Tutin, T.G., Burges, N.A., Chater, A.O., Edmondson, J.R., Heywood, V.H., Moore, D.M., Valentine, D.H., Walters, S.M. & Webb, D.A. 1993: Flora Europaea 1, ed. 2
but modified and names used differing
1Inflorescence usually composed of distinct though sometimes small, axillary, dichasial cymes; sepals in fruit free almost to base
1'Inflorescence composed of small, axillary, sessile clusters of flowers; sepals in fruit more or less connate
2Sepals in fruit connate to near apex; calyx saccate and net-veined dorsally; seeds 0.9-1.5 mm in diam.; leaves mostly pinnatifid
2'Sepals in fruit free at least in the upper half; calyx neither saccate nor net-veined dorsally, seeds 0.5-0.8 mm in diam.; leaves usually lanceolate, entire, dentate or rarely laciniate