Xylopia phloiodora Mildbraed, Notizbl. Bot. Gart. Berlin-Dahlem 8: 55-56. 1921.

Johnson, David M. & Murray, Nancy A., 2018, A revision of Xylopia L. (Annonaceae): the species of Tropical Africa, PhytoKeys 97, pp. 1-252 : 159-161

38. Xylopia phloiodora Mildbraed, Notizbl. Bot. Gart. Berlin-Dahlem 8: 55-56. 1921. Fig. 35A-L

Type.

CAMEROON. South Region, zwischen Bipindi und Ebolowa bei Malakat , Dec 1913, J. Mildbraed 7592 (lectotype, here designated: B! [100153152]; isolectotype: K! [000199053]) .

Description.

Tree up to 38 m tall, d.b.h. up to 80 cm, bole straight, cylindrical, sometimes with small buttresses up to 1.5 high extending up to 50 cm from the base, rarely with stilt roots, secondary branches radiating horizontally from trunk to form a small crown; bark yellowish gray to light gray, finely fissured and brown-punctate. Twigs brown, eventually light gray, initially densely appressed-pubescent, the hairs 0.1-0.4 mm long, soon glabrate; nodes occasionally with two axillary branches, young shoots often with flattened conduplicate leaves. Leaf with larger blades 5.7-17.2 cm long, 1.9-5.9 cm wide, chartaceous or subcoriaceous, concolorous or slightly discolorous, elliptic or oblong-elliptic to lanceolate, apex obtuse to gradually acuminate, base broadly cuneate, rounded, or rarely subcordate, sometimes slightly oblique, short-decurrent on petiole, glabrous or with a few hairs along the midrib adaxially, initially golden-sericeous but soon sparsely appressed-pubescent abaxially; midrib slight impressed to slightly raised adaxially, raised abaxially, secondary veins arcuate, indistinctly brochidodromous, often drying pinkish red and contrasting with the gray of the lamina, 10-16 per side, diverging at 40-60° from the midrib, these and higher-order veins slightly raised on both surfaces; petiole 3.5-8 mm long, flattened to canaliculate, pubescent. Inflorescences axillary or from the axils of fallen leaves, 1-10-flowered, commonly 2-3-flowered, pubescent; peduncle 1 per axil, 2-4 mm long; pedicels 3 per peduncle or not pedunculate, 2.5-5.5 mm long, 0.9-1.0 mm thick; bracts 2, both attached near the pedicel midpoint, the lower caducous and the upper persistent, 1.5-2.5 mm long, ovate, semicircular, or rounded, apex obtuse to bifid; buds linear-lanceolate to linear-oblong, often falcate, apex obtuse. Sepals slightly spreading at anthesis, 1/5-2/3 connate, 2-3.6 mm long, 2.5-2.8 mm wide, coriaceous, ovate to broadly ovate or triangular, apex obtuse to acute, appressed-pubescent abaxially. Petals cream-colored to pale yellow with a blotch of purple at the base in vivo; outer petals spreading at anthesis, 19-23 mm long, 3-4.3 mm wide at base, 1.7-2 mm wide at midpoint, fleshy, linear-lanceolate, apex obtuse, densely puberulent except for the glabrous base adaxially, sericeous to the base abaxially; inner petals spreading, possibly bent outward at anthesis, 15.5-21 mm long, 2-3 mm wide, 0.6-0.8 mm wide at midpoint, fleshy, linear, apex acute, base with undifferentiated margin, puberulent on both surfaces except for glabrous base. Stamens ca. 120; fertile stamens 1.3-2 mm long, narrowly oblong, apex of connective 0.1-0.3 mm long, shieldlike or slightly hemispheric, overhanging anther thecae, glabrous, anthers 20-24-locellate, filament 0.4-0.5 mm long; outer staminodes 1.3-1.6 mm long, broadly clavate to narrowly oblong, apex obtuse, rounded, bifid, or truncate; inner staminodes 1.1-1.3 mm long, broadly clavate, apex truncate; staminal cone 1.2-1.6 mm in diameter, 1.1-1.5 mm high, completely concealing the ovaries, rim even. Carpels 5-8; ovaries 1.1-2 mm long, narrowly ellipsoid, pubescent, stigmas connivent, 2.1-3.0 mm long, linear, sometimes widened at the midpoint, glabrous, sometimes warty, rarely with a few hairs at the apex. Torus flat, 2-2.5 mm in diameter. Fruit of up to 9 glabrate monocarps borne on a pedicel 5-16 mm long, 5-8 mm thick, glabrate; torus 11-19 mm in diameter, 6-12 mm high, depressed-globose. Monocarps with greenish purple, dark brown, brownish gray, reddish brown, or cinnamon-colored exterior and light pink endocarp in vivo, 2.7-4.3 cm long, 1.7-3.1 cm wide, 1.7-2.4 cm thick, ovoid, oblong, or broadly ellipsoid, not torulose, apex rounded, base sessile but slightly narrowed, slightly rugose, usually conspicuously lenticellate; pericarp 1.5-4 mm thick. Seeds 7-12 per monocarp, in two rows, lying nearly perpendicular to long axis, 16-21 mm long, 7-10 mm wide, 4.5-7 mm thick, oblong, elliptic to wedge-shaped in cross-section, truncate at micropylar end, rounded at chalazal end, brown to blackish brown, smooth, glossy or dull, raphe/antiraphe not evident, micropylar scar 1.7-2.5 mm long, 1.6-2.7 mm wide, oblong, obovate, or triangular; sarcotesta orange, fleshy in vivo, sometimes visible as a white crust on dried seeds; aril absent.

