Silver-leaf Phacelia, Compact Phacelia, Timberline Phacelia: Phacelia hastata var. compacta - Tufted, low plants. Many leaves entire, but some with 1 pair of triangular lateral lobes at the base of the blade. Several to many ascending stems from 10-30 cm high. Herbage greenish with some silver highlights and stiff, coarse, and spreading hairs on the stems. Plants of higher elevations from 5000-8000'.
Varileaf Phacelia: Phacelia heterophylla ? - Many (but not all) leaves with 1-2 pairs of lateral lobes at the base of the blade. Single erect stem (often greater than 50 cm) with several lesser stems surrounding it. Herbage grayish, not silvery, and often consisting of spreading bristles. Plants of low to mid-elevations.
Narrow-sepaled Phacelia, Narrow-sepal Scorpion-weed: Phacelia hastata var. leptosepala (Synonym: Phacelia leptosepala) - Most leaves entire, those with lateral lobes having a single pair at the base of the blade. Several to many spreading to ascending stems (often curved at the base) from 15-50 cm high, generally of equal height. Herbage fairly green with some silvery hairs. Plants of low to mid-elevations.
Threadleaf Phacelia, Thread-leaf Scorpion-weed: Phacelia linearis -
Oregon Phacelia, Woodland Phacelia, Shade Phacelia: Phacelia nemoralis var. oregonensis (Synonym: Phacelia nemoralis ssp. oregonensis) -
Tall Phacelia, Tall Scorpion-weed: Phacelia procera - Leaves pinntatifid, with 2-4 pairs of lobes. Stems erect and leafy without tufts of basal leaves, arising 50-200 cm high. Herbage of appressed hairs below the inflorescence. Flowers greenish-white. Plants of mid-elevation to near timberline.
Silky Phacelia, Alpine Phacelia: Phacelia sericea ssp. sericea (Synonyms: Phacelia sericea ssp. sericea, Phacelia sericea var. caespitosa) - Leaves pinnatifid into many lobes. Herbage of leaves and stems silky-hairy. Flowers bluish violet. Plants of high elevations, typically well above timberline.