From The Collaborative International Dictionary of English v.0.48 [gcide]:
Florideae \Flo*rid"e*[ae]\, prop. n. pl. [NL., from L. flos,
floris, a flower.] (Bot.)
A subclass of alg[ae] including all the red or purplish
seaweeds; the Rhodosperme[ae] of many authors; -- so called
from the rosy or florid color of most of the species.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Rhodosperm \Rho"do*sperm\, n. [Gr. "ro`don the rose + spe`rma a
seed.] (Bot.)
Any seaweed with red spores.
[1913 Webster]
Note: As the name of a subclass, Rhodosperms, or
Rhodospermeae, is synonymous with Florideae (which
see.)
[1913 Webster]