Novelties from the Northern Mountains Complex of Madagascar IV: A new Rinorea Aubl. (Violaceae) of restricted range from the Galoko and Kalabinono massifs
Author
Wahlert, Gregory A.
Missouri Botanical Garden, P. O. Box 299, St. Louis, Missouri, 63166 - 0299, U. S. A.
rinorea@gmail.com
text
Candollea
2016
2016-08-02
71
2
205
210
journal article
3012
10.15553/c2016v712a6
c224c07b-2a23-4a59-92a2-9843f4a7e687
2235-3658
5721545
Rinorea callmanderi
Wahlert
,
spec. nova
(
Fig. 1
).
Typus
:
MADAGASCAR
. Prov.
Antsiranana
:
Ambilobe
,
Beramanja
,
Anketrabe
, forêt
de Kalabenono
,
13°38’50”S
48°40’34”E
,
778 m
,
23.XI.2006
, fl.,
Callmander et al. 582
(holo-:
G
[
G00341675
]!; iso-:
K
!,
MO
!,
P
[
P00853251
]!,
TAN
)
.
Rinorea callmanderi Wahlert
is similar to
R. mutica (Tul.) Baill.
by its opposite-leaved phyllotaxy and contracted, subsessile, few-flowered cymose inflorescence, but differs by its oblanceolate leaves to
13 cm
long (vs. broadly oval-elliptic leaves to
9 cm
long in
R. mutica
), the inner surface of the petals sparsely pubescent near the middle (vs. the inner surface with a tuft of hairs near the apex), the presence of a linear, ventral scale on the anther connective (vs. ventral scale absent), and the presence of an ovate dorsal scale on the anther connective (vs. dorsal scale absent).
Shrub
to
3 m
tall; young branches flattened in cross section, glabrous to puberulent; stipules not seen.
Leaves
opposite, equal to anisophyllous; petiole
1.5-5 mm
long, glabrous; blade 4-13 ×
1.2-5 cm
, oblanceolate, glabrous on both surfaces; base attenuate-cuneate, symmetrical, aequilateral to suboblique; secondary vein pairs 6-9, divergent to ascending, tertiary veins reticulate; margin serrulate, often revolute; apex acuminate;
D
1 cm
A
2 cm
3 mm
C
1 mm
B
1 cm
Fig. 1. –
Rinorea callmanderi
Wahlert.
A.
Inflorescence
;
B.
Flowering branch;
C.
Flower;
D.
Leaf, abaxial surface. [
Callmander
582,G] [Drawing: R. L. Andriamiarisoa
]
Fig. 2. –
Distribution map of
Rinorea callmanderi
Wahlert
(stars) in Madagascar plotted on a map of forest cover in 2000 (grey) following HARPER et al. (2007). Areas outlined in black are protected areas.
domatia absent.
Inflorescence
a terminal few-flowered cyme to
2 cm
long; peduncle
4-5 mm
long, glabrous; pedicels
0.9-1.6 mm
long, glabrous; pedicel bractlets persistent, triangular to subulate, 0.7-1 ×
0.5-0.8 mm
, glabrous, keeled, margin ciliate, apex acute, mucronate.
Flowers
3.5-3.9 mm
long.
Sepals
unequal, ovate-deltoid, 0.9-1.8 ×
1-1.2 mm
, keeled, glabrous, margin ciliate, apex acute to rounded, usually mucronate.
Petals
subequal, lanceolate, 3-3.3 ×
1.1-1.3 mm
, outer surface glabrous, inner surface sparsely pubescent near the middle, margin entire to ciliolate, apex subacute to acute, erect.
Stamens
2.7-2.8 mm
long; staminal tube
0.4-0.5 mm
tall, outer and inner surfaces glabrous; anthers subsessile, filaments c.
0.1 mm
long, anthers c. 0.7 ×
0.5 mm
; anther ventral connective scales linear, 0.4-0.5 ×
0.1-0.15 mm
, apex bifid; anther dorsal connective scales 1.4-1.5 × c. 1.0 mm, apical, ovate, scarious, drying white, surface glabrous, margin entire, apex acute.
Pistil
2.7-2.8 mm
long; ovary ovoid, 0.5-1 × c.
0.5 mm
, glabrous; style
2-2.2 mm
long, erect, fluted in crosssection, straight, glabrous.
Fruit
not seen.
Etymology
. – The new species is named in honor of Martin W. Callmander, who collected the
type
material while he was coordinating the “Northern Highlands project” in
Madagascar
(see Callmander et al., 2009). Martin has collected extensively throughout
Madagascar
, among other areas, and his excellent field collections have helped to advance the knowledge of the Malagasy flora, as well as the taxonomy and diversity of other taxa, especially the
Pandanaceae
.
Distribution and ecology.
– The species is known only from the Galoko and Kalabinono massifs in
Antsiranana Province
in
Madagascar
(
Fig. 2
), in lowland evergreen tropical forests at an altitude of
200-800 m
in the Sambirano Domain (sensu Humbert, 1955).
Phenology
. – Based on herbarium specimen label data, the species flowers in November; fruiting specimens have not been collected.
Conservation status
. –
Rinorea callmanderi
is known from only two localities sensu
IUCN (2012)
, which are
7.5 km
apart. The lowland tropical evergreen forests of the Galoko and Kalabinono massifs are now protected but are still threatened by human activities; particularly slash and burn agricultural practices. With only two threatened locations and a restricted range distribution,
R. callmanderi
is assigned a preliminary conservation status of “Endangered” [EN B1ab(iii)+ B2ab(iii)].
Notes
. –
Rinorea callmanderi
is morphologically most similar to
R. mutica
, but is easily differentiated by its longer, lanceolate leaves to
13 cm
long (compared to broadly ovalelliptic leaves to
9 cm
in
R. mutica
), the sparse pubescence near the middle of the inner surface of the petal (vs. a tuft of hairs at the base of the inner surface of the petal), and by the anthers which bear ventral and dorsal connective scales, both of which are absent in
R. mutica
—a unique character state for the subsection. Based on herbarium specimen label data, the distributions of
R. callmanderi
and
R. mutica
appear to be non-overlapping.
Rinorea callmanderi
is known only from the Galoko and Kalabinono massifs at elevations of
200-800 m
, whereas
R. mutica
is almost entirely confined to Nosy Be island at elevations of
20-
300 m
. A single collection of
R. mutica
is recorded from the “montagnes de Sambirano”
(Perrier de la Bâthie 5045),
at an elevation of
600 m
, but the species has not been collected from the Galoko or Kalabinono massifs (Wahlert, 2010). Both
R. callmanderi
(as “
Rinorea
sp. nov.
1”) and
R. mutica
were sampled in the phylogenies of Wahlert & Ballard (2012) and van Velzen et al. (2015). The results from both studies recovered the two species in a highly supported Verticillatae clade, but no relationships among species were resolved within the clade. Based on the opposite-leaved phyllotaxy and similar floral structure shared by other species in the subsection, as well as the results from molecular phylogenies,
R. callmanderi
is placed in
R.
subsect.
Verticillatae
. The description of
R. callmanderi
now brings to 19 the number of species belonging to the subsection, however, further study is needed for a comprehensive understanding of the species diversity within the group.
Paratypus
. –
MADAGASCAR
. Prov.
Antsiranana
:
Ambilobe, Beramanja, Anketrabe, Belinta, forêt
de Galoka
,
13°35’23”S
48°42’43”E
,
210 m
,
6.X.2013
, fl. bud,
Razakamalala et al. 7669
(
G
,
MO
,
P
,
TAN
)
.