The Collaborative International Dictionary
Thallogen
Thallogen \Thal"lo*gen\, n. [Gr. ? young shoot or branch, frond + -gen.] (Bot.) One of a large class or division of the vegetable kingdom, which includes those flowerless plants, such as fungi, alg[ae], 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.
Wiktionary
thallogen
n. (context botany English) Any of a large number of plants that consist of a thallus only, with no flower, leaves etc.
Usage examples of "thallogen".
The lowest members of the vegetable series, the Thallogens, apparently circumnutate.
The lowest members of the vegetable series, the Thallogens, apparently circumnutate.