Ethnobotanical
Leaflets 12: 361-372. 2008.
Swertia L. (Gentianaceae) in Nepal Himalaya: Checklist, Phytogeography, Ethnobotany and Conservation Status Kunjani
Joshi* and Ananda Joshi** *Department of Botany, Patan
Campus, At present: Harvard University
Herbaria, **President, Environmentalist’s Association of Nepal (EAN) Email: kunjanijoshi@hotmail.com; ajoshi9@gmail.com Issued Abstract Swertia L., a morphologically diverse but
taxonomically distinct genus’s circumscription has often been debated. Four
problems still need to be solved: species delimitation, section delimitation,
and relation with allied genera and domestication of the species for economic
benefits. In the present paper an attempt has been made to prepare a
checklist of Swertia species, and
documentation of distribution patterns, existing ethnobotanical uses and
conservation practices in Nepal. Some integrated measures, which might help
to fill up the gaps in our knowledge, are also recommended. Key words: Swertia, taxonomy, phytogeography,
conservation, ethnobotany, Nepal Himalaya. Introduction Swertia L (Gentianaceae – Gentianeae –
Swertiinae) is a morphologically diverse but taxonomically distinct genus.
The taxa in its present circumscription comprises ca 150 species and is
annual, biennial or perennial herb ranging from 2-4 cm. to over 1.5 m in
hight with 4-5 merous flowers, 1 or 2 nectaries at the base of characteristically
rotate corolla lobes. The genus mostly occurs in alpine or temperate habitats
in Asia, Africa and N. America. The circumscription of the genus has often
been debated, resulting disagreement amongst taxonomists due to the
morphological similarities (nectariferous and rotate corolla lobes) among the
species of Swertia and the related
genera. Nepal, a central segment of Himalayan
mountain systems, is rich in species diversity due to its transitional
location between the Paleoartic and Indo-Malayan realms, and a great variety
of physiographical characteristics and abundant diverse ecosystems within a
short span of space. The meadow, open forest and scrub ecosystems of the
mountainous regions of Eastern, Central and Western regions of the country
are the suitable habitats of Swertia species
(Joshi, 2007). Information on taxonomy, distribution, ethnobotany and
conservation of the Swertia species
are very limited (Bhattarai, 1992; Joshi, 1988, Joshi, 2000, 2004; Joshi and
Joshi, 2005; Manandhar, 2002; Sacherer, 1979; Shrestha et al., 1998). Although several authors have tried to enumerate
the species and varieties, systematic classification of Swertia has still been a problematic. Four problems still need to
be solved: species delimitation, section delimitation, and relation with
allied genera and domestication of the species for economic benefits. In the
present paper an attempt has been made to prepare a checklist of Swertia species, documentation of
distribution patterns, ethnobotanical uses and conservation practices and to
recommend some measures which might help to fill up the gaps in our
knowledge. Materials and Methods The plant materials were collected from the diverse
habitats of various villages and adjoining areas of Rasuwa, Sindhupalchok,
Dolakha, Makwanpur, Kathmandu, and Lalitpur Districts and identified with the
help of local floras. Information relating to the distribution, ethnobotany
and trade and conservation practices including people perception were
gathered using various techniques such as interviews, discussion with local
people, traders and direct observation on the way the useful plants and their
parts were being collected and used (Joshi and Edington, 1990). For
preparation of checklist, specimens have been checked with the herbarium
specimens of the National Herbarium, and Plant Laboratories, Godavari (KATH),
and Central Department of Botany, Tribhuvan University (TUCH), Nepal and
Harvard University Herbaria, USA. Voucher specimens are housed in the
Biodiversity Research Center, Taxonomy: Checklist of Swertia species Although Nepal remained
almost completely closed to foreigners until 1949, the flora of the country
was no means entirely unknown. Many earlier workers have collected and
described the plants from the different parts of the country. After 1960,
major botanical expeditions, particularly from British Museum, England and
Kyoto and Tokyo Universities of Japan have explored the country. The major
contributions relating to the species of Swertia
found in Nepal was made by national, regional and international botanists
and institutions. Among the contributions on documentation of the taxa, the
significant collections and studies of the species of Swertia date back to Smith (1970), who had described three new
species : Swertia acaulis, collected
on open slopes, foot of Wabak
khola, east of Num, Arun valley, 4600m; S.
