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Sonerila janakiana sp. nov., a stoloniferous species of
Melastomataceae from India
M. K. Ratheesh Narayanan , C. N. Sunil , M. Sivadasan , M. K. Nandakumar , V. V. Naveen Kumar ,
A. H. Alfarhan and M. H. Sameh
M. K. Ratheesh Narayanan, Dept of Botany, Payyanur College, Edat, Kannur, Kerala, India. – C. N. Sunil, V. V. Naveen Kumar, Dept of Botany,
S. N. M. College, Maliankara, Ernakulam, Kerala, India. – M. Sivadasan (drmsivadasan@gmail.com), A. H. Alfarhan, M. H. Sameh, Dept of
Botany and Microbiology, College of Science, King Saud Univ., Riyadh, Kingdom of Saudi Arabia. – M. K. Nandakumar, Community
Agrobiodiversity Centre, M. S. Swaminathan Research Foundation, Puthoorvayal, Wayanad, Kerala, India.
Sonerila janakiana , a new tuberous, scapigerous and stoloniferous species of Melastomataceae collected from exposed wet
rocks of evergreen and semi evergreen forests in the Nilgiris and Wayanad districts of Tamil Nadu and Kerala states on the
Western Ghats in India is described and illustrated. Apart from other characteristics, it is distinguished from all hitherto
known species of the genus in India by having stolons and dimorphic leaves. e stolons produced from tubers terminate
and develop into new tubers producing new plants.
e genus Sonerila of the tribe Sonerileae (Melastomataceae)
with about 180 species (Stevens 2001 onwards) is charac-
terized by consistently trimerous fl owers. In the Plant List
(2016), only 248 names are recorded and the list seems
to have not been updated since 2011 as evidenced by the
absence of Sonerila nayariana Murugesan and Balasubra-
maniam (2011) which was published in December 2011.
Out of the 248 names, only 6 names are reported as
accepted, 15 recognized as synonyms, and the rest remains as
‘ Unresolved ’ . In contrast, IPNI (2012) contains 274 names.
Recently, two more species, viz. Sonerila nairii Soumya and
Maya (2016) and Sonerila ponmudiana Deepthikumary
and Pandurangan (2016) have been described from Kerala,
India which are caulescent herbs. e genus is distributed
from Sri Lanka and India to the Indo-Pacifi c (Cellinese
1997). A general account on characteristics of the fam-
ily and the genus with a brief history of the taxonomic
inventory of Indian species has been provided by Ratheesh
Narayanan et al. (2015).
During a systematic exploration of the species of Sonerila
of Western Ghats, interesting tuberous and stoloniferous
specimens were collected from Naadukaani in the Nilgiri
District, Tamil Nadu state and Ambukuthimala in Wayanad
District, Kerala state at altitudes ⫾ 1000 m a.s.l., and
found to be quite distinct from all hitherto known species.
Detailed study of the specimens revealed their novelty and
hence they are described and illustrated here as belonging to
a new species. e new species has some superfi cial resem-
blance with S. wallichii, but S. wallichii lacks tubers and
stolons. Reproductively, it is more similar to S. vatphouensis
Munzinger and Martin (2000), a tuberous species described
from Champassak in Laos as having stolons produced from
tubers that terminally develop into new tubers produc-
ing new plants. In its foliar dimorphism it also resembles
S. tuberosa Hansen (1990), another tuberous species described
from Cambodia.
Sonerila janakiana Ratheesh, Sunil & Sivadasan sp.
nov. (Fig. 1 – 2)
A species resembling S. wallichii in general morphology, but
diff ering by having a stoloniferous habit, up to 11 leaves,
infl orescence with up to 15 fl owers, glabrous peduncle,
pedicel and hypanthium, urn-shaped glabrous capsules
and seeds with non-excurrent raphe. It also resembles
S. vatphouensis in its stoloniferous tubers and S. tuberosa in
its foliar dimorphism, but strikingly diff ers in size, shape,
structure and texture of petioles and fl owers.
