The origin of Spartina Townsendii
From its characteristics and the circumstances of its origin, practically all competent observers are convinced thatSpartina Townsendii arose from hybridization betweenS. alterniflora andS. stricta.
The somatic chromosome number ofS. Townsendii is 126, by far the highest number yet recorded in theGraminae.
One of its putative parents,S. alterniflora, has 70 chromosomes and the other,S. stricta, has 56.
S. Townsendii has evidently originated by chromosome doubling, following on interspecific hybridisation.
It is an extremely successful new species, having spread widely from its point of origin, and has almost completely eliminated its parent species wherever it has come into competition with them.
It seems to be an outstanding example of the significance of allopolyploidy in plant evolution.