gracilescens, collected on grass slopes, Kali gandaki valley, Taglung, south of Tukucha, 3700m; and S. staintonii, collected on open
slopes, Arun valley, Chhoyang Khola, west of Num, 3800m. In
1976, 21 species of Swertia found
in Nepal: S. acaulis, S. alata, S. angustifolia,
S. bimaculata, S. chirayita, S. cordata, S. cuneata, S. dilatata, S.
gracilescens, S. hispidicalyx, S. hookeri, S. kingii, S. multicaulis, S.
nervosa, S. paniculata, S. pedicellata, S. petiolata, S. purpurascens, S.
racemosa, S. speciosa, and S.
tetragona have documented in Catalogue of Nepalese Vascular Plants
(Malla et al, 1976a). Similarly, Hara et al. (1982) in Enumeration of Flowering Plants of Nepal Vol. The circumscription of Swertia has been subject to major
change ever since its establishment. The identification and systematic
arrangement of species have carried out based on only morphological
characteristics. These works show controversy in species and varieties
boundaries. Some species are excluded in the respective groups and some are
placed as synonames and some new species added to the family. During the present
study, a checklist was prepared studying our own collected specimens and
checking and reviewing the herbarium specimens stored in universities and
research institutions and consulting various relevant documents and papers. Table 1 presents the 31 species of Swertia with varieties and their
distribution in Nepal. Table 1. Species of Swertia and their Distribution in Nepal.
Swertia shows wide range of morphological
variation within and among the population resulting a considerable
uncertainty about the delimitation of species. Among the collected plant
specimens from different areas., S.
racemosa shows a pronounced variation in the presence of cilia on margin
of leaf, sepals, and bracts as well as on veins. Similarly wide ranges of
variation in morphological traits among the population of S. chirayita and S. nervosa were also reported by Raskoti and Sakya (2004) and
Pant and Bimb (2005) respectively. Biogeography of Swertia species Nepal’s diverse geomorphology over a wide range of
latitude, longitude, and elevation has provided an abundance of habitats and
ecological niches, which help to explain spectacular diversity of plant species
growing in the region (Bajracharya, 1996). Among the phytogeographical
features, the Himalaya and adjacent ranges are not only regarded as a
‘meeting places’ of different floristic elements entering from different
directions (Banerji, 1963), but also
gave rise to many new and endemic species, especially in the alpine zone,
i.e. Androsace nortonii, Primula
wollastonii, Swertia acaulis.
Thus Nepalese flora is not only represented by a mix of the southern slopes
of Himalayas, but also a mix of high and dry plateau flora of Tibet (China)
with that of the humid monsoon region of Indian sub-continental plains floras
(Kanai, 1966; Yoshida, 2006a & b). Swertia species are widely distributed in
tropical to alpine habitats of the Eastern, Central and Western regions. Out
of 75 districts of the country, Swertia
species have documented from 54 districts so far (Fig.1). Such wide
distribution of the species of Swertia
and other plant communities could also be highlighted with the help of recent
evidence of the geological past of the Asian region and migration of species
from the neighboring continents. However, as there are no fossil records
relating to the Swertia and other
species of Gentiniaceae in Nepal, it is not possible to discuss the phylogeny
and biogeographical distribution from the palenological point of view. But
formation of Tibetan Plateau and upliftment of Himalyas and other mountain
ranges (Karakoram, Kunlun Shan, Tian Shan, Hengduan mountains) due to collide of Deccan plate with the southern
Laurasia coastline at about 45 million years BP in Eocene times and
geobotanical development of the Himalaya might have changed climatic patterns
and encounter some important changes with the dispersal and distribution of
plants. At present, it is difficult to interpreate these issues due to lack
of data as well as generic relation of inter and intraspecies relationships
are not yet well enough resolved. Priority should be given to integrated
study of the taxa and its eco-distribution for a conclusive biogeographic interpretation.
