A new species of Lysionotus (Gesneriaceae) from Arunachal Pradesh, India

Abstract

During a taxonomic revision of Lysionotus (Gesneriaceae) in India, a new species was found in Arunachal Pradesh that is described here. Lysionotus ziroensis resembles Lysionotus atropurpureus and Lysionotus sessilifolius, but differs markedly by its habit, leaf color, shape of bracts, appendages of anther connectives, etc. We provide a description, illustration, pictures, and information about the habitat of the new species. L. ziroensis is confined to a small area of the Lower Subansiri district, and further explorations are necessary to confirm the conservation status and is provisionally assessed here as “Data Deficient” in accordance with IUCN criteria.

Full text

Short Communication
A new species of Lysionotus (Gesneriaceae) from Arunachal Pradesh, India
Mannar Kandy Akhil, Nikhil Krishna, Athalappil Amrutha, Santhosh Nampy
*
Department of Botany, University of Calicut, Calicut University P.O., Kerala, 673304, India
article info
Article history:
Received 17 August 2020
Received in revised form
14 September 2020
Accepted 15 September 2020
Available online xxx
Keywords:
Data Deficient
IUCN
Lysionotus sect. Lysionotus
Lysionotus ziroensis
Ziro
abstract
During a taxonomic revision of Lysionotus (Gesneriaceae) in India, a new species was found in Arunachal
Pradesh that is described here. Lysionotus ziroensis resembles Lysionotus atropurpureus and Lysionotus
sessilifolius, but differs markedly by its habit, leaf color, shape of bracts, appendages of anther connec-
tives, etc. We provide a description, illustration, pictures, and information about the habitat of the new
species. L. ziroensis is confined to a small area of the Lower Subansiri district, and further explorations are
necessary to confirm the conservation status and is provisionally assessed here as “Data Deficient”in
accordance with IUCN criteria.
Ó2020 National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA), Publishing
Services by Elsevier. This is an open access article under the CC BY-NC-ND license (http://
creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction
The genus Lysionotus D. Don (Gesneriaceae; subfamily: Didy-
mocarpoideae; tribe: Trichosporeae; subtribe: Didymocarpinae)
includes mostly epiphytic, sometimes climbing or terrestrial ever-
green subshrubs easily distinguished by its opposite or whorled
phyllotaxy, tubular funnel-shaped corolla with an inflated upper
half, two stamens, connivent anthers with or without connective
appendages and seeds with appendages. The genus is distributed
mainly in Southeastern Asia including China, Bhutan, Nepal, North
India, Myanmar, North Thailand, North Vietnam, Laos, and South
Japan (Möller et al 2017). According to Wang (1983), there are two
centers of distribution for the genus: Guangxi-Yunnan-Guizhou
Karst area (center of maximum variation) and Western Yunnan
and Southeastern Tibet to Northeastern India. The genus is repre-
sented by about 32 species (Mabberley 2017;Taram et al 2019),
nine of which are known from India (ca 28% of world’s distribu-
tion). Sinha and Datta (2016) have recognized seven species in their
revision of Lysionotus in India, four of which are treated as imper-
fectly known. Two species and a variety were recently described
from India viz., Lysionotus bijantiae D. Borah & A. Joe (Borah and Joe
2018); Lysionotus gamosepalus var. biflorus (Joe et al 2017), and
Lysionotus chatungii M. Taram, A. P. Das & H. Tag (Tara m et a l 2019)
while (Akhil et al 2019) reported L. gamosepalus W. T. Wang as a
new addition to the flora of India. L. bijantiae now being synony-
mized under Henckelia oblongifolia (Roxb.) D.J.Middleton & Mich.-
Möller (Cai et al 2020) and the taxonomic status of L. gamosepalus
var. biflorus is uncertain as the characters pointed out by the au-
thors to differentiate their variety falls within the range of
L. gamosepalus. Around 50% of Indian species are endemic. Wang
(1983) divided the genus into three sections and six series while
Li and Wang (2004) retained only the sections, but not the series: (i)
Lysionotus sect. Didymocarpoides W. T. Wang,includes erect sub-
shrubs without a woody trunk, having opposite phyllotaxy, distinct
calyx lobes, unappendaged anther connectives, and seeds with
shorter appendages; (ii) Lysionotus sect. Lysionotus includes erect or
gradually ascending subshrubs without a woody trunk, having
ternate, opposite or rarely alternate phyllotaxy, calyx lobes distinct
or fused by midway, anther connectives appendaged or not, and
longer seed appendages and (iii) Lysionotus sect. Cyathocalyx W. T.
Wang includes climbing small shrubs with a woody trunk, having
opposite phyllotaxy, shallowly lobed calyx, unappendaged anther
connectives, and seed appendages nearly equal to the length of
seeds. All Indian species belong to the sect. Lysionotus in having
erect or gradually ascending habit, nonwoody stem, usually ternate
phyllotaxy, 5-lobed calyx divided to or near the base (rarely
connate calyx lobes), anthers with or without appendages, and
seed appendages as long as or longer than the length of seeds.
As part of the ongoing revisionary study on the family Gesner-
iaceae in India, the authors collected an interesting specimen of
Lysionotus with abaxially vinaceous colored leaves from Ziro in
*Corresponding author.
E-mail address: santhoshnampy2019@gmail.com (S. Nampy).
Peer review under responsibility of National Science Museum of Korea (NSMK) and
Korea National Arboretum (KNA).
Contents lists available at ScienceDirect
Journal of Asia-Pacific Biodiversity
journal homepage: http://www.elsevier.com/locate/japb
https://doi.org/10.1016/j.japb.2020.09.009
pISSN2287-884X eISSN2287-9544/Ó2020 National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA), Publishing Services by Elsevier. This is an open
access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Journal of Asia-Pacific Biodiversity xxx (xxxx) xxx
Please cite this article as: Akhil MK et al., A new species of Lysionotus (Gesneriaceae) from Arunachal Pradesh, India, Journal of Asia-Pacific
Biodiversity, https://doi.org/10.1016/j.japb.2020.09.009