Phenology.

Specimens with flowers have been collected in all months of the year except October, and with fruits in January, and from April to September.

Distribution

(Fig. 36 ). Occurs from south-central Nigeria east to northeastern Democratic Republic of the Congo and south to southern Republic of the Congo and southeastern Democratic Republic of the Congo. It has also been reported from Angola ( Paiva 2008) but it is not possible from the specimen images (LISC 16349, 16350) to confirm the identification. Xylopia phloiodora has been collected from a variety of lowland moist forest habitats, at elevations of 200-900 m.

Local names.

Aghako (Kennedy 2612), bendjo (Corbisier-Baland 1627), bompaie bo fufow (Turumbu, Louis 2477), ddong-éli (Fang, Duboislouveau 903), mbeb (Balavele, Grison FG 22/RC 827), molo-nzange (Lissongo, Tisserant 955), molo-mosome (Lissongo, Tisserant 1113), molo-nyama (Lissongo, Tisserant 1138), molonzangue (Issongo, Guigonis 2320), odjobbo (Bulu, Mildbraed (1921)), odzobi (Service Forestier du Cameroun 67), ohunegbo (Kennedy 2612), sange (Bibaya, Letouzey & Villiers 10418; Kibila, Hart TH 1177; Hart 1654), sangue (Baya & Babinga, Guigonis 3078), uyen (Kennedy 2612).

Additional specimens examined.

