Herbs with alternate (rarely opposite) leaves, acrid watery juice, separate sepals and petals, numerous stamens, and several or many (rarely only 1) simple pistils. Petals present or absent, in the latter case the sepals are usually petal-like in appearance. 1a. Climbing plants with opposite leaves (flowers in late summer) (Virgin's Bower) --2. 1b. Aquatic plants with dissected submerged leaves (flowers in late spring and summer) (Water Crowfoot) --3. 1c. Terrestrial or mud plants, not agreeing with 1a or 1b --6. 2a. Flowers white, 2-3 cm. wide =Virgin's Bower, Clematis virginiana.= 2b. Flowers pink-purple, 5-8 cm. wide =Virgin's Bower, Clematis verticillaris.= 3a. Flowers white --4. 3b. Flowers yellow --5. 4a. Leaves rigid, not collapsing when removed from the water =Water Crowfoot, Ranunculus circinatus.= 4b. Leaves soft, collapsing when removed from the water =Water Crowfoot, Ranunculus aquatilis var. capillaceus.= 5a. Submerged leaves divided into hair-like segments =Water Crowfoot, Ranunculus delphinifolius.= 5b. Submerged leaves palmately divided into linear lobes =Water Crowfoot, Ranunculus purshii.= 6a. Flowers blue, irregular, with one spur (4-8 dm. high, summer) =Larkspur, Delphinium ajacis.= 6b. The five petals each prolonged into a spur; flowers showy (4-8 dm. tall) (Columbine) --7. 6c. Flowers regular, without spurs --8. 7a. Spurs nearly straight; flowers scarlet and yellow (spring) =Wild Columbine, Aquilegia canadensis.= 7b. Spurs strongly incurved; flowers blue or white (spring, early summer) =Columbine, Aquilegia vulgaris.= 8a. Flowers yellow --9. 8b. Flowers of various colors, but never yellow --28. 9a. Petals none; sepals petal-like; leaves crenate or dentate (2-4 dm. high, flowers in early spring) =Cowslip, Caltha palustris.= 9b. Petals small; sepals petal-like; leaves deeply palmately lobed (4-6 dm. tall; flowers in late spring) =Globe-flower, Trollius laxus.= 9c. Petals yellow; sepals green or yellowish --10. 10a. Leaves linear to narrowly oblong, entire or with minute teeth (flowers 10-15 mm. wide, in summer) --11. 10b. Leaves broader, some or all of them lobed or divided, or cordate-ovate and not lobed --12. 11a. Stems ascending (4-8 dm. high), rooting at the lower joints; fruits pointed with a long slender beak =Spearwort, Ranunculus laxicaulis.= 11b. Stems prostrate and trailing, rooting at the joints; fruits tipped with a minute short beak =Spearwort, Ranunculus flammula var. reptans.=