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
13.
Xylopia australis
D. M.Johnson & N. A.Murray
,
sp. nov.
(
Figs 15L-U
;
16A, G
)
One of a group of
Xylopia
species in
Madagascar
with short broad petals and clavate stigmas, distinguished by the strongly raised reticulation of the leaves, the secondary veins often joining to form a sinuous intramarginal vein, the narrowly oblong or elliptic-oblong to lanceolate shape of the leaf blades, the corrugated adaxial surface of the inner petals, and the oblong glaucous and glabrate monocarps.
TYPE. —
Madagascar
.
Prov. Toliara
,
Préfecture de Taolagnaro
[“
Tôlanaro
”] (
Fort-Dauphin
),
Petriky forest
,
c.
15 km
WSW of Taolagnaro
[“
Tôlanaro
”] (
Fort Dauphin
),
25°04’S
,
46°51’E
,
0-10 m
,
9.III.1989
(fl.),
Schatz et al. 2641
(holo-,
MO
!;
iso-, BR!; K!; WAG!).
PARATYPES
. —
Madagascar
. Prov.
Toliara
, forêt
de Vinanibe
près
Fort-Dauphin
,
5-50 m
,
2.IV.1947
(fl.),
Humbert
20767
(P)
;
Région de l’Anosy
,
Bemangidy Forest
,
c.
3 km
W of Antsotso
, along RN 12a,
65 km
N of
Ft. Dauphin
, E of
Ivohibe
peak,
24°35’02”S
,
47°12’44”E
,
100-250 m
,
7.II. 2006
(fl.),
Lowry
et al. 6669
(
MO
)
;
Anosy Region
, ouest du village
Malana
, vers sommet
entre Andohavola et Tanimena
, FKT:
Farafara Vatambe, CR
:
Mahatalaky
,
Dist.
:
Taolagnaro
,
Rég.
:
Anosy
,
24°51’22”S
,
47°00’27”E
,
411 m
,
16.XI.2009
(fl., fr.),
Rakotovao et al. 4575
(
MO
)
;
Fiv.
Fort Dauphin
,
Com. Ampasinampoa
,
Fkt. Analambendrana
à
4 km
(vol d’oiseau) à l’ouest
d’Ampasinapoa
,
24°59’06”S
,
46°57’37”E
,
400 m
,
24.XI.2002
(fr.),
Randrianaivo
et al. 838
(
MO
)
;
Anosy Region
,
Fort-Dauphin
,
Iaboko
,
Antsotso
, Forêt
Ivohibe
,
24°34’14”S
,
47°12’04”E
,
265 m
,
28.XI.2005
(fr.),
Razakamalala
et al. 2414
(
MO
, P[P06901342])
;
Anosy Region
,
Taolagnaro
,
Iaboko
,
Antsotso
Avaratra,
24°34’16”S
,
47°12’06”E
,
271 m
,
8.XII.2007
(fr.),
Razakamalala
et al. 3797
(
MO
, P[P06490487])
.
DISTRIBUTION, ECOLOGY AND CONSERVATION STATUS. —
Xylopia australis
,
sp. nov.
, is restricted to a small area in southeastern
Madagascar
, where it occurs in humid forest, sometimes on forested dunes or sand, at elevations from sea level to
c.
400 m
(
Fig. 28
). Specimens with flowers have been collected from February to April and in November, and with fruits in November and December. With its small EOO and AOO values,
185 km
2 and
24 km
2, respectively,
X. australis
,
sp. nov.
, is given a preliminary conservation assessment of Endangered (
Table 2
). Several of the collections come from the general area of the Tsitongambarika forest, an area of high endemism (
Razakamalala
et al.
2011
), which was designated as a protected area in 2015. The forests there are tropical in structure (
Goodman
et al.
1997
) but lie south of the Tropic of Capricorn.
LOCAL NAME. — Ovaria (
Rakotovao et al. 4575
).
DESCRIPTION
Tree or shrub
up to
8 m
tall; d.b.h. up to
10 cm
.
Twigs
glabrous to sparsely pubescent, the hairs
0.2-0.4 mm
long, soon glabrate; nodes with a single axillary branch.
Leaves
with larger blades
8.7-17.2 cm
long,
2.2-4.4 cm
wide, subcoriaceous, discolorous, light gray to grayish green adaxially, orange-brown to brown abaxially, or concolorous, narrowly oblong or elliptic-oblong to lanceolate, apex acute to acuminate, the acumen
4-20 mm
long, base rounded to broadly cuneate, short-decurrent on petiole, margin slightly revolute, glabrous adaxially, sparsely and finely appressedpubescent abaxially, the hairs sometimes restricted to the midrib; midrib pale yellow to brown or concolorous with blade adaxially, secondary veins distinctly brochidodromous, forming a wavy intramarginal vein, 14-17 per side, diverging at 60-90° from midrib, these and higher-order veins strongly raised and forming a conspicuous reticulum on both surfaces; petiole
2-9 mm
long, shallowly canaliculate to semi-terete, transversely wrinkled and longitudinally striate, glabrous to sparsely pubescent.
