Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 May 2025 | 17(5): 27014–27020
ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.9147.17.5.27014-27020
#9147 | Received 17 May 2024 | Final received 10 May 2025 | Finally
accepted 12 May 2025
Studies on Heliotropium
rottleri Lehm. (Heliotropiaceae) – a threatened endemic plant of Tamil
Nadu, India
Shamsudheen Abdul Kader 1 &
Gothandam Gopal 2
1,2 Department of Plant Biology &
Plant Biotechnology, Presidency College (Autonomous), Chennai, Tamil Nadu
600005, India.
1 sakfri@rediffmail.com
(corresponding author), 2 gopalgothandam@gmail.com
Abstract: Heliotropium rottleri Lehm.
(Heliotropiaceae; previously Boraginaceae)
is endemic to Coimbatore region. Its taxonomic status is ambiguous and
unresolved because of mistaken identity of H. marifolium
J. Koenig ex Retz. and H. scabrum Retz. by
later botanists. So far, no efforts have been taken to assess its distribution,
population size, and conservation. While working on Heliotropium
L. genus in Tamil Nadu, we have collected it from four localities in the
erstwhile undivided Coimbatore district (two in Udumalpet
taluk, one in Palladam taluk) in January 2021 and
identified with Madras Herbarium, Botanical Survey of India Southern Regional
Centre. Our study indicates that it is now Critically Endangered as the
habitats are very rapidly altered and changing due to real estate business.
Unless urgent actions are taken, certainly this species will disappear.
Therefore, it is suggested to take immediate action to conserve this species in
its natural habitat.
Keywords: Coimbatore, Critically Endangered, curved raceme, divaricate branches,
endangered, leaf margin revolute, perennial, Thiruppur.
Introduction
The
cosmopolitan genus Heliotropium L. (Heliotropiaceae; previously Boraginaceae)
comprises of about 255 accepted species (POWO 2024 )
distributed mostly in the arid and semi-arid habitats of the world (Luebert et al. 2016). In British India, Wight (1850) had
first reported six species and one variety, namely: H. coromandelianum
Retz., H. linifolium Lehm.,
H. marifolium Retz., H. rottleri
Lehm., H. scabrum Retz.,
H. supinum L. var. supinum,
and H. supinum var. malabaricum.
Later, Clarke (1885) had documented 16 species and four varieties in the ‘Flora
of British India’ (Hooker 1885). Furthermore, H. keralense was discovered by Sivarajan
& Manilal (1972). Presently, there are about 22 Heliotropium sensu lato species, two subspecies and four varieties in India
(Meena et al. 2020). Euploca Nutt. was
delimited from Heliotropium L. based on
presence of bracts in the inflorescence, fruit breaking up into four nutlets,
nutlets with pits on endocarp and curved embryo (Dheeren
2021).
Heliotropium rottleri was first published by Lehmann
in 1818 from India without specifying precise locality in ‘Plantae e Familiae Asperifoliarum Nuciferae’. Later, Wight (1850) and Gamble (1921) had
collected this species from Coimbatore and the former provided a description
and an illustration. Despite, its taxonomic status, it has been considered as
unresolved (WFO 2023) because later botanists, namely, Ramamoorthy
(1976), Matthew (1983), Sasidharan (2011), and Rao et
al. (2019) have confused its identity with H. marifolium
J.Koenig ex Retz. and H.
scabrum Retz. Based on the above literature, Rao
et al. (2019) have wrongly reported it from Andhra Pradesh, Telangana, and
Kerala in ‘Flora of Peninsular India’. In fact, these three species are
distinct and have been collected from Tamil Nadu during the revisionary studies
by us. According to Wight (1850) H. rottleri
was frequent in Coimbatore. In 1964, Chandrabose
collected it from R.S. Puram and the subsequent workers have collected it from
the foot-hills of Kuridimalai and Thadagam
(all in Coimbatore) but now it is not found in Coimbatore city and rare in Kuridimalai and Thadagam. Ahmedullah & Nayar (1987)
categorized its threat status as Endangered in southern Deccan, Coimbatore.
