The Germination Traits of the Threatened Plant Cyperus exaltatus Retz. var. iwasakii T. Koyama

Abstract

Cyperus exaltatus Retz. var. iwasakii T.Koyama is considered threatened, and concern has been expressed about its potential for extinction. We examined the germination of C. exaltatus seeds in order to elucidate this phenomenon. The resultsindicated that this plant responds to fluctuating temperatures but does not germinate when under vegetative cover, even at the optimal temperature for germination. It has been suggested that this phenomenon is a result of disturbances to soil that contains seed banks of this species, and to the effects of fluctuating temperature on the seeds.Therefore, conserving dredged soil containing seed banks would be an effective means of protecting this species.