EQUISETACEAE.
Equisetum arvense (L.) Common from Kankakee county north. Reported by Patterson as common throughout the state. Though usually growing in moist sand or gravel, it is often found in the Chicago region in masses along dry railway embankments.
Equisetum palustre (L.) “Wet places. Peoria county, Wolff, Brendel.” (P.)
Equisetum fluviatile (L.) In shallow water or very wet ground. Quite frequent about Chicago. “Cass county, Mead; Peoria, Brendel; McHenry. Vasey. Scarce.” (P.) Joliet, common, Ferriss.
Equisetum laevigatum (A. Br.) Cook and Kankakee counties. “In dry or moist clay or sand from Henderson and Peoria counties southward.” (P.) In the Chicago region generally in moist sands; Hancock county, Mead.
Equisetum hyemale (L.) Moist places. Cook, Will and Lake counties. Frequent, as well as throughout the state according to Patterson.
Equisetum Ferrissii (Clute.) Moist banks, Will county.
Equisetum robustum (A. Br.) On moist or wet banks of streams. Thornton and La Grange, Cook county. “River banks from Peoria county southward.” (P.)
Equisetum variegatum (Schleich.) In clayey ravines at Lake Forest and in wet sands at Waukegan, Lake county, Peoria, Brendel. Var. Jesupi, A. A. Eaton, and var. Nelsoni, A. A. Eaton, are credited to Illinois in Gray’s New Manual of Botany. The latter variety occurs in Lake county, Ind., bordering Illinois, and is likely to be found in the neighboring parts of this state, but those from Lake county, Ill., agree better with the typical form.
Equisetum scirpoides (Michx.) Moist shaded ravines, Lake Bluff, Lake county. Reported by Cowles at Lake Forest. “Ringwood, McHenry county, Vasey.” (P.)