Diospyros moutsambotei E. Mestre, Meeprom, H. N. Rakouth & Lowry, 2025

Mestre Serra, Edgard, Puglisi, Carmen, Linan, Alexander G., Meeprom, Nattanon, Rakouth, Hasina N., Schmidt, Heidi H. & Lowry II, Porter P., 2025, A taxonomic revision of the continental African material previously included in Diospyros ferrea (Ebenaceae), Plant Ecology and Evolution 158 (1), pp. 82-99 : 82-99

3. Diospyros moutsambotei E. Mestre, Meeprom, H. N. Rakouth & Lowry sp. nov.

Figs 1 C , 2 C , 5 , 6

Type

GABON – Ogooué-Ivindo • PN d’Ivindo, station de recherche Ipassa ; 00°30’10”N, 12°47’45”E; 477 m; 14 Mar. 2019; fr.; Bidault et al. 4494; holotype: MO! [ MO-6956210 ]; isotypes: BR, BRLU [ BRLU 0026875 ], LBV, P! [ P 01085637 ], WAG .

Diagnosis

Diospyros moutsambotei E. Mestre, Meeprom, H. N. Rakouth & Lowry can be distinguished from other African species previously included in D. ferrea by the combination of leaves with a symmetric (not falcate) lamina that has an evident pair of basal glands and an acuminate (rarely acute) apex, a broadly ellipsoid fruit 12–15 × 9–11 mm, and a fruiting calyx with 3 very broadly rounded-triangular lobes ca 2–3 × 9–11 mm.

Description

Treelet 2–8 m tall. Bark dark grey-brown, surface irregular, lenticels brown, round and prominent. Young stems terete, dark brown to black, with dense, persistent, shortly hispid, pale hairs ca 0.5 mm long, and sparse, caducous, longer, golden hairs <0.1 mm long. Leaves alternate; petiole 1.5–5 mm long, 0.5–1 mm diam., terete, flat or shallowly sulcate above, with the same two types of indument as the stem; lamina 1.5–10.5 × 1–4.5 cm, ovate to elliptic, rarely obovate or suborbicular, consistently symmetric (never falcate), coriaceous, glabrous on both sides, concolourous to weakly discolourous, glossy, dark green above, pale green below, with an evident pair of glands toward the base, borne equally or unequally distant to the petiole, base obtuse to acute, margin slightly thickened, sometimes minutely revolute, apex acuminate, rarely acute, the acumen to 15 mm long and rounded; venation pinnate, midvein sulcate above, raised below, secondary and tertiary venation visible on both sides, more so below, darker in younger leaves and lighter in older leaves, raised below and slightly so above; secondary venation forming a nearly right angle with the midrib and slightly decurrent to it, veins (6) 8 or 9 (10) per side, brochidodromous, forming loops 2 / 3 or more of the way between the midrib and margin, the most apical ones smaller and more steeply angled; tertiary venation slightly finer than the secondary, forming a nearly horizontal reticulation and further loops between the secondary veins and the margin. Male flowers in dense, axillary clusters of up 9 flowers, pedicel <1 mm; calyx moderately covered in straight, appressed, golden to golden brown hairs 0.5–0.75 mm long outside, nearly glabrous inside, basal portion cupuliform, ca 3.5 × ca 4 mm, lobes 3, broadly triangular, 1.5 × 3–3.5 mm, acute; corolla creamy white (in vivo), with dense, appressed, golden to light brown hairs 0.75–1 mm long outside, glabrous inside, tube narrowly urceolate, 4–5 × 2.5–3 mm, lobes 3, ovate, ca 3.5 × 2 mm, imbricate, apex acute; stamens 5, inserted at the base of the corolla tube, very pale cream-brown (in vivo), filament 0.5–1 mm, anther 3.5–4 mm; pistillode broadly ovoid, 1–1.5 × 1–2 mm, densely covered in erect, straight, golden hairs 0.75 mm long. Female flowers axillary, solitary or in short, few-flowered cymes, axes with sparse straight, appressed, whitish-golden hairs ca 0.25 mm long, pedicel 1–2 mm long; calyx moderately covered outside and more sparsely inside in straight, appressed, whitish-golden hairs ca 0.25 mm long, basal portion cupuliform, 4.5–5 × 3.5–4 mm, lobes 3, shallowly and broadly triangular, spreading, ca 0.5 × 3 mm, short-acuminate; corolla densely covered in straight, appressed, whitish-golden hairs to 1 mm long, becoming glabrous towards the lobe margins, glabrous inside, tube slightly urceolate, 5.5–6 × 3–3.5 mm, lobes 3 (4), broadly ovate, spreading, weakly imbricate, 2–2.5 × 2–2.5 mm, apex rounded-acute; staminodes lacking; ovary ovoid, rounded-triangular in cross section, ca 3 × 2 mm, densely covered in straight, appressed, golden hairs 0.75 mm long, style 1.0– 1.5 mm long, base with minute, appressed hairs, apex glabrous. Fruits axillary, solitary or in pairs, pedicel 1–1.5 mm, indumentum persistent; calyx cupuliform, 9–11 mm wide, dark brown (in sicco), with moderately dense, appressed, greyish-white hairs to 1 mm long outside, sparser, shorter and darker inside, basal portion cupuliform, 5–6 × ca 9–11 mm, lobes 3, shallow, entire, very broadly rounded-triangular, ca 2–3 × 9–11 mm, apex short-acuminate; fruit globose when immature, broadly ellipsoid when ripe, 12–15 (– 20) × 9–11 mm, surface smooth, with sparse, appressed, golden hairs, denser toward the apex, brown (in sicco), style persistent at the apex. Seed 1, 12–20 × 4–6 mm, narrowly obloid, slightly asymmetrical, minutely rugose, dark reddish brown and somewhat glossy (in sicco).

