“…Weaver ( 1919Weaver ( , 1920 and Weaver and Fitzpatrick ( 1934) have included observations and descriptions of rhizomes in their extensive studies on grasslands. Among the few sources of information on rate of spread are the studies of H elianthus scaberrimus (Cooper and Stoesz, 1931), Agt·opyron rep ens (Kephart, 1931), Buchloe dactyloides (Savage, 1934), and Convolvulus soldanella (Purer, 1936). Similar information for woody plants has been published by Duncan (1935).…”