Chromosome Number of Marsilea

Abstract

THE genus Marsilea has not previously been investigated by modern cytological methods, and we have only the early investigations of Strasburger¹ and de Litardiere² using techniques which experience has shown³ to be unreliable when applied to ferns. It is therefore perhaps of importance to record a clear count of n = 20 (see Fig. 1) for a race of Marsilea minuta from northern India. We believe this to be a diploid and have found 2n = 40 in squashes of root tips. Other cytotypes are, however, also present in this species, notably a sterile triploid with 2n = 60, which reproduces vegetatively but which is otherwise very like the diploid and frequently intermixed with it. Further observations on this material will be published elsewhere.