Ascomycetes \As`co*my*ce"tes\, n. pl. [NL.; ascus + Gr. ?, ?, fungus.]

(Bot.) A large class of higher fungi distinguished by septate hyph[ae], and by having their spores formed in asci, or spore sacs. It comprises many orders, among which are the yeasts, molds, mildews, truffles, morels, etc. -- As`co*my*ce"tous, a.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Fungi \Fun"gi\, n. pl. (Bot.) A group of thallophytic plants of low organization, destitute of chlorophyll, in which reproduction is mainly accomplished by means of asexual spores, which are produced in a great variety of ways, though sexual reproduction is known to occur in certain Phycomycetes, or so-called algal fungi.

Note: The Fungi appear to have originated by degeneration from various alg[ae], losing their chlorophyll on assuming a parasitic or saprophytic life. By some they are divided into the subclasses Phycomycetes, the lower or algal fungi; the Mesomycetes, or intermediate fungi; and the Mycomycetes, or the higher fungi; by others into the Phycomycetes; the Ascomycetes, or sac-spore fungi; and the Basidiomycetes, or basidial-spore fungi.

Source: Webster's Revised Unabridged Dictionary (1913)