A taxonomic revision of the genus Noronhia Stadtm. ex Thouars (Oleaceae) in Madagascar and the Comoro Islands
Author
Hong-Wa, Cynthia
Missouri Botanical Garden P. O. Box 299 St. Louis MO 63166 - 0299 U. S. A & Claude E. Phillips Herbarium Delaware State University 1200 N. DuPont Hwy, Dover DE 19901 - 2277 U. S. A.
chwa@desu.edu
text
Boissiera
2016
2016-10-21
70
1
292
journal article
22287
10.5281/zenodo.7599432
f2ceb54b-e71d-4433-9e67-b75b62f8a902
978-2-8277-0086-8
0373-2975
7599432
79.
Noronhia stevensiana
Hong-Wa, spec. nova (
Fig. 64
,
65A
).
Typus
:
MADAGASCAR
.
Prov.
Antsiranana
:
DIANA
,
Diégo
II
,
Antsalaka
,
Montagne d’Ambre AP
,
12°37’17”S
49°10’46”E
,
1038 m
,
12.
VI
.2010,
Hong-Wa 711
(holo-: MO-6615564!; iso-: P!, TAN!).
Diagnosis
Noronhia stevensiana
Hong-Wa can be distinguished from other members of the genus by its partially woody petioles, its chartaceous and lanceolate leaf blades, its somewhat compact inflorescences, with cupuliform, cream-white pinkish flowers, and its crustaceous, subglobose fruits without a distinct apex.
Description
Trees
to
14 m
tall, trunk to
20 cm
diameter; young twigs flattened to cylindrical,
0.5-2 mm
diameter, glabrous; bark dark gray, smooth to rugose.
Leaves
opposite, persistent; bud scales deciduous; blades medium green above, lighter below, lanceolate to oblong, 6-14
3
1.5-4 cm
, chartaceous, glabrous, domatia absent, base acute, margin flat to slightly undulate, apex acuminate, the acumen
5-22 mm
long, midrib flat to slightly sunken above, raised below, secondary veins conspicuous, 8-15 per side,
6-16 mm
apart, looping
1.5-4 mm
from the margin; petiole medium gray, 4-12
3
1-1.7 mm
, partially woody, glabrous.
Thyrses
solitary to geminate, pauciflorous, compact to somewhat diffuse; peduncle
5-10 mm
long, moderately pubescent; pedicel
2-5 mm
long, moderately pubescent; calyx moderately pubescent outside, glabrous inside, lobes triangular, 0.8-1.5
3
1-2 mm
; corolla pink fading to white cream tinged pink, cupuliform,
2.5-3.5 mm
long, glabrous on both sides, the tube
1.3-2.5 mm
long, lobes widely ovate, apex obtuse; corona present,
1-1.5 mm
long, undivided; stamens
1.5-1.7 mm
long, anthers obovate,
1-1.1 mm
long; pistil
1.3-2.2 mm
long, stigma capitate.
Fruiting
pedicel 4-5
3
1.6-1.8 mm
; young fruits green, purplish black when mature, subglobose to ovoid, 17.5-21
3
14.5-19 mm
, surface smooth to rugose, sometimes covered with a white pellicle, apex flat; dry pericarp
0.7-0.8 mm
thick; endocarp crustaceous; seed 19
3
8.5 mm
.
Etymology
This name honors Peter F. Stevens for his contribution to the knowledge of the
Malagasy
flora, for his invaluable mentorship, and for sharing his passion for plants.
Distribution, ecology and phenology
Noronhia stevensiana
occurs in mid- to high-elevation humid forests on lavas on the Montagne d’Ambre in the north (
Fig. 62
). It produces flowers and fruits from January to June.
Conservation status
Noronhia stevensiana
is currently known only from nine collections representing seven localities. With an EOO of
33 km
2
, an AOO of
24 km
2
, and three subpopulations representing three locations, all included within Montagne d’Ambre PN, which is still sub-ject to continuing decline in habitat quality and loss of mature individuals as a result of illicit exploitation and encroachment for crop and khat cultivation,
N. stevensiana
is assigned a preliminary status of “Endangered” [EN B1ab(iii,v)+2ab(iii,v)].
256
Boissiera 70
Notes
Noronhia stevensiana
resembles
N. schatzii
, but these two taxa can be distinguished by the texture of their petioles, the density of their inflorescences, the pubescence of their peduncles and pedicels, and the shape of their fruits. Identifying features include partially woody petioles, chartaceous and lanceolate leaf blades, somewhat compact inflorescences, with cupuliform, cream-white pinkish flowers, and crustaceous, subglobose fruits without a distinct apex.
Paratypi
MADAGASCAR
.
Prov.
Antsiranana
: Joffreville,
Montagne d’Ambre PN
,
12°32’19”S
49°09’32”E
,
1219 m
,
23.
I
.2009,
Hong-Wa 577
(
MO
,
P
,
TAN
);
ibid. loc.
,
Hong-Wa 578
(
MO
,
P
,
TAN
);
ibid. loc.
,
Hong-Wa 580
(
MO
,
P
,
TAN
); ibid. loc
.
,
12°30’55”S
49°10’34”E
,
891 m
,
24.
I
.2009,
Hong-Wa 590
(
MO
,
P
,
TAN
); ibid. loc
.
,
12°30’56”S
49°10’40”E
,
931 m
,
16.
V
.2010,
Hong-Wa &
Ortiz
680
(
MO
,
P
,
TAN
); ibid. loc
.
,
12°32’35”S
49°08’46”E
,
1315 m
,
17.
V
.2010,
Hong-Wa &
Ortiz
685
(
MO
,
TAN
); ibid. loc
.
,
12°36’17”S
49°11’22”E
,
1035 m
,
9.
V
.2008,
Trigui
et al. 383
(
G
,
MO
,
TEF
); ibid. loc
.
,
12°37’48”S
49°10’44”E
,
1030 m
,
16.
VI
.2008,
Trigui
et al. 543
(
G
,
MO
,
TEF
)
.