Distribution

Cameroon, Central African Republic, Gabon, Democratic Republic of the Congo, and Republic of the Congo (Fig. 4 ).

Habitat

Diospyros moutsambotei is known from riverine and periodically inundated forests, often associated with vegetation dominated by Gilbertiodendron dewevrei (De Wild.) J. Léonard ( Fabaceae ). It has been recorded at 350–700 m elevation.

Phenology

Flowering material has been collected in December and from February to April, and fruiting material in February, March, May, and June.

Etymology

This species is named in honour of Jean-Marie Moutsamboté (1953–2022), who was one of the most highly regarded botanists working in Central Africa. Prof. Moutsamboté contributed greatly to our knowledge of the forests of the Republic of the Congo, participating in dozens of botanical expeditions throughout the country. He served as Head of the Botany Laboratory at the Centre d’Études sur les Ressources végétales and the National Herbarium in Brazzaville from 1986 to 2001 and then taught plant biology and forestry at the Université Marien N’Gouabi before returning to the National Herbarium in 2015, where he headed the Ecology-Phytosociology unit. Jean-Marie has left an important legacy and will long be remembered by the many students and colleagues who had the pleasure of working with him.

Preliminary IUCN conservation assessment

Diospyros moutsambotei has an Extent of Occurrence of 449,586 km 2 and a minimum Area of Occupancy of 92 km 2. The species is known from 25 collections representing ten different occurrences, some of which fall within formally protected areas whereas others that do not are likely subjected to several threats, including land clearing for agriculture and forest exploitation. Targeted collecting at all these sites is needed to confirm the status of the extant subpopulations. A continuing decline is inferred for the extent of occurrence, area of occupancy, area, extent, and / or quality of habitat, number of locations, and number of mature individuals. With respect to the most serious plausible threat (land clearing), Diospyros moutsambotei has been recorded at ten locations and is thus assessed as Vulnerable: VU B 2 ab (i, ii, iii, iv, v).

