Sandy or gravelly shores of the Great Lakes (or similarly sandy disturbed sites slightly inland); plants from southern Michigan are from disturbed sites and along railroads and are doubtless introduced.

Sometimes confused with P. aviculare, P. erectum or P. achoreum, but more erect than any form of the variable P. aviculare and with the fruiting perianths 3.5–4.5 mm long, at least partly on exserted pedicels; in P. aviculare the perianth is smaller and the pedicels nearly or quite hidden in the ocreolae. The leaves are more narrow and acute than in any plants of P. erectum and P. achoreum, which may be erect but have more broadly elliptic to obovate blades.