§ 1. PHACELIA proper. Seeds and ovules only 4 (two on each placenta); corolla campanulate, with narrow folds or appendages within, the lobes entire.
1. P. bipinnatífida, Michx. Biennial; stem upright, hairy (1–2° high), leaves long-petioled, pinnately 3–5-divided, the divisions or leaflets ovate or oblong-ovate, acute, coarsely and often sparingly cut-lobed or pinnatifid, racemes elongated, loosely many-flowered, glandular-pubescent; pedicels about the length of the calyx, spreading or recurved.—Shaded banks, in rich soil, Ohio to Ill. and southward. May, June.—Corolla bright blue, 6´´ broad, with 5 pairs of longitudinal ciliate folds, covering as many externally keeled deep grooves. Stamens bearded below and with the style exserted.
§ 2. COSMÁNTHUS. Ovules and seeds as in § 1; corolla almost rotate, with fimbriate lobes, and no appendages within; filaments villous-bearded, rarely exserted; leaves pinnatifid, the upper clasping.
2. P. Púrshii, Buckley. Sparsely hairy; stem erect or ascending, branched (8–12´ high); lobes of the stem-leaves 5–9, oblong or lanceolate, acute; raceme many-flowered; calyx-lobes lance-linear; corolla light blue, varying to white (about ½´ in diameter).—Moist wooded banks, W. Penn. to Minn., and southward. April–June.
3. P. fimbriàta, Michx. Slightly hairy, slender; stems spreading or ascending (5–8´ long), few-leaved; lowest leaves 3–5-divided into roundish leaflets; the upper 5–7-cleft or cut-toothed, the lobes obtuse; raceme 3–10-flowered; calyx-lobes linear-oblong, obtuse, becoming spatulate; corolla white (3–4´´ broad).—Woods, high mountains of Va. to Ala. May.
§ 3. COSMANTHOÌDES. Ovules and seeds 2–8 on each placenta; corolla rotate or campanulate, with entire lobes and no appendages.
4. P. parviflòra, Pursh. Somewhat hairy, slender, diffusely spreading (3–8´ high); leaves pinnately cleft or the lower divided into 3–5 short lobes; racemes solitary, loosely 5–15-flowered, pedicels filiform, at length several times longer than the oblong calyx-lobes; corolla open-campanulate, bluish-white (4–6´´ broad); filaments hairy; capsule globular, 6–12-seeded, a half shorter than the calyx.—Shaded banks, Penn. and Ohio to Mo., south to S. C. and Tex. April–June.
Var. hirsùta, Gray. More hirsute and the stems less slender, apparently growing in more open dry soil; corolla larger, 5–7´´ in diameter; seeds 4–8.—Prairies and barrens, S. W. Mo. to E. Tex.; also Va. and Ga.
5. P. Covíllei, Watson. Like the last; racemes 2–5-flowered; calyx-lobes linear, in fruit 3´´ long or more; corolla tubular-campanulate with erect limb; filaments glabrous; capsule depressed-globose; seeds 4, large.—Larkspur Island in the Potomac, five miles above Washington. (F. V. Coville.)
§ 4. EÙTOCA. Ovules and seeds numerous on each placenta; corolla rotate-campanulate, with 10 vertical lamellæ within.