Lower Subansiri district of Arunachal Pradesh. Critical analysis of
morphological characters, scrutiny of relevant literature and her-
barium specimens revealed that the specimens collected represent
a hitherto undescribed species which is described and illustrated as
Lysionotus ziroensis. The new species differs from the morphologi-
cally allied Lysionotus sessilifolius Hand.-Mazz. and Lysionotus
atropurpureus Hara by its habit, margins and coloration of leaves,
size of peduncles, shape of bracts, length, fusion and coloration of
calyx, appendages of anther connectives, etc.
Materials and methods
The research was based on live specimens collected from Aru-
nachal Pradesh in India. Habitat and habit photos were taken with a
D750 DSLR Camera (Nikon, Japan). Microphotographs and
measurements were taken with an Axiocam 105 color camera
attached to a Stemi 508 Stereo Microscope (Zeiss, Germany). The
description was prepared after examining all available specimens.
CAL, ARUN, and ASSAM (Thiers, 2020, continuously updated) were
consulted for the analysis of Indian Lysionotus species. Images of
type specimens of all Lysionotus species were obtained from Index
Herbariorum (http://sweetgum.nybg.org/science/ih/), Tropicos
(http://www.tropicos.org), and JSTOR Global Plants (http://plants.
jstor.org). The conservation status was assessed as per IUCN Red
List Categories and Criteria (2019).
Key to the species of Lysionotus sect. Lysionotus in India
1. Calyx divided from or above middle ...... L. gamosepalus
1. Calyx divided to or near the base ....................2
2. Bracts absent; flower solitary ................ 3
Figure 1. Lysionotus ziroensis Nampy et al: A, Flowering twig; B, Flower; C, Bracts; D, Calyx; E, Corolla split open; F, Glandular hairs on the inside of the corolla; G, Stamen also see
gland dotted anther connective appendages; H, Pistil showing disc at base; I, Dehisced capsule. Drawn by Akhil M. K. based on Nikhil Krishna & Amrutha A. 159843 (CALI).
MK Akhil et al. / Journal of Asia-Pacific Biodiversity xxx (xxxx) xxx2
Please cite this article as: Akhil MK et al., A new species of Lysionotus (Gesneriaceae) from Arunachal Pradesh, India, Journal of Asia-Pacific
Biodiversity, https://doi.org/10.1016/j.japb.2020.09.009

