Ecological and geographical separation of three varieties of Sporobolus vaginiflorus (Poaceae) in eastern Ontario

Résumé

Field and herbarium studies of the three varieties of Sporobolus vaginiflorus (var. inaequalis, var. vaginiflorus, and var. ozarkanus) in eastern Ontario found that (1) there is a strong tendency for the varieties to occur alone; (2) var. inaequalis occurs primarily on roadside gravels, river shores, and granite barrens and is the only variety associated with acid as well as alkaline substrates; and (3) both var. vaginiflorus and var. ozarkanus are confined to alvar landscapes but occupy different geographical regions. The ecological and geographical differentiation of these taxa supports their taxonomic recognition and the protection of alvar landscapes to conserve subspecific variants.