Endemic
Impatiens (Balsaminaceae)
of Western Ghats
Owing to the most congenial
climatic conditions, Western Ghats are endowed with rich assemblage of diverse
plant species including many endemic taxa and qualifies as the only Indian
center, among the five distinct diversity hotspots of the genus Impatiens L. The genus Impatiens consists of about 1000
species, distributed in the tropical and subtropical regions of the Old world
as well as in the northern temperate regions. In India there are about 215 species
of Impatiens recorded so far, of
which 142 species are endemic and about 106
species occur in Western Ghats. The diversity occurs in two regions viz., the
Eastern Himalayas and the Western Ghats.
The
richness of flowering plants makes India one of the mega diversity countries in
the world with four biodiversity hotspots and three mega centres of endemism.
The flora of India shows high diversity in terms of families, genera and
species of angiosperms. Many genera and families are known to be represented by
a large number of endemic species, one amongst them is the genus Impatiens of
the family Balsaminaceae. The family Balsaminaceae comprises annual as well as
perennial herbs, undershrubs and shrubs that show salient floral morphology. It
comprises two widespread genera viz., Hydrocera Wight & Arn., a
monotypic genus and Impatiens L., a genus with a large number of
species. Hydrocera can be distinguished by its five free petals and
capsular berry, while Impatiens has four petals that are fused to form
two lateral petals and a 5-valved capsule. Hydrocera triflora (L.) Wight
& Arn. is a semi-aquatic herb distributed in the Indomalesian region.
Many
species of Impatiens L. are cultivated as ornamental and some are used
in medicine and cosmetic. Species of this genus are commonly known as ‘Balsams’
or ‘Jewel Weeds’. The effective
pollinators of most Impatiens species
are honeybees, while the flowers are also visited by butterflies, aphids,
stingless bees and beetles which aid pollination in absence of
honeybees. Some species of Sect. Annuae are self-pollinated.
