Systematics studies on section epiphyticae of family balsaminaceae.

Abstract

Systematics studies on section Epiphyticae of family Balsaminaceae The genus Impatiens belongs to the family Balsaminaceae, is a species rich genus distributed in five major hot spots around the world. This genus is notorious among the botanists due to delicate nature of the flowers, variations in morphological characters, rapid hybridization, and high degree of endemism. Due to these intricacies, the classification of genus Impatiens is still incomplete. The intergeneric classification proposed by Hooker divides this genus into 7 sections and one among them is section Epiphyticae. This section is a narrow endemic, distributed only in Southern Western Ghats. The section includes 7 species located at various locations of Southern Western Ghats. The present study deals with the taxonomy, anatomy, palynology, seed morphology and potential distribution of Impatiens belongs to the section Epiphyticae. All the species belongs to section Epiphyticae are epiphytes on trees and do not show any preference to the host tree. Due to the unique nature of the spur they are also known as, Parrot billed Impatiens. Critical examination of a specimen collected from Wagamon was identified to be noval and was confirmed as a novelty hence recognized as a new species. This species is closely allied with I. parasitica and known only from the type locality. The variation in morphology of I. parasitica collected from different localities confirmed the rapid evolution- taking place in this genus. During the study 8 different morpho types of I. parasitica was collected. They show variations in floral characters but the seed and fruit are similar. In the future, these morphotypes may develop to new species. On critical examination of the type specimen of I. kulamavuensis concluded that it is a synonym of I. parasitica. The ambiguity remained in the structure of floral parts especially lateral united petal of Epiphyticae Impatiens was resolved in this study. This is the first attempt to elucidate the anatomical features of Epiphyticae Impatiens. This attempt resulted in significant data on the anatomy of leaf and stem. The pollen grains of all the species under study have a medium size and shape is oblate spheroidal in I. auriculata and prolate spheroidal in all other 6 species under consideration. The surface of the pollen grains consists of reticulate ornamentation. All the pollen grain under study is tetrazonocolpate. The MaxEnt algorithm helps to predict the potential distribution of species under study. Only four species out of the seven species reported a good result hence the final model is accepted. According to the model all the studied species show distribution in Idukki district as well as Agasthyamalai regions.