Xylopia retusa D.M.Johnson & N.A.Murray, 2020

Johnson, David M. & Murray, Nancy A., 2020, A revision of Xylopia L. (Annonaceae): the species of Madagascar and the Mascarene islands, Adansonia 42 (1), pp. 1-88 : 78-80

32. Xylopia retusa D.M.Johnson & N.A.Murray , sp. nov. ( Figs 2A ; 27L-R )

Xylopia species resembling X. buxifolia in the small leaves having retuse to emarginate apices, but differing in the leaves proportionally narrower, 0.6-1.1 versus 1.2-2.7 cm wide, the densely sericeous petals with the apices of the inner petals strongly bent outward at anthesis, the stigmas c. 0.8 mm long and oblong versus 1.9-3.3 mm long and filiform, the monocarps 3.2 cm long or shorter that are obliquely wrinkled and have a broad beak at the apex, and the orange sarcotesta of the seeds.

TYPE. — Madagascar. Prov. Toamasina, Fivondronana Sainte Marie, Firaisana Lokintsy , Fokontany Ambohidena , 16°51’11”S, 49°57’18”E, 18.II.2004 (fl.), Rabevohitra et al. 5073 (holo-, MO!; iso-, OWU!).

PARATYPES. — Madagascar. Prov. Toamasina, Antsinanana Region, Mahavelona Foulpointe , sur la piste des lémuriens, 17°42’21”S, 49°27’21”E, 72 m, 8.X.2011 (fr.), Andriamiarinoro & Amosa 256 ( MO, P[P01197860]) ; Est: forêt sublittorale, sur sables, à Ambila-Lemaitso , 14.XII.1967 (fr.), Capuron 28028 SF (K, OWU) ; Est: partie méridionale de la forêt de Vohibola (Tampina), au lieu-dit Ankany ny nofy, 17.XII.1967 (fr.), Capuron 28060_SF ( AAU, B) ; Pref. Brickaville, Com. Amboniaonana, Fok. Andranokoditra , 18°35’53”- 18°34’20”S, 49°14’42”- 49°14’54”E, 53 m, 7.I.2003 (fr.), Ludovic & Rakotoarivony 212 ( MO, OWU) ; Fivondronana: Brickaville, Firaisana : Ambinaninony , Fokontany : Andranonkoditra , forêt littorale sur sable du label Conservation Biodiversité Développements ( CBD) à Vohibola , 18°34’50”S, 49°15’16”E, 10 m, 8.XII.2001 (fr.), Rabenantoandro et al. 855 ( MO [2 sheets]) ; Fivondronana Brickaville, Firaisana Ambinaninony, Fokontany Andranokoditra , 18°35’32”S, 49°14’02”E, 5 m, 11.II.2003 (fr.), Rabenantoandro et al. 1244 ( MO, OWU, P[P01986994]) ; Fivondronana Brickaville, Firaisana Ambinaninony, Fokontany Andranokoditra , 18°35’32”S, 49°14’02”E, 5 m, 11.II.2003 (fr.), Rabenantoandro et al. 1249 (K, MO, OWU, P[P01986991]) ; Toamasina District, Analalava forest, far southwest corner of the forest occurring north of the road from Foulpointe to Sahamamy , 17°42’28”S, 49°27’04”E, 17.VI.2005 (fr.), Skema et al. 73 ( MO) .

DISTRIBUTION, ECOLOGY AND CONSERVATION STATUS. — Xylopia retusa , sp. nov., is restricted to central-eastern Madagascar, in littoral forests on sandy soil near the coast at elevations from sea level up to 70 meters ( Fig. 30 ).The specimen with flowers was collected in February, those with fruits have been collected in January, February, June, October, and December. Xylopia retusa , sp. nov., was estimated to have an EOO of 1751 km 2 and an AOO of 32 km 2, and is given a preliminary conservation assessment of Endangered ( Table 2 ).

LOCAL NAME. — Hazoambo (Andriamiarinoro & Amosa 256, Skema et al. 73).

