Historical collections are known also from Maine (1903) and New York (1943).

Herniaria glabra, variable in habit, vestiture, flower size, and fruit length (H. W. Pugsley 1930), has been reported to hybridize naturally with H. hirsuta (M. N. Chaudhri 1968). It makes a dense mat of foliage, being occasionally planted as a ground or grave cover.