Type : India. Tamil Nadu: Nilgiris District, Naadukaani,
humus covered rocks in evergreen forest, 11 ° 25 ′ 12.83 ″ N,
76 ° 24 ′ 25.29 ″ E, ⫾ 1000 m a.s.l., 12 Sep 2014, M. K.
Ratheesh Narayanan, C. N. Sunil and M. K. Nandakumar
SNMH 1721 (holotype: CAL, isotypes: MH, SNMH).
Etymology
e epithet is proposed in honor of the late Dr E. K. Janaki
Ammal, a renowned Indian botanist, in recognition of her
valuable contributions in cytogenetics, phytogeography
and ethnobotany and also for her service in reorganizing
the Botanical Survey of India (BSI) in her initial capacity as
© 2017 e Authors. Nordic Journal of Botany © 2017 Nordic Society Oikos
Subject Editor and Editor-in-Chief: Torbj ö rn Tyler. Accepted 21 November 2016
Nordic Journal of Botany 000: 001–006, 2017
doi: 10.1111/njb.01297, ISSN 1756-1051
Early View (EV): 1-EV
Figure 1. Sonerila janakiana sp. nov. (A) habit, (B) fl ower bud, (C) single fl ower, (D) petal, abaxial view, (E) stamen, (F) hypanthium,
(G) seeds. Rl = rudimentary leaf, st = stolon. Drawings by V. V. Naveen Kumar.
2-EV
Figure 2. Sonerila janakiana sp. nov. (A) habit, (B) habit showing stolon, (C) tubers with stolon, (D) base of the plant showing rudimentary
leaves, stolon and tubers, (E) apical portion of peduncle with fl ower buds and immature fruits, (F) single fl ower, (G) petal, abaxial view,
(H) stamen, (I) fruit. Rl = rudimentary leaf, st = stolon.
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Offi cer on Special Duty and later as the Director-General of
the BSI. She was honored with several prestigious awards and
recognitions including the award Padma Shri by the Govern-
ment of India. e Ministry of Environment and Forests,
Government of India has instituted the E. K. Janaki Ammal
National Award on Taxonomy, in her commemoration to
encourage and promote taxonomy in India.
Description
Tuberous, stoloniferous herb; tubers up to 1 cm in diam-
eter, orbicular, white. Stolons produced from tubers, usu-
ally one stolon from each tuber, 2 – 4 cm long, 0.3 – 0.4 cm
wide, subterranean, more or less terete with a very shallow
groove near the basal part, glabrous, resembling petiole and
peduncle in colour and shape, terminally developing into
new tubers which produce new plants. Leaves dimorphic,
normal and rudimentary or reduced, arising from the tuber.