DESCRIPTION Tree up to 12 m tall; d.b.h. up to 18 cm.

Twigs finely pubescent, the hairs 0.1-0.2 mm long, soon glabrate; nodes with one or often two axillary branches.

Leaves with larger blades 2.4-3.6 cm long, 0.6-1.1 cm wide, chartaceous to subcoriaceous, slightly discolorous, pale graygreen adaxially, dull brown abaxially, elliptic, narrowly oblong, oblanceolate, or linear-lanceolate, apex rounded and retuse to emarginate, base cuneate, short-decurrent on petiole, margin slightly revolute, glabrous adaxially, sparsely appressed-pubescent abaxially, a tuft of hairs often visible in the apical notch; midrib concolorous with blade adaxially, secondary veins weakly brochidodromous, 9-11 per side, diverging at 50-70° from midrib, these and higher-order veins indistinct to slightly raised

on both surfaces; petiole 0.8-2 mm long, semi-terete, smooth, with a few scattered hairs.

Inflorescences axillary, 1-flowered, not pedunculate, pubescent; pedicels 5-6.3 mm long, 0.5-0.7 mm thick; bracts 3,

one attached just distal to the pedicel base and the other 2 on the distal 1/3 of the pedicel, caducous or sometimes persistent, 1-1.5 mm long, semicircular to triangular; buds lanceolate, apex obtuse.

Sepals slightly spreading at anthesis, ¹⁄5-1/2-connate, 1.6- 2.4 mm long, 2.0- 2.2 mm wide, coriaceous, broadly ovate, triangular, or semicircular, apex obtuse to rounded, appressedpubescent abaxially.

Petals yellow to yellowish orange in vivo; outer petals erect at anthesis, 9.3-11.4 mm long, 1.7-2.2 mm wide at base, 0.7- 1.0 mm wide at midpoint, coriaceous, linear, keeled from midpoint to apex adaxially, keeled abaxially, apex obtuse, densely puberulent except for the glabrous base adaxially, sericeous abaxially; inner petals erect with the apices sharply bent outward at anthesis, 6.0- 7.5 mm long, 1.9-2.6 mm wide at base, 0.5-0.7 mm wide at midpoint, coriaceous, long-subulate, keeled adaxially except for concave base, slightly keeled abaxially, apex acute, base concave with undifferentiated margin but transversely thickened at the widest point, puberulent on both surfaces except for the glabrous base.

Stamens c. 120; fertile stamens 0.8-1.1 mm long, narrowly oblong, anther connective apex 0.1-0.2 mm long, capitate to depressed-globose, overhanging anther thecae, papillate, anthers 7-8-locellate, filament 0.2-0.3 mm long; outer staminodes c. 1.0 mm long, clavate, apex obliquely truncate; inner staminodes c. 1.0 mm long, clavate, apex truncate-emarginate; staminal cone 1.2-1.4 mm in diameter, 0.4-0.5 mm high, completely concealing the ovaries, rim even.

Carpels 2-3; ovaries 0. 4-0.5 mm long, oblong, pubescent, stigmas connivent, c. 0.8 mm long, narrowly oblong, glabrous or with a few hairs.

Fruit of up to 5 monocarps borne on a pedicel 8-12 mm long, 3-3.5 mm thick, glabrate; torus 5.5-8 mm in diameter, 5.7- 7 mm high, depressed-globose to globose; monocarps with greenish red exterior and red endocarp in vivo, 2.4-3.2 cm long, 1.2-1.6 cm wide, 1.2-1.5 cm thick, oblong, sometimes slightly torulose, apex rounded to a broad beak 1-2 mm long, base contracted into a stipe 1-4 mm long, 4-5 mm thick, verrucose, obliquely wrinkled, usually with a prominent longitudinal ridge abaxially, dull, glabrate; pericarp c. 1 mm thick.

Seeds up to 4 per monocarp, in a single row, perpendicular to long axis, 10-11.7 mm long, 7.9-8.7 mm wide, 4.8-7.0 mm thick, ellipsoid to broadly ellipsoid, flattened-elliptic or semicircular in cross-section, light brown, smooth, dull, perichalazal ring not evident; sarcotesta orange in vivo; aril absent.

