A revision of the genus Ocotea Aubl. (Lauraceae) in Madagascar and the Comoro Islands
Author
Werff, Henk Van Der
Missouri Botanical Garden, P. O. Box 299, St. Louis, MO, 63166 (USA)
henk.vanderwerff@mobot.org
text
Adansonia
2013
3
2013-12-31
35
2
235
279
http://dx.doi.org/10.5252/a2013n2a5
journal article
10.5252/a2013n2a5
93b27db0-ab0a-40d9-862c-1a5c68678186
1639-4798
5206484
1.
Ocotea ambrensis
van der Werff
,
sp. nov.
(
Figs 1
,
2
)
Ocoteae racemosae
similis, sed tepalis persistentibus, bracteis basi gemmarum terminalibus magnis recedit.
TYPUS
. —
Madagascar
. Prov.
Antsiranana
,
Parc National de Montagne d’Ambre
,
12°32’S
,
49°11’E
,
900-1100 m
,
16-20.XI.1992
, fls,
Malcomber
,
Leeuwenberg
,
van Bergen
,
Andriatiana
&
Randriamampionona
1817
, (holo-,
P
!
;
iso-
,
MO
! [
6240678
],
TAN
).
PARATYPES
. —
Madagascar
.
Antsiranana
, Montagne d’Ambre PN,
12°32’S
,
49°07’E
, fr.,
Andrianantoanina
&
Solotiana
60
(
MO
,
P
[
P01977609
],
TAN
)
;
s. loc.,
Andrianantoanina
&
Solotiana
69 (
MO
,
TAN
)
;
Parc National de la Montagne d’Ambre
,
12°27’S
,
49°13’E
, fr.,
Andrianantoanina
&
Rocsce
270
(
MO
,
P
[
P01977608
],
TAN
)
;
Roussettes
,
Montagne d’Ambre
, fls,
Service Forestier
5467
(
P
[
P01977610
],
TEF
)
;
Montagne d’Ambre
,
Service Forestier
(
Capuron
) 11290
(
P
[
P01977611
],
TEF
)
;
Montagne d’Ambre
,
Trigui
et al. 518
(
G
,
MO
,
P
[
P01976697
]).
ALTITUDINAL DISTRIBUTION. — None of the collections of
O. ambrensis
sp. nov.
gives a specific altitude; instead ranges of altitude are given. The lowest is from
250- 500 m
, the highest from
990-1100 m
.
PHENOLOGY. — Flowering: November-December; fruiting: April (young fruits), August (older fruits).
DESCRIPTION
Trees, to
30 m
.
Twigs slightly angular, moderately appressed pubescent, becoming glabrous with age; terminal buds densely white pubescent, often with pubescent bracts,
4-6 mm
long, at their base. Leaves 5-9 ×
1.5-3.5 cm
, elliptic, alternate, chartaceous, base and apex acute, margin flat, glabrous or nearly so, the lower surface minutely gland-dotted, this less visible on older leaves, venation immersed on upper surface, slightly raised on lower surface, lateral veins poorly visible, 5-7 on each side, domatia absent. Inflorescences crowded along leafless short shoots,
2-4 cm
long, racemose or paniculatecymose, moderately to sparsely pubescent, some bracts persisting on the inflorescences, but these less conspicuous than the bracts near the terminal buds. Flowers cream white,
5-6 mm
in diameter, the tepals spreading at anthesis; tepals
2-2.5 mm
long, sparsely pubescent outside, densely pubescent inside, stamens 9, all 4-celled,
1 mm
long, the filaments short, pubescent; glands present at the base of the inner stamens; staminodia clavate,
0.7 mm
long, the thickened head glabrous, the filament pubescent; pistil glabrous,
1.5 mm
long, the style as long as the ovary, stigma peltate, receptacle glabrous inside. Young fruits (
1 cm
in diameter) enclosed in the cupule, this crowned by the persisting tepals, resembling small rose hips, older fruits (approaching
2 cm
in diameter) ⁴⁄5 enclosed in the cupule, this splitting and with teeth-like remnants of the tepals; mature fruits 2.5 ×
1.5 cm
, cupule deeply cup-shaped,
1.8 cm
in diameter, with teeth-like remnants of the tepals.
REMARKS
Ocotea ambrensis
sp. nov.
resembles the widespread and variable
O. racemosa
(Danguy) Kosterm.
Kostermans (1957)
annotated the sole specimen he saw of
O. ambrensis
sp. nov.
as
O. laevis
Kosterm.
, which I treat as a synonym of
O. racemosa
. However, the four collections of
O. ambrensis
sp. nov.
made in the last 15 years show consistent differences from
O. racemosa
, viz. the large, persistent bracts at the base of the terminal buds (lacking in
O. racemosa
), the persistent tepals on the cupule (tepals deciduous in fruit in
O. racemosa
), the very deep cupule (vs shallow cupules), the thinner leaves and the minute, dense gland dots at the lower surface of the leaves, at least of the flowering specimens (gland dots lacking in
O. racemosa
). The new species, known only from the Montagne d’Ambre in the far North, is also geographically separated from
O. racemosa
.