A new species of Torenia (Linderniaceae) from Gabon, remarks on Torenia mannii Skan, and a key to the African and Madagascan Torenia species
Author
Fischer, Eberhard
Institut für Integrierte Naturwissenschaften - Biologie, Universität Koblenz-Landau, Universitätsstrasse 1, 56070 Koblenz, Germany; e-mail: efischer @ uni-koblenz. de
Author
Lachenaud, Olivier
Service d’Evolution Biologique et Ecologie - CP 160 / 12, Université Libre de Bruxelles, 50 Avenue F. Roosevelt, 1050 Bruxelles, Belgium; e-mail: olachena @ ulb. ac. be
text
Phytotaxa
2013
2013-08-21
125
1
40
46
http://dx.doi.org/10.11646/phytotaxa.125.1.6
journal article
10.11646/phytotaxa.125.1.6
1179-3163
5085181
Torenia daubyi
Eb.Fischer & O.Lachenaud.
sp. nov.
(
Fig. 1
)
Type
:—
GABON
.
Ngounié
:
Est du Parc National de la Waka
, à plus ou moins
5 km
au
Sud
de la rivière
Mayi
,
581 m
, lat.
1.21542°S
, long.
11.30553°E
, ancien débardage, forêt dense de terre ferme,
Dauby
,
Nguema
,
Mounoumoulossi
,
Bissiemou
&
Bissienguou GD
836,
23.2.2008
(
holotype
BRLU!, isotypes LBV!, MO, WAG!)
.
Diagnosis:
—The new species is related to
Torenia silvicola
A.Raynal
and especially
Torenia mannii
Skan. It
differs distinctly from
T. silvicola
in the acute calyx lobes, the broader calyx wings
1.5–2.5 mm
wide, the pink and white corolla, and the geniculate base of the abaxial stamens with a clavate appendage
1.8–2 mm
long.
Torenia silvicola
has obtuse calyx lobes, narrower calyx wings
1 mm
wide, a white corolla, the geniculate base of the abaxial stamens forming a Z and lacking a clavate appendage. It differs from
Torenia mannii
in the shorter and relatively broader leaves (length:width ratio 1:1–1.12: 1), the broader calyx wings, the smaller corolla not exceeding
13 mm
of length, the curved appendage of the abaxial filaments that narrows at apex, and the equal thecae of the anthers. The leaves in
T. mannii
are ovate-lanceolate, the calyx wings are narrower (<
0.7 mm
broad), the corolla is
17–21 mm
long, the appendages are straight to only slightly curved and widest at apex, and the thecae of the abaxial anthers are slightly unequal.
Perennial herbs. Stems creeping to ascendent or procumbent, quadrangular, 20–28 (30) cm long, glabrous. Leaves opposite, long petiolate, petiole
7–15 mm
long, lamina broadly ovate, obtuse to subacute, 20–28 ×
20– 25 mm
, margin dentate, with 7–8 teeth, papyraceous, upper and lower face concolorous. Bracts leaf-like, each node usually with one fertile bract. Flowers pedicellate, pedicel up to
15 mm
long, elongating in fruit to
25 mm
. Bracteoles minute, at base of pedicel, linear-filiform, 1.2 ×
0.3 mm
. Calyx bilabiate, broadly winged on mid-veins of lobes, wings
1.5–2.5 mm
wide, tube
7–8 mm
long, lobes
3–4 mm
long, acute, glabrous. Corolla c.
13 mm
long, pink and white, tube pink, upper lip pink and white, lower lip
8–9 mm
long, upper lip emarginate at apex, 3 (–4) ×
3–3.5 mm
, lower lip 3-lobed, up to
5 mm
long, lobes 3 ×
2–2.5 mm
, with an area of papillae present on palate of lower lip near throat. Stamens 4, didynamous; abaxial pair
4–5 mm
long, filaments curved, base with a clavate appendage
1.8–2 mm
long, covered with glandular hairs and papillae; adaxial pair
2 mm
long, filaments straight; anthers with equal thecae,
1.5–1.8 mm
long. Ovary
2 mm
long, style
7 mm
long, stigma bilobed. Fruit unknown.
Distribution
:—Only known from the
type
gathering from the northern edge of the Chaillu massif, in south-central
Gabon
.
Ecology
:—The
type
was collected on a former skidding trail in high forest on firm ground,
581 m
in altitude.
Conservation status
:—Data deficient (DD). We do not know enough about the natural populations to be able to assess the conservation status of the species, However, the species is only known from the
type
gathering at an unprotected locality.