The reproduction and phenology of Antithamnion cruciatum (Rhodophyta: Ceramiaceae) in insular Newfoundland

• Published in: Canadian Journal of Botany
• Main Authors: Whittick, Alan, Hooper, Robert G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1977
• Subjects: Plant Science; Newfoundland
• Online Access: http://dx.doi.org/10.1139/b77-062; http://www.nrcresearchpress.com/doi/pdf/10.1139/b77-062

Antithamnion cruciatum (C.Ag.) Näg. is reported from insular Newfoundland, its most northerly known location in North America. It exhibits a variable morphology occurring as the typical erect form, as a prostrate form, and as a fragmented form by which it perennates. Zonately divided sporangia containing four spores have been observed, but their function is unknown. Culture experiments show that the species grows at 10 °C and above, but fertility was not induced. Cytological studies indicate there is no genetic alternation of generations, and chromosome numbers suggest the population may be polyploid.