A revision of Xylopia L. (Annonaceae): the species of Madagascar and the Mascarene islands
Author
Johnson, David M.
Author
Murray, Nancy A.
text
Adansonia
2020
2020-02-05
42
1
1
88
journal article
21758
10.5252/adansonia2020v42a1
28f94b79-38d7-4c25-ac76-cf64809114fc
1639-4798
3877215
22.
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]!).
DISTRIBUTION, ECOLOGY AND CONSERVATION STATUS. —
Xylopia ghesquiereana
is known only from the
type
locality in east-central
Madagascar
(
Fig. 29
). 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
).
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
FIG. 23. —
Xylopia lokobensis
,
sp. nov.
, and
X. galokothamna
,
sp. nov.
A -E
,
X. lokobensis
,
sp. nov.
:
A
, petiole and base of leaf blade;
B
, leaf;
C
, fruit, side view;
D
, seed, side view;
E
, flower, side view.
F -N
,
X. galokothamna
,
sp. nov.
:
F
, outer petal, adaxial view;
G
, inner petal, adaxial view;
H
, habit, with fruit;
I
, petiole and base of leaf blade;
J
, outer staminode, abaxial view;
K
, fertile stamen,abaxial view;
L
, stigmas with adhering inner staminodes,side view;
M
, monocarp;
N
, seed, side view.
A
,
D
,
E
, from
Antilahimena 340
(P);
B
, from
Antilahimena 340
(MO);
C
, from
Birkinshaw 186
(OWU);
F
,
G
,
J
,
K
,
L
, from
Callmander et al. 585
(P);
I
, from
Callmander et al. 585
(MO);
H
,
N
, from
Callmander et al. 585
(OWU);
M
, from
Buerki et al. 20
(MO). Scale bars: A, E-G, I, 5 mm; B-D, H, M, N, 1 cm; J-L, 1 mm.
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
.