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
28.
Xylopia lokobensis
D.M.Johnson & N.A.Murray
,
sp. nov.
(
Fig. 23A-E
)
In the relatively broad flowers with sepals exceeding
4 mm
in length and the short obliquely oblong monocarps,
Xylopia lokobensis
,
sp. nov.
, is most similar to
X. capuronii
, but it is distinguishable by the sparse yellowish brown indument on the twigs, leaves, and monocarps, the oblong leaf blades with flat margins, the broad leaf acumen
4-10 mm
long, and the outer petals
13-19 mm
long.
Xylopia capuronii
, in contrast, has dense dull red indument on the twigs, leaves, and monocarps, narrowly oblong to elliptic leaf blades with strongly revolute margins, a narrow leaf acumen
5-9 mm
long, and outer petals
11-13 mm
long.
TYPE. —
Madagascar
.
Prov. Antsiranana
,
Fivondronana Nosy-Be
,
Lokobe Réserve intégrale
,
Ampasindava
,
13°24’44”S
,
48°18’53”E
,
300 m
,
7.XII.1996
(fl., fr.),
Antilahimena 340
(holo-,
P
[
P01986965
]!;
iso-, MO!).
PARATYPES
. —
Madagascar
. Prov.
Antsiranana
,
Réserve
naturelle intégrale No. 6 –
Lokobe
, south side of the reserve (“Study Site” for the Black Lemur Forestry Project),
5 km
SE of Hell Ville
,
Nossi Be
,
13°25’S
,
48°18’E
,
50 m
,
24.XI.1992
(fl., fr.),
Birkinshaw 186
(
MO
n. v.,
OWU
, P[P01986963])
;
région
Diana
,
Ampasindava
, forêt
de Bongomihirahavavy
,
13°45’34”S
,
48°05’54”E
,
400 m
,
2.XII.2012
(fr.),
Gautier LG
6068
(G, n. v., P[P00982774])
.
DISTRIBUTION, ECOLOGY AND CONSERVATION STATUS. —
Xylopia lokobensis
,
sp. nov.
, occurs in northwestern
Madagascar
, on Nosy-Be island and the nearby Ampasindava peninsula, in humid forest at elevations from
50 to 400 m
(
Fig. 29
). Specimens with both flowers and fruits were collected in November and December. With an EOO value of
144 km
2
and an AOO of
8 km
2
the species is given a preliminary conservation assessment of Endangered. One of its known populations, however, lies within the protected Lokobe Reserve.
LOCAL NAMES. — Hazoabo, moranga (
Antilahimena 340
).
DESCRIPTION
Tree
up to
18 m
tall; d.b.h. up to
8 cm
.
Twigs
densely yellowish brown-pubescent, the hairs
0.2-0.5 mm
long, eventually glabrate; nodes with one axillary branch.
Leaves
with larger blades 8.0-
13.4 cm
long,
2.7-4.8 cm
wide, subcoriaceous, discolorous, dark brown to olive-gray adaxially, brown abaxially, oblong, apex obtuse to short-acuminate, the acumen
4-10 mm
long, base broadly cuneate to rounded, short-decurrent on petiole, margin flat, not revolute, glabrous except for the pubescent midrib adaxially, appressed-pubescent abaxially; midrib often darkened adaxially, secondary veins irregularly brochidodromous, 14-20 per side, diverging at 60-80° from midrib, these and higher-order veins slightly raised on both surfaces; petiole
5-10 mm
long, shallowly canaliculate, smooth, pubescent.
Inflorescences
axillary, 1-flowered, not pedunculate, yellowish brown-pubescent; pedicels
6-8.3 mm
long,
1.2-1.4 mm
thick; bracts 2, one near midpoint, one just proximal to the sepals, caducous or somewhat persistent,
3-3.8 mm
long, semicircular; buds broadly lanceolate, apex obtuse, slightly falciform.
Sepals
somewhat spreading at anthesis, ¼-1/3-connate,
4.2- 4.6 mm
long, 5.0-
5.2 mm
wide, coriaceous to slightly fleshy, broadly ovate to triangular, apex broadly acute to obtuse, pubescent abaxially.
Petals
light green in bud
in vivo
; outer petals slightly spreading at anthesis,
13-19 mm
long,
3.5-6 mm
wide at base,
1.8- 3 mm
wide at midpoint, fleshy, lanceolate, keeled on apical ¼ but otherwise flat adaxially, slightly keeled abaxially, apex obtuse to acute, densely puberulent except for the glabrous base adaxially, densely appressed-pubescent abaxially; inner petals probably slightly spreading at anthesis,
8.3-13 mm
long,
c.
2.8 mm
wide at base,
c.
1.3 mm
wide at midpoint, slightly fleshy, lanceolate, keeled except for the concave base adaxially, keeled abaxially, apex acute to obtuse, base concave with undifferentiated margin, densely puberulent except for glabrous base on both surfaces.
Stamens and carpels
not examined.
Fruit
of up to 5 monocarps borne on a pedicel
9-11 mm
long,
4-7 mm
thick, glabrate; torus
9-17 mm
in diameter,
8-10 mm
high, irregularly globose; monocarps with green exterior and red endocarp
in vivo
, 2.4-3.0 cm long,
1.4-2.3 cm
wide,
1.4- 1.6 cm
thick, obliquely oblong, occasionally slightly torulose, apex rounded to obtuse, base sessile or contracted into a stipe
2-3 mm
long,
4-8 mm
thick, finely verrucose, obliquely wrinkled, dull, finely tomentose; pericarp
0.6-1.7 mm
thick.
Seeds
up to 4 per monocarp, in two rows, oblique to perpendicular to long axis,
9.5-12.6 mm
long,
5.6-8 mm
wide,
4.5-6.5 mm
thick, oblong-ellipsoid to obovoid, wedge-shaped, broadly elliptic, or semicircular in cross-section, brown, smooth to slightly wrinkled and pitted, dull, perichalazal ring not evident; sarcotesta color
in vivo
not determined; aril absent.
NOTES
Xylopia lokobensis
,
sp. nov.
, belongs to the group of sect.
Stenoxylopia
species with clavate stigmas, and is one of several species with medium-sized leaves, moderately large flowers and subsessile oblong monocarps. The species has a tendency for the midrib and secondary veins to be darkened on the adaxial surface.Two of the three collectors of this species remarked on the strong aroma of the foliage, a characteristic not noted for other
Madagascar
Xylopia
species.
Xylopia lokobensis
,
sp. nov.
, may distinguished from
X. galokothamna
,
sp. nov.
, which occurs in the same general region of
Madagascar
, by the tree rather than shrub habit, the leaf blade short-decurrent on a longer petiole (cf.
Fig. 23A, I
), and the absence of both beak and stipe on the monocarps.
Xylopia lokobensis
,
sp. nov.
, was identified as
Xylopia
sp. in
Birkinshaw (2001)
, where it was listed as a minor food source for the Black Lemur (
Eulemur macaco macaco
).
Xylopia lokobensis
,
sp. nov.
, is one of the few large-fruited
Madagascar
Xylopia
species for which monocarp dehiscence and red endocarp color have been documented, but color of the sarcotesta covering the seed has not been reported. The specimen
Birkinshaw 186
was included in the molecular phylogenetic analysis of
Stull
et al.
(2017)
, where it was one of four accessions identified as
Xylopia
sp.
aff.
fananehanensis
, which, although they are recognized in this treatment as four distinct species, formed part of a single subclade in the phylogenetic analysis.