A NEW SCAPIGEROUS SPECIES OF IMPATIENS ( BALSAMINACEAE ) FROM INDIA

Impatiens minae Ratheesh, Anil Kumar & Sivad. a new scapigerous species of Impatiens from Wayanad district in Kerala, India is described and illustrated. The new species resembles Impatiens denisonii and I. scapiflora by its 3-lobed lateral united petals and lower sepal with a long spur; but differs from the latter in having a curved band of dense fleshy clavate papillae at the base of lateral united petals, and from the former in the absence of a dorsal filiform appendage or auricle at the base of the lateral united petals.


Introduction
The genus Impatiens L. (Balsaminaceae) is one of the largest and difficult genera of angiosperms comprising over 1000 species (Mabberley, 2008), and several new species are being recognized and described each year.The earliest detailed study of the genus was by Hooker and Thomson (1859); and revision by Warburg and Reiche (1895) with infrageneric classification.
The major contributions on Indian species are those of Hooker (1874Hooker ( -1875Hooker ( , 1904Hooker ( , 1905Hooker ( , 1906)).In India the genus is represented by over 203 taxa mainly distributed in three major centres of diversity, i.e.Western Himalayas, North East India and the Western Ghats, each characterized by its own species groups and sections (Hooker, 1910;Gamble, 1915;Rajalal et al., 1996;Vivekananthan et al., 1997).The scapigerous species of Impatiens have very restricted distribution in South Indian-Sri Lankan region with very low diversity and high rate of endemism compared to non-scapigerous species (Grey-Wilson, 1980;Nair, 1991;Vivekananthan et al., 1997).Except Impatiens acaulis, which is distributed throughout the wet tropical forests of Western Ghats and Sri Lanka, all other species have very narrow distribution pattern in various small microcenters in Western Ghats, especially in its southern part.They are highly delicate ephemerals thriving mainly on moss covered tree-trunks or on wet rocks for a short duration in monsoon season.Classification of the 'Scapigerae' section is mainly based on the lobes of the lateral petals, the spur of the lip and the dorsal auricle on the lateral petals.Vivekananthan et al. (1977) reported 19 species of scapigerous Impatiens from Western Ghats in his treatment for the flora of India, and the major centre of distribution is considered to be Nilgiri phytogeographical region of southern Western Ghats (Bhaskar, 1981(Bhaskar, , 2006;;Bhaskar and Razi, 1982;Vivekananthan et al., 1997;Viswanathan and Manikandan, 2003).Out of the 30 species of Impatiens reported from Periyar Tiger Reserve in Kerala, 3 are scapigerous (Augustine et al., 1999).In a recent study Dessai and Janarthanam (2011) recognized seven scapigerous species in the northern and parts of central Western Ghats.

Impatiens minae
Impatiens minae is allied to Impatiens denisonii Bedd.and Impatiens scapiflora Heyne ex Roxb., but distinctly differs from both by the characters given in the Table 1 Etymology: The specific epithet of the new taxon is in honour of Ms. Mina Swaminathan, Advisor, M. S. Swaminathan Research Foundation, who has dedicated her life for the education and empowerment of underprivileged children and women in rural areas, and also in creating awareness among them on values and importance of biodiversity and its conservation.
Notes: Impatiens minae resembles I. denisonii Bedd.and I. scapiflora Heyne ex Roxb. in having 3-lobed lateral united petals and lower sepal with a long spur, but differs from I. denisonii by its fleshy, broadly ovate-orbicular leaves, absence of a dorsal filamentous appendage or auricle at the base of lateral united petals, and seeds having short, blunt spinous projections.It differs from I. scapiflora in having a slightly curved band of dense clavate papillae just above the base of lateral united petals.The seed-surface in I. scapiflora are hispid in contrast to the short, blunt spinous projections in I. minae.Phenology: Flowering starts from July and peak time is August.Fruit matured during September-October.
Distribution and ecology: So far known only from the Chembra-Vellarimala hill ranges of Wayanad district in Kerala (Fig. 3).Grows in open wet and dripping rocky slopes in grasslands at altitudes of 1600-2000 m associated with Habenaria rariflora A. Rich., Ipsea malabarica Hook.f., Satyrium nepalense D. Don, Chlorophytum malabaricum Baker, Eriocaulon spp., etc.  Population structure and conservation status: The species is seen in open grassy slopes in clusters along with grasses, mainly along the slopes between 1500 and 1700 m above the sea level of Chembra-Vellarimala hill ranges.It is observed that they are distributed in isolated patches from southern to northern part of the hill ranges.The southern most population is located in the high altitude grassy slopes of south-east side of Chembra hills of Meppady forest range and major population is in the north-west slopes of the Chembra hills belonging to the same forest range of Wayanad district.The populations are small and scattered along this hill ranges and are restricted to 30 sq. km area.This hill ranges are not under any protected areas.Increased anthropogenic interference in the form of tourism and forest fire enhance the crisis.Its geographic range (extent of occurrence) and the quality of habitat are declining continuously.By following IUCN criteria (IUCN, 2001) for assessing the status of Rare and Threatened plants, M. minae is assessed as belonging to Critically Endangered (CR) category.