Sonerila konkanensis (Melastomataceae), a new species from South Goa, India
Author
Resmi, Sekarathil
Department of Botany, University of Calicut, Malappuram District, Kerala 673 635, India.
Author
Nampy, Santhosh
Department of Botany, University of Calicut, Malappuram District, Kerala 673 635, India.
santhoshnampy2019@gmail.com
Author
Akshatra, Pracy Fernandes
Department of Botany, Goa University, Taleigao Plateau, Goa 403 206, India.
text
Candollea
2021
2021-05-20
76
1
139
143
journal article
3355
10.15553/c2021v761a14
698874a5-ca24-4aac-a827-003226816fb0
2235-3658
5684636
Sonerila konkanensis
Resmi & Nampy
,
sp. nov.
(
Fig. 1–2
).
Holotypus
:
INDIA
.
Goa
:
South Goa Dist.
,
Salcete
taluk,
Mulem
,
Chandreshwar hills
, on the way to Chandreshwar temple, Ghat road cuttings,
15°13'16"N
74°01'59"E
, c.
220 m
,
3.IX.2019
, fl. & fr.,
Resmi
&
Akshatra
164408
(
CALI
!
;
iso-
:
G
!,
MH
!).
Sonerila konkanensis Resmi & Nampy
differs from
S. talbotii G.S. Giri & M.P. Nayar
in petiole length (2–3.5 vs.
1–2 cm
long), lamina shape (ovate to elliptic vs. elliptic to lanceolate), peduncle length (4–7 vs.
3–5 cm
), flower number (6–20 vs. 3–12 per cyme), bract shape (ovate to elliptic vs. subulate) and petal shape (ovate to oblong vs. elliptic to oblong). The new species differs from
S. sreenarayaniana Sunil et al.
in root stock
type
(tuberous vs. non-tuberous), peduncle length (4– 7 vs.
8–13 cm
), bracts (persistent vs. apparently absent) and petals shape (ovate to oblong vs. ovate-obovate).
Herbs
perennial, erect, caulescent,
5–30 cm
tall.
Root stocks
tuberous; tubers globose,
0.5–1.5 cm
diam., white to pale green with tufts of roots all over.
Stems
angular with prominent leaf scars on nodes, sub-angular at the base,
0.2 –0.6 cm
thick, green with a claret tinge, fleshy, corners distinctly marked with a dark pink colour, simple or branched; internodes
2–5 cm
long, densely hairy at nodes. Stems, branches, petioles, laminae, bracts, peduncles, pedicels and hypanthia covered with dense glandular trichomes (trichomes <
2.5 mm
long).
Leaves
simple, decussate, sometimes clustered at the distal nodes; petioles adaxially grooved or canaliculate, 2–3.5 ×
0.2–0.27 cm
, green with a claret tinge towards apex; laminae ovate to elliptic, 3– 8 ×
1.5– 4 cm
, lime green adaxially, pale green abaxially, cordate or sub-rounded at base with non-overlapping margins, acute to acuminate at apex, densely glandular-hairy adaxially but only on midrib and lateral veins abaxially, margins serrate to dentate with each tooth ending in a terminal glandular trichome; veins pinnate, 2 pairs from the base and 2 to 3 pairs from midrib above, less branched, impressed adaxially, conspicuous abaxially.
Inflorescences
scorpioid cymose, terminal, unbranched, usually 1 to 2 cymes arising from the distal node of the stem and branches (sometimes 3 to 5), 6 to 20-flowered; peduncles angular, 4–7 ×
0.15–0.25 cm
, longer than petioles; bracts leaf-like, ovate to elliptic, 0.5–2.5 ×
0.5–1.5 cm
, persistent.
Flowers
trimerous, rarely tetramerous, 1–1.6 ×
1–1.5 cm
; pedicels sub-angular, 4–10 ×
1–1.8 mm
, longer in fruit, claret coloured.
Hypanthia
campanulate, 4–5 ×
1.5–2.7 mm
, 3-lobed, obscurely 3-ribbed, green with a claret tinge towards apex; lobes triangular, 1–2 ×
1–2 mm
, acute at apex.
Petals
3, ovate to oblong, 8–12 ×
4–5 mm
, pale pink with a darker midrib, obtuse at base, mucronate at apex, glabrous adaxially, with glandular trichomes on midrib abaxially.
Stamens
3, alternate to petals; filaments
5–6 mm
long, dark pink, pale towards apex, glabrous, dilated and twisted downwards; anthers sagittate to deeply cordate at base,
5–6 mm
long, yellow, acuminate to rostrate at apex, dehiscing through apical pores.
Pollen grain
3-zonocolporate, oblate-spheroidal, striate with sculpturing parallel to the apertures and subsidiary colpi.
