Taxonomic studies of Diospyros (Ebenaceae) from the Malagasy region. VI. New species of large trees from Madagascar
Author
Schatz, George E.
Author
Lowry Ii, Porter P.
Author
Rakouth, Hasina N.
Author
Randrianaivo, Richard
text
Candollea
2021
2021-07-07
76
2
201
236
http://dx.doi.org/10.15553/c2021v762a3
journal article
10.15553/c2021v762a3
2235-3658
Diospyros lowryi
G.E. Schatz
,
sp. nov.
(
Fig. 11
).
Holotypus
:
MADAGASCAR
. Reg. Analanjirofo [Prov.
Toamasina
]:
Masoala Peninsula
,
21.II.1989
, fr.,
Schatz
&
Lowry
2617
(MO-3706473!; iso-:
K
,
P
[
P03975074
]!,
TAN
[
TAN001945
]!,
WAG
[
WAG
.1180486] image!)
.
Diospyros lowryi G.E. Schatz
is distinguished from other members of the genus in
Madagascar
by its ovate to elliptic, glabrous lamina with an abruptly short acuminate apex and its paired axillary infrutescences, each with 3– 6 fruits, the ovoid to elliptic fruit densely covered with short, appressed, beige trichomes
0.2–0.4 mm
long, rendering the fruit beige in vivo, light brown in sicco.
Tree
20–25 m
tall,
25 cm
DBH.
Young stems
terete, sparsely covered with minute, erect, white trichomes
0.1 mm
long.
Leaves
distichous, lamina 2.7–6 ×
1.2–3.3 cm
, ovate to elliptic, chartaceous, glabrous on both surfaces, base rounded to cuneate to acuminate, margin flat to slightly revolute, apex abruptly short acuminate, acumen
3– 8 mm
long, the very tip rounded, midvein very slightly impressed above, raised below, venation brochidodromous, with 5–7 secondary veins per side, indistinct above, slightly raised below, tertiary venation reticulate; petiole
3–5 mm
long,
1 mm
in diam., rather sparsely covered with short, appressed trichomes c.
0.3 mm
long, glabrescent.
Male flowers
in axillary cymose inflorescences of 2–4 flowers,
2–4 mm
long, each flower subtended by a bracteole, the axes and bracteole orange-brown, pedicel c.
1 mm
long, <
1 mm
in diam., densely covered with short, appressed, light beige trichomes c.
0.3 mm
long; calyx broadly urceolate, 1 ×
1.5 mm
, entire, rather densely covered with short, appressed, light beige trichomes c.
0.2–0.3 mm
long; corolla obconical in bud; stamens c. 18, immature.
Female flowers
not seen.
Fruits
axillary, borne in paired cymose infructescences, each with 3– 6 fruits, the axes densely covered with short, appressed, light brown trichomes c.
0.2–0.3 mm
long; pedicel in fruit c.
1 mm
long, c.
1.5–2 mm
in diam., densely covered with appressed, light brown trichomes c.
0.2 mm
long; fruiting calyx broadly cupuliform, 2 ×
5–6 mm
, entire, sparsely covered with appressed, light brown trichomes c.
0.2 mm
long, margin entire, flat, dark chocolate brown in sicco, pedicel scar
1.5 mm
in diam.; fruits ovoid to ellipsoid, 12–15 ×
6–8 mm
, slightly asymmetrical, beige in vivo, light brown in sicco, densely covered with short, appressed, beige trichomes c.
0.2–0.4 mm
long, apex acute, shortly apiculate, apiculum
0.5 mm
long.
Seeds
1–3, ovoid to ellipsoid, 10–12 ×
4–5 mm
, glabrous, black, shiny.
Etymology.
– The specific epithet honors my colleague Porter P. Lowry II, who has led the Missouri Botanical Garden’s program in
Madagascar
since 1986. Although he is a specialist in
Araliaceae
, in 2009 he agreed to work together with me on a revision of Malagasy
Ebenaceae
, a collaboration that has surpassed our wildest expectations.
Vernacular names.
– “Maintipototra” (
Service Forestier 12978
); “Maintimpototra à petites feuilles” (
Service Forestier 15365
).
Distribution and ecology. –
Diospyros lowryi
is restricted to the area around the Baie d’Antongil, where it has been collected at just two sites, near Ambanizana, situated just outside Masoala National Park, and at the Farankaraina Forestry Station, to the east of Maroantsetra (
MADAGASCAR
CATALOGUE, 2021
). It occurs in low-elevation humid forest.
Phenology.
– Flowering material has been collected in
November, and fruits in February and March.
Conservation status. –
Diospyros lowryi
has an extremely restricted geographic range in the form of an Area of Occupancy of
8 km
². It is known from just outside the protected area of Masoala, where it is threatened by exploitation of trees for firewood and house construction material, which will result in continuing decline. With respect to the most serious
mm [
A–D:
Réserves Naturelles 9731
, P;
E:
Lowry et al. 7482
, from photo] [Drawing: Alain Jouy]
Fig. 10. –
Diospyros grandiflora
G.E. Schatz & Lowry.
A.
Branch
in fruit;
B.
Branch with female flowers;
C.
Schematic section of female flower;
D.
Corolla of female flower;
E.
Fruit.
plausible threat of exploitation of trees for firewood and house construction material,
D. lowryi
exists at two locations, and it was recently assessed for its risk of extinction as “Endangered” [EN B2ab(iii,v)] (
IUCN, 2021
).
Notes. –
Diospyros lowryi
belongs to a loosely defined group of species in
Madagascar
characterized by 3-merous flowers and a small calyx that is generally cupuliform and entire or shallowly lobed, which includes several species previously placed by
PERRIER DE LA BÂTHIE (1952)
in the genus
Maba
(see above under
D. andohahelensis
), as well as perhaps 25 additional new species that remain to be described. Within this group,
D. lowryi
can be distinguished by its ovate to elliptic, glabrous lamina with an abruptly acuminate apex and its axillary, paired infructescences, each with 3–6 fruits, the ovoid to elliptic fruits densely covered with appressed, beige trichomes
0.2–0.4 mm
long, rendering the fruit beige in vivo, light brown in sicco.
Additional specimen examined.
–
MADAGASCAR
.Reg. Analanjirofo [Prov.
Toamasina
]:
Farankaraina
,
4.III.1955
, fr.,
Service Forestier
12978
(
MO
,
P
,
TEF
);
ibid. loco
,
25.XI.1955
,
♂
fl.,
Service Forestier 15365
(
G
,
MO
,
P
,
TEF
)
.