoire naturelle, Paris.

Figure 81. Distribution map of Uvariopsis solheidii. Shades of grey represent elevation, from white (sea level) to darker grey (higher elevation). The inset shows the extent of the map over Africa.