Xylopia piratae 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 : 161-165

39. Xylopia piratae D. M. Johnson & N. A. Murray sp. nov. Figs 3F , 33H-J

Diagnosis.

Species resembling Xylopia thomsonii in the twig indument consisting of both short and long erect hairs, the one-flowered inflorescence with multiple overlapping bracts on the short pedicel, and the linear petals, but differing in the more strongly lianescent habit with ultimate branches departing at right angles to the twig that bears them, the leaves only 4.1-11.3 cm long, the outer petals reaching 73 mm in length, carpels only 4-9 per flower, and monocarps only 0.5-0.7 cm in width with a more pronounced beak.

Type.

IVORY COAST. Grand Bassam Department, forêt de l’Abouabou, between Abidjan and Grand Bassam , 2 m, 6 Jan 1959, A. J. M. Leeuwenberg 2365 (holotype: WAG! [0005952]; isotypes: K! P!) .

Description.

Liana extending to 20 m, or occasionally a shrub, the ultimate branches often departing at right angles to the twig that bears them and slightly thickened at the base. Twigs brown, pubescent, the hairs 0.5-1.2 mm long, soon dark brown to gray-brown, glabrate, sometimes with bark exfoliating; no nodes with two axillary branches seen. Leaf with larger blades 4.1-11.3 cm long, 1.9-3.9 cm wide, chartaceous, concolorous to discolorous, elliptic, oblong, oblong-oblanceolate, or lanceolate, apex acuminate, the acumen 2-11 mm long, base broadly cuneate to rounded, pubescent on the midrib but otherwise glabrous adaxially, finely appressed-pubescent to glabrate abaxially; midrib plane adaxially, raised abaxially, secondary veins weakly brochidodromous, 8-15 per side, diverging at 65-70° from the midrib, these and higher-order veins indistinct to raised adaxially, slightly raised to raised abaxially; petiole 1.2-3.5 mm long, shallowly canaliculate, sparsely pubescent to glabrate. Inflorescences axillary, 1-flowered, pubescent; pedicels 3.2-4.5 mm long, 0.8-1.2 mm thick; bracts 4-5, imbricate over length of pedicel, persistent, 1.7-3 mm long, ovate to circular, apex acute to rounded; buds linear-lanceolate, somewhat falciform, apex acute. Sepals slightly spreading at anthesis, 1/4-1/3-connate, 2.4-3.1 mm long, 2.2-3.0 mm wide, chartaceous, ovate to broadly triangular, apex acute to acuminate, sericeous abaxially. Petals cream-colored to white in vivo; outer petals spreading but curved inward toward the apices at anthesis, 24.3-73 mm long, 2.6-4 mm wide at base, 1.0-1.5 mm wide at midpoint, subcoriaceous, linear, apex acute, puberulent but becoming glabrous and warty in the proximal 1/3-1/2 adaxially, puberulent abaxially; inner petals spreading but curved inward toward the apices at anthesis, 25.8-48 mm long, 2.1-3.4 mm wide at base, 0.6-1.0 mm wide at midpoint, subcoriaceous, linear, apex acute, base with undifferentiated margin, puberulent, glabrous in the proximal 1/3 adaxially, sparsely puberulent abaxially. Stamens ca. 100; fertile stamens 0.9-1.5 mm long, narrowly oblong, apex of connective ca. 0.2 mm long, shieldlike to dome-shaped, overhanging the anther thecae, glabrous, anthers ca. 12-13-locellate, filament 0.2-0.4 mm long; outer staminodes 1.3-1.6 mm long, clavate, apex obtuse to obliquely truncate; inner staminodes 0.8-1 mm long, oblong to clavate, apex truncate; staminal cone 1.7-2.0 mm in diameter, 0.6-1.1 mm high, concealing lower half of the ovaries, rim laciniate. Carpels 4-9; ovaries 1.0-1.4 mm long, narrowly oblong, densely pubescent, stigmas connivent, 3.4-4 mm long, filiform, apex acute, with short tuft of hairs at apex but otherwise glabrous. Torus flat, ca. 2.4 mm in diameter. Fruit of up to 6 sparsely pubescent to glabrate monocarps borne on a pedicel 6.5-6.8 mm long, 2.2-2.7 mm thick, sparsely pubescent to glabrate; torus ca. 5.5 mm in diameter, 3.5 mm high, depressed-globose. Monocarps with a green, sometimes purple-tinged, exterior and red endocarp in vivo, 3.1 -6.6 cm long, 0.5-0.7 cm wide, ca. 0.7 cm thick, narrowly oblong and slightly falciform, torulose, apex with a curved beak 1.5-3 mm long or occasionally rounded, base contracted into a stipe 5-12 mm long, 1.2-3.2 mm thick, verrucose; pericarp ca. 0.4 mm thick. Seeds up to 9 per monocarp, in a single row, lying oblique to long axis, 9-10.9 mm long, 5.5-7.5 mm wide, 5.6-6.1 mm thick, ellipsoid, broadly elliptic in cross-section, obliquely truncate at micropylar end, rounded at chalazal end, light brown, smooth, dull, raphe/antiraphe not evident, micropylar scar 1.7-5 mm long, 1.4-3.5 mm wide, elliptic, oblong, or circular with the endostome protruding; sarcotesta pale gray to green in vivo; aril absent.