Additional material examined

GABON – Ogooué-Lolo Province • Parc National de l’Ivindo ; 00°15’10”S, 12°44’16”E; 393 m; 12 Feb. 2010; Dauby 2292; BRLU, LBV, MO • Lastoursville ; 00°15’19”S, 12°44’06”E; 387 m; 18 Apr. 2010; Nguema 1248; BRLU, K, LBV, MO, P • 10 km S of Majojou ; [00°30’39”N, 12°48’13”E]; 500 m; 24 Feb. 1979; Florence 1676; P [ P 04539709 ] . – Woleu-Ntem Province • Minkébé area ; [01°30’00”N, 12°49’00”E]; 16 May 1990; Minkébé Series W 341 ; MO [ MO-6055800 ], WAG [ WAG.1778699 , WAG.1778700 ] • Minkébé district, Nsye valley ; [01°30’00”N, 12°48’00”E]; 21 Feb. 1990; Wieringa 599; BR [ BR 0000021712791 ], K, MO [ MO-6379125 ], WAG [ WAG.1778707 ] .

CAMEROON – Central Region • Ndanan 2; [03°36’29”N, 11°34’41”E]; 710 m; 22 Mar. 2004; Cheek 11937; K, MO [ MO-4875195 ], WAG [ WAG.1778730 ] • Mefou National Park ; [03°37’12”N, 11°34’48”E]; 700 m; 23 Mar. 2004; Tadjouteu 570; BR [ BR 0000009522992 ], K [ K 000339048 ], MO [ MO-4811439 ], WAG [ WAG.1778728 ] . – East Region • 2 km W of the Sangha River ; [02°21’00”N, 16°07’00”E]; 350 m; 17 Nov. 1998; Harris 6459; E [ E 01021159 ] . – South Region • between N’Kolandom and N’Koemvone ; [02°47’00”N, 11°09’00”E]; 650 m; 24 Feb. 1975; de Wilde 7995; BR [ BR 0000016101654 ], K [ K 001394634 ], MO [ MO-5654747 ], P [ P 04589936 ], WAG [ WAG.1778733 , WAG.1778734 ] .

CENTRAL AFRICAN REPUBLIC – Haute-Sangha Prefecture • Dzanga-Sangha Reserve ; [02°21’00”N, 16°09’00”E]; 350 m; 9 Sep. 1988; Harris 1091; BR [ BR 0000100027273 ], MO [ MO-5965327 ] • 45 km S of Lidjombo ; [02°22’00”N, 16°09’00”E]; 350 m; 11 Feb. 1989; Harris 1823; BR [ BR 0000100027242 ], K [ K 001561010 ], MO [ MO-3823625 ] • 40 km S of Lidjombo ; [02°25’00”N, 16°09’00”E]; 350 m; 15 Feb. 1989; Harris 1876; BR [ BR 0000100027266 ], MO [ MO-5965320 ] • 45 km S of Lidjambo ; [02°21’00”N, 16°09’00”E]; 350 m; 23 Feb. 1989; Harris 1918; BR [ BR 000016101630 ], FHO [ FHO-164548 ], K, MO [ MO-5672092 ], WAG [ WAG.1778732 ] • 45 km S of Lidjombo ; [02°22’00”N, 16°11’00”E]; 350 m; 12 Mar. 1989; Harris 2032; BR [ BR 000016101623 ], FHO [ FHO-164549 ], K [ K 001561012 ], MO [ MO-5672091 ], WAG [ WAG.1778731 ] • 12 km S of Lidjombo ; [02°34’00”N, 16°05’00”E]; 28 Mar. 1994; Harris 4854; BR [ BR 0000100027297 ], E [ E 01021135 ] .

