Ranunculus aquatilis

Wiegleb, Gerhard, Bobrov, Alexander A. & Zalewska-Gałosz, Joanna, 2017, A taxonomic account of Ranunculus section Batrachium (Ranunculaceae), Phytotaxa 319 (1), pp. 1-55 : 27-28

16. Ranunculus aquatilis L., Sp. Pl.: 556 (1753).

≡ Batrachium aquatile (L.) Dumort., Fl. Belg.: 127. 1827.

Type: Habitat in Europae aquis undosis, fossis, rivulis, C. Linnaeus ( LINN 715.75, lectotype designated by Cook (1966a: 123)).

= Ranunculus aquatilis subsp. diversifolius Ehrh., Hannover. Mag. 1780 (15): 225 (1780).

= Ranunculus diversifolius (Ehrh.) Schrank, Baier. Fl. 2: 103 (1789).

Described from Germany.

= Ranunculus heterophyllus Weber in F.H. Wigg., Prim. Fl. Holsat.: 42 (1780).

Described from Germany (‘Holsatiae (Holstein)’).

= Ranunculus peltatus Moench, Methodus 214 (1794), non Schrank, Baier. Fl. 2: 103 (1789).

= Batrachium peltatum (Moench) Bercht. & J. Presl, Prir. Rostlin Aneb. Rostl. 1: Rammic. 49 (1823).

Described from Germany (‘Hessen’).

= Ranunculus triphyllus Wallr., Linnaea 14: 584 (1840).

= Batrachium triphyllum (Wallr.) Dumort. Bull. Soc. Roy. Bot. Belg. 2: 214 (1863).

Described from Germany (‘Harz’).

= Ranunculus radians Revel, Actes Soc. Linn. Bordeaux 19: 120 (1853).

= Batrachium radians (Revel) Dumort., Bull. Soc. Roy. Bot. Belg. 2: 215 (1863).

= Ranunculus aquatilis subsp. radians (Revel) A.R. Clapham in A.R. Clapham et al., Fl. Brit. Isles: 98 (1952).

Described from France.

= Ranunculus godronii (Gren.) Gren., Rev. Fl. Monts Jura: 25 (1865).

Described from France (‘Jura’).

= Batrachium carinatum Schur, Verh. Naturf. Ver. Bruenn 15(2): 28 (1877).

= Ranunculus carinatus (Schur) Freyn in A. Kern., Sched. Fl. Exsicc. Austr.- Hung. 1: 21 (1881).

Described from Austria (‘Vienna’).

= Batrachium gilibertii V.I. Krecz., Fl. URSS 7: 345 (1937).

Described from Belorussia (‘Ezery’).

– Ranunculus capillaceus Thuill., Fl. Env. Paris , éd. 2: 278 (1799).

– Batrachium aquatile var. capillaceum (Thuill.) Garrett, Spring Fl. Wasatch , ed. 3: 35 (1917).

Described from France.

Description

Summer green perennial, rarely annual, hydrophyte; aquatic state mostly with laminar and capillary leaves (batrachid), laminar leaves occasionally lacking in flowering state (myriophyllid), terrestrial state caespitose with rigid capillary leaves. Shoots of aquatic state 50–150 cm long, glabrous, greenish, internodes of the middle part of the shoot longer than adjacent leaf. Laminar leaves present or absent, alternate, 15 mm long and 30 mm wide, reniform to semicircular, with 3–7 primary lobes, deeply dissected, primary lobes broadly cuneate at base, secondary lobes 7–15(–19), margin dentate, basal sinus of the lamina 0–90°, glabrous; petiole up to 90 mm long. Intermediate leaves often present, divided into capillary segments at base ( aquatilis - type). Capillary leaves present, alternate, 20–60 mm long, obconical to suborbicular, green, glabrous, segments subrigid, divergent, middle part shorter than or equal to the lateral ones, length between first and second bifurcation 5–15 mm, number of the lamina divisions 3–5(–6), number of final segments up to 100; petiole up to 25 mm long. Stipules more than 2/3 adnate to the petiole, triangular, free portion inconspicuous, glabrous. Peduncles up to 50 mm long, mostly opposite to laminar leaf, rarely to a capillary leaf, shorter than the petiole of opposite leaf, often recurved, glabrous. Sepals 5, 3–5 mm long, obovate to elliptical, greenish, spreading. Petals 5, 5–12 mm long, broadly obovate, white with yellow claw, contiguous during anthesis. Nectar pits 1 per carpel, usually cup-shaped, circular, rarely lunate or slightly elongated. Stamens 14–22. Carpels 20–68, 1.2–1.8 mm long, obovate, glabrous or hairy, style lateral or subterminal, caducous. Receptacles subglobose, densely pubescent.—Chromosome number. 2n = 16, 32, 40, 48, 48+.