Xylopia ghesquiereana Cavaco & Keraudren, 1957

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 : 62-64

publication ID

https://doi.org/ 10.5252/adansonia2020v42a1

persistent identifier

https://treatment.plazi.org/id/417D87A4-FFC2-FFAD-FC83-56CE32BDF96D

treatment provided by

Tatiana

scientific name

Xylopia ghesquiereana Cavaco & Keraudren
status

 

22. Xylopia ghesquiereana Cavaco & Keraudren ( Fig. 19A-I View FIG )

Bulletin du Jardin botanique de l’État à Bruxelles 27: 87 (1957). — Type: Madagascar. Prov. Toamasina [“Est”], Vohimarangitra (district de Tamatave) [= Betampona, 17°55’S, 49°13’E], 22.II.1950 (fl.), Réserves Naturelles R N 2440 bis (holo-, P[P030392]!; GoogleMaps iso-, P[P030393, P030394]!).

DISTRIBUTION, ECOLOGY AND CONSERVATION STATUS. — Xylopia ghesquiereana is known only from the type locality in east-central Madagascar ( Fig. 29 View FIG ). The type specimen with flowers was collected in February. In light of the fact that the species is only known from a single collection made in 1950 it is given a preliminary conservation assessment of Critically Endangered ( Table 2 View TABLE ).

LOCAL NAME. — Hazoambomena.

DESCRIPTION Tree.

Twigs densely brown-tomentose, the hairs 0.4-0.6 mm long, at length glabrate; nodes with two axillary branches.

Leaves with larger blades 4.6-5.8 cm long, 2.1-2.5 cm wide, subcoriaceous, slightly discolorous, dark purple brown adaxially, brown abaxially, elliptic to elliptic-ovate or obovate, apex acuminate, the acumen 6-8 mm long, base broadly cuneate

A

to rounded, short-decurrent on petiole, margin slightly recurved, densely pubescent along midrib but otherwise glabrous adaxially, barbate along midrib and margins but otherwise sparsely appressed-pubescent to glabrate abaxially; midrib concolorous with or slightly paler than rest of blade toward base adaxially, secondary veins weakly brochidodromous, 10-12 per side, diverging at 50-70° from midrib, these and higher-order veins slightly raised and forming a conspicuous reticulum on both surfaces; petiole 4.5-5 mm long, shallowly canaliculate, smooth, densely pubescent.

Inflorescences axillary, 1-flowered, not pedunculate, pubescent; pedicels 2.9-5.5 mm long, 0.9-1.3 mm thick; bracts 2,

one attached near pedicel base and the other just proximal to the sepals, lower bract caducous, distal bract often persistent, 1.5-2.0 mm long, broadly ovate to nearly circular; buds linear, apex acute, slightly falciform.

Sepals spreading to slightly recurved at anthesis, ¹⁄5-1/3-connate, 2.3-2.8 mm long, 2.2-2.8 mm wide, coriaceous, slightly fleshy at base, triangular, apex acute to obtuse, densely pubescent abaxially.

Petals with color in vivo unknown; outer petals with position at anthesis unknown, possibly curved outward, 21-28 mm long, 2.9-3.2 mm wide at base, c. 1.2 mm wide at midpoint, fleshy, linear, sinuous, keeled only at the apex adaxially, weakly keeled abaxially, apex acute to obtuse, densely puberulent except for glabrous base adaxially, densely sericeous abaxially; inner petals with position at anthesis unknown, possibly erect, c. 18 mm long, 2.3-2.5 mm wide at base, 0.7-1.0 mm wide at midpoint, fleshy, linear, sinuous, keeled except for the base on both surfaces, apex acute to obtuse, base concave with undifferentiated margin, puberulent except for the glabrous base on both surfaces.

Stamens c. 140; fertile stamens 1.5-1.8 mm long, narrowly oblong, anther connective apex 0.2-0.3 mm long, hemispherical to capitate, slightly overhanging the anther thecae, papillate, anthers 13-14-locellate, filament 0.5-0.7 mm long; outer staminodes 1.6-1.9 mm long, oblong, apex obtuse to rounded; inner staminodes 1.5-1.7 mm long, oblong to clavate, apex truncate to rounded; staminal cone 1.4-1.8 mm in diameter, 0.8-1.4 mm high, concealing all but the apices of the ovaries, rim irregularly laciniate.

Carpels 5-7; ovaries c. 1.6 mm long, oblong, densely pubescent along the edges, stigmas connivent, 3.0- 3.4 mm long, narrowly clavate, pubescent.

Fruits and seeds unknown.

NOTES

Xylopia ghesquiereana is a morphologically isolated species. The sharply short-acuminate leaves with pronounced hairs along the midrib resemble those of X. lemurica , but the leaves of X. ghesquiereana are proportionately broader. The relatively long stamens with long filaments also distinguish X. ghesquiereana from X. lemurica . The pedicels of the flowers are relatively short, and densely covered with a brown tomentum. The sepals spread widely and are somewhat recurved at the apices. The petals are the longest of any Madagascar species, only approached by those of X. fananehanensis , which lacks hairs on the leaves and has a much longer pedicel.

In the original description Cavaco and Keraudren compared X. ghesquiereana to X. madagascariensis , distinguishing it from the latter by the tan tomentum of its young branches and petioles, the presence of hairs on the leaf midrib, the shorter pedicel, the persistent bract subtending the calyx, the large calyx, composed of 3 equal lobes that are not erect, and by absence of punctate glands on the style. The type specimens of both species came from the same locality and superficially resemble each other in leaf size and shape, but X. madagascariensis is more similar in flower, fruit, and seed morphology to X. humblotiana of sect. Xylopia .

Kingdom

Plantae

Phylum

Tracheophyta

Class

Magnoliopsida

Order

Magnoliales

Family

Annonaceae

Genus

Xylopia

Loc

Xylopia ghesquiereana Cavaco & Keraudren

Johnson, David M. & Murray, Nancy A. 2020
2020
Loc

Xylopia ghesquiereana

Xylopia ghesquiereana Cavaco & Keraudren ( Fig. 19A-I ) Bulletin du Jardin botanique de l’État à Bruxelles 27: 87 (1957). — Type: Madagascar . Prov. Toamasina [“Est”], Vohimarangitra (district de Tamatave) [= Betampona, 17°55’S, 49°13’E], 22.II.1950 (fl.), Réserves Naturelles R N 2440 bis (holo-, P[P030392]!; iso-, P[P030393, P030394]!).