98f. Eriogonum ovalifolium Nuttall var. pansum Reveal, Phytologia. 66: 259. 1989.
Branched cushion wild buckwheat
Plants 2-5 dm wide. Leaf blades usually elliptic, (0.6-)1-2(-2.5) cm, densely tomentose, margins not brownish. Scapes erect, (5-)7-20 cm, thinly tomentose. Inflorescences umbellate, 1-5(-7) × (1.5-)2-5 cm, thinly tomentose; branches absent. Involucres 1 per node, 4-5 mm. Flowers 2.5-5(-7) mm; perianth white.
Flowering Jun-Aug. Sandy to gravelly flats and slopes, sagebrush communities, conifer woodlands; 900-2200 m; Idaho, Mont.
Variety pansum occurs in two disjunct series of scattered populations. One is in central Idaho (Blaine, Boise, Custer, Elmore, Lemhi, and Valley counties); the second is in western Montana (Lewis and Clark, Lincoln, Missoula, Powell, Sanders, and Silver Bow counties). This variety bridges the morphologic gap between E. ovalifolium and E. strictum var. proliferum. The inflorescence of var. pansum is umbellate with branches up to 3 cm long, but never compoundly branched as in E. strictum. The umbellate condition becomes obvious only in late anthesis or during early fruit-set, so immature plants of var. pansum might be mistaken for var. purpureum, large specimens of var. depressum, or short-scaped plants of var. ochroleucum. Still, careful observation of such specimens will show an early branching condition, although this can be obscured by bracts subtending the inflorescence or an abundance of early flowers in the numerous involucres. The branched cushion wild buckwheat is certainly worth consideration as an ornamental.