Meehan (1898: 47) reports the species as Aspidium spinulosum Sw. (in J. Bot. (Schrad.) 1800(2): 38. 1801), a synonym of Dryopteris austriaca (Jacq.) Woynar ex Schinz & Thell. (in Vierteljahrs Nat. Ges. Zürich 60: 330. 1915), itself now considered a synonym of D. carthusiana, but used in the more recent literature (e.g., Hitchcock in Univ. Wash. Publ. Biol. 17(1): 73. 1969). The specimen was identified recently as D. expansa (C. Presl) Fraser-Jenk. & Jermy (in Brit. Fern Gaz. 11: 338. 1977) by Schuyler, and Moulton (in press) lists the sheet under this name. Based on the key by Montgomery & Wagner (Fl. N. Amer. 2: 280-288. 1994), the specimen is D. carthusiana. The label data is confusing according to Coues (1898: 315), but this was due to an error by Meehan who gives the collection date as 20 Jun 1806, misreading the actual date on the label of 20 Jan 1806. (The Lewis & Clark Herbarium Digital Imagery Study Set, ANSP, 2002) On deposit at the Academy of Natural Sciences, Philadelphia Collected by:Meriwether Lewis & William Clark Collection date:01/20/1806