Increasing germination of 2 upland sedges, Carex inops ssp. inops and Carex tumulicola

Abstract

Propagation of native plants is generally more successful when plant scientists and managers have a broad understanding of the natural history of a species, including the conditions that seeds of that species require to germinate. We studied 2 sedges, Carex inops L.H. Bailey ssp. inops (long-stolon sedge [Cyperaceae]) and Carex tumulicola Mack. (splitawn sedge), that grow in upland prairies of western North America. We tested multiple combinations of stratification period and germination temperature to identify the best regime for increasing germination of each species. We also conducted smaller tests of smoke treatments and perigynia removal, which are additional ways to enhance germination. Based on our results, we recommend that C. tumulicola receive 2 mo of cold moist stratification and then be exposed to day/night temperatures of 15/8 °C (59/46 °F) or 19/11 °C (66/52 °F) for 1 mo. We recommend that C. inops not receive cold moist stratification but instead be exposed to the same germination conditions for at least 2 mo. Germination patterns differ: C. tumulicola germinates rapidly and uniformly, whereas C. inops germinates non-uniformly over an extended period. Perigynia removal clearly increases germination of C. inops. Smoke treatments had minimal effects on germination. Many of the germination requirements that we identified are consistent with the natural history of these species, such as differences in timing of seed maturation. By increasing the feasibility of propagating these species from seeds, our work enables genetically diverse populations of these species to be incorporated into restoration projects.