Word Study
thallogen
CIDE DICTIONARY
thallogen, n. [Gr. young shoot or branch, frond + -gen.].
One of a large class or division of the vegetable kingdom, which includes those flowerless plants, such as fungi, algæ, and lichens, that consist of a thallus only, composed of cellular tissue, or of a congeries of cells, or even of separate cells, and never show a distinction into root, stem, and leaf. [1913 Webster]
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