While working on the genus Heliotropium in
Tamil Nadu, we have collected H. rottleri from
Masagoundanputhur and Raavanapuram
(Udumalpet taluk), Puliyampatti,
Kamanayakkan Palayam (Palladam taluk) and in adjacent Thiruppur
district, Tamil Nadu during January 2021. Recently, Ancy
et al. (2024) have published H. rottleri as Euploca wightiana
sp. nov. Therefore, the aim of the present paper is
to provide a complete botanical description and to establish the correct
identity of H. rottleri, and the current
status in Tamil Nadu.
Materials
and Methods
Extensive
field survey was carried out for Heliotropium
rottleri in its type locality and its neighbourhood regions. Specimens were studied at Presidency
College, Chennai. Photographs were taken and
taxonomical characters were recorded. The collected plant materials were
processed following standard herbarium methods and made into herbarium
specimens. The specimens were identified using relevant literature such as
Hooker (1885) and Gamble (1921), and compared with
authentic specimens deposited in the Madras Herbarium (MH). For threat status
assessment, the number of individuals was recorded during each visit to the
locations. The primary and secondary information required for assigning the
criteria as per IUCN Red List Categories and Criteria were collected, following
the IUCN guidelines (Standards and Petitions Working Group IUCN 2006).
Results
Botanical Description
Habitat: Marginal waste lands in the
plains with grassy, rocky, and calcareous soils. Habit: Erect stiff undershrubs; branches stout, divaricate, covered with white
appressed strigose hairs (Image 1a). Leaves: Simple, alternate, scattered;
petioles 2–4 mm long, lamina ovate-lanceolate acute with revolute margins, 6–15
× 3–5 mm, white-strigose (Image 1b,c). Inflorescence:
Racemes terminal, curved, on divaricate branches, stiff; peduncles 4.6–8.4 cm
long with distant leaves (Image 1d). Flowers: c. 2 mm across at mouth (Image
1e), pedicels 1–3 mm long (Image 1f). Calyx: 5-lobed, lobes basally connate,
green, ovate-elliptic acuminate, white-strigose, accrescent (Image 1g).
Corolla: Campanulate, 5-lobed, white with yellow centre
(Image 1e). Fruits: 4-lobed depressed nutlets, c. 4 mm in diam. c. 3 mm
thickness, completely covered with short grey adpressed
hairs (Image 1g).
Flowering and Fruiting period: Almost throughout the year.
Associate species: Acacia leucophlea
(Roxb.) Willd., Abutilon pannosum (G.Forst.)
Schltdl., Azadirachta
indica A.Juss., Barleria buxifolia L., B. cuspidata F.Heyne ex Nees, Dichrostachys
cinerea (L.) Wight
& Arn., Parthenium
hysterophorus L., Passiflora foetida L., Pergularia daemia (Forssk.) Chiov., Prosopis juliflora (Sw.) DC., Senna
auriculata (L.) Roxb., and grasses.
A comparative account of Heliotropium rottleri
Lehm. (Image 1), H. marifolium
J.Koenig ex Retz. (Image 2) and H. scabrum Retz. (Image 3) are given in Table 1.
Discussion
Although, Heliotropium
rottleri Lehm. (Image
1) resembles H. marifolium J.Koenig ex Retz. (Image 2) and H. scabrum Retz. (Image 3) in flower, bracts and appressed
hairs its habitat and habit differ. Heliotropium
rottleri typically inhabits marginal waste lands
in the plains with grassy rocky and calcareous soils; usually grows
gregariously reaching up to 30 cm height and easily recognized by its whitish
round growth habit. Heliotropium marifolium ssp. wallichii
is a perennial decumbent plant with, divaricate straight slender fleshy
branches, flat leaf margins and flowers in forked little curved spikes as shown
in Image 2, while H. scabrum is an annual
procumbent plant with twiggy branches, revolute-margined leaves and flowers in
sub-capitate inflorescence among leaf-like bracts as shown in Image 3.
Furthermore, H. marifolium var. rottleri is a different plant (Image 4). Despite, Ancy et al. (2024) have recently published H. rottleri Lehm. as Euploca wightiana,
we have already reported H. rottleri Lehm. from Coimbatore and Thiruppur
districts and its conservation status (Kader & Akram
2020; Kader & Gopal 2022).