Phenology.

Specimens with flowers have been collected from October to February and in April, May, July, and August; specimens with fruits have been collected from November to January and in July and August.

Distribution

(Fig. 34 ). Occurs from southern Ivory Coast east to southwestern Ghana, growing in coastal thickets and savanna, sometimes in secondary forest, at elevations from sea level up to 50 m.

Additional specimens examined.

IVORY COAST. Bords de la lagune Ebrié, 1932 (fr), Aubréville 1537 (K); Km 25 Sassandra-Gagnoa, ca. 5.5N, 6.5W, 30 Oct 1968 (fl), Breteler 5856 (K, MO, WAG); near Grand Bassam, NW along Rd. to Aboisso, ca. 5°13'N, 3°43'W, 12 Nov 1968 (fl), Breteler 5983 (B, K, M, MO, NY, U, WAG); near Maféré, 5°23'N, 3°05'W, 23 Apr 1974 (fl), Breteler 7445 (MO); Banco Forest Reserve, near Abidjan, 50 m, 24 Jan 1970 (fl), de Koning 84 (WAG-2 sheets); Banco Forest Reserve , 22 Dec 1972 (fl), de Koning 983 (WAG); 25 Apr 1973 (fl), de Koning 1555 (WAG); 10 Dec 1974 (fl), de Koning 4999 (WAG-2 sheets), 10 Dec 1974 (bud, fr), de Koning 5000 (WAG); Abidjan, Banco Forest Reserve , 5 May 1976 (fl), de Koning 6856 (WAG-2 sheets); forêt de l’Abouabou, between Abidjan and Grand Bassam , 5°14'N, 3°33'W, 2 m, 1 Aug 1970 (fl), Leeuwenberg 8022 (B, K, MO, P, U); about 10 km W of Jacqueville, island Aladian, 5°11'N, 4°32'W, 0 m, 3 Aug 1970 (yg fr), Leeuwenberg 8089 (K); E of Tabou , Yokobo , 4°26'N, 7°22'W, 9 Nov 1981 (fl), Leeuwenberg 12304 (WAG); Ile Bonbay, près Adiopodoumé, 29 Aug 1955 (fr), Nozeran s. n. (BR, P); savane d’Abouabou, between Abidjan and Grand Bassam, 28 Nov 1963 (fl), Oldeman 682 (K, P); Arboretum, forêt du Banco (cultiv.), 6 Dec 1956 (fl), de Wilde 982 (WAG); I. R. H. O. (Cocos cultures) ca. 20 km W of Grand Bassam, near the beach on sandy soil between Port Bouet and G. Bassam, 1 Jul 1963 (fl), de Wilde 354 (K, P), 1 Jul 1963 (fr), de Wilde 356 (K, P); ca. 5 km SE of O. R. S. T. O. M., Ile Boulay, beyond Lagune Ebrié, 22 Jul 1963 (fr), de Wilde 497 (BR, K); forêt d’Andouin, 24 Aug 1955 (fr), de Wit 7999 (WAG) . GHANA. Princes [Town], 9 Jan 1939 (fl, fr), Akpabla 767 (K-2 sheets); Atwabo, W. Province, Feb 1934 (fl), Irvine 2299 (K); Western, Bia Reserves, along borderline between Bia National Parc and Bia Production Reserve, near Camp 15, 6°32'42"N, 3°02'00"W, 13 Nov 1993 (fr), Jongkind et al. 1301 (MO) .