Normal leaves in clusters of 4 – 11; petiole 6 – 15 cm long,
cylindric, deeply canaliculate on adaxial side, pinkish, deep
pink towards base, its lower portion glabrous, sparsely to
densely hairy towards apex; lamina light green, leathery,
ovate to orbicular, at base deeply cordate with overlapping
margins, serrate to doubly serrate with sharply pointed tip,
acute to sub-acute at apex, 6 – 10 ⫻ 4 – 8 cm, sparsely hairy
on both surfaces; veins pinnate, 4 – 7 pairs, 3 – 4 pairs from
base, impressed above and prominently raised below, light
pinkish. Rudimentary or reduced leaves usually 1; petiole
0.8 – 1.0 cm long, cylindric; lamina pale green, sparsely hairy
on upper side, broadly ovate, with margins serrate with
bristles, sub-acute at apex, ca 1.2 ⫻ 0.8 cm. Infl orescence an
unbranched scorpioid cyme, usually 1 per plant, rarely up to
6, 6 – 8( – 15)-fl owered; peduncle inconspicuously quadrangu-
lar, glabrous, 8 – 17 cm long, pinkish with light green tinge;
bract minute, rose-colored, linear acute, persistent until fruit-
ing, 1.0 – 1.5 ⫻ 0.2 – 0.3 mm. Flowers 3-merous; pedicel 2 – 3
mm long, glabrous, terete, light green, elongating in fruit;
hypanthium ca 3 mm long, funnel-shaped, light green with
pink tinge towards apex, glabrous, obscurely 3-ridged; calyx
lobes 3, each ca 2 mm long, broadly triangular, deep pinkish
at base with greenish tip, glabrous; petals broadly obovate to
elliptic, pink, 9 – 11 ⫻ 6 – 7 mm, rounded to cuneate at base,
shortly acute to mucronate at apex, with nerves not promi-
nent, glabrous above but with a few scattered hairs along
midrib on abaxial side. Stamens 3; fi laments ca 5 mm long,
fi liform, glabrous, pinkish; anthers deep yellowish, cordate
at base, long acuminate at apex, slightly beaked, ca 5 mm
long, glabrous. Ovary glabrous, style ca 1 cm long, deep pink
at base, glabrous; stigma punctiform. Capsules urn-shaped,
pedicellate, ca 0.5 ⫻ 0.3 cm, enclosed in the persistent calyx
tube, prominently 3-ridged, glabrous, green with pink tinge.
Seeds many, minute, 0.5 – 0.6 mm long, yellowish, broadly
oblong, tubercled; raphe prominent, non-excurrent.
Phenology
Flowering commences from early July with peak in August.
Fruiting during September to October.
Distribution, habitat and ecology
Sonerila janakiana is endemic to India where it grows
on humus covered moist shady rocks in evergreen and
semi-evergreen forests at altitudes of 900 – 1200 m a.s.l. It
is known from the Naadukaani Ghat area of Nilgiris dis-
trict, Tamil Nadu state, and Edakkal and Fantom rocks at
Ambukuthimala and Ambalavayal respectively in Wayanad
district, Kerala state. A good population of this species
has been observed growing on humus-covered shady rocks
of evergreen forest of Naadukaani. e population at
Ambukuthimala is small and fragmented. e species appears
during the onset of the southwest monsoon (June – July).
Some of the associated species are Sonerila veldkampiana ,
Habenaria longicornu , Impatiens gardneriana , Henckelia
fi scheri , Argostemma courtallense , Strobilanthes spp., etc .
Conservation status
Only three well separated populations were noticed at
almost similar altitudes, one at Edakkal rocks area in
Ambukuthimala, another at Fantom rocks, Ambalavayal,
both in Wayanad district, Kerala and the third at Naadu-
kaani Ghats, Nilgiris district, Tamil Nadu. e popula-
tion at Naadukaani Ghats is large compared to that at
Ambukuthimala. None of the localities are protected. e
population at Naadukaani is adjacent to the State highway,
and the area is highly subjected to various kinds of distur-
bances. e population at Ambukuthimala is adjacent to
human habitation and is highly disturbed due to quarry-
ing activities. Eff ective eff orts are essential to protect the
existing populations. In the absence of any detailed data on
populations, the species is categorized as ‘ Data Defi cient ’
(DD) (IUCN 2014).
Similar species
Sonerila janakiana is a unique tuberous and scapigerous
species with stolons produced from tubers. It resembles
S. wallichii Bennett (1838) in general vegetative morphology
but the stoloniferous habit and foliar dimorphism make it
quite distinct.
e possession of stolons is very characteristic for the
species as a means of vegetative propagation and establish-
ment of clonal colonies. e stolons resemble the petiole and
peduncle in shape and color and are devoid of nodes. Only
one stolon is produced from a tuber and it terminates in
a new tuber at its apex as a propagating and perennating
organ.
e Lao species, Sonerila vatphouensis , though possessing
tubers that produce stolons, diff ers from S. janakiana by
having winged petioles and peduncles in addition to the
diff erences in other characters. Hansen (1990) fi rst reported
foliar dimorphism, a rare feature in Sonerila and its presence
in S. janakiana forms fi rst report of this feature in an Indian
species of the genus.
