Ascomycetes (ascolichens) regularly produce spores . During germination, the spore form branching out in all directions hyphae. If hyphae comes in co

Spore production in lichen [Formation, Sporulation, Ascomycetes]

Ascomycetes (ascolichens) regularly produce spores. During germination, the spore form branching out in all directions hyphae. If hyphae comes in contact with a suitable alga, it constitutes an additional branches that envelop alga. Cooperative growth of algae and fungus result in the formation of lichen. If none of the hyphae branches will meet algae — the fungus will die.

Sporulation of the fungus is known for the very few lichens. The vast majority of them form fruiting bodies — apothecia, perithecia. Sometimes they form conidia.

Fruiting bodies — apothecia and perithecia — are bordered with hymenium layer (diagram 296). Sacs grow vertically between hymeniums, but never rise above them. Development of the sacs never comes at the same time; some lichen apothecia can continue to produce sacs for several years. Throwing ascospores of these perennial apothecia goes continuously, but only in wet weather. Taken from http://worldofschool.org

Diagram 296. Cross section of apothecia
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