Cummings, Williams & Seymour, Lich. Bor.-Amer. [Wellesley (Massachusetts)]
Cummings, C.E.; Williams, T.A.; Seymour, A.B. [1-280]
IndExs #238641321

Academy of Natural Sciences of Drexel University - Lichens
Catalog #: PH00095730
Thomas A. Williams #219 00 May 1898
Placidium arboreum (Schw. ex Michener) Lendemer
United States, Maryland, Montgomery, Sligo Creek.