Characteristic features of Sonerila janakiana , S. wallichii ,
S. tuberosa and S. vatphouensis are provided in Table 1.
Additional specimens examined (paratypes)
India. Kerala: Wayanad District, Edakkal rocks,
Ambukuthimala, 11 ° 37 ′ 58.54 ″ N, 76 ° 12 ′ 10.06 ″ E, 14 Sep
2015, M. K. Ratheesh Narayanan and M. K. Nandakumar
MSSH 8012 (SNMH); Wayanad District, Fantom rocks,
Ambalavayal, 27 Sep 2015, M. K. Ratheesh Narayanan
MSSH 8052 (SNMH).
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Table 1. Diagnostic morphological characters of Sonerila janakiana sp. nov., S. walllichii, S. tuberosa and S. vatphouensis .
Characters S. janakiana S. wallichii S. tuberosa S. vatphouensis
Habit Tuberous herbs with stolons; stolons
glabrous
Tuberous herbs without stolons Tuberous herbs without stolons Tuberous herbs with stolons; stolons
hairy
Leaves Dimorphic – normal and rudimen-
tary; normal leaves up to 11;
petiole cylindric, lower portion
glabrous, sparsely to densely hairy
towards apex; lamina
10 – 14-nerved, pinnate, 3 – 4 pairs
of nerves arising from base of the
lamina; sparsely hairy on both
surfaces; margins serrate to doubly
serrate with sharply pointed tips;
rudimentary leaves usually 1; short
petiolate; broadly ovate, ca 1 cm
long, greenish, with bristles on
margins
Isomorphic, up to 6; petiole
cylindric, glabrous: lamina
12 – 14-nerved, pinnate, 3
pairs of nerves arising from
the base of the leaf; sparsely
hairy to glabrous on upper
side, glabrous below;
margins dentate.
Dimorphic – normal and rudimen-
tary; normal leaves: 1 – 2; petiole
cylindric with thin long curly
whitish hairs; lamina 7-nerved,
palmate; thin curly whitish hairy
on both surfaces, sparse on adaxial
surface; margins entire to
subdenticulate; rudimentary
leaves: several; sessile or
short-petiolate; broadly cordate to
reniform, ca 1 – 5 mm long and
wide, reddish brown, with
conspicuous 1 – 3 mm long bristles
on margin
Isomorphic, up to 3; petiole winged,
long-haired; lamina 7-nerved,
palmate; long hairy on both
surfaces, but sparse on abaxial
surface mainly along the nerves;
margins dentate
Infl orescence Scorpioid cymes, 1 – 6 per plant, each
with about 15 fl owers
Scorpioid cymes, usually 1 per
plant, each with about 20
fl owers
Scorpioid cymes, usually 1 per plant
with few – several fl owers
Scorpioid cymes, 1 per plant with
2 – 3 fl owers
Peduncle Quadrangular, glabrous Quadrangular with sparsely
glandular hairs
Cylindric with thin long curly whitish
hairs
Winged with long hairs
Bract Prominent, linear lanceolate,
rose-colored
Not prominent Similar to rudimentary leaves or
much reduced
Leafy or tiny, sometimes reduced to
hairs
Pedicel Terete, shorter than or equal to the
length of hypanthium, glabrous
Quadrangular, longer than the
length of hypanthium,
glandular haired
Terete, equal to or slightly longer
than hypanthium, glandular haired
More or less winged, longer than
hypanthium, glabrous
Hypanthium Funnel-shaped, obscurely 3-ridged,
glabrous
Funnel-shaped, obscurely
3-ridged, sparsely glandular
hairy
Subtriangular, glabrous Subtriangular, glabrous
Petals (mm) 9 – 11, broadly obovate to elliptic 7 – 9, broadly elliptic 4 – 5, broadly elliptic 7 – 9, elliptic