Ethnobotanical value of Swertia The
rural people of Nepal rely heavily on plant resources for their primary
healthcare and treatment of diseases. The people have developed unique indigenous
knowledge related to the uses of plant resources due to constant association
with the forests. The traditional knowledge related to the therapeutic uses
of plants may be utilized for the improvement of the economic status of the
local communities. However, less priority has given to document these
valuable practices and plant resources. The works relating to the
ethnobotanical investigation and sustainable management of the resources
including Swertia species are very
sporadic (Baral and Kurmi 2005; Bhattarai, 1992, Bhattarai et al, 2007; Jha et al, 2001; Joshi, 1988; Joshi and Edington, 1990, Lama et al, 2001; Manandhar, 2002; Siwakoti
and Siwakoti, 2003, Shrestha, 1991). Recently, Joshi (2008) has documented
the medicinal uses of some species of Swertia
(Table 2). Besides this, some works on the ethnomedicinal uses of S. alata, S. bimaculata; S. cuneata; S.
kingii, S. tetragona have also carried out (Ghimire, 2001; Manandhar,
2002; Sacherer, 1979; Subedi, 2006). Among the species, S. chirayita is the important for its medicinal properties.
Herbal medicines such as Diabecon, Melicon V-ointment, Ayush-64 and Mensturyl
syrup contain chirata (Swertia)
extract in different amount for its antipyretic, hypoglycemic, antifungal and
antibacterial properties (Joshi and Dhawan, 2005). Table 2. Ethnomedicinal uses of some
species of Swertia
Source: Joshi (2008) Conservation Status The
rural people collect the ‘Chiraito” (Swertia)
or their products directly from the wild populations of the forest, meadow,
scrub or shady habitats which are already dwindling due to over-exploitation
and unsustainable land-use, thus accelerating their genetic erosion. Unsustainable collection of the
species has been done due to their usefulness to cure various ailments, their
increasing price, and increasing demand as raw materials for preparation of
Ayurvedic and Allopathic medicines. Every year a huge amount of medicinal
plants are collected for export. The income from the chiraito was used by
collectors for foodstuffs, including salt, clothes, to pay off loans and to
buy cattle (Daniggelis, 1999). The plants are collected before the
maturation of seeds. The whole plant is pulled out, sun-dried for a few days,
wrapped by bamboo slip and sold to the local traders as dried brownish stems
with root and leaves intact. Unsustainable harvesting without considering the
age of the plant and seed maturity reduces regeneration significantly.
Extensive collection and unscientific harvesting practices of these plants
from the natural habitat leads to an increasing danger of extinction
(Bhattarai and Shrestha, 1996; Edwards, 1993; Joshi, 2008). The present rate
of exploitation has rendered some species to the status of threatened and
endangered species (Joshi and Joshi, 2005; Joshi, Joshi and Joshi, 2000;
Joshi, Shrestha and Joshi, 2003; Joshi and Joshi 1991). Swertia species occupies one of the major
portions in the trade of medicinal and aromatic plants from Nepal. About Nine
species (S. chirayita, S. angustifolia,
S. ciliata, S. dilatata, S. multicaulis, S. racemosa, S. tetragona, S. alata, S. nervosa) have
been reported under trade in different trading centers of Nepal (Barakoti,
2002) with common name “chiraito” except for Swertia multicaulis (sarmaguru). Among these species, Swertia chirayita plays dominant role
in trade and is considered superior in quality. Adulteration of chiraito with
other low quality species of Swertia
and other related species are very common in the trade of chiraito. |