According to Wight (1850), and Ahmedullah & Nayar (1987), H.
rottleri is found only in Coimbatore region of
Tamil Nadu, in India. Our study also supports the views of earlier reports that
H. rottleri Lehm. is
strictly confined to Coimbatore and Thiruppur
districts. So far, no efforts have been
taken to assess its distribution, population size and conservation. Our study
based on survey indicates that it is Critically Endangered as the habitats are
very rapidly altered and changing due to real estate business (one habitat is
located along the National Highway and the other near main road). Populations
in one location is declined to 50% and have been extirpated in other location
within three years (between 2021 and 2023). The present population is of less
than 500 mature individuals, of which about 100 individuals are restricted in a
very small area (less than 1 km2) at Raavanapuram.
Data collected during the present study indicates that Heliotropium
rottleri fulfils the necessary criteria (Appendix
1) to place it in the ‘Critically Endangered’ category as it faces a high risk
of extinction. Therefore, it is strongly suggested here that implementation of
effective in situ conservation measures are necessary to prevent this
habitat-specific narrowly endemic species from extinction. We appeal the
competent authorities to intervene and take immediate action to conserve this
species in its natural habitat.
Conclusion
The present study revealed that Heliotropium rottleri Lehm., Euploca marifolium (J. Koenig ex Retz.) Ancy
and P. Javad, E. marifolia
var. rottleri (Lehm.)
Ancy and P.Javad,
and H. scabrum Retz. are different species and all occur in Tamil Nadu. Furthermore, H. rottleri Lehm. occur only in Coimbatore and Thiruppur
districts of Tamil Nadu, and its reports of occurrence in other southern Indian
states are based on misidentification. Finally, recently published Euploca wightiana Ancy et al., from Coimbatore is relegated as a
synonym under H. rottleri Lehm.
Table 1.
Morphological differences between Heliotropium
rottleri Lehm., H. marifolium J.Koenig
ex Retz., and H. scabrum Retz.
|
|
Morphological characters |
Heliotropium rottleri |
marifolium |
H. scabrum |
|
1 |
Habit |
Perennial, erect undershrub
attaining about 30 cm height; branches divaricate and curved. |
Procumbent annual herb;
branches divaricate, and straight. |
Prostrate woody annual herb;
branches radiating from the root stock. |
|
2 |
Leaves |
Shortly petiolate, small, ovate-lanceolate
acute with revolute margins, white-strigose, alternate but distant on stem. |
Sub-sessile, ovate-lanceolate
acute with flat margins, hispid, less scabrous, alternate, dense on stem. |
Shortly petiolate,
ovate-lanceolate acute with revolute margins, strigose-hirsute, scabrous,
alternate and dense on stem. |
|
3 |
Inflorescence |
2.5–5 cm long stiff curved
raceme. |
Simple spikes of 2.5–5 cm long;
bracts conspicuous. In H. marifolium ssp. wallichii, the spike is forked. |
Subcapitate among leaf-like
bracts. |
|
4 |
Flowers |
Pedicellate, 2 mm across,
distantly arranged. |
Sessile, 1 mm across. |
Sessile, 2 mm across. |
For
images - - click here for full PDF
References
Ahmedullah, M. & M.P. Nayar (1987). Endemic Plants of the Indian Region, Vol. 1. Botanical
Survey of India, Calcutta, 262 pp.
Ancy, A.A., P. Javad
& A. Antony (2024). Euploca wightiana
(Heliotropiaceae), a new species from south India. Nordic
Journal of Botany 2024(5): e03920. https://doi.org/10.1111/njb.03920
Clarke, C.B.
(1885). Boragineae, pp. 134–179. In: Hooker, J.D. (ed.). The
Flora of British India. Vol. IV. L. Reeve & Co., London, 780 pp.
Dheeren P. (2021). Taxonomic studies of genera Euploca and Heliotropium
(Heliotropiaceae) in Indian Thar Desert. Journal
of Economic and Taxonomic Botany 45(1–4): 116–127.
Gamble, J.S.
(1921). Flora of
the Presidency of Madras, Vol. II. Adlard &
Son Co. Ltd., London, pp. 578–1346.
Hooker, J.D.