Inflorescences
axillary, 1-flowered, not pedunculate, sparsely appressed-pubescent; pedicels
4.7-6.5 mm
long,
1.1-1.6 mm
thick; bracts 3, evenly spaced along pedicel, caducous or persistent,
2.3-2.7 mm
long, triangular; buds ovoid to oblong, apex obtuse.
Sepals
somewhat spreading at anthesis, ¼-1/3-connate,
3-4.7 mm
long,
3.9-4.5 mm
wide, coriaceous, broadly triangular, apex acute, appressed-pubescent abaxially.
Petals
pale yellow to creamy white, the inner petals also red at the base
in vivo
; outer petals spreading at anthesis,
11-18.8 mm
long,
3-5.9 mm
wide at base,
4.9-5.7 mm
wide at midpoint, fleshy, oblong-lanceolate to oblong-ovate, flattened and some- what concave but keeled at apex adaxially, not keeled abaxially, apex obtuse, pubescent toward apex and glabrous toward base adaxially, appressed-pubescent abaxially; inner petals erect at anthesis,
13.1-15.2 mm
long,
2.5-3.9 mm
wide at base, 2.0-
2.4 mm
wide at midpoint, fleshy, lanceolate, keeled at apex, flat and corrugated in center adaxially, keeled abaxially, apex acute, base shallowly concave with undifferentiated margin, puberulent on distal ¼ on both surfaces.
Stamens
200-250; fertile stamens
1.4-1.8 mm
long, narrowly oblong, anther connective apex
0.2-0.4 mm
long, shield-shaped, overhanging anther thecae, papillate, anthers 7-11-locellate, filament
0.3-0.4 mm
long; outer staminodes
1.4-1.7 mm
long, oblong, apex obtuse; inner staminodes
1.4-1.7 mm
long, clavate to oblong, apex obtuse; staminal cone
2.7-3.1 mm
in diameter, 1.6-2.0 mm high, completely concealing the ovaries, rim irregularly laciniate.
Carpels
5-7; ovaries
c.
1.3 mm
long, narrowly oblong, pubescent, stigmas free or loosely connivent,
2.6-2.9 mm
long, clavate and somewhat falciform, sparsely pilose.
Fruit
of up to 5 monocarps borne on a pedicel
4.5-7.3 mm
long,
2.5-3.3 mm
thick, pubescent; torus
4.7-5.7 mm
in diameter, 4.5-5.0 mm high, ovoid to globose; monocarps with glaucous-green exterior
in vivo
,
2.9-5.3 cm
long, 1.3-2.0 cm wide, 1.2-2.0 cm thick, ovoid to oblong, sometimes weakly torulose, apex rounded or with a blunt beak
2-4 mm
long, base sessile or contracted into a stipe
3-5 mm
long,
4-6 mm
thick, finely verrucose and wrinkled, with a glaucous bloom, dull to slightly shiny, glabrate; pericarp
0.4-1 mm
thick.
Seeds
up to 4 per monocarp, in a single row, lying oblique to nearly perpendicular to long axis,
12-14.4 mm
long,
9-10.3 mm
wide,
c.
9.5 mm
thick, ellipsoid to broadly ellipsoid, somewhat quadrangular in cross-section, light brown, wrinkled and pitted, dull, perichalazal ring visible as a slightly raised line; sarcotesta not detected; aril absent.
NOTES
Xylopia australis
,
sp. nov.
, is readily identifiable by its relatively large, but narrow, long-acuminate subcoriaceous leaves, with the higher-order venation raised and forming a conspicuous reticulum on both surfaces. The secondary veins frequently unite to form a wavy intramarginal vein. The corrugated surfaces of the inner petals and the glaucous monocarps are unique characters among
Madagascar
Xylopia
species. This southern distribution of the species in
Madagascar
is the basis for the specific epithet. The collection
Lam & Meeuse 6013
(L, WAG), Tamatave, Rés. Nat. Betampona,
450 m
,
19.XII.1938
(fr.), bears monocarps that resemble those of
X. australis
,
sp. nov.
, in the blunt apex, the glabrate surface, and the small number of large seeds. The leaves differ from those of
X. australis
,
sp. nov.
, in being elliptic to obovate, smaller (up to
9.4 cm
long), and chartaceous in texture. The monocarps are distinctly stipitate, with a flat truncate apical beak. It has not been re-collected, despite recent plant inventory efforts in the Betampona Reserve.