Description
Plains Phlox is a perennial herb with loosely tufted stems that are 4-10 cm high arising from creeping rhizomes. The 5-8 pairs of opposite, linear leaves have prominent midveins and whitish bases and are 10-25 mm long, ca. 1 mm wide and come to a sharp point. Foliage is glabrous to sparsely hairy. Stems are white. 1-5 white flowers are borne at the stem tips. Each flower has 5 petals and a tubular corolla. The calyx is also tubular, with 5 lobes, tangled long hairs, and 6-11 mm length.
Diagnostic Characteristics
The leaves of PHLOX HOODII are usually less than 10 mm long, and the leaves of P. ALYSSIFOLIA are 2-5 mm wide. Flowers are needed for determination, and hybridization between these species is reported elsewhere in the range.