Anthers Narrowly ovate-acuminate, shortly
beaked, cordate at base
Narrowly acuminate and
beaked, deeply cordate at
base
Narrowly ovate acuminate, not
beaked, cordate at base
Narrowly ovate, not beaked, cordate
at base
Capsule Urn-shaped, smooth, glabrous Hemispheric, sparsely hairy Turbinate, upper half glabrous, lower
half wrinkled
Trigonal with six longitudinal ridges,
glabrous
Seeds Tubercled Tubercled Slighly rough Tubercled
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Acknowledgements – e President and Principal of the Payyanur
College, Payyanur, the Manager, S. N. M. College, Maliankara, and the
Executive Director of the M.S. Swaminathan Research Foundation
(MSSRF), Chennai encouraged the present study. J. F. Veldkamp (L)
spared his valuable time to read and comment on the draft of the man-
uscript. V. Mini and K. T. Satheesh of the Community Agrobiodiversity
Centre of MSSRF provided various help during the course of the study.
e third author thankfully acknowledges the fund provided by the
National Plan for Science, Technology and Innovation (MAARIFAH),
King Abdulaziz City for Science and Technology, Kingdom of
Saudi Arabia, through Award number 11-ENV1753-02.
References
Cellinese, N. 1997. A new Sonerila (Melastomataceae) from central
Kalimantan, Borneo. – Novon 7: 103 – 105.
Bennett, J. J. 1838. Sonerila wallichii . – In: Horsfi eld, T. et al. (eds),
Plant æ Javanicae Rariores. William H Allen & Co., p. 215.
Deepthikumary, K. P. and Pandurangan, A. G. 2016. Sonerila
ponmudiana (Melastomataceae), a new species from the
Western Ghats of Kerala, India. – Int. J. Curr. Sci. Technol.
4: 166 – 168.
Hansen, C. 1990 ( “ 1989 ” ). New species of Pseudodissochaeta Nayar
and Sonerila Roxb. (Melastomataeae) from Indo-China.
– Bull. Mus. Natl Hist. Paris 4 ser. 11, 1989, sect. B, Adansonia
3: 279 – 286.
IPNI 2012. e international plant names index. Published on the
internet. – < http://www.ipni.org > , accessed 29 Mar 2016.
IUCN 2014. Guidelines for using the IUCN red list categories and
criteria, ver. 11. e Standards and Petitions Subcommittee.
– < http://www.iucnredlist.org/documents/RedListGuidelines > ,
accessed 29 Mar 2016.
Munzinger, J. and Martin, C. V. 2000. Sonerila vatphouensis
(Melastomataceae), nouvelle esp è ce du Laos. Adansonia, s é r.
3, 22: 211 – 215.
Murugesan, M. and Balasubramaniam, V. 2011. A new species of
Sonerila (Melastomataceae) from the Western Ghats, India.
Taprobanica 3: 93 – 95 ⫹ 1 pl.
Plant List 2016. e plant list, ver. 1.1. – < http://www.theplantlist.
org/tpl1.1/search?q = sonerila > , accessed 28 Mar 2016.
Ratheesh Narayanan, M. K. et al. 2015. Sonerila gadgiliana , a
new scapigerous species of Melastomataceae from India.
– Bangladesh J. Plant Taxon. 22: 9 – 15.
Soumya, M. and Maya, C. N. 2016. Sonerila nairii (Melastomata-
ceae) – a new species from the southern Western Ghats, India.
– Phytokeys 62: 15 – 23.
Stevens, P. F. 2001 onwards. Angiosperm phylogeny website, ver.
12, July 2012. – < http://www.mobot.org/MOBOT/research/
APweb > , accessed 29 Mar 2016.
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