Studies of Malagasy Eugenia (Myrtaceae) - III: Seven new species of high conservation concern from the eastern littoral forests
Author
Snow, Neil
Herbarium Pacificum, B. P. Bishop Museum, 1525 Bernice Street, Honolulu, Hawaii 96825, USA
nsnow2@mt.gov
Author
Rabenantoandro, Johny
Rio Tinto / QIT Madagascar Minerals S. A., Villa 3 H Lot J, 169 Antananarivo, 101, MADAGASCAR; E-mails: johny. rabenantoandro @ riotinto. com;
johny.rabenantoandro@riotinto.com
Author
Randriatafika, Faly
Rio Tinto / QIT Madagascar Minerals S. A., Villa 3 H Lot J, 169 Antananarivo, 101, MADAGASCAR; E-mails: johny. rabenantoandro @ riotinto. com;
johny.rabenantoandro@riotinto.com
Author
Rabehevitra, David
Rio Tinto / QIT Madagascar Minerals S. A., Villa 3 H Lot J, 169 Antananarivo, 101, MADAGASCAR; E-mails: johny. rabenantoandro @ riotinto. com;
johny.rabenantoandro@riotinto.com
Author
Razafimamonjy, N. Darie
Department of Botany, University of Antananarivo, MADAGASCAR; E-mail: dariejosmail @ yahoo. com
Author
Cable, Stuart
Royal Botanic Gardens, Kew, Richmond, Surrey, UNITED KINGDOM; E-mail: s. cable @ kew. org
text
Phytotaxa
2012
2012-03-15
48
1
39
60
http://biotaxa.org/Phytotaxa/article/view/phytotaxa.48.1.7
journal article
10.11646/phytotaxa.48.1.7
1179-3163
4776766
Eugenia vanwykiana
N. Snow
sp. nov.
(
Figs. 1
,
9
).
A congeneribis madagascariensibus combinatione characterum sequentium distinguitur: arbor mediocris; ramuli juniores et hypanthium dense tomentosum, pilis dibrachiatis aliquantum ferrugineis; ramuli complanati vel teretes; folia obovata vel elliptica, (20–)30–47 x (10–)
15–39 mm
, nervo medio supra sulcato; hypanthium valde costata.
Type:
―
MADAGASCAR
. Prov.
Antsiranana
:
Vohémar
,
Nosibe
,
Anjiabe. Village
le plus proche:
Anaborana
près du lac
Sahaka
,
13°04’43’’S
,
49°54’04’’E
,
10 m
,
23 Février 2003
,
J. Rabenantoandro
1319,
R
.
Rabevohitra
,
R
.
Razakamalala
&
S. Mathieu
(
holotype
MO! [sheet no. 6038327]; isotypes BISH! [sheet no. 731731], P, TAN)
.
Trees
10–12 meters; bark unknown. Indumentum on young branchlets and hypanthium dense (trichomes dibrachiate and somewhat ferrugineous).
Branchlets
laterally compressed becoming rounded, brownish-gray, becoming slightly scaly or fissured, densely sericeous; internodes 1.2–3.0 cm long.
Leaves
coriaceous, evenly distributed along branchlets, discolorous (fresh color unknown), matte above and below; venation brochidodromous. Stipules absent.
Petioles
4.2–10.5 mm
long, deeply sulcate above, densely hairy, becoming glabrous and somewhat rugose-wrinkled.
Leaf blades
(2.0–)3.0–5.5 x (1.0–)
1.5–3.9 cm
, narrowly elliptic or elliptic to narrowly obovate or obovate, base cuneate, margin flat to slightly revolute, laminar surface flat to mildly wavy, apex obtuse, tip acute (or less frequently acute); adaxial surface sparsely hairy along midvein and proximally but becoming glabrous, oil glands faint or not visible, midvein sulcate proximally becoming flush distally; abaxial surface sparsely hairy becoming glabrous, oil glands relatively occasional to common, flush, faint and of uniform size, midvein protruding and striate but becoming flush distally, secondary veins relatively few and not particularly distinct, the distal ends of secondary veins connected by a somewhat arching intramarginal vein less than
1.5–5.5 mm
from laminar margin at midpoint.
