Carex Working Group

Carex eburnea discovered in northeast Washington (March 10, 2009)

Katy Beck collected a delicate sedge from the banks of a river in Pend Oreille County, Washington, during 2008. Peter Zika has identified it as Carex eburnea, which was not previously known from Washington.

Carex eburnea has very narrow leaves, usually less than 0.5 mm wide. Its trigonous perigynia have distinct though short beaks. The inflorescences are tricky to figure out. They obviously have short pistillate spikes, each spike atop a relatively long, ascending peduncle. The terminal spike is staminate - but where is the terminal spike? Eventually one realizes that the little cone of hyaline bracts that appears to be near the base of the inflorescence is not an aborted spike but the staminate terminal spike! That spike is sessile, so the pistillate lateral spike surpass it.

Carex eburnea usually grows in upland sites conifer or mixed forests, often on calcareous substrates, but it is sometimes in sunnier, wetter habitats. It is widespread across Alaska, Canada, and much of eastern North America. It grows in the Rocky Mountains of eastern British Columbia down to the southeast corner of the province.

These links show photos of C. eburnea:
http://www.eflora.bc.ca/
http://www.missouriplants.com/GSR/Carex_eburnea_plant.jpg
http://plants.usda.gov/java/profile?symbol=CAEB2

Illustration at left is from: USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the Northern United States, Canada and the British Possessions. Vol. 1: 396.