#hypotrachyna

Hypotrachyna spumosa

Frothy loop

Yesterday a student asked me if I ever go to tropical places to look for lichens and I told her no, not really. She asked me why and I was just like ". . . huh, I don't know." So here is to making plans to go see some tropical lichens like H. spumosa in the future! This foliose lichen grows on trees and occasionally rocks in tropical habitats. It has a closely appressed thallus of imbricate lobes with marginal cilia and laminal isidia. The upper surface is pale green-gray, the medullary layer (interior fungal hyphae) is pale yellow, and the lower surface is black and densely rhizinate. It'll be awhile, but with lichens like H. spumosa out there waiting for me, I hope it doesn't take toooo long.

images: source

Growing on a Scarlet Oak in the Christchurch botanical gardens.

Formerly Parmelia afrorevoluta, and Parmelinopsis afrorevoluta. The current binomial refers to the rough underside of the fronds, and the fact that it grows in Africa and resembles H. revoluta. However, there's some evidence that afrorevoluta is actually a species complex, so the genus probably needs further revision.

Most often recorded in Europe, but widespread, and found growing on bark, wood and stone.

Hypotrachyna minarum

Hypotrachyna britannica

Hypotrachyna rockii

This foliose lichen has irregular, sublinear lobes with lobulate margins and plane to convex apices. The upper surface is whitish gray and often wrinkled and cracked. It has laminal, crater-like soralia full of farinose or granular soredia. The lower surface is black with brown edges, and has scattered black rhizines. It rarely produces apothecia, which have a crenulate or sorediate margin and a brown disc. H. rockii grows on pine bark in montane forests in the neotropics and east Africa.

images: source | source

Hypotrachyna sinuosa

Hypotrachyna minarum

Hairless-spined loop

Hypotrachyna physcioides

This foliose lichen grows on rock, soil, and bark in neotropical and SE Asian forests. It has elongated, sublinear, leathery lobes, that grow in patches up to 15 cm in diameter. The upper surface is gray with white patches, and the lower surface is black with black, branched rhizines. It produces brown-disked apothecia with crenulate margins. I am trying hard to feature more lichens from the tropics and the southern hemisphere, but pictures of and info on these little guys are harder to come by than lichens from cooler climates and the northern hemisphere. Totally unfair! So please don't let these less-than-stellar pictures deter you from giving all your love to H. physcioides.

images: source | source