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
21.
Xylopia galokothamna
D.M.Johnson & N.A.Murray
,
sp. nov.
(
Figs 16C, D
;
23F-L, N
)
Xylopia
species belonging to the
Madagascar
group with relatively broad outer petals and clavate stigmas, but distinguishable from the other species of the group by the shrub habit, cuneate to broadly cuneate leaf bases, stamens 1.5-2.0 mm long borne on a staminal cone
c.
1.8 mm
high, monocarps with a beak
1.5-3 mm
long and stipe
4-5 mm
long and
2.8-4.8 mm
thick, and ovoid seeds
11.8-13.3 mm
wide.
TYPE. —
Madagascar
.
Prov. Antsiranana
,
Diana Region
,
Ambilobe
,
Beramanja
,
Anketrabe
,
forêt de Kalabenono
,
Ambatoharanana
,
13°38’46”S
,
48°40’30”E
,
706 m
,
24.XI.2006
(fl., fr.),
Callmander et al. 585
(holo-,
P
[
P01986966
]!;
iso-, MO!, OWU!).
PARATYPE
. —
Madagascar
.
Prov. Antsiranana
,
Diana Region
,
Ambilobe
,
Beramanja
,
Ambatoharanana
,
Anketrabe belinta
,
Kalobinono Manongarivo
,
5 km
au sud de Belinta
,
13°38’40”S
,
48°40’26”E
,
700 m
,
28.IX.2013
(fr.),
Ratovoson
2065
(
MO
,
P
[
P01044912
]).
DISTRIBUTION, ECOLOGY AND CONSERVATION STATUS. — Like
X. kalabenonensis
, this is a new species revealed by recent collecting efforts in the Galoka Mountain chain of northwestern
Madagascar
(
Callmander
et al.
2009
).
Xylopia galokothamna
,
sp. nov.
, is known from a single locality in humid forest at
c.
700 m
elevation (
Fig. 29
). The specimen with flowers was collected in November, the specimens with fruits in September and November. The small EOO and AOO values,
5 km
2 and
8 km
2, respectively, lead to a preliminary conservation assessment of Endangered (
Table 2
).
DESCRIPTION
Shrub
up to
6 m
tall.
Twigs
sparsely appressed-pubescent, the hairs
0.1-0.3 mm
long, soon glabrate; nodes with one axillary branch.
Leaves
with larger blades 10.4-14.0 cm long, 3.7-5.0 cm wide, subcoriaceous, concolorous or slightly discolorous and brownish green adaxially, reddish brown abaxially, elliptic to oblong-elliptic, apex acuminate, the acumen
5-9 mm
long, base cuneate to broadly cuneate, decurrent on petiole, margin flat or slightly recurved, glabrous but densely verrucose adaxially, sparsely appressed-pubescent and soon glabrate abaxially; midrib darkened toward base adaxially, secondary veins brochidodromous, 15-18 per side, diverging at 60-90° from midrib, these and higher-order veins slightly raised or indistinct adaxially, raised and distinct abaxially; petiole
4-8 mm
long, canaliculate, wrinkled, sparsely pubescent to glabrate.
Inflorescences
axillary, 1-flowered, not pedunculate, densely pubescent; pedicels 2.0-
4.5 mm
long, 1.6-2.0 mm thick;
FIG. 22. — Plate including illustration of
Xylopia fananehanensis
Cavaco & Keraudren
(
A -F
), reproduced from
Cavaco & Keraudren (1958)
.
bracts not seen; buds linear-lanceolate, apex acute, slightly falciform (
Fig. 16C
).
Sepals
spreading at anthesis,
c.
1/3-connate,
2.3-3.5 mm
long,
3.8-4.5 mm
wide, coriaceous, broadly triangular, apex acute, densely pubescent abaxially.
Petals
yellow
in vivo
; outer petals slightly spreading at anthesis,
c.
18 mm
long,
4.4-5.9 mm
wide at base, 2.7- 3.0 mm wide at midpoint, slightly fleshy, linear-lanceolate, keeled on apical ¼ but otherwise flat adaxially, weakly keeled abaxially, apex obtuse, densely puberulent except for the glabrous base adaxially, densely appressed-pubescent abaxially; inner petals with apices spreading at anthesis,
11.4-12.8 mm
long,
3.3-3.5 mm
wide at base,
c.
