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
7182965
Diospyros taikintana
G.E. Schatz & Lowry
,
sp. nov.
(
Fig. 18
).
Holotypus
:
MADAGASCAR
. Reg. Sofia
[Prov.
Mahajanga
]:
Ambohimirahavavy
,
19.I– 12.II.1951
,
♀
fl.,
Humbert
&
Capuron
24919
(MO-6956011!; iso-:
G
[
G00341739
]!,
K
!,
P
[
P00580401
,
P03829461
]!,
TAN
!,
US
!,
W
!)
.
Diospyros taikintana G.E. Schatz & Lowry
resembles other members of the Squamosa group in having leaves with the midvein impressed adaxially and female flowers enclosed within multiple distichous, overlapping, scale-like bracts in bud, but is distinguished by its small leaves (3–5.5 ×
0.8–2.3 cm
) with dense indumentum on the abaxial surface, often 3-merous female flowers, and squamose floral bracts that form a nearly spherical cluster around each bud.
Tree
18 –25 m
tall,
25 – 40 cm
DBH. Bark thin (
5 mm
), nearly entirely black.
Young stems
terete, dark brown to blackish, with numerous small lenticels, moderately densely covered with short, erect, straight to curly trichomes c.
1 mm
long and/ or long, fauve, appressed trichomes c.
1 mm
long, glabrescent.
Leaves
distichous, lamina 3–5.5 ×
0.8–2.3 cm
, narrowly ovate to elliptic or occasionally oblong, coriaceous, glossy above, initially with appressed trichomes c.
0.1 mm
long, glabrescent, matte below, initially densely covered with white, silky, appressed trichomes to c.
1 mm
long and rusty, appressed trichomes c.
0.1 mm
long below, glabrescent, base obtuse to rounded, margin flat, apex acute to acuminate, midvein raised to slightly impressed above, glabrous or densely covered with white, curly, semi-appressed trichomes, raised below, venation weakly brochidodromous, with 6–9 secondary veins per side, indistinct to faintly visible and slightly raised above, slightly raised below; petiole
1–4 mm
long,
0.7–1 mm
in diam., terete to slightly flat-topped or canaliculate, densely covered with curly, semi-appressed, white to light golden trichomes
0.7 mm
long and appressed, rusty trichomes
0.1 mm
long, glabrescent.
Male flowers
not seen.
Female flowers
solitary, in the axils of leaves, 3(–4)-merous, pedicel
1–2 mm
long,
0.5 mm
in diam., bearing 7–9 distichous, overlapping, cucullate, scale-like bracts enclosing the flower in bud, 1.5–5 ×
1.5–6 mm
, broadly elliptic to circular, cucullate, becoming progressively larger from the base to apex of the pedicel, densely covered outside with white and fauve, appressed trichomes, glabrous inside, the margins densely ciliate; sepals fused into a cupular calyx, 3–4 ×
4.5 mm
, apex truncate, without any evident lobes or sometimes with three or four groups of trichomes slightly exserted above the rim, densely covered outside with appressed, fauve trichomes, glabrous inside; fused corolla with short (
1.5 mm
) urceolate tube and 3–4 spreading lobes, cream white, lobes 3 ×
3 mm
, apex rounded, densely covered outside with fauve, appressed trichomes, glabrous inside; staminodia 9, inserted on the corolla tube just below the lobes; ovary ovoid,
2–3 mm
long, style
1–2 mm
long, with 3–5 flat-topped stigmatic branches.
Fruits
axillary, solitary, pedicel in fruit
1 –1.5 mm
,
2 mm
in diam., glabrous, bearing numerous bract scars; fruiting calyx broadly cupuliform, 4–5 ×
9–10 mm
, 3–4-lobed, the lobes broadly triangular, 2 ×
5 mm
, margin revolute, the apex strongly reflexed, densely covered outside with a mixture of semi-appressed, blackish and dark brown trichomes
1–1.5 mm
long, glabrous inside except with shorter trichomes apically along the rim and exposed surface of lobes, pedicel scar
2 mm
in diam.; fruit spherical to slightly obloid, the apex slightly depressed, 7.5–8.5 ×
7.5–9 mm
, glabrous, light brown, shiny, crowned by the persistent style/stigma,
1–1.3 mm
long.
Seeds
3–4, flattened ellipsoid, 6–7 ×
4–5 mm
, glabrous, black, shiny.
Etymology.
– The species epithet is the Malagasy word for pill bugs, members of the isopod family
Armadillidiidae
, which, when rolled into a ball to assume a defensive posture, strongly resemble the squamose bracts that subtend the flower buds of
Diospyros taikintana
.
Distribution and ecology. –
Diospyros taikintana
is known from a single locality in the Ambohimirahavavy massif in the northern part of the island (
MADAGASCAR
CATALOGUE, 2021
), where it was collected in high-elevation subhumid to montane forest.
Phenology.
– Flowering and fruiting material was collected in February.
Conservation status. –
Diospyros taikintana
has an extremely restricted geographic range in the form of an Area of Occupancy of
4 km
². It is present only in the protected area of COMATSA Nord. Given the isolated and remote nature of its distribution, there are no known external threats. Therefore,
D. taikintana
can be assessed as “Least Concern” [LC], with the caveat that such a status is contingent upon the effective management of the COMATSA Nord protected area.
Fig. 18. –
Diospyros taikintana
G.E. Schatz & Lowry.
A.
Branch
with flower buds;
B.
Branch with fruits;
C.
Detail of leaf venation (abaxial surface);
D.
Detail of flower bud with subtending bracts;
E.
Fruit (seen from side);
F.
Fruit (seen from above).
[
A, D:
Service Forestier 983
, P;
B–C, E–F:
Service Forestier 988
, P] [Drawing:Alain Jouy]
Notes. –
Diospyros taikintana
is possibly a member of the Squamosa group, which comprises nine species characterized by having leaves with the midvein impressed adaxially, and female buds and flowers enclosed within multiple distichous, overlapping, scale-like bracts (SCHATZ & LOWRY, 2020). Within the Squamosa group,
D. taikintana
would be distinguished by its leaves with small lamina (3–5.5 ×
0.8–2.3 cm
) bearing dense indumentum on the abaxial surface, often 3-merous female flowers, and floral bracts that form a nearly spherical cluster around each bud.
We strongly suspect that the material of this species represents just two collections, one in flower comprising
Humbert & Capuron 24919
and
Service Forestier 983
, and the other in fruit, represented by
Humbert & Capuron 24927
and
Service Forestier 988
. Indeed, when Capuron was in the field with Humbert (and others, e.g. Leandri), he routinely reserved material of woody collections for the Service Forestier series, resulting in a single gathering entered into both Humbert’s and the Service Forestier number series.
Additional specimens examined.
–
MADAGASCAR
.
Reg. Sofia
[Prov.
Mahajanga
]:
Ambohimirahavavy
,
19.
I
–12.II.1951
, fr.,
Humbert
&
Capuron
24927
(
FHO
,
MO
,
P
,
TAN
,
WAG
)
;
ibid. loco
,
5.II.1951
,
♀
fl.,
Service Forestier
983
(
G
,
MO
,
P
[2 sheets],
TEF
)
;
ibid. loco
,
6.II.1951
, fr.,
Service Forestier
988
(
G
,
K
,
NY
,
P
[2 sheets],
TEF
,
US
,
W
)
.