NIGERIA. "S. Nigeria" [without definite locality, probably Sapoba], 2 Apr 1945 (fl), Kennedy 2612 (A, BR, F, MO, PR, US, YF). CAMEROON. Est, Ndakan, Sango River, 02°22'N, 16°09'E, 10 May 1988 (st), Gentry et al. 62649 (MO); près Ngola (30 km à l’Est de Yokadouma, 11 May 1963 (fl, fr), Letouzey 5027 (P-2 sheets; mistakenly cited as Letouzey 5057 in Le Thomas (1969)); a 24 km à l’Ouest de Masea (village situé à 50 km au SSW de Yokadouma, 4 Jul 1963 (fl), Letouzey 5401 (P); a 25 km environ à l’ENE de Mikel village siuté à 85 km au N de Moloundou au route de Yokadouma, 24 Feb 1971 (fl), Letouzey & Villiers 10418 (K, P); près Nkongong II sur axe Lomie-Ngoila-Souanke, à 15 km SSW de Ngoila, 22 Feb 1973 (st), Letouzey 12026 (BR, K); 20 km ENE of Moloundou-Nguilili chantier, 10 Mar 1973 (fl), Mbenkum 310 (P); Bezirk Kribi, Vorland mit einzeln Hügeln bei Adjab, 35 km östlich Groß-Batanga, ca. 100 m, Jul 1911 (fr), Mildbraed 6090 (HBG); Reserve d’Ototomo prés Yaoundé, s. d. (fr), Service Forestier du Cameroun 67 (P); bank Nyong River, near the new bridge, about 65 km SW of Eséka, alt. ca. 200 m, 16 Jul 1964 (buds), de Wilde & de Wilde-Duyfjes 2838A (BR, K, MO, WAG-2 sheets), 2838B (WAG-2 sheets); Bipinde or Yaunde Nknambe, 1907 (fl), Zenker & Staudt 3314 (A, B, BM-2 sheets, G-81404, G-81405 as to leaves only, K, L, MO). CENTRAL AFRICAN REPUBLIC. Sangha Economic Prefecture, Ndakan Gorilla Study Area, 2°20'N, 16°09'E, 21 Jun 1988 (fr), Fay & Harris 8457 (MO); Grima, 25 Dec 1961 (fl), Guigonis 2320 (P); Sekamba Route 6° parallèle, 16 May 1964 (fl), Guigonis 3078 (P); Région de Mbaiki et Boukoko, 5 Jun 1948 (fl), Tisserant 955 (BM, P); Région de Mbaïki, Station Central de Boukoko, 27 Aug 1948 (fl), Tisserant 1113 (BM); 9 Sep 1948 (fr), Tisserant 1138 (BM, P). GABON. Estuaire: Liby, 25 Feb 1952 (fl, yg fr), Duboislouveau 903 S. R. F. (P).- Ogooué-Ivindo: Bélinga Mines de Fer, 20 Jul 1966 (fl), Hallé & Le Thomas 104 (P); Bélinga, Mines de Fer, 4 km on the road to Mvadi, 900 m, 1°05'N, 13°12'E, 5 Nov 2005 (fr), Sosef et al. 2218 (OWU); E border of Lopé-Okanda Reserve, along roads S of SEG lumber camp, W of Offoué River, 0°27'S, 11°45'E, 14 Jan 1993 (fl), McPherson 16058 (OWU).- Woleu-Ntem: ca. 25 km WSW of Mitzic [ “Mintsic”], 7 Feb 1987 (st), 0°44'N, 11°22'E, Reitsma & Reitsma 2900 (MO, NY, WAG). REPUBLIC OF THE CONGO. Ouesso, 25 Apr 1971 (fl), Grison FG 22/RC 827 (P); Ile M’Bamou, forêt et prairie à 10 km environ de Moutou ya N’Gombé-Brazzaville, 16 May 1967 (fl), Sita 1634 (P). DEMOCRATIC REPUBLIC OF THE CONGO. Équateur: Eala, 3 Aug 1932 (fl), Corbisier-Baland 1627 (BR); Bikoro, 31 Mar 1958 (fl, yr fr), Evrard 3849 (K); Wendji [near Coquilhatville], Aug 1930 (fl), Lebrun 1014 (BM, K, MO, NY, P, RSA, US).-Ituri: Epulu, Zone: Mambasa (Ituri), 1°25'N, 28°35'E, 750 m, 25 Jun 1986 (fl), Hart 628 (BR, MO); Haut-Zaire: Zone de Mambasa (Ituri Forest), Epulu, 1°25'N, 28°35'E, 750 m, 6 Jul 1991 (fl), Hart TH 1177 (BR, K); Zone de Mambasa (Ituri Forest), Afarama, 1°33'N, 28°23'E, Hart 1654 (K, MO).- Kasai Oriental: camp de Kifuku, 27 Jan 1949 (fr), Michelson 881 (K, P).- Maniema: Secteur Bangengele, Parc National Proposé de la Lomami, ca. 6.2 km au NNE de Katopa, 02°42'00"S, 025°08'10"E, 470 m, 19 Apr 2015 (fr), Gereau et al. 7565 (MO) .-Tshopo: Yangambi, 12 Jan 1936 (bud), Louis 1007 (BM, NY); Yangambi, km 8, 400 de la route de Ngazi, à l’E (abatages pour extensions Elaeis), 20 Aug 1936 (fr), Louis 2477 (BR); Yangambi, ca. 470 m, 19 May 1937 (old fl), Louis 3909 (NY, RSA); Yangambi, ca. 470 m, 25 Dec 1937 (fl), Louis 7220 (K, MO, US, WAG); 7918 (FI-T, MO), 27 Jan 1939 (fl), Louis 13430 (K, MO, NY, US); Kisangani [ “Stanleyville”], 12 Mar 1939 (fl), van der Meiren 70 (K, P).

