REPRODUCTIVE STRATEGIES OF LAURENCIA-PERFORATA (BORY) MONTAGNE (CERAMIALES, RHODOMELACEAE) IN THE CANARY-ISLANDS

Laurencia perforata (Bory) Montagne was originally described from the Canary Islands. It is a red alga characterized by its creeping thallus , with arcuate sub-erect branches attached to the rocky substrate or t o other branches by small terminal secondary holdfasts. The sequential development of the holdfasts and their ecological role in the asexual reproduction of the plant are described. After meeting another branch of the substrate, the tips of arcuate branches begin to develop rhizo idal proliferations. In later stages these proliferations form discoid al secondary holdfasts, from which new axes may arise. This vegetative propagation process is rather common in natural populations. In the p resent paper, tetrasporangia of L. perforata are described for the fir st time. Tetrasporangia occur in right-angle disposition and are cut o ff abaxially. These characteristics together with those of the cortica l cells confirms earlier suggestions on the taxonomic position of this species in the subgenus Chondrophycus.