How to use Lichen in a sentence
The water moved silently over moss and lichen covered slabs of rocks, forming small pools in the low spots.
The reproductive organs of the lichen are of a typically fungal character, i.e.
The thallus or body of the lichen is of very different form in different genera.
The relations of the Alga and the Fungus, which have formed a close associationship in the structure known as the Lichen, were established many years ago.
Schimper distinguishes moss tundra, Pot ytrichum tundra, and lichen tundra; and the lichen tundra is subdivided into Cladonia tundra, Platysma tundra, and Alectoria heath.Advertisement
Owing to its northerly position a large part of Ungava is treeless, and belongs to the barren grounds where caribou roam and feed on the socalled caribou moss, a greyish lichen.
There is an important crustose lichen assemblage on the rocks.
An application of ' masonry biocide ' would then retard growth of algae and lichen.
The whole site is biologically rich, with many woodland plant communities represented and rich bryophyte and lichen assemblages.
They get somewhat dirty with lichen in the apple tree in a break in the weather.Advertisement
You will arrive at an imposing lichen encrusted gateway.
The lichen and bryophyte flora of the complex is outstanding, and the vascular plant flora is also extremely rich.
Patches of yellow lichen cover the ground at intervals, gleaming absolutely golden under the evening sun.
The pressure of the jet is carefully adjusted as the job proceeds, to remove lichen and grime without undue force.
Current status This crustose lichen grows on the trunks of mature trees with basic bark.Advertisement
The orange foliose lichen in the close-up is Xanthoria parietina.
Note the junction between the brown-black lava stone and green and leafy lichen.
They wore wigs of gray lichen beneath their red caps.
The fungus seems, on the other hand, to stimulate the algal cells to special development, for those in the lichen are larger than those in the free state, but this is not necessarily adverse to the idea of parasitism, for it is well known that an increase in the size of the cells of the host is often the result of the attacks of parasitic fungi.
The remarkable case of life in common first observed in lichens, where a fungus and an alga unite to form a compound organism - the lichen - totally different from either, has now been proved to be universal in these plants, and lichens are in all cases merely algae enmeshed in the interwoven hyphae of fungi (see Lichens).Advertisement
The incense sticks and pastils known all over India under the names of ud-buti (" benzoin-light") or aggar-ki-buti (" wood aloes light") are composed of benzoin, wood aloes, sandalwood, rock lichen, patchouli, rose-malloes, talispat (the leaf of Flacourtia Cataphracta of Roxburgh), mastic and sugar-candy or gum.
Above this grows a species of pine, which becomes dwarfed and disappears at an altitude of about 6000 ft., beyond which is a zone of lichen and moss covered or almost bare rock.
He investigated the exact relation of fungus and alga and showed that the same alga is able to combine with a number of different fungi to form lichens; thus Chroolepns umbrinus is found as the gonidia of 13 different lichen genera.
The lichen algae are not alone in their specializa tion to the symbiotic (or parasitic) mode of life, for, as stated earlier, the fungus appear in the majority of cases to have completely lost the power of independent development since with very rare exceptions they are not found alone.
No lichen is known to be possessed of any poisonous properties to man, although Chlorea vulpina is believed by the Swedes to be so.Advertisement
The lichen flora of temperate regions again is essentially distinguished from the preceding by the frequency of corticolous species belonging to Lecanora, Lecidea and Graphidei.
The highest specimen obtained was a lichen (Lecanora subfusca, L.) on the south side of Chimborazo, 18,400 ft.
The heathland is rich in lichens, including the rare golden hair lichen.
Of the rivers draining from the plateau, only the Glenarm has records of Priority Species the otter and the river jelly lichen.
The herb layer is not diverse and the epiphytic moss and lichen flora is also poor.
The algae part of the lichen provides food to the fungus using photosynthesis.
When these spores germinate they must find a suitable photosynthetic partner in order to re-establish the lichen symbiosis.
The dry lichen thallus is brittle, so fragments can be broken off easily and transported by wind or by animals.
Unlike hot summer wildfires the lichen and reptile interest is unharmed and the impact on invertebrates is minimal and short term.
An association of two organisms to their mutual advantage is known as symbiosis, and the lichen in botanical language is described as a symbiotic union of an alga and a fungus.
The lichen, however, is able to grow as the alga supplies organic food material and the fungus has developed a battery of acids (see below) which enable it actually to dissolve the most resistant rocks.
It must be borne in mind that the exact nutritive relations of the two constituents of the lichen have not been completely elucidated, and that it is very difficult to draw the line between symbiosis and parasitism.
The ear may be regarded, fancifully, as a lichen, Umbilicaria, on the side of the head, with its lobe or drop.
Even old concrete building foundations left undisturbed can develop useful lichen heath and ruderal communities.
Jane Bevan Spatial and temporal dynamics of terricolous lichen assemblages and their bioprotective role in the El Cantino badlands, S E Spain.
There was a swag of lichen hanging from nearly every branch of the old tree.
Lichen planus-A noncancerous, chronic itchy skin disease that causes small, flat purple plaques on wrists, forearm, ankles.
Neurodermatitis-An itchy skin disease (also called lichen simplex chronicus) found in nervous, anxious people.
The view of the dual nature of lichens had hitherto been based on analysis; the final proof of this view was now supplied by the actual synthesis of a lichen from fungal and algal constituents.
Thus in the case of saxicolous lichens the mineralogical character of the rock has of itself little or no influence upon lichen growth, which is influenced more especially and directly by their physical properties, such as their capacity for retaining heat and moisture.
The mango, lichen, pear and orange are indigenous, and several fruits and esculents have been introduced.
In such districts lichen vegetation is entirely or almost entirely absent.
Zukal has considered that the lichen acids protect the lichen from the attacks of animals; the experiments of Zopf, however, have cast doubt on this; certainly lichens containing very bitter acids are eaten by mites though some of the acids appear to be poisonous to frogs.
Another nutritious lichen is the " Tripe de Roche " of the arctic regions, consisting of several species of the Gyrophorei, which when boiled is often eaten by the Canadian hunters and Red Indians when pressed by hunger.
But the most singular esculent lichen of all is the " manna lichen," which in times of drought and famine has served as food for large numbers of men and cattle in the arid steppes of various countries stretching from Algiers to Tartary.
The relation of the two constituents of the lichen have been briefly stated in the beginning of this article.