A Spartinetum at Baldoyle in Ireland

Abstract

IN 1870, a species of Spartina, known later as S. townsendii (H. and J. Groves), was collected from the mud-flats near Southampton. It was growing in a mixed community of S. alterniflora and S. maritima (then S. stricta). It resembled the latter species so strongly that it was labelled ‘S. stricta’ and was overlooked until 1878, when Townsend recorded the species officially in his Flora of Hampshire¹. It was assumed generally that the intermediate S. townsendii was a hybrid between S. alterniflora and S. stricta; for example, Stapf² stated “the evidence is circumstantial but strong, resting upon many of the characters being intermediate between those of its presumed parents, its pronounced instability, and its varying fertility”. [The italics are ours.] In 1930, Huskins³ furnished cytological evidence favouring this assumption when he found that S. townsendii had a mitotic chromosome count of 2n = 126, while S. alterniflora and S. maritima have 2n = 70 and 2n = 56, respectively.