Xylopia carinata D. M. Johnson & N. A. Murray 2020, sp. nov.
Creators: name: Johnson, David M.
name: Murray, Nancy A.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Magnoliales
Annonaceae
Xylopia
Xylopia carinata

description: 17. Xylopia carinata D.M.Johnson & N.A.Murray, sp. nov. (Fig. 19J-Q)
Species resembling X. capuronii and X. lokobensis, sp. nov., in the subcoriaceous leaves, sepals exceeding 4 mm in length, and broad acute outer petals, but differing from the former in the recurved rather than strongly revolute leaf margins and the sparse yellow-brown rather than dense dull red indument of the twigs and leaves, from the latter in the longer pubescence of the twigs and the recurved rather than flat leaf margins, and from both species in the more pronounced keel on the abaxial surface of the outer petals.
TYPE. — Madagascar. Prov. Toamasina [“ Est ”], sur sables de Mangalimaso à l’ouest de Foulpointe, 29.X.1963 (fl.), Capuron 22777-SF (holo-, P [P00524381]!; iso-, A!, K![K001208446, K001208447]).
PARATYPE. — Madagascar. Prov. Antsiranana [“ Est (Nord)”], forêt d’Analamateza, au Sud d’Antsirabe-Nord, 25-27.III.1967 (fl.), Capuron 27564-SF (P [P01585923, P01585924]).
DISTRIBUTION, ECOLOGY AND CONSERVATION STATUS. — Xylopia carinata, sp. nov., is known from only two collections, both from northeastern Madagascar in humid forest at elevations up to 200 meters, one collection on sand (Fig. 28). It is possible that X. carinata, sp. nov., is a habitat specialist, as the type specimen was collected from sublittoral forest on sand, to which a number of other Madagascar Xylopia species appear to be restricted, but the paratype specimen label does not give any habitat information and was collected some distance inland. The collections, both with flowers only, were collected in March and in October. The AOO of 8 km 2 and its known occurrence at only two localities make this a species of conservation concern, and it is given a preliminary assessment of Endangered (Table 2).
DESCRIPTION
Tree up to 20 m tall.
Twigs yellowish brown-pubescent, the hairs 0.1-0.5 mm long, eventually glabrate; nodes with one or often two axillary branches.
Leaves with larger blades 7.5-9.7 cm long, 2.6-4.0 cm wide, subcoriaceous, discolorous, olive-gray to dark brown adaxially, brown abaxially, oblong to oblong-elliptic, apex acute to acuminate, the acumen 5-8 mm long, base broadly cuneate to rounded, short-decurrent on petiole, margin recurved, pubescent along midrib but otherwise glabrous adaxially, sparsely appressed-pubescent, hairs densest on the midrib abaxially; midrib concolorous or darkened toward base adaxially, secondary veins brochidodromous, 11-15 per side, diverging at 60-70° from midrib, these and higher-order veins slightly raised to indistinct on both surfaces; petiole 4-8 mm long, canaliculate to semi-terete, wrinkled, pubescent.
Inflorescences axillary or from axils of fallen leaves, occasionally pseudoterminal from the abortion of the terminal bud, 1-2-flowered, not pedunculate, yellowish brown-pubescent; pedicels 2.5-12.1 mm long, 1.0- 1.8 mm thick; bracts 2, one attached near pedicel midpoint and caducous, the other just proximal to the sepals and persistent, 3.3-4.9 mm long, broadly ovate to semicircular; buds lanceolate, apex acute.
Sepals erect to spreading at anthesis, ¼-1/3-connate, 4.5-5.5 mm long, 4.6-6 mm wide, coriaceous to slightly fleshy, broadly ovate, apex acute to obtuse, densely brown-pubescent abaxially.
Petals yellowish in vivo; outer petals probably slightly spreading at anthesis, 16-25 mm long, 5.2-6.0 mm wide at base, 2.9- 3.7 mm wide at midpoint, slightly fleshy, lanceolate, keeled on apical 1/2 but otherwise flat adaxially, keeled abaxially, apex acute to obtuse, densely puberulent except for the glabrous base adaxially, velutinous abaxially; inner petals probably with apices spreading at anthesis, 10.2-17 mm long, 3-4.3 mm wide at base, 1.2-1.7 mm wide at midpoint, slightly fleshy, lanceolate, keeled on apical 1/2 adaxially, sharply keeled abaxially, apex acute, base concave with undifferentiated or slightly thickened margin, densely puberulent except for glabrous base on both surfaces.
Stamens 120-200; fertile stamens 1.3-1.8 mm long, narrowly oblong, anther connective apex c. 0.4 mm long, hemispherical, overhanging anther thecae, long-papillate, anthers 7-9-locellate, filament 0.2-0.5 mm long; outer staminodes 1.7-1.8 mm long, clavate, apex obtuse, truncate, or emarginate; inner staminodes 1.4-1.7 mm long, narrowly oblong, apex truncate to obtuse; staminal cone 1.3-3.0 mm in diameter, 0.8-1.3 mm high, concealing all but apical 1/3 of ovaries, rim irregularly laciniate.
Carpels 6-17; ovaries c. 0.8-1.8 mm long, narrowly oblong, pubescent, stigmas connivent, 2.4-3.2 mm long, narrowly clavate, glabrous or hairy at the apices.
Fruits and seeds unknown.
NOTES
The keel on the abaxial surface of the outer petals, for which Xylopia carinata, sp. nov., is named, is conspicuous in both of the collections. In the type collection some flowers arise at the proximal nodes of an expanding axillary shoot from which the subtending leaves have precociously fallen, giving the appearance of a multi-flowered inflorescence. Xylopia carinata, sp. nov., is a member of the group of Madagascar Xylopia species with clavate stigmas, and, as noted in the diagnosis, is most similar to X. capuronii and X. lokobensis, sp. nov. The type specimen was determined by Keraudren as X. ghesquiereana, but it does not have the linear petals and barbate leaf midrib and leaf margins found in that species.
Fruits and seeds are not known for this species. However, two Xylopia collections with fruits, Capuron 18178 SF (P[P01986948, P01986949]) from Rantolava, NW de Tam- polo – Fénérive, 1.IX.1957, and Service Forestier 15268-SF (P[P01986952]), Manakara, 27.VIII.1955, are tentatively placed here, as the leaves, while more chartaceous, are similar in size and indument to those of X. carinata, sp. nov., and the specimens were both collected from coastal locations in the general area of the type locality. The collection Service Forestier 15268-SF is further noteworthy in including a mass of monocarps that have dehisced. The monocarps of both specimens are ellipsoid and sparsely pubescent. A photograph posted on iNaturalist in 2017, taken in the Analalava Nature Preserve near the type locality, shows a similar mass of dehisced monocarps, as well as an orange sarcotesta on the seeds (Fig. 2C).
description: Published as part of Johnson, David M. & Murray, Nancy A., 2020, A revision of Xylopia L. (Annonaceae): the species of Madagascar and the Mascarene islands, pp. 1-88 in Adansonia 42 (1) on pages 52-54, DOI: 10.5252/adansonia2020v42a1, http://zenodo.org/record/3877215