Collema
Sign in to saveCollema (jelly lichen) is a genus of lichens in the family Collemataceae. The photobiont is the cyanobacterium genus Nostoc. Species in this genus typically grow on nutrient-rich bark or somewhat siliceous or calcareous rocks in humid environments.
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Collema (jelly lichen) is a genus of lichens in the family Collemataceae. The photobiont is the cyanobacterium genus Nostoc. Species in this genus typically grow on nutrient-rich bark or somewhat siliceous or calcareous rocks in humid environments.
==Description== Collema lichens are characterized by their medium to large size, with a diameter of . They have a leaf-like, membranous structure that does not swell noticeably when wet. The upper surface of the thallus is dark olive-green to brown-black and is not hairy. The are 2 to 15 mm broad, rounded, and usually flat or partially raised, with smooth or surfaces adorned with elongated ridges or folds.