Xylopia tenuipetala D.M. Johnson & Goyder, Kew Bull. 72:11: 3, 5, 7-8. 2017.

Johnson, David M. & Murray, Nancy A., 2018, A revision of Xylopia L. (Annonaceae): the species of Tropical Africa, PhytoKeys 97, pp. 1-252 : 79-80

11. Xylopia tenuipetala D.M. Johnson & Goyder, Kew Bull. 72:11: 3, 5, 7-8. 2017. Figs 3B , 4D , 20

Type.

MOZAMBIQUE. Cabo Delgado Province, ca. 1 km W of Quiterajo airstrip on track towards Namacubi Forest , Waypoint JT 627, 11°45'58.9"S, 40°23'59.8"E, 88 m, 21 Nov 2009, D. J. Goyder et al. 6090 (holotype K!; isotypes LMA, LMU, P) .

Description.

Shrub or tree up to 8 m tall; bark gray, smooth. Twigs green to brownish gray, glabrous, with epidermis soon exfoliating; nodes occasionally with two or more axillary branches. Leaf with larger blades 4.6-5.7 cm long, 2.3-2.7 cm wide, chartaceous to subcoriaceous, concolorous, lanceolate to ovate, apex gradually acuminate with an acumen 4 -11 mm long, base broadly cuneate to rounded, glabrous on both surfaces; midrib plane adaxially, raised abaxially, secondary veins weakly brochidodromous; 9-12 per side, diverging at 60-70° from the midrib, these and higher-order veins slightly raised on both surfaces; petiole 3.5-5 mm long, nearly terete to shallowly canaliculate adaxially, glabrous. Inflorescences axillary, rarely pseudoterminal from abortion of the terminal bud, 1-flowered, glabrous; peduncle rudimentary; pedicels 6.7-7.2 mm long; bracts 2, persistent, the lower one proximal to the pedicel midpoint, 0.7 - 0.8 mm long, ovate, the upper one distal to the pedicel midpoint, 0.9-1.4 mm long, broadly ovate; buds lanceolate, apex acute. Sepals slightly spreading at anthesis, 3/5-connate, 1.7-2.6 mm long, 2.1-2.5 mm wide, chartaceous, broadly ovate, apex acute, glabrous abaxially. Petals yellow-green in vivo; outer petals spreading at anthesis, 13-16 mm long, 2.9-3.4 mm wide at base, 1.6-1.9 mm wide at midpoint, membranous with venation evident, lanceolate, flat, shallowly concave adaxially, apex acute, sparsely pubescent in the center, becoming more densely pubescent toward margins adaxially, appressed-pubescent abaxially; inner petals erect at anthesis, 9.0-10.5 mm long, 1.8-2.1 mm wide at base, 1.2-1.7 mm wide at midpoint, membranous with venation evident, linear-lanceolate, apex acute, base with undifferentiated margin, glabrous. Stamens ca. 50; fertile stamens 1.2-1.5 mm long, narrowly oblong, apex of connective minute, truncate, not exceeding anther thecae, glabrous, anthers 8-10-locellate, filament 0.5-0.7 mm long; outer staminodes absent; inner staminodes 1-1.1 mm long, oblong, apex truncate; staminal cone ca. 0.8 mm in diameter, ca. 0.6 mm high, concealing only the bases of the ovaries, rim laciniate. Carpels 2-5; ovaries 1.1-1.5 mm long, narrowly oblong, glabrous; stigmas loosely appressed, 1.1-1.2 mm long, lanceolate-falcate, apex acute, glabrous; Torus flat, ca. 1 mm in diameter. Fruit of up to 2 glabrous monocarps borne on a pedicel ca. 6.3 mm long, ca. 1.3 mm thick, glabrous; torus 2.8 mm in diameter, 1.5 mm high, globose. Monocarps green with a red endocarp in vivo, ca. 1.8 cm long, ca. 0.9 cm wide, ca. 0.5 cm thick, oblong, flattened-ellipsoid in cross section, apex truncate and obliquely mucronate (1.5 mm), base contracted into a stipe ca. 4 mm long, 1.4 mm thick, finely verrucose; pericarp ca. 0.3 mm thick. Seeds 4-5 per monocarp, in a single row, lying perpendicular to long axis, 7.1-7.9 mm long, 4.4-4.7 mm wide, 3.3-3.7 mm thick, oblong-ellipsoid, elliptic to oblong in cross section, obliquely truncate at micropylar end, rounded at chalazal end, blue-gray to black, smooth, shiny, raphe/antiraphe not evident, micropylar scar 1.2-1.5 mm in diameter, circular; sarcotesta absent; aril white in vivo, amber-colored when dried, cupular, 3.9-4.4 mm in diameter, 2.0-2.4 mm high, fleshy, smooth.

