Fourteen species of the genus Herposiphonia are described. The following
species and varieties are new: H. armata, H. crassa, H. delicatula, H. dendroidea,
H. dendroidea var. minor, H. dubia, H. nuda, H. obscura, H. parca var.
interrupta, H. pacifica, H. trichia, H. variabilis. The distributional range is extended
for H. parca, H. subdisticha, and H. tenella. H. secunda is reduced to a form of
H. tenella.
Emphasis is given to the nature and arrangement of trichoblasts and of sexual
reproductive structures as features of taxonomic importance
