Syrenia A ndrz.

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 : 275

19. Syrenia A ndrz. 1

Like Erysimum but the median nectaries absent; hairs on the siliqua usually medifixed, lying transversely across the siliqua; style at least | as long as the rest of the siliqua; seeds in 2 rows in each loculus.

1 Pedicels 3-5 mm in flower, up to 6 mm in fruit, about | as long as the calyx and siliqua 3. siliculosa

1 Pedicels 0-5—2(—2-5) mm in flower, up to 3(—5) mm in fruit, not more than f as long as the calyx and siliqua

2 Siliqua compressed laterally; valves narrowly winged on the back; style 6-12 mm, about as long as the siliqua

4. montana

2 Siliqua square in cross-section; valves keeled but not winged; style 3-7 mm, usually shorter than siliqua

3 Siliqua 5-20(-25) mm; pedicels not more than 2 mm; hairs medifixed 1. cana

3 Siliqua 15-40 mm; pedicels 2-5 mm; hairs medifixed and 3-fid 2. talijevii