Cyperus × deamii

From Flora of Indiana (1940) by Charles C. Deam

This form was described by Geise in Amer. Midland Nat. 15: 253. 1934. I collected specimens in the dried-up mucky soil on the south side of Lake Cicott, Cass County, in 1931 and 1932 which were years of severe drought. I also found a few specimens in a similar habitat on the border of an extinct lake about 2 miles north of North Liberty, St. Joseph County. The domirant associate was Cyperus ferruginescens. This plant is conspicuous and can be distinguished from any other Cyperus at a long distance. After a careful study of this form, it seems to me that it is a hybrid of Cyperus strigosus and Cyperus ferruginescens. The plants (2.5-15 cm high) are too small for Cyperus strigosus, and the spikelets have about twice the number of flowers that average plants of that species have. The cormlike base is a character of Cyperus strigosus but the terete, reddish brown spikelets belong to Cyperus ferruginescens.