§ 3. RANUNCULUS proper. Petals with a little scale at the base, yellow; achenes nerveless.
[*] Achenes smooth; mostly perennial.
[+] Aquatic; immersed leaves filiformly dissected, as in § Batrachium.
4. R. multífidus, Pursh. (Yellow Water-Crowfoot.) Stems floating or immersed, with the leaves all repeatedly 3-forked into long filiform divisions, or sometimes creeping in the mud (perennial by rooting from the nodes, if at all); emersed leaves with shorter and linear or wedge-shaped divisions, or else kidney-shaped and sparingly lobed or toothed; petals 5–8, deep bright yellow, 4–6´´ long, much larger than the calyx; carpels in a round head, pointed with a straight beak.—E. New Eng. to S. Penn., Mo., and northward. May–July.—Out of water it is often pubescent, especially in
Var. terréstris, Gray. Stem rooting in the mud or ascending from the base; leaves all smaller, coarsely dissected, round-reniform in outline; flowers and fruit twice or thrice smaller.—N. Ohio to N. Ill., Minn., and westward.
[+][+] Terrestrial but growinq in very wet places, glabrous or nearly so; leaves entire or barely toothed, all or else all but the lowest lanceolate or linear; carpels forming a globular head. (Spearwort.)
5. R. ámbigens, Watson. (Water Plantain Spearwort.) Stems ascending (1–2° high), often rooting from the lower joints; leaves lanceolate or the lowest oblong, mostly denticulate (3–5´ long), contracted into a margined half-clasping petiole; petals 5–7, bright yellow, oblong (2–3´´ long); carpels flattened, large (1´´ long), pointed with a long narrow-subulate beak. (R. alismæfolius, Man., not Gey.)—N. Eng. to Ont., Minn. and southward; common, especially at the north. June–Aug.
6. R. Flámmula, L. (Smaller Spearwort.) Stem reclining or ascending, rooting below, leaves lanceolate or linear, or the lowest ovate-oblong to lanceolate, entire or nearly so, mostly petioled (1–2´ long), petals 5–7, much longer than the calyx, bright yellow, carpels small, flattish but turgid, mucronate with a short abrupt point.—Only a small form (var. intermèdius) met with in this country (shore of L. Ontario, and northward), a span high, with flowers 3–5´´ in diameter, passing into
Var. réptans, E. Meyer. (Creeping S.) Small, slender, the filiform creeping stems rooting at all the joints; leaves linear, spatulate, or oblong (¼–1´ long); flowers small.—Gravelly or sandy banks; Newf. to Penn., north and westward. June–Sept. (Eu.)
7. R. oblongifòlius, Ell. Usually annual; stem erect or ascending, often pubescent below, slender (1–2° high), diffusely branched above and many-flowered; leaves serrate or denticulate, lower long-petioled, ovate or oblong (½–1½´ long), uppermost linear; flowers 3–5´´ broad; petals 5, bright yellow, 1–3´´ long; carpels minute, almost globular, the small style deciduous.—Wet prairies, Ill., Mo., and in S. States. June.