Carex aboriginum auct. non M.E. Jones,

Idaho: [locality and coordinates withheld; status in Idaho: S1 (Critically Imperiled; IDNHP)],
Plants found growing in loamy soils located in an ephemerally moist habitat with Achillea millefolium, Artemisia ludoviciana, Bromus arvensis, Eleocharis pachycarpa, Helianthus annuus, Juncus confuses, Juncus howellii, Poa secunda, Potentilla gracilis, and Senecio hydrophiloides Plants are cespitose with culms reaching up to 55-80 cm in length. Inflorescences are characterized by a long peduncle bearing an erect terminal spike with proximal bracts that are generally exceed the inflorescence. Leaves are restricted to the lower third of the stem and are flat, narrow, and blueish-green in coloration. Flowering stems can reach up to 1 m tall and can exceed the leaves by up to 60 cm. In addition, the weight of the floral spike usually results in drooping in the otherwise erect flowering stems. Ovate to elliptic, somewhat inflated, scales of the perigynia are reddish-brown at maturity and surround a triangular achene with three stigmas.

D. Pensinger s.n , Jul 18, 2019
With Cheyney, M. Hankins, K.
CIC, Accession: 56650