Melanohalea gomukhensis
Melanohalea gomukhensis is a species of corticolous foliose lichen in the family Parmeliaceae. It is found in northern India.
Taxonomy
The lichen was described as a new species in 2001 by the lichenologists Pradeep Divakar, Dalip Kumar Upreti, and John Elix. The type specimen was collected by Dharani Dhar Awasthi and Shri Ram Singh on 30 June 1976, and is housed in the lichen herbarium at AWAS. The species name gomukhensis refers to Gomukh, the geographical location in the Uttarkashi district of Uttarakhand, India, where the type was collected. The authors originally classified the taxon in the genus Melanelia. It was reclassified as a member of the segregate genus Melanohalea in 2004.The species is related to Melanohalea poeltii from Nepal, but differs in having dense pseudocyphellae and structures that develop from granular soredia contained within the cavity of the pseudocyphella. While M. poeltii has sparse or absent pseudocyphellae on some lobes, and its isidia develop on small, more or less spherical, with the isidia being cylindrical to irregular and becoming branched.
Description
Melanelia gomukhensis has a thallus that grows up to 9 cm wide. Its are contiguous to weakly, irregular, irregularly branched, and 2–3 mm wide with subrotund apices. The upper thallus surface is red-brown to dark brown, flat or weakly concave, smooth, shiny at the apices but dull within, and . The species lacks isidia but is densely pseudocyphellate. These pseudocyphellae are laminal, fleck-like and whitish at first, but soon darken and expand, becoming rounded or irregular, and eventually .The soredia are coarse and, becoming partly and forming . These pseudoisidia are in shape and develop from granular soredia contained within the cavity of the pseudocyphella, which is a distinctive characteristic of this species.
The medulla is white. The lower surface is shiny, minutely wrinkled, black but dark brown at the margins. The rhizines are sparse to moderately dense, simple, and brown to dark brown. Both apothecia and pycnidia are absent in the specimens examined, indicating that the species reproduces primarily through vegetative means via soredia.