This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Annual, biennial or perennial, mostly hirsute hispid or scabrous herbs, with alternate entire dentate lobed pinnatifid or dissected leaves, the lowest rarely opposite, and blue purple violet or white flowers in terminal scorpioid cymes or racemes. Calyx 5-lobed, somewhat enlarging in fruit; sinuses not appendaged. Corolla campanulate, nearly rotate, tubular or funnelform, the tube sometimes appendaged within, opposite the lobes, the lobes imbricated in the bud. Stamens exserted or included, attached near the base of the corolla; anthers mostly ovate. Ovary 1-celled, the 2 placentae narrow, affixed to the walls; styles united below; ovules 2 or several on each placenta. Capsule 1-celled, or falsely nearly 2-celled by the intrusion of the placentae, 2-valved. Seeds usually reticulated. [Greek, a cluster, referring to the clustered flowers of some species.]
About 90 species, natives of the New World. Besides the following, some 60 others occur in the western parts of North America. Type species: Phacelia secunda J. F. Gmel.
Corolla manifestly appendaged within, between the stamens. Leaves entire.
1. P. leucophylla.
2. P. integrifolia.
Leaves pinnately divided, or pinnatifid, the segments incised. Racemes loose; pedicels slender; ovules 2 on each placenta.
3. P. bipinnatifida.
Racemes dense; pedicels short; ovules numerous.
4. P. Franklinii, Appendages of the corolla inconspicuous or none. Filaments pubescent; calyx-lobes oblong. Puberulent; flowers 4"-5" broad.
5. P. dubia.
Hirsute; flowers 6"-7" broad.
6. P. hirsuta.
Filaments glabrous; calyx-lobes linear.
7. P. Covillei.
Corolla nearly rotate, its lobes fimbriate. Lobes of the leaves and calyx acute.
Lobes of the leaves and calyx obtuse.
9. P. fimbriata.
Phacelia leucophylla Torr. Frem. Rep. 93. 1845.
Perennial by a stout rootstock, pale, densely silky-pubescent, the hairs appressed or ascending. Stem simple or branched, 1°-1 1/2° high; leaves lanceolate to oblong, entire, pinnately veined, 2'-4' long, 4"-12" wide, the lower long-petioled, the upper sessile or nearly so; spike-like branches of the scorpioid cymes very dense, nearly straight and 1-3' long when expanded; flowers sessile, very numerous, about 4" high; calyx-lobes hispid, oblong-lanceolate or linear, somewhat shorter than the white or bluish, 5-lobed corolla; corolla-appendages conspicuous, in pairs between the filaments; filaments exserted, glabrous; ovules 2 on each placenta; capsule ovoid.
In dry soil, South Dakota to Idaho, British Columbia, Nebraska and Colorado. May-Aug. The species has been taken for P. hetcrophylla Pursh, of the far west, which has spreading brown hairs, some of the leaves usually pinnatifid, and pilose filaments.