Xylopia phloiodora is most easily identified in fruit. Its monocarps are among the largest of the African species, 2.7-4.3 by 1.7-3.1 cm, brown, oblong, sessile, glabrate, and strongly lenticellate, and lacking external ridges at maturity. The leaves, with a fine raised reticulum on the adaxial surface, are variable in size and shape, but have strongly arcuate secondary veins often drying a pinkish red color that contrasts with the grayish background color of the lamina. The bark, as noted in the specific epithet, is aromatic when cut, a trait frequently noted by collectors.

Specimens in flower, especially those with smaller and narrower leaves, are more difficult to identify. The pedicels are short, with a persistent bract closely subtending the rigid calyx. The petals are narrow and densely pubescent on both surfaces. The anthers have more locelli, 20-24, than those of any other African species, and the staminal cone is dome-shaped with an even rim, completely enclosing the ovaries (Fig. 35B ).

Xylopia phloiodora most closely resembles X. paniculata , but that species has shorter petioles, more pronounced branching of the inflorescence, shorter petals, and a shorter more open staminal cone with a laciniate rim. Xylopia cupularis is also similar to X. phloiodora , but it has longer pedicels with caducous bracts and larger numbers of carpels. In the sum of its characters, X. phloiodora belongs to the group of African Xylopia species with large thick-walled monocarps and large seeds with light green sarcotestas, but the labels of two specimens, Louis 2477 and Harris 2622, report the seeds to be orange. The fallen monocarps of Harris 2622 were all split into three segments, as happens in other species of this group, such as X. hypolampra .

The habitat of Xylopia phloiodora is not well defined. Reported associates in the southwestern Central African Republic are Eribroma oblonga and species of Celtis , Entadophragma , Guibortia , Myrianthus , Tetrapleura , and Megaphrynium . Seeds are reported to be taken by hornbills (Harris 2622) and the fruits fed upon by monkeys (Fay & Harris 8457). The conservation status of the species was assessed by Onana and Cheek (2011), who proposed Not Threatened (NT) status. The range of the species covers a large area but it was only represented in this study by 42 collections.

Mildbraed (1921) based the name Xylopia phloiodora on Mildbraed 7592 and Mildbraed 6090, neither of which was designated as a type. The former agrees well with the protologue and was identified as the type of this name by Le Thomas; we formally designated it here as the lectotype.

Figures

Figure 35. Xylopia phloiodora, X. paniculata, and X. calva. A-L X. phloiodora A Opening flower, lateral view B Old floral receptacle, showing staminal cone C Leaf, narrow extreme D Habit E Expanding vegetative shoot F, G Stamens, abaxial view to show size variation H Outer petal, adaxial view I Inner petal, adaxial view J Fruit K Seed, view from micropylar end L Seed, lateral view M-P X. paniculata M Inflorescence N Flower with petals and stamens removed, to show staminal cone O Inner petal, adaxial view P Outer petal, adaxial view Q-T X. calva Q Inflorescence R Flower with stamens and petals removed, to show staminal cone S Inner petal, adaxial view T Outer petal, adaxial view. A, B, D, F-I from Louis 13430 (US) C from Louis 7220 (WAG) E from Tisserant 1113 (BM) J from Tisserant 1138 (P) K, L from Fay and Harris 1138 (MO) M-P from Reitsma & Reitsma 1163 (NY) Q-T from Letouzey 10306 (P).

Figure 36. Distributions of Xylopia phloiodora, X. paniculata, and X. calva. Bolder lines represent country borders, fainter lines lakes and major rivers.