Studies on the Origin of Caucasian Bluestem, Bothriochloa caucasica (Trin.) C. E. Hubbard

IN 1929, seed of Caucasian bluestem was sent to the United States by the Director of the Botanic Garden at Tiflis, Georgia, U.S.S.R. It was given the P.I. Number 78758 and distributed to several experiment stations. A planting was made in the early 1930's by J. Roy Quinby, then superintendent, Texas substation No. 12 at Chilicothe, Texas, and remained extant for about 30 years. The same material was widely distributed by the Soil Conservation Service Nursery, Manhattan, Kansas, under the number K. G. 40 (4). In 1952, the Oklahoma Agricultural Experiment Station began an intensive investigation of the generic section Bothriochloininae which includes an agamic complex involving a number of species in the genera Bothriochloa, Dichanthium, and Capillipedium (5, 6). In the course of assembling materials for the study, a second introduction of Caucasian bluestem was obtained from the Royal Botanical Gardens at Kew, England. This was given the accession number 4066 and appears to be identical to the material obtained from Tiflis. Additional collections were obtained from South Africa, Greece, and other places; but these all appear to have been material sent from the U.S.A. and returned under plant exchange programs. The natural distribution of B. caucasica is not known. Soviet botantists (7) have reported this grass as occurring in southern Kazakhstan, southern Uzbekistan, western Tadzhikistan and the Caucasus, Georgia, Dagestan, Armenia and Azerbaidzhan. Examinations of herbarium specimens at Kew and at Baku, however, have shown that what the Soviet botantists have called B. caucasica is not the material