Webster's 1913 Dictionary
PROTOPHYTE
Pro "to *phyte, n. Etym: [Proto- + Gr. (Bot. )
Defn: Any unicellular plant, or plant forming only a plasmodium, having reproduction only by fission, gemmation, or cell division.
Note: The protophytes (Protophyta ) are by some botanists considered an independent branch or class of the vegetable kingdom, and made to include the lowest forms of both fungi and algæ, as slime molds, Bacteria, the nostocs, etc. Cf. Carpophyte, and Oöphyte.
Duden Dictionary
Protophyte
Pro to phy te Substantiv, feminin Biologie , die Protophyton |Protoph y te |zu griechisch phytón = Pflanze einzellige Pflanze
The Wordsmith Dictionary