Rorippa Scop. Rorippa austriaca, (Crantz) Besser

38. Rorippa Scop. 1

Annual to perennial herbs; glabrous or with unbranched hairs. Leaves simple to pinnate. Inner sepals saccate at base; petals yellow. Fruit a short siliqua or a silicula; valves veinless or with a weak median vein; style short; stigma slightly 2-lobed. Seeds more or less in 2 rows in each loculus. 1 Petals shorter than or equalling sepals

2 Inflorescence with numerous branches, forming a corymb 6. prolifera

2 Inflorescence not corymbose 5. islandica

1 Petals longer than sepals

3 Leaves entire, with conspicuous auricles 1. austriaca

3 Leaves ± divided, or without conspicuous auricles

4 Cauline leaves usually entire; fruits ovoid, less than half as long as the pedicel 2. amphibia

4 Cauline leaves ± divided

5 Basal leaf-rosette present at flowering time; cauline leaves usually auricled

6 Fruits 3-6 mm, broadly ellipsoidal 8. pyrenaica

6 Fruits more than 6 mm, lanceolate or linear-lanceolate

7 Fruits more than 10 mm, linear-lanceolate; petals

4-5 mm 9. lippizensis

7 Fruits 6-10 mm, narrowly lanceolate; petals 2-2-5 mm

10. thracica

5 Basal leaf-rosette withered at flowering time; cauline leaves not or only slightly auricled

8 Fruits 3 mm, ellipsoidal or almost spherical 7. brachycarpa

8 Fruits more than 5 mm, often linear

9 Fruits 5-6 mm; upper leaves ± sessile, not very deeply divided, sometimes entire 3. prostrata

9 Fruits usually more than 6 mm; upper leaves petiolate, pinnate or pinnatifid 4. sylvestris

1. R. austriaca (Crantz) Besser , Enum. Pl. Volhyn. 103 (1822).

Perennial 30-90 cm, stoloniferous, more or less glabrous. Leaves elliptical, simple, irregularly toothed; the lower shortly petiolate, the upper sessile, deeply cordate and auriculate-amplexicaul. Petals slightly longer than sepals. Silicula 1-5-3 mm, globose; pedicels 7-15 mm, slender; style about as long as silicula. 2n= 16. C. & E. Europe; frequently naturalized or casual further west. Au Bu Cz Ge Hu Ju Po Rm Rs (B, C, W, K, E) Tu [Be Br D a G a Ge He Ho It N o Su].

2. R. amphibia (L.) Besser , op. cit. 27 (1822)

( Nasturtium amphibium (L.) R.Br. ).

Perennial 40-120 cm, often stoloniferous, usually glabrous. Lower leaves shortly petiolate, very variable in shape, entire, toothed or pinnatifid, sometimes pectinate; the upper sessile, lanceolate, usually without auricles, entire or irregularly toothed. Petals about twice as long as sepals. Silicula 3-6 x 1-3 mm, ovoid, straight; pedicels 6-17 mm, horizontal or deflexed; style 1-2 mm. 2n = 16, 32. Wet places. Most o f Europe except the extreme north, but rare in the Mediterranean region. All except Al Az BI Cr Fa Is Sa Sb.

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.