Definition: U. S. Great Plains. One of the 10 regional U.S. Army Corps of Engineers wetland delineation regions for the U.S. and its territories used by the National Wetland Plant List.
Definition: Of plant duration, a plant whose life span ends within one year after germination, e.g. a winter annual germinating in the autumn and flowering in the spring (esp. in Mediterranean climates), approximately synonymous to therophyte, c.f. biennial, ephemeral, perennial, c.f. also of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic.