NOTES

The small leaves of X. retusa , sp. nov., which are retuse to emarginate at the apex, resemble those of X. buxifolia , which occurs in some of the same habitats and localities. This appears to represent a convergence, as X. retusa , sp. nov., by virtue of its pubescent petals with the apices of the inner petals bent strongly outward and the orange sarcotesta of the seeds, most closely resembles X. arenaria of eastern Africa. Additional features of X. retusa , sp. nov., distinguishing it from X. buxifolia include the narrowness of the leaves, the outer petals densely sericeous rather than sparsely so (and not turning black when dried), and the smaller and somewhat beaked monocarps usually marked by strong oblique wrinkles on the surface. The short stigmas that barely exceed the tops of the stamens are also unusual.

Figures

FIG. 2. — Fruits and seeds of Madagascar Xylopia L. species: A, fruits of X. retusa, sp. nov., showing at left a dehiscent monocarp with one seed covered by an orange sarcotesta (Rabenantoandro et al. 1249); B, fruit of X. perrieri Diels, one monocarp dehiscing to reveal barely visible seed with light green sarcotesta (Antilahimena 7187); C, dehiscing monocarps of a Xylopia sp., possibly X. carinata, sp. nov., with orange sarcotesta of seeds visible; D, fruit of X. bemarivensis Diels, with one dehiscing monocarp and seed with orange sarcotesta visible (Ranirison PR 808); E, immature fruit of X. flexuosa Diels, showing the elongate monocarp characteristic of species in sect. Xylopia (Rakotovao 4687); F, fruit of X. humblotiana Baill., with one dehisced monocarp and black seeds with white arils visible (Rakotovao 4886); G, fruits of X. sclerophylla, sp. nov.; monocarp at lower right is probably recently dehisced because green sarcotesta of seed is fully intact (Nusbaumer LN 943); H, dehisced monocarp of X. sclerophylla, sp. nov., at a slightly later stage, showing the sarcotesta collapsing and losing its color (Nusbaumer LN 943). Photos: A, P. P. Lowry II; B, P. Antilahimena; C, J. Tan; D, P. Ranirison (© Conservatoire et Jardin botaniques de la Ville de Genève); E, F, C. Rakotovao; G, H, by L. Nusbaumer (© Conservatoire et Jardin botaniques de la Ville de Genève). A, B, D, E, F, used under the terms of the Creative Commons license for Tropicos,the botanical information system at the Missouri Botanical Garden; C, used under the terms of the the Creative Commons license for iNaturalist.

FIG. 27. — Xylopia sclerophylla, sp. nov.,and X.retusa, sp. nov. A-K, X. sclerophylla, sp. nov.: A, leaves;B, leaf base, lower surface;C, flower, side view; D, flower bud,side view;E, inner petal,adaxial surface;F, outer petal,adaxial surface;G, monocarps;H, seed, side view;I, seed, view of micropylar end; J, stamen,abaxial view; K, outer staminode, abaxial view. L-R, X. retusa, sp. nov.: L, leaves; M, leaf base, abaxial surface; N, monocarps; O, seed, side view; P, seed, view of micropylar end; Q, outer petal, adaxial surface; R, inner petal, adaxial surface. A-K, from Capuron 20041_SF (OWU); L-N, from Capuron 28060_SF (B); O, P, from Ludovic & Rakotoarivony 212 (OWU); Q, R, from Rabevohitra et al. 5073 (OWU). Scale bars: A, G-I, L, N-P, 1 cm; B-D, M, 5 mm; E, F, Q, R, 3 mm; J, K, 1 mm.

FIG. 30. — Distributions of Xylopia perrieri Diels, X. ravelonarivoi, sp. nov., X. retusa, sp. nov., X. sclerophylla, sp. nov., X. sericolampra Diels and X. sahafariensis Cavaco & Keraudren on Madagascar.