Inflorescence
axillary or terminal, in fascicles of monads, triads (3-flowered cymes) or few-flowered panicles.
Peduncles
2–15 mm
long, terete to laterally compressed, stiff. Pedicels
3–4 mm
long, densely hairy, anthopodia and metaxyphylls absent.
Bracteoles
0.7–1.3 x <
0.5 mm
, narrowly triangular to broadly ovate or oblate, scale-like, mostly densely hairy.
Hypanthium
3–4 mm
long,
4–5 mm
wide at base of calyx lobes, obconic, prominently ribbed in flower, densely hairy, oil glands (if present) completely obscured by hairs.
Calyx lobes
4, 3–
4 mm
long, ovate to broadly ovate, hairy below especially near margins and center, yellowish.
Petals
4, 7.5–9.5 x
7–8 mm
, broadly obovate to very broadly obovate, glabrous, yellowish, oil glands absent or sparse. Staminal ring densely hairy, 3.0–
3.2 mm
wide.
Stamens
ca. 75–100; filaments
6–10 mm
; anther sacs 0.8–1.0 mm long, globose to subcylindrical, dorsifixed, eglandular.
Style
10.5–11.5 mm
, glabrous, sparsely glandular; stigma terete and scarcely if at all capitate. Locules 2; placentation axile; ovules 15–17 per placenta, apically (i.e., opposite point of attachment) broad with well-defined angular sides but narrowing towards base, radiating from centrally positioned, rounded placenta.
Fruit
evidently green (not confirmed).
Field characters:—
Tree to
12 m
tall; leaves elliptic to obovate, upper midvein impressed above in lower half of blade; hypanthium conspicuously ribbed in flower and densely hairy; calyx green, petals yellow, fruits green.
Distribution:—
Eugenia vanwykiana
is known from two collections from the Analabe littoral forest near Lac Sahaka, located east of Anaborano and about
2.8 km
west of the coastline (
Fig. 1
). This general area is approximately
33 km
northwest of Vohémar and about equidistant from the coastal outlets of the Manambato and Manankolana rivers.
Habitat and ecology:—
In littoral forest over sand.
Phenology:—
Flowering February through May. Fruiting indicated from both known gatherings (February and May) but none seen by the first author.
Additional specimen examined (
paratypes
):—
MADAGASCAR
:
Antsiranana
:
Fivondronana
:
Vohémar
,
Firaisana
:
Nosy Be
(Nossi-be),
Fokontany
:
Anjiabe
,
13°04’43’’S
,
49°54’04’’E
,
13 May 2004
,
R
. Razakamalala 1324 et al.
(BISH! [sheet nos. 731742, 731743], MO!, P, TEF)
.
Eponomy:—
The specific epithet honors Dr. Abraham van Wyk (1952–) of the University of Pretoria,
Gauteng Province
,
South Africa
, whose studies provided important insights into the the anatomical and morphological variability of the South African species of
Eugenia
.
FIGURE 9.
Isotype of
Eugenia vanwykiana
(
Rabenantoandro 1319 et al.
[BISH]).
Conservation status:—
Recent satellite imagery suggests that the Analabe littoral forest near Lac Sahaka remains relatively undisturbed and relatively free of roads. However,
Consiglio
et al
. (2006)
estimated only ca. 2200 hectares of remaining littoral forests in this region. Unlike the other species proposed herewith, recent field observations are unavailable for
Eugenia vanwykiana
and no attempt was made to estimate its population size at Analabe.With just two collections, an AOO of
9 km
2
, and a single subpopulation constituting a single location not encompassed within a protected area,
E
.
vanwykiana
is assigned a preliminary status of “Endangered” (EN: B2ab(i, iii)) because of the relatively undisturbed area where the species is growing.
Discussion:—
The label on the
type
specimen indicates the fruits are greenish but we have seen no fruits on herbarium material, and green typically applies only to immature fruits in
Eugenia
.