DEMOCRATIC REPUBLIC OF THE CONGO – Équateur Province • Bolomba ; [00°03’44”N, 19°19’38”E]; 26 Feb. 1958; Evrard 3541; BR [ BR 0000016101715 ], WAG [ WAG.1778735 ] . – Ituri Province • Epulu, zone de Mambasa (Ituri Forest) ; [01°25’00”N, 28°35’00”E]; 750 m; 5 Dec. 1987; Hart 783; MO [ MO-4292715 ] . – Tshuapa Province • Befale ; [00°22’20”N, 20°50’19”E]; 3 Jun. 1958; Evrard 4166; BR [ BR 0000016101692 , BR 0000016101708 ], FHO [ FHO-105514 ] .

REPUBLIC OF THE CONGO – Sangha Department • Nouabalé-Ndoki National Park ; [02°10’00”N, 16°31’00”E]; 10 Jun. 2002; Harris 7961; E [ E 01021158 ] • 2.5 km NNE of Bomassa village ; [02°13’30”N, 16°11’43”E]; 22 Mar. 2010; Harris & Moutsamboté 9672; E [ E 00397397 ], IEC • [Without precise locality]; [02°11’54”N, 16°17’28”E]; 22 May 2011; Ndolo Ebika 607; E [ E 00607099 ], IEC, WAG [ WAG.1778729 ] • 33.5 km NE of Kabo ; [02°01’53”N, 16°21’12”E]; 10 Nov. 2006; Nzolani Silaho 1133; E [ E 01021156 ], IEC • 55 km NE of Kabo, Nouabalé-Ndoki National Park ; [02°22’17”N, 16°28’25”E]; 25 Feb. 2007; Nzolani Silaho 2724; E [ E 01021155 ], IEC • Makambi Bai ; [02°09’37”N, 16°15’17”E]; 350 m; 22 Mar. 2010; Nzolani Silaho 4573; E [ E 01021130 ], IEC .

Notes

Of the taxa treated here, Diospyros moutsambotei is the only one whose distribution overlaps with that of another species, namely the widespread D. smeathmannii . It can, however, be easily distinguished by its symmetrical leaves that are not falcate (vs some or all asymmetric and falcate in D. smeathmannii ), the presence of a pair of basal glands, most prominently visible on the abaxial leaf surface (vs varying numbers of scattered, minute glands), and its broadly ellipsoid fruits that measure 12–15 × 9–11 mm (vs ellipsoid and 10–14 × 5–9 mm).

Figures

Figure 1. Leaves of Diospyros depicting abaxial (left) and adaxial (right) surfaces. A. D. angolensis (Gossweiler 9182, K 001561021). B. D. guineensis (de Koning 6007, NY 02610014). C. D. moutsambotei (Tadjouteu 570, BR 0000009522992). D. D. smeathmannii (Morton SL 1201, MO- 2865964). E. D. suaheliensis (Faulkner 2151, K 001561011). Photos by Alexander Linan.

Figure 2. Fruits of Diospyros. A. D. angolensis (holotype, Gossweiler 789, P 04595254). B. D. guineensis (Aubréville 903, P 04595333). C. D. moutsambotei (Bidault et al. 4494, MO- 6956210). D. D. smeathmannii (Jongkind 4327, MO- 6379106). E. D. suaheliensis (Faulkner 2151, K 001561011). Photos by Porter P. Lowry II.

Figure 4. Distribution map in Africa of the five species recognized among the African material previously included in Diospyros ferrea.

Figure 5. Isotype of Diospyros moutsambotei (Bidault et al. 4494, P 01085637).

Figure 6. Photos of Diospyros moutsambotei in the field. A. Lower surface of branch with fruits. B. Upper surface of same branch. C. Fruits on lower surface of branch. D. Detail of fruits. E. Closeup of leaf base (abaxial surface) showing pair of glands. F. Inflorescence of male flowers (side view). G. Inflorescence of male flowers (top view). A – E, Bidault et al. 4494, photos by Ehoarn Bidault; F – G, Harris & Moutsamboté 9672, photos by David J. Harris.