Search results
Results from the WOW.Com Content Network
Spot tests on the foliose lichen Punctelia borreri showing thallus (top) and medulla (bottom). The pinkish-red colour change of the medulla in the C and KC tests indicate the presence of gyrophoric acid, a chemical feature that helps to distinguish it from similar species in the same genus.
A lichen (/ ˈ l aɪ k ən / LIE-kən, UK also / ˈ l ɪ tʃ ən / LI-chən) is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungi species, along with yeasts and bacteria [1] [2] embedded in the cortex or "skin", in a mutualistic relationship.
Usnea filipendula – one of about 20,000 described species of lichen. The following outline provides an overview of and topical guide to lichens.. Lichen – composite organism made up of multiple species – a fungal partner, one or more photosynthetic partners, which can be either green algae or cyanobacteria, and, in at least 52 genera of lichens, a yeast. [1]
A leprose lichen, which is typically considered to be a form of crustose lichen, is one with a powdery or dust-like appearance. Its undifferentiated thallus is an irregular mix of fungal hyphae and scattered photobiont cells, lacking a cortex or any definable layers. [6] [47] Morphologically, it is the simplest growth form. [48]
This is possible due to the action of lichen phenolics such as usnic acid derivatives. [34] From the 1950s the lichen product usnic acid was the object of most antitumour research. These studies revealed some in vitro antitumour activity by substances identified in two common lichens Peltigera leucophlebia and Collema flaccidum. [35]
The lichen dye is usually extracted by either boiling water or ammonia fermentation. Although usually called ammonia fermentation, this method is not actually a fermentation and involves letting the lichen steep in ammonia (traditionally urine) for at least two to three weeks. In North America the most significant lichen dye is Letharia vulpina ...
Caloplaca is a lichen genus comprising a number of distinct species. Members of the genus are commonly called firedot lichen, [1]: 235 jewel lichen. [1]: 235 gold lichens, "orange lichens", [2] [3] but they are not always orange, as in the case of C. albovariegata. [4]
A lichen with a shrub-like or hairy thallus attached to the substrate at a single point. [204] fruticulose Also fruticulous . A smaller version of a fruticose lichen. [204] See related: microlichen. fulvous An yellow-brown or tawny color. [43] funiculus See umbilicate lichen. funoid Made of fibers or rope-like strands. [43] furcate Forked. [215 ...