Lepraria indica
Lepraria indica is a species of leprose crustose lichen in the family Stereocaulaceae. It was discovered in the Amarkantak region of Madhya Pradesh in central India, where it grows on rocks and soil in tropical forests at elevations between 150 and 500 metres. The lichen forms green to light grey powdery patches with distinctive lobed edges that have slightly raised rims and a thick white inner layer. Chemical analysis has identified several lichen substances in the species, including stictic acid, atranorin, and zeorin, which help distinguish it from similar powdery lichens.
Taxonomy
Lepraria indica was described as new to science by Rajesh Bajpai and Dalip Kumar Upreti in a 2018 treatment of Indian Lepraria and Leprocaulon. The holotype specimen was collected in Madhya Pradesh on rock over soil. The epithet refers to India. The authors distinguished the species by its lobed, weak-rimmed margin and a clearly developed white medulla, and by a chemistry of stictic acid with atranorin and zeorin. They noted contrasts with superficially similar taxa: it shares chemistry with L. lobificans but has more strongly developed marginal lobes; resembles Leprocaulon coriense in form but differs chemically ; and differs from L. santosii, L. elobata and L. caesioalba in its combination of well-formed lobes and chemistry. The key provided in the paper separates L. indica on its lobed, raised margin and distinct medulla.
Description
The thallus is leprose and soft, green to light grey, forming patches with well-developed marginal that have a slightly raised rim. The inner layer is well developed and usually thick, white; a basal is rarely visible and then pale brown. The surface is sorediate, with abundant, loosely packed soredia generally fine and about 85–95 μm across, often well separated; short projecting hyphae can be seen among them. Spot tests are K+, C−, KC− and Pd+, consistent with the presence of stictic acid together with atranorin and zeorin.
Habitat and distribution
As of its original publication, the species was known only from a few localities in the Amarkantak area of central India, where it grows on rock and on soil over rock in tropical settings between about 150–500 m elevation. No occurrences outside this part of Madhya Pradesh were reported in the original account. It was later recorded from the Goodrical Reserve Forest in the Pathanamthitta district of Kerala.