(1885). The Flora
of British India, Vol. IV. L. Reeve & Co., 5, Henrietta Street,
Covent Garden, London, 780 pp.
Kader, S.A.
& S.A.W. Akram (2020). Taxonomic Status of Six South
Indian Heliotropium (L.) (Boraginaceae) Species, pp. 36. In: Proceedings of the
International Symposium of Plant Taxonomy and Ethnobotany organized by
Botanical Survey of India, Kolkata on 13 and 14 February 2020.
Kader, S.A.
& G. Gopal (2022). An Appeal to Conserve Heliotropium rottleri Lehm. (Boraginaceae) – A Critically Endangered Endemic Plant of
Tamil Nadu, pp. 213. In: Proceedings of the XXXII Annual Conference of Indian
Association for Angiosperm Taxonomy and National Symposium on ‘The Contribution
of Angiosperm Diversity to Human Wellbeing and The Risks Associated with its
Decline’ organized by Department of UG, PG & Research in Botany, Karnatak University’s Karnatak
Science College, Dharwad, Karnataka on 11–13 November 2022.
Lehmann, J.G.C. (1818). Plantae
e Familiae Asperifoliarum Nuciferae, Vol. I. Sumptibus
F. Dummler, MDCCCXVIII, Berolini,
478 pp.
Luebert, F., L. Cecchi,
M.W. Frohlich, M. Gottschling,
C.M. Guilliams, K.E. Hasenstab-Lehman,
H.H. Hilger, J.S. Miller, M. Mittelbach,
M. Nazaire, M. Nepi, D. Nocentini, D. Ober, R.G. Olmstead, F. Selvi, M.G. Simpson,
K. Sutorý, B. Valdés, G.K. Walden & M. Weigend (2016). Familial classification of the Boraginales. Taxon 65(3): 502–522.
Matthew, K.M.
(1983). The Flora
of Tamilnadu Carnatic, Vol. II. Rapinat Herbarium, St. Josephs College (Autonomous),
Tiruchirappalli, pp 689–1284.
Meena, S.L.,
S. Mishra, P.M. Padhye, R.P. Pandey & P. Harikrishna (2020). Boraginaceae,
pp. 155–176. In: Dash, S.S. & A.A. Mao (eds.). Flowering Plants of
India: An Annotated Checklist. Dicotyledons, Vol. II. Botanical Survey of
India, Kolkata.
POWO (2024). Heliotropium
L. http://powo.science.kew.org. The Royal Botanic Gardens. Electronic version
accessed on 12 June 2023.
Ramamoorthy, T.P. (1976). Boraginaceae,
pp. 477–484. In: Saldanha, C.J. & D.H. Nicolson (eds.). Flora of the
Hassan District (Karnataka State, India). Amerind Publishing Company, New
Delhi, 923 pp.
Rao, K.S.,
R.K. Swamy, D. Kumar, R.A. Singh & K.G. Bhat (2019). Flora of Peninsular India. http://peninsula.ces.iisc.ac.in/plants.php?name
= Heliotropium rottleri.
Electronic version accessed on 12 June 2023.
Sasidharan, N. (2011). Flowering Plants of Kerala.
DVD, Vol. 2. Kerala Forest Research Institute, Peechi,
Kerala, India.
Sivarajan, V.V. & K.S. Manilal (1972). A new species of Heliotropium L. from south India. The Journal of
The Indian Botanical Society 51(1–4): 348–350.
Standards and
Petitions Working Group (2006). Guidelines for using the IUCN Red List Categories and
Criteria. Version 6.2. Prepared by Standards and Petitions Working Group of the
IUCN SSC Biodiversity Assessments Sub-Committee in December 2006. Available
from http://app.iucn.org/webfiles/doc/SSC/RedList/RedListGuidelines.pdf
WFO (2023). Heliotropium
rottleri Lehm. http://www.worldfloraonline.org.
Electronic version accessed on 12 June 2023.
Wight, R. (1850). Icones
Plantarum Indiae Orientalis.
Vol. IV, Messrs. Franck and Co., Madras, 537 pp.
Appendix 1. IUCN Red List
Assessment: Heliotropium rottleri Lehm.
