Definitions for "Prothallus"
The minute primary growth from the spore of ferns and other Pteridophyta, which bears the true sexual organs; the oƶphoric generation of ferns, etc.
Sperm and egg producing structure developed from a spore
In ferns, a small heart-shaped bisexual gametophyte. PICTURE
a relatively undifferentiated plant body, which is small and flattened