Ranunculus vertumnus (C.D.K. Cook) Luferov, Novosti Sist. Vyssh. Rast.

Wiegleb, Gerhard, Bobrov, Alexander A. & Zalewska-Gałosz, Joanna, 2017, A taxonomic account of Ranunculus section Batrachium (Ranunculaceae), Phytotaxa 319 (1), pp. 1-55 : 18

9. Ranunculus vertumnus (C.D.K. Cook) Luferov, Novosti Sist. Vyssh. Rast. 44: 82 (2013).

≡ Ranunculus penicillatus (Dumort.) Bab. var. vertumnus C.D.K. Cook, Mitt. Bot. Staatssamml. München , 6: 160 (1966).

≡ Ranunculus penicillatus (Dumort.) Bab. subsp. pseudofluitans (Syme) S.D. Webster var. vertumnus (C.D.K. Cook) S.D. Webster, Watsonia 17(1): 20 (1988).

≡ Batrachium vertumnum (C.D.K. Cook) A.A. Bobrov, Gidrobotanika : metodologiya, metody: 73 (2003).

Type: GREAT BRITAIN: In the Basingstoke Canal where it meets the River Greet, Greywell, about 8 km east of Basingstoke, Hampshire, England, 18 May 1958, C.D. K. Cook ( K).

Description

Wintergreen perennial, hydrophyte; aquatic state erect or prostrate with capillary leaves only (myriophyllid), terrestrial state not seen. Shoots of aquatic state up to 150 cm long, glabrous, green, internodes of the middle part of the shoot considerably longer than adjacent capillary leaves. Laminar leaves absent. Intermediate leaves absent. Capillary leaves present, alternate, up to 25–70 mm long, longer in winter, obconical to globose, green, glabrous, segments flaccid to subrigid, divergent, middle part equal to the lateral ones, length between first and second bifurcation max. 5 mm, number of the lamina divisions 3–10 and more, number of final segments 100–900; petiole 1–32 mm long. Stipules more than 1/2 adnate to the petiole, apex obtuse, glabrous. Peduncles up to 60 mm long, longer than the opposite leaf. Sepals 5, 3–5 mm long, greenish, spreading. Petals 5, 10–15 mm long, broadly obovate, white with yellow claw, usually contiguous in anthesis. Nectar pits 1 per petal, pyriform. Stamens 15–25. Carpels 15–30, 1.5–2.2 mm long, obovate, glabrous or hairy, style subterminal, caducous. Receptacles subglobose, pubescent.—Chromosome number. 2n = 48.