Morphological and taxonomic studies on some little-known species of Gracilaria (Gracilariales: Rhodophyta) from Venezuela. 1. G. damaecornis

The morphology, anatomy and reproduction (tetrasporic, male and female) of a poorly known species of Gracilaria i.e., G. damaecornis was studied, using material collected in eastern Venezuela. Spermatangia are produced in well-defined and deeply immersed multicavitied conceptacles ("m" type). Nutritive filaments are present both at the floor and top (outer pericarp) of the cystocarp. The lectotype of G. damaecornis is illustrated for the first time. Hydropuntia albornozii (Polycavernosa albornozii ) is shown to be a synonym of G. damaecornis . In agreement with recent research, it is concluded that generic attributes of Hydropuntia (= Polycavernosa ) based mainly on sexual reproductive structures are of doubtful taxonomic value.