Rorippa prostrata, (J. P. Bergeret) Schinz & Thell.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1964, Flora Europaea - Volume 1. Lycopodiaceae to Platanaceae, Cambridge University Press : 283

3. R. prostrata (J. P. Bergeret) Schinz & Thell. , Viert. Naturf. Ges. Ziirich 58: 62 (1913)

( Nasturtium anceps (Wahlenb.) Reichenb. ).

Perennial 30-90 cm. Leaves very variable, petiolate, coarsely lyrate-pinnatifid with lanceolate segments; the upper more or less sessile, less deeply divided, sometimes broadly lanceolate, entire, and variably lobed or toothed. Petals c. 4 mm, exceeding the sepals. Silicula 5-6 mm, variable, usually narrowly ellipsoidal or linear-lanceolate, horizontal or ascending, slightly curved, compressed, sometimes imperfect or with few seeds; pedicels as long as fruit or somewhat longer; style 1-2mm. C. & E. Europe and locally in the west and south. Au Cz Fe Ga Ge He Ho Hu It Ju Lu Po Rm Rs (C, W, K, E) Su [Be Br]. R. prostrata is more or less intermediate between 2 and 4, and is generally considered to be of hybrid origin, though it sometimes occurs in the absence of one of the parents. It comprises a series of variants which range from those near R. amphibia at one end to those near R. sylvestris at the other (e.g. R. sylvestris subsp. stenocarpa (Godron)) . It is however recorded as a species in many parts of Europe and is therefore given specific rank here. It may well consist of a mixture of first-cross and backcross hybrids of varying degrees of fertility, and may also include fertile allopolyploid derivatives.