Kingdom: Plantae
Division: Tracheophyta
Class: Dicots
Order: Boraginales
Family: Heliotropiaceae
Genus: Heliotropium
Species: rottleri
Authority: Lehmann, J.G.C.
Common name: Nil
Taxonomic notes: The species was described by
Lehmann in 1818 from India without specifying precise locality and published in
‘Plantae e Familiae Asperifoliarum
Nuciferae’. Later, Wight (1850) had collected
this species from Coimbatore and provided a description and an illustration. It
is a low erect perennial plant reaching only about 30 cm height, having
characteristic divaricate curved stiff branches covered with whitish hairs and
small ovate-lanceolate very shortly-petioled
revolute-margined leaves.
ASSESSMENT INFORMATION
Red List Category and Criteria
(Version 3.1): Critically
Endangered B1ab(iii)+2ab(iii)
Justification: Heliotropium rottleri
Lehm. is assessed
as Critically Endangered as it is restricted only with the extent of occurrence
less than 50 km2 area. In 2006, only two mature individuals per
hectare were recorded in Masagoundanputhur; in 2020,
more than 250 individuals per hectare area was recorded in Raavanapuram,
and about 25 individuals per acre in Kamanayakkan Palayam. But in 2022
no individuals was recorded in Masagoundanputhur; less than less than 100 individuals were
recorded in Raavanapuram as the locality was
converted into industrial purpose; and in Kamanayakkan
Palayam site was completely used for house
construction.
GEOGRAPHIC RANGE / DISTRIBUTION
INFORMATION
Range description: The species is restricted to
Coimbatore and Thiruppur Districts of Tami Nadu,
India.
Countries of occurrence: Native to India (Tamil Nadu
State).
Extent of Occurrence (EOO): EOO is approximately 1 km2
area considering the present population at Raavanapuram.
The present population is at about 60 km away from the type locality.
Area of Occupancy (AOO): AOO is 1,143 km2.
Number of locations: The species is currently
restricted to four locations. The species is extirpated from its type locality
and other two locations. No other populations have been observed until now.
POPULATION INFORMATION
Population: The species is estimated to have
less than 500 mature individuals, of which about 100 individuals are restricted
to Raavanapuram.
Population trend: The population appears to be declining
at present. Over the last three years road widening, industrial development,
real estate business and house constructions have caused severe damage to the
population. Populations in one location is declined to 50% and have been
extirpated in other location.
HABITAT AND ECOLOGICAL
INFORMATION
Habitat and ecology: Marginal fallow lands in the plains
with grassy, rocky, and calcareous soils. The habitat is shared by Acacia leucophlea (Roxb.) Willd., Abutilon pannosum (G.Forst.) Schltdl.,
Azadirachta indica
A.Juss., Barleria buxifolia L., B. cuspidata F.Heyne ex Nees, Dichrostachys cinerea (L.) Wight & Arn.,
Parthenium hysterophorus L., Passiflora foetida L., Pergularia daemia (Forssk.) Chiov., Prosopis juliflora (Sw.) DC., Senna auriculata
(L.) Roxb., and grasses.
INFORMATION ON THREAT
Threats: The main threats to the
remaining population are road widening and developmental activities. The
present available population is near the highway and thus the road widening can
cause severe damage to the population.
Additional threats: Real estate business and other
developmental activities.
USE AND TRADE INFORMATION
Use: Local people do not collect the
species as there is no usage value for the plant.
Livelihoods and sustenance: Communities are not dependent on
this species for their livelihoods or sustenance.
Trend in off take from the wild: Not yet observed.
Trend in off take from
cultivation: It is not
cultivated.
Commercial value: The species has no known local,
domestic, national or international commercial value.
INFORMATION ON CONSERVATION ACTIONS
Conservation actions: Until now no actions.
Research in Place: There is no systematic research
in place other than causal surveys.
Research needed: Systematic surveys, monitoring,
propagation studies, effects of threats on population, and in situ conservation.
Monitoring in place: There is no monitoring off the
species, population or habitat in place.
Monitoring needed: Population and site monitoring is
essential and must be implemented at the earliest.
Education in place: No formal or informal education
about the species is in place.
Education needed: Outreach programmes
about the species to local communities and forest department are crucial.