Xylopia monticola D. M. Johnson & N. A. Murray, 2018

Johnson, David M. & Murray, Nancy A., 2018, A revision of Xylopia L. (Annonaceae): the species of Tropical Africa, PhytoKeys 97, pp. 1-252 : 154-156

36. Xylopia monticola D. M. Johnson & N. A. Murray sp. nov. Fig. 39D-E

Diagnosis.

Species resembling Xylopia acutiflora s. s. and X. thomsonii in its indument of mixed long and short hairs, and 1-flowered inflorescences with the short pedicels bearing 3 or more persistent bracts, but differing from X. acutiflora in the prominent abaxial leaf reticulum, the longer pedicels (5.2-8.1 mm), the outer petals (15.6-) 36-52 mm long, and the monocarps with wrinkled stipes 8-13 mm long and 3-5 seeds in a single row; from X. thomsonii it differs in the erect tree habit and the monocarps not exceeding 4 cm in length with proportionately longer stipes.

Type.

NIGERIA. Taraba [" N. E. State "] State, Sardauna Province, Kurmin Kugapa , below Kurmin Dodo below the western edge of Cabbal Wade ["Chappal Waddi"], ca. 5500 ft, 28 Feb 1975, J. D. Chapman 3755 (holotype: K!) .

Description.

Tree up to 10 m (-20 m) tall. Twigs brown, pubescent, the hairs 0.1-1.2 mm long, eventually light grayish brown, glabrate; no nodes with two axillary branches seen. Leaf with larger blades 7.8-10.9 cm long, 2.7-5.1 cm wide, chartaceous to subcoriaceous, concolorous, lanceolate, lanceolate-oblong, elliptic to oblong or oblong-oblanceolate, apex blunt-acuminate, the acumen 4.5-16 mm long, base broadly cuneate to nearly rounded, pubescent on the midrib but otherwise glabrous adaxially, sparsely pubescent to glabrate abaxially; midrib plane adaxially, raised abaxially, secondary veins somewhat arcuate, weakly brochidodromous, 7-13 per side, diverging at 65-70° from the midrib, plane to slightly raised adaxially, raised abaxially, higher-order veins plane or slightly raised and distinct in patches adaxially, raised and reticulate abaxially; petiole 3.5-9 mm long, shallowly canaliculate, sometimes slightly flattened, sparsely pubescent to pubescent. Inflorescences axillary, 1-flowered, pubescent; pedicels 5.2-8.1 mm long, 1-1.3 mm thick; bracts 3-4, evenly spaced along pedicel, persistent, 2-3.1 mm long, ovate but sometimes bifid when torn down the middle, apex acute; buds linear, slightly falciform, apex acute. Sepals slightly spreading at anthesis, connate at base, 2.7-3.5 mm long, 2.9-3.1 mm wide, coriaceous, triangular to ovate, apex acute, pubescent abaxially. Petals creamy white in vivo; outer petals spreading, (15.6-) 36-52 mm long, 2.7-3.6 mm wide at base, 1.6-1.7 mm wide at midpoint, coriaceous, linear, weakly longitudinally ridged abaxially, apex acute, pubescent adaxially, sericeous abaxially; inner petals erect to spreading, (15.5-) 29-37 mm long, 2.0-2.6 mm wide at base, 0.7-0.8 mm wide at midpoint, coriaceous, filiform, apex obtuse, base with undifferentiated margin, with weak longitudinal ridges on both surfaces, pubescent on both surfaces except for glabrous base. Stamens 160-200; fertile stamens 1.8-2.2 mm long, narrowly oblong, apex of connective 0.2-0.3 mm long, shieldlike, overhanging the anther thecae, glabrous, anthers 10-12-locellate, filament ca. 0.6 mm long; outer staminodes 1.5-1.9 mm long, clavate, apex truncate or sometimes emarginate; inner staminodes 0.7-0.9 mm long, broadly clavate or oblong, apex truncate; staminal cone 1.7-1.9 mm in diameter, 1.3-1.5 mm high, completely concealing the ovaries, rim laciniate. Carpels 7-8; ovaries 1.2-1.3 mm long, lanceolate or narrowly oblong, densely pubescent, stigmas loosely connivent, 2-3.4 mm long, linear, glabrous except for a tuft of hairs at the apex. Torus flat, 1.7-2.4 mm in diameter. Fruit of up to 5 glabrate monocarps borne on a pedicel 6-8.7 mm long, 1.5-2.8 mm thick, sparsely pubescent, sometimes with bracts or sepals persistent; torus 3.1-5 mm in diameter, 1.5-2.9 mm high, depressed-globose. Monocarps with a green exterior and red endocarp in vivo, 3.4-4.0 cm long, 0.9-1.0 cm wide, 0.6-0.7 cm thick, narrowly oblong and slightly falciform, torulose, apex obtuse, occasionally with an offset beak 0.5-2 mm long, base contracted into a stipe 8-13 mm long, 2.1-2.6 mm thick, longitudinally wrinkled with furrows extending down stipes, verrucose; pericarp 0.2-0.4 mm thick. Seeds up to 5 per monocarp, in a single row, lying oblique to long axis, 11-13.1 mm long, 6.4-6.5 mm wide, 5.8-6.2 mm thick, oblong, broadly elliptic to circular in cross-section, truncate at micropylar end but with endostome protruding, rounded at chalazal end, tan, smooth, faintly shiny, raphe/antiraphe visible only as a faintly raised ridge, micropylar scar 2.1-3.2 mm long, 1.8-3.3 mm wide, irregularly circular; sarcotesta glaucous in vivo; aril absent.