Phenology.

Specimens with flowers have been collected in November, the one specimen with fruit was collected in December.

Distribution

(Fig. 19 ). Endemic to northeastern Mozambique, where it occurs in coastal dry sand forest at elevations of 65-134 m.

Additional specimens examined.

MOZAMBIQUE. Cabo Delgado: Namacubi Forest (the Banana), W of Quiterajo, 11°45'55"S, 40°23'45"E, 25 Nov 2008 (st), Burrows & Burrows 10746 (BNRH, K); Quiterajo, within Namacubi Forest , W of Quiterajo, 11°45'47.0"S, 40°21'14.8"E, 29 Nov 2008 (fl), Crawford et al. FC265 (K-2 sheets); Palma area 1 km E of Muangaza, S of Palma, 10°55'24.5"S, 40°23'34.8"E, 65 m, 5 Dec 2008 (fr), Goyder et al. 5089 (K); Quitarajo Pt 463, 11.7676S, 40.3743E, 24 Nov 2009 (fl), Luke & Luke 13884 (EA, K, LMA, P); Macomia District , Quiterajo , Namparamnera forest , 11°49'03.8"S, 40°20'33.1"E, 29 Nov 2008 (fl), Timberlake et al. 5570 (K-738101) .

This poorly known species resembles Xylopia mwasumbii , which occurs to the north of its range in central Tanzania, but in X. tenuipetala the leaf blades are lanceolate to ovate, broadly cuneate to rounded at the base and acuminate at the apex, the pedicels and petals are longer, and the ovaries are glabrous. The petals of X. tenuipetala are unusual in the genus-thin, membranous, and translucent rather than coriaceous or fleshy. It occurs in the same area of high plant endemism as X. lukei ( Timberlake et al. 2011). A conservation assessment of Endangered was assigned to it in Johnson et al. (2017; Table 1 ).

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 4. Fruits and seeds of representative Xylopia species. A Xylopia staudtii from Democratic Republic of the Congo B Xylopia aethiopica from Republic of the Congo C Xylopia quintasii from Cameroon D Xylopia tenuipetala from Mozambique E Xylopia collina from Mozambique F Xylopia gracilipes from Mozambique G Xylopia hypolampra from Gabon H Xylopia tanganyikensis from Tanzania. A by Quentin Luke B by David Harris C, G by Thomas L. P. Couvreur D by Jonathan Timberlake E, F by Mervyn Loetter H by Noriko Itoh. C reproduced with permission of Thomas L. P. Couvreur and of the American Society of Plant Taxonomists D reproduced with the permission of Jonathan Timberlake and of the Board of Trustees, Royal Botanic Gardens Kew.

Figure 19. Distributions of Xylopia lukei, X. mwasumbii, and X. tenuipetala in eastern Africa. Bold lines represent country borders.

Figure 20. Xylopia tenuipetala. A Leaf B Habit C Fruit, showing one dehisced and one undehisced monocarp D Seed, view of micropylar end E Seed, side view F Carpel, with ovary dissected to show two ovules G Stamen, abaxial view H Flower I Inner petal, adaxial view J Outer petal, adaxial view. A, F-J from Goyder et al. 6090 (K) B from photograph of same in vivo C-E from Goyder et al. 5089 (K). Reproduced with the permission of the Board of Trustees, Royal Botanic Gardens Kew.