Pleurogyne fontana A. Nelson, Proc. Biol. Soc. Wash. 17: 177. 1904

Herbs 10–50(–60) cm. Stems (especially as seen in herbarium, greener when fresh) usually yellow or amber, occasionally reddish brown; branches and pedicels appressed-ascending. Leaves: basal usually absent at flowering; cauline blades narrowly lanceolate to linear, 1.5–4 cm × 0.7–3(–4) mm, apex acute to acuminate. Flowers: calyx lobes acumi­nate; corollas white, often suffused with pale blue abaxially and along darker blue veins, or occasionally pale blue throughout.

Flowering summer–fall. Alkaline or saline wet mead­ows, fens, stream banks, drainage ditches; 400–3000 m; Alta., B.C., Man., N.W.T., Sask., Yukon; Alaska, Colo., Idaho, Mont., N.Mex., Utah, Wyo.

The name Lomatogonium rotatum subsp. tenuifolium (Grisebach) A. E. Porsild has often been applied to this taxon but was based on Asiatic plants with which those of interior North America are not equated taxonomically here. Plants of this species with strongly ascending branches like those of Rocky Mountain plants do occur in eastern Asia, but such Asian specimens seen in studies for this flora had larger flowers with more deeply blue-pigmented corollas and proportionately wider corolla lobes. Pending molecular comparisons, it is assumed here that the Rocky Mountain plants have a separate origin from those in Asia.