Perigynia removal improved germination in two native Carex species

Carex spp. are frequently used in rain gardens, bioretention basins and wetland restoration projects because of their perceived tolerance of saturated soils. For large areas, the sowing of achenes is the most economical method of planting. Carex achenes can be difficult to germinate. Even when physiological and physical dormancies are alleviated, germination of the achenes may take many weeks. Removing the perigynium, a papery covering that surrounds the achene, has improved the speed and percentage of germination in some Carex spp. An experiment was conducted to test the effects of perigynia removal on the germination of C. annectens, C. brevior, C. hystericina and C. muskingumensis achenes. Perigynia removal significantly increased percent germination of C. annectens achenes and reduced the length of time needed to reach 50% germination of C. annectens and C. hystericina achenes. The germination of C. muskingumensis and C. brevior achenes were not affected by perigynia removal. Therefore, the benefits of perigynia removal for seed germination is species-specific.