2. Bracts 2; flowers more than one in a cyme ......... 4
3. Leaves lanceolate, 1.2e2.2 cm long; staminodes ca 5 mm long-
........................... L. levipes
3. Leaves ovate elliptic to rounded ovate, 10e20 cm long; stamin-
odes ca 2 mm long .................. L. chathungi
4. Leaf margin entire to sub entire..........L. confertus
4. Leaf margin serrate to dentate or crenate.......... 5
5. Anther connectives unappendaged ............. 6
5. Anther connectives appendaged............. .7
6. Leaves pubescent beneath the nerves ...... L. pubescens
6. Leaves glabrous .............. L. atropurpureus
7. Anther connectives gland dotted ......... L. ziroensis
Figure 2. Lysionotus ziroensis Nampyet al: A, Habitat; B, Habit; C, Leaf abaxial surface; D, Flowering twig; E, Flower; F, Flower split open; G, Bracts; H, Calyx; I, Stamen, see glands on
the connective; J, Disc; K, Pistil. Photos by Nikhil Krishna & Amrutha A.
MK Akhil et al. / Journal of Asia-Pacific Biodiversity xxx (xxxx) xxx 3
Please cite this article as: Akhil MK et al., A new species of Lysionotus (Gesneriaceae) from Arunachal Pradesh, India, Journal of Asia-Pacific
Biodiversity, https://doi.org/10.1016/j.japb.2020.09.009

7. Anther connectives with horn like appendages .......8
8. Terrestrial subshrubs; petioles 0.2e0.3 cm long .. L. palinensis
8. Epiphytic subshrubs; petioles 1.8e2.5 cm long ... L. serratus
Systematic accounts
Lysionotus ziroensis Nampy, Nikhil, Amrutha & Akhil, sp. nov.
(Figures 1e2).
Type. INDIA. Arunachal Pradesh: Lower Subansiri district, Ziro, 15
Aug. 2018, Nikhil Krishna, Amrutha A 159843 (holotype: CALI! iso-
type: CAL!).
Diagnosis. Lysionotus ziroensis can be easily distinguished from
the morphologically allied L. atropurpureus and L. sessilifolius, by its
serrate-spinose leaf margins, vinaceous color of leaves abaxially,
ovate to ovate-lanceolate bracts, pale green calyx and gland dotted
anther connectives. In L. atropurpureus, the leaves are denticulate
and pale green abaxially, bracts linear, calyx purplish, and anther
connectives unappendaged, whereas in L. sessilifolius, the leaves are
serrate and pale green abaxially, bracts lanceolate or ovate-obovate,
calyx purplish, and anther connectives unappendaged.
Description. Epiphytic subshrubs. Rooting at the basal nodes.
Stems branched, drooping, 30e60 cm long, sparsely pubescent,
terete, green or claret; internodes 4e7 cm long. Leaves three per
node, unequal; petioles 0.2e0.5 cm long, pubescent; lamina 2.5e
70.7e2.5 cm, linear-lanceolate to ovateeelliptic, vinaceous
below, dark green above but pale green along the veins, sparsely
pubescent; cuneate to rounded at base; acute to acuminate at apex;
serrateespinose at margin; lateral veins 5e8 on each side. Cymes
subterminal or axillary, ca 10-flowered, bisexual; peduncles 4e11
cm long, terete, pale green, sparsely puberulent. Bracts 2, ca 0.6 
0.5 cm, ovate to ovate-lanceolate, cordate to truncate at base; acute
to obtuse at apex; serrate to spinose at margin, slightly incurved,
yellowish green; minutely pubescent. Pedicels ca 0.5 cm long,
sparsely pubescent, terete, pale green. Flowers: Calyx lobes 5,
seldom fused at base; 0.8e1cm long, linear-oblong, pale green, 3-
nerved, acute at apex, entire at margin, reflexed, sparsely
puberulent. Corolla 2.5e3.5 cm long, purpleemauve, 2-lipped; tube
2e2.5 0.1e0.5 cm, slender, funnelform, inflated slightly at base,
moderately glandular pubescent in, glabrous out; lower lip ca 0.6 
0.3 cm; upper lip ca 0.5 0.4 cm, lobes elliptic, sparsely glandular
hairy out and densely within, purple out, gradually become mauve
along the tube, mauve with dark purplish veins in; two yellow
folding on the throat, from the point of attachment of filaments
toward lower median lobe, arched by a purple boarder. Stamens 2,
coherent; filaments 0.6e0.8 cm long, inserted above the middle of
Figure 3. Distribution map of Lysionotus ziroensis Nampy et al.
Table 1. Diagnostic morphological characters of Lysionotus atropurpureus, Lysionotus
sessilifolius and Lysionotus ziroensis.
Character Lysionotus
atropurpureus
Lysionotus
sessilifolius
Lysionotus ziroensis
Stem Pilose distally Glabrous Sparsely pubescent
Leaves Margins
denticulate;
lamina dark green
above, pale below
Margins serrate;
lamina dark green
above, pale below
Margins serrate
espinose; lamina dark
green above, pale green
along the mid vein and
lateral nerves and
vinaceous below
Petioles 0.3e1.5 cm long 0.1e0.6 cm long or
absent
0.2e0.5 cm long
Cymes 1e4flowered 2e15 flowered ca 10 flowered
Peduncles 5.5e7.5 cm long,
glabrous
4.5e8 cm long,
glabrous
4e11 cm long, sparsely
puberulent
Bracts 0.2e0.4 0.05
e0.08 cm; linear
0.3e0.8 0.12e0.4
cm; lanceolate,
ovateeobovate,
ca 0.6 0.5 cm, ovate to
ovate-lanceolate
Pedicels 0.7e2 cm long,
glabrous
0.4e1 cm long,
glabrous
ca 0.5 cm long, sparsely
pubescent
Calyx 5-sect from base,
lobes 0.4e0.7 cm
long, lanceolate,
purplish
5-sect from base;
lobes 0.4e0.6 cm
long, oblong,
recurved; purplish
5-sect from just above
the base; lobes 0.8e1cm
long, linear oblong, pale
green.
Corolla Tube width up to
0.8 cm.
Tube width up to 0.5
cm.
Tube width up to 0.5 cm.
Filaments 4e6 mm long ca 2 mm long 6e8 mm long
Anthers Oblate Ovoid Globose
Connectives Unappendaged Unappendaged Gland dotted
Staminodes 0.1e0.2 cm long 0.1 cm long 0.5e0.6 cm long
Capsules 6e7.5 cm long 2 cm long 5e6.5 cm long
MK Akhil et al. / Journal of Asia-Pacific Biodiversity xxx (xxxx) xxx4
Please cite this article as: Akhil MK et al., A new species of Lysionotus (Gesneriaceae) from Arunachal Pradesh, India, Journal of Asia-Pacific
Biodiversity, https://doi.org/10.1016/j.japb.2020.09.009