1.3 mm
wide at midpoint, slightly fleshy, linear-lanceolate, keeled on apical 1/2 adaxially, keeled abaxially, apex acute, base concave with undifferentiated margin, densely puberulent except for glabrous base on both surfaces, with a band of papillae across widest point adaxially.
Stamens
c.
170; fertile stamens 1.5-2.0 mm long, narrowly oblong, anther connective apex
0.3-0.4 mm
long, capitate to slightly conical, overhanging anther thecae, papillate, anthers 12-14-locellate, filament
0.5-0.7 mm
long; outer staminodes
1.6-2.6 mm
long, clavate or narrowly oblong, apex obtuse; inner staminodes
1.1-1.4 mm
long, oblong, apex rounded; staminal cone
c.
2.4 mm
in diameter,
c.
1.8 mm
high, concealing all but the apices of the ovaries, rim irregularly laciniate.
Carpels
5-7; ovaries <
2 mm
long, oblong, pubescent, stigmas connivent,
2.8-3.2 mm
long, narrowly clavate, with a few hairs.
Fruit
of up to 3 monocarps borne on a pedicel
5-8 mm
long,
3-3.7 mm
thick, sparsely pubescent; torus
5-6 mm
in diameter,
4.5-5 mm
high, ovoid; monocarps with yellow exterior
in vivo
,
2.9-5.1 cm
long, 2.0-
2.8 cm
wide, (0.7-)
1.4-2.4 cm
thick, oblong or ovoid, not torulose to slightly torulose, apex rounded to a broad beak
1.5-3 mm
long, base contracted into a stipe
4-5 mm
long,
2.8-4.8 mm
thick, verrucose, obliquely wrinkled and with a narrow ridge encircling the monocarp lengthwise, dull, finely pubescent; pericarp 1.0-2.0 mm thick.
Seeds
up to 5 per monocarp, in a single row, oblique to perpendicular to long axis,
14.1-16.2 mm
long,
11.8-13.3 mm
wide,
8.6-11.2 mm
thick, ovoid, sometimes slightly flattened, broadly elliptic to semicircular in cross-section, light yellowbrown, smooth, dull, perichalazal ring visible as a flat darkened band; presence of sarcotesta not determinable; aril absent.
NOTES
Xylopia galokothamna
,
sp. nov.
, is one of the few
Madagascar
Xylopia
species with a shrub habit. It is part of the species group with clavate stigmas and often relatively broad petals, and within that group stands out by the combination of short thick flower pedicels, distinct beak and stipe on the fruits, and the broad seeds. It occurs in the same gen- eral region of
Madagascar
as
X. lokobensis
,
sp. nov.
, but leaf shape, pedicel length, and habit distinguish the two species. The
type
specimen was one of several identified as “
Xylopia
sp.
aff.
fananehanensis
” in
Stull
et al.
(2017)
that are recognized in this work as distinct species.
The type and
paratype
collections have monocarps that are finely pubescent, with a pericarp
1-2 mm
thick. Three additional specimens collected from the same general area of the Galoka Mountains have in common the shrub habit, relatively large seeds, and a broad beak and stipe of the monocarps:
Buerki et al. 20
(MO), Diana Region, Chaîne Galoka, Mont Galoka, Anketrabe-Belinta, Ambilobe, Beramanja, Camp Bilahy,
13°35’20”S
,
48°43’42”E
,
928 m
,
23.II.2005
(fr.);
Callmander et al. 720
(MO), Ambanja, commune Beramanja,
13°38’40”S
,
48°40’09”E
,
518 m
,
22.XI.2007
(fr.);
Rakotovao et al. 3823
(MO). Ambilobe, Beramanja, Anketrabe, village le plus proche Antanambao Belinta,
1007 m
,
13°39’10”S
,
48°40’29”E
,
28.XI.2007
(fr.). All of these specimens, however, have monocarps that are glabrous, more elongate (up to
7 cm
long), and strongly torulose (
Figs 16E
,
23M
), with the pericarp only
0.2-0.7 mm
thick; the labels of all three specimens indicate that the monocarps are tinged with red and the label of
Buerki 20
describes the seeds as orange. The leaves of these specimens are more lanceolate, glabrous to glabrate, and lack the verrucose adaxial surface. Given the degree of disparity in the fruit, and to a lesser extent the vegetative features, we exclude these specimens as
paratypes
of
X. galokothamna
,
sp. nov.
, but draw attention to the similarities and the fact that additional collections are needed to resolve their status.