Xylopia piratae bears pure white flowers with slender petals that, at 70 mm, are among the longest known in the genus. The climbing habit of the plants is more strongly developed than in any other species of Xylopia : label descriptions invariably refer to the climbing or scrambling growth form, and on the label of de Koning 983 the plant is described as reaching a length of 20 m. Plants identified as X. acutiflora by Hall and Swaine (1981) from forest plots in southwestern Ghana and described as "a woody climber with leafy shoots of limited growth inserted approximately at right angles to the main stem, as in Uvaria ovata ," probably represent this species rather than X. acutiflora . In addition, there is a tendency in X. piratae for the shoots inserted at right angles to have a slight thickening where they join the supporting branch; Xylopia dinklagei shows a similar tendency. The sweet scent of the flowers has been noted by many collectors; Leeuwenberg 12304 added that the flowers were fragrant at 1700 h. This species is named in memory of Celine Pirat, who photographed the plants (Fig. 3F ) on Ile Assoko, Ivory Coast, on 10 May 2014 .

Xylopia piratae most closely resembles X. thomsonii from central Africa. Both species have a tendency for the branches to become lianescent, although this is more extreme in X. piratae . Both have a mixture of both long and short erect hairs persistent on the twigs. The petals of X. thomsonii , while they do not reach the length of those of X. piratae , are long for this species subgroup but broader. The liana habit and extremely long petals combine to distinguish X. piratae from both X. acutiflora and X. dinklagei , the other two species of the X. acutiflora subgroup found in West Africa.

Three specimens from southern Togo may represent Xylopia piratae : Schäfer 7577 (GH, MO, WAG-2 sheets), de Wit & Morton A2895 (WAG), and Ern 2710 (B-2 sheets). The specimens are incomplete, and no habitat information is given for these specimens.

Xylopia piratae is one of three Xylopia species endemic to the Guinea Coast region of West Africa, all of them with relatively narrow distributions and all belonging to the Xylopia acutiflora subgroup. For Xylopia piratae , we calculated an EOO of 31,476 km 2 and an AOO of 64 km 2. Its narrow coastal savanna distribution may make it vulnerable to habitat loss. It may be somewhat tolerant of disturbance, however, as several collections are from secondary forest habitat and the collection Leeuwenberg 8022, bearing flowers, was taken from a shoot regenerating from a stump in Alchornea cordifolia thicket.

Figures

Figure 3. Flowers of representative Xylopia species. A Flower from type collection of Xylopia globosa from Gabon B Xylopia tenuipetala from Mozambique C Xylopia quintasii from Gabon D Xylopia aethiopica from Gabon E Xylopia longipetala from Mali, representing a record for the country not otherwise documented F Xylopia piratae from Ivory Coast G Xylopia odoratissima from Zambia H Xylopia arenaria from Tanzania I Xylopia collina from Tanzania. A, D by Thomas L. P. Couvreur B by Frances Chase C by Ehoarn Bidault E by Philip Birnbaum F by Celine Pirat G by Warren McClelland H and I by D. M. Johnson.

Figure 33. Xylopia unguiculata, X. acutiflora, and X. piratae. A-D, L-O X. unguiculata A Monocarp, lateral view B Seed C Leaves D Flower, lateral view L, M Staminodes, abaxial view N Stamen, abaxial view O Carpel, lateral view with ovary wall cut away to show arrangement of ovules E-G X. acutiflora E Monocarp, lateral view, attached to pedicel F Leaves G Flower, lateral view H-K X. piratae H Flower bud, lateral view I Leaves J Flower, lateral view K Fruit. A-B from Le Testu 1179 (BM) C-D from Reitsma & Reitsma 1923 (NY) E-G from Beentje 879 (WAG) H-J from de Koning 4999 (WAG) K from de Wilde 356 (P) L-O from McPherson 16960 A (MO).

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.