corolla tube, slightly curved, white at base, dark purple above;
anthers dithecous, ca 0.3 cm diam., globose, whitish-cream; con-
nectives appendaged, gland-dotted, black. Staminodes 2, 0.5e0.6
cm long, straight. Disc ring like, 5-lobed, ca 0.3 0.2 cm. Ovary ca
1.5 0.1 cm, cylindrical, slightly curved, greenish, glabrous; style ca
0.5 cm long, cylindrical, greenish, glabrous, lies between the folding
of corolla tube; stigma ca 2 mm diam., slightly discoid. Capsules 5e
6.5 cm long, straight, linear, dehiscing loculicidally to base; valves 4,
straight, glabrous. Seeds not seen.
Phenology. Flowers and fruits from August to October.
Distribution. Lysionotus ziroensis is currently known only from
Ziro in Lower Subansiri district of Arunachal Pradesh, from 2300 to
2430 m elevation (Figure 3).
Etymology. The specific epithet is derived from the type locality
‘Ziro’in Arunachal Pradesh.
Habitat. It is a subshrub in shady forest margins, growing
epiphytically on large trees with drooping branches. The roots
attach firmly on moist mulchy branch clefts along with mosses and
Procris crenata C. B. Rob. (Urticaceae).
Notes. Because Lysionotus bijantiae being synonymized under
Henckelia oblongifolia by Cai et al (2020), it is excluded from the
taxonomic key. The presence or absence of anther connective
appendage is a diagnostic character for species delineation in
Lysionotus.InL. ziroensis, several black glands together form a
reduced appendage on the either side of the connective. The dif-
ferences between the morphologically similar L. atropurpureus and
L. sessilifolius are given in Table 1.
Conservation status.Lysionotus ziroensis occurs only in the type
locality, where a single population with about 25 mature in-
dividuals was found. The area of occupancy falls below 2 km
2
.
Further explorations are needed in similar habitats of Northeastern
India and neighboring countries to ascertain its conservation status.
Nevertheless, there exist threats to the existing population due to
deforestation and widening of roads. In accordance with IUCN Red
List Categories and Criteria (2019), the species is provisionally
assessed here as “Data Deficient”.
Conflict of interest
The authors declare that there is no conflict of interest.
Acknowledgments
The authors thank the head, Department of Botany, University of
Calicut for facilities and Arunachal Pradesh Forest Department for
granting permission to collect specimens. AMK and SN are thankful
to the Science and Engineering Research Board, India for financial
assistance (No. EMR/2016/007346 dated 01.11.2018).
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Please cite this article as: Akhil MK et al., A new species of Lysionotus (Gesneriaceae) from Arunachal Pradesh, India, Journal of Asia-Pacific
Biodiversity, https://doi.org/10.1016/j.japb.2020.09.009