Ranunculus longirostris Godr., Mém. Soc. Roy. Sci. Nancy 1839: 39

Wiegleb, Gerhard, Bobrov, Alexander A. & Zalewska-Gałosz, Joanna, 2017, A taxonomic account of Ranunculus section Batrachium (Ranunculaceae), Phytotaxa 319 (1), pp. 1-55 : 40

29. Ranunculus longirostris Godr., Mém. Soc. Roy. Sci. Nancy 1839: 39 (1840).

≡ Batrachium longirostre (Godr.) F.W. Schultz, Arch. Fl. Fr. et Allem. 1: 71 (1844).

Type: USA: Eaux courantes, St. Louis, Missouri, Juin 1838, N. Riehl, no. 52 (P, isotype K).

Description

Wintergreen or summer green perennial, rarely annual, hydrophyte; aquatic state with capillary leaves only (myriophyllid), terrestrial state caespitose with subrigid capillary segments. Shoots up to 100–150 cm long, internodes of the middle part of the shoot longer than adjacent leaf, glabrous, green. Laminar leaves absent. Intermediate leaves absent. Capillary leaves present, alternate, 15–30 mm long, obconical to suborbicular, green, glabrous, segments subrigid, divergent, middle part equal to the lateral ones, length between first and second bifurcation 1–3 mm, number of the lamina divisions 3–5(–6), number of final segments up to 80–100; sessile or with petioles up to 5–7 mm long, rarely up to 10 mm long. Stipules 1/2 to 3/4 adnate to the petiole, apex of free part acute, glabrous. Peduncles 20–60 mm long, straight, glabrous. Sepals 5, 2–3 mm long, ovate to elliptical, yellow-green to purplish, spreading. Petals 5, 6–8 mm long, spathulate to obovate, white with small yellow claw, undulate at apex, not contiguous during anthesis. Nectar pits 1 per petal, deeply circular to cup-shaped. Stamens 10–20. Carpels 7–25, 1.3–1.7 mm long, obovate, glabrous, style terminal, 0.7–1.1 mm long, persistent. Receptacles subglobose, pubescent.—Chromosome number. 2n = 16.