Phenology.

Specimens with flowers have been collected in February and March, and with fruits in February, March, and May.

Distribution

(Fig. 34 ). Easternmost Nigeria and adjoining Cameroon; gallery forest along streams and in understory of foothill forests: the label of Chapman 2739 lists as associates species of Dracaena , Osmunda , Salix , and Vitex , as well as Phoenix reclinata ; at elevations of 650-1670 m.

Local name.

Kimba ( Chapman and Chapman 2001).

Additional specimens examined.

NIGERIA. Adamawa: Gongola State, Ganye, Local Govt. area , well up the western slopes of Vogel Peak above Jangla , 24 Feb 1977 (fl), Chapman 4730 (K).- Taraba: N. E. State, Mambilla Plateau, bank of the Jigawal stream about 1½ hours walk downstream from the Maisamari plantation, 28 Mar 1972 (fl), Chapman 2739 [ FHI 45180 ] (K); N. E. State, Sardauna Province , Mambilla Plateau, SW foothills, ca. 3500 ft, 31 Mar 1975 (fl), Chapman 3786 (K); Gongola State, Ngel Nyaki F. /R., Mambilla Plateau, Sardauna Division, 3 Feb 1977 (fr), Chapman 4618 (K); Gongola State, Sardauna Div., Leinde Fadale ["Linedi Faadahree"] high up on the Mambilla escarpment at the NE corner overlooking Mayo Sabere, 5000 ft, 11 Feb 1977 (fr), Chapman 4671 (K); Gongola State, Sardauna, L. G. area, western foothills of Mambilla Plateau, Akwaizantar [ “Akwaijantar”] forest, ca. 3500 ft, 2 Feb 1978 (fl), Chapman 5186 (K) . CAMEROON. Southwest: savanna with forest galleries near Aguosho, 10 km SSW of Akwaya, 6°18'N, 9°28'E, 1200 m, 19-20 Mar 1985 (fl, young fr), Thomas 4558 (MO); Takamanda Forest Reserve , along footpath from Malishi to Kaluma, 06°15'N, 09°26'E, 650 m, 1 May 1987 (fr), Thomas et al. 7400 (B, K, MO) .

Xylopia monticola is another segregate of X. acutiflora s. l., which may be distinguished by the leaves with a prominent vein reticulum abaxially, relatively long outer petals (up to 52 mm long, exceeded only by X. mildbraedii and X. piratae in the X. acutiflora subgroup), and relatively small monocarps with proportionally long stipes. Unlike the seeds of X. acutiflora , those of X. monticola are up to 5 per monocarp and arranged in a single row. Xylopia monticola is most similar to X. thomsonii , which, in addition to the distinctions above, is a scandent shrub rather than a tree.

Chapman and Chapman (2001) provided habitat details for X. monticola in eastern Nigeria, where it was consistently an understory species of lower montane forest. At the Cabbal Wade site, the canopy dominants were Newtonia buchananii , Aubrevillea kerstingii , Parkia filicoidea , Albizia sp., and Polyscias fulva . In the Leinde Bumay forest on the Tiba Plateau, A. kerstingii and P. filicoidea were again present as canopy species, and, in addition, Symphonia globulifera . Xylopia monticola was stated to be locally common at several of the Nigerian localities, but the species is not widely distributed: it has an EOO of 14,393 km 2 and an AOO of 36 km 2 (Table 1 ). Some collections were from designated forest reserves, but the current protection status of these reserves is not known. This is, however, a poorly explored area botanically.

The label of Chapman 5186 states that the fruit is an ingredient in “yaje,” (Hausa: pepper) and local people gather the wild fruits of this species ( Chapman and Chapman 2001).

Figures

Figure 34. Distributions of Xylopia acutiflora, X. dinklagei, X. monticola, X. piratae, X. thomsonii, and X. unguiculata. Bolder lines represent country borders, fainter lines lakes and major rivers.

Figure 39. Xylopia thomsonii, X. monticola, X. talbotii, and X. dinklagei. A-C X. thomsonii A Fruit B Leaf C Flower D-E X. monticola D Flower E Leaf and fruit F X. talbotii, flower, side view G-I X. dinklagei G Leaf H Flower I Fruit. A from de Wilde & de Wilde-Duyfjes 2703 (K) B, C from Talbot & Talbot 3267 (BM) D from Chapman 3755 (K) E from Thomas et al. 7400 (MO) F from Thomas 3204 (MO) G, H from Dinklage 1840 (A) I from Baldwin 10805 (K).