Lactuca

but supplemented and rearranged
1Cauline leaves much reduced, the bases strongly decurrent, forming interrupted green wings down the stem
1'Cauline leaves sometimes auriculate, but not forming wings down the stem
6Capitula containing 5 (or more, rarely 4) florets; ligules 2.5-3 mm wide; plant biennial, 35-150 cm high; branches usually virgate; partial inflorescences spiciform
6'Capitula containing 4 florets; ligules 4 mm wide; plant perennial, 7-30 cm high; branches not virgate; inflorescence corymbose
2Flowers yellow or yellowish (purplish or reddish externally, or sometimes blue when drying); achene beak without lobes at the base
2'Flowers white with pink tinge; achene beak +/- 2-lobed at base
3Achenes strongly compressed or flattened; plant with fusiform tuber, woody rootstock or tap root
3'Achenes not strongly compressed; rhizome globose, 2-4 cm diam.
4Involucre 1.5-2.5 cm long at anthesis (up to 3 cm long in fruit); achenes almost flattened with a narrow marginal wing; root tuberous
4'Involucre less than 1.5 cm long at anthesis; root not tuberous
5Base of stem , and undersurface of leaf-midrib prickly; leaf-blade held in a vertical plane (edgewise) to stem; achene beak 3-3.5 mm long
5'Base of stem, and undersurface of leaf-midrib smooth; leaf-blade held horizontally; achene beak c. 6 mm long