Ovaries
inferior, united with the hypanthium by half of its length, 2–2.5 ×
2–3 mm
; styles filiform,
8–10 mm
long, dark pink, equal or shorter than stamens; stigmas capitate, pink, rugose, glabrous.
Capsules
urceolate, 4–5 ×
4–5 mm
, green with a claret tinge, obscurely 3-ribbed, densely glandular pubescent, many seeded.
Seeds
obovoid, 0.4–0.5 ×
0.2–0.25 mm
, pale brown; raphes not prominent; testae sparsely tuberculate at dorsal angle and densely pusticulate throughout; tubercles with broad base and head, not covered with pusticles, with somewhat smooth surface.
Fig. 1.–
Sonerila konkanensis
Resmi & Nampy.
A–B.
Plants in their natural habitat (see tetramerous flower within the same population);
C.
Cymes;
D.
Stem base showing tuberous root stock;
E.
Angular stem;
F.
Inflorescence;
G.
Tetramerous flower;
H.
Bract, adaxial view;
I.
Hypanthium;
J.
Ovate petals, adaxial view;
K.
Oblong petals, adaxial view;
L.
Hypanthium with stamens and pistil;
M.
Pistil;
N.
Stamens;
O.
Immature capsules;
P.
Mature capsules and a persistent bract. [
Resmi & Akshatra 164408
, CALI] [Photos: S. Resmi].
Etymology.
– The specific epithet refers to the
type
locality, which lies within the region of iconic biodiversity called “Konkan”.
Distribution, habitat and phenology
. – Known only from the
type
locality, Chandreshwar hills in South Goa district. It grows in wet humus and on damp rocks along the Ghat road cuttings, between elevations of
210–
280 m
. Plants usually perennate by dormant tubers. It is found in association with
Adiantum lunulatum
Burm. f. (
Adiantaceae
)
,
Arachniodes aristata
(G. Forst) Tindale (
Dryopteridaceae
)
,
Athyrium
sp. (
Athyriaceae
)
,
Begonia integrifolia
Dalzell. (
Begoniaceae
)
,
Cheilanthes
sp. (
Pteridaceae
)
,
Exacum petiolare
Griseb. (
Gentianaceae
)
,
Ixora
sp. (
Rubiaceae
)
,
Leea asiatica
(L.) Ridsdale (
Leeaceae
)
,
Lygodium flexuosum
(L.) Sw. (
Lygodiaceae
)
,
Pteris scabripes
Wall. ex J. Agardh (
Pteridaceae
)
and
Selaginella
sp. (
Selaginellaceae
)
. Flowers and fruits have been observed from August to September.
Conservation status. –
Sonerila konkanensis
is currently known only from one locality with two sub-populations in an unprotected area, separated by a distance of
200–300 m
. A total of 90 mature individuals were found in an area of c.
4 km
². It is likely that more populations in similar habitats in the same hill are not yet known and further surveys are needed to determine the exact distribution range of this species. The
type
locality being a tourist destination, and considering the possibility of further ecological disturbances of this restricted range species, we provisionally assess the new species as “Vulnerable” [VU
B1
ab(iii)] according to IUCN Red List Categories and Criteria (2012).
Notes
. –
Sonerila konkanensis
is a tuberous species with angular stems, lime green leaves, pale pink flowers and acuminate to rostrate anthers. Many other species of
Sonerila
in
India
also have angular stems and tuberous root stocks but none of them are morphologically closely related to the new taxon.
Sonerila konkanensis
and
S. talbotii
are recognised by their stems, branches, petioles, laminae, peduncles, pedicels and hypanthia all covered by dense glandular trichomes. The density of the glandular trichomes on the laminae in
S. konkanensis
is variable and the glandular heads dry up when old.
Sonerila konkanensis
also differs from
S. talbotii
and
S. sreenarayaniana
in having obovoid seeds without prominent raphe (vs. ellipsoid with prominent raphe) and the testa tubercles somewhat smooth (vs. covered with small pusticles). This species is further characterised by its large (0.5–2.5 ×
0.5–1.5 cm
), leaf-like, persistent bracts, which are not reported in any other
Sonerila
species from
India
.
Fig.2.–
SEM images of
Sonerila konkanensis
Resmi & Nampy.
A.
Pollen grains;
B–C.
Seed.
Additional specimens examined.
–
INDIA
.
Goa
:
South Goa dist.
,
Salcete
taluk,
Chandreshwar
hills,
Chandranath
,
16.IX.1997
,
Joshi
&
Rajkumar
962
(Goa University Herb.)
;
near
Bhoothnath
temple,
9.IX.2007
, fl. & fr.,
Ashish
532
(Goa University Herb.)
;
on the way to
Chandreshwar
temple, [
15°12'57"N
74°02'12"E
],
273 m
,
3.IX.2019
, fl. & fr.,
Resmi
&
Akshatra
164409
(
CALI
).