Dormancy and Germination in Alpine Carex from the Colorado Front Range

The nature of achene dormancy was studied in two species of alpine sedges, Carex albonigra and C. ebenea, from the Rollins Pass area of the Colorado Front Range. Germination response of achenes was determined under various treatments, including stratification, scarification, leaching, extraction, exposure to light, and application of various plant growth regulators. Two distinctly different requirements for seed germination are exhibited by the two species. In C. albonigra, only scarficiation at the basal end of the achenes resulted in germination. Only fluorescent and red light were effective in promoting germination in C. ebenea achenes, suggesting a reversible photoreaction as the mechanism responsible for dormancy in this species. The light effect was apparently cumulative, with a minimum of about 15 days of continuous light being required for the initiation of germination.