1	Well-developed plants with one single large (20–25 mm in diameter) capitulum per flowering stem	S. halleri
	Note: Hybridizes with S. incanus in areas where both species co-occur (Wilczek 1900); these hybrids are morphologically intermediate.
-	Well-developed plants with two or more smaller (10–15 mm in diameter) capitula per flowering stem, arranged in a terminal synflorescence	2
2	Ray flowers absent	S. persoonii
-	Ray flowers present	3
3	All leaves white-greyish tomentose, rosette leaves deeply incised with narrow lateral segments; achenes pubescent on the upper part	S. incanus
-	All leaves green and subglabrous to white-greyish tomentose, rosette leaves shallowly lobed or with almost entire margin to deeply incised, but never in the combination described above; achenes glabrous	4 (S. carniolicus agg.)
4	Leaves densely persistently hairy, whitish; 2–5(6) capitula per flowering stem	S. insubricus
-	Leaves glabrous to sparsely hairy, green or greyish, or young leaves densely hairy and older leaves glabrescent; (4)6–15(23) capitula per flowering stem	5
5	Flowering stem (2.7)3.8–8.1(9.3) cm long; corolla of ray flowers (4.3)4.6–6.7(7.5) mm long; pollen grains (23)25–31(35) μm in diameter; grows in open, exposed habitats, fellfields, rock crevices; eastern part of the central Eastern Alps in Austria	S. noricus
-	Flowering stem (3.4)5.3–17.3(27) cm long; corolla of ray flowers (3.9)6.1–11.2(12.6) mm long; pollen grains (26)28–40(43) μm in diameter; grows in alpine meadows, dwarf shrub communities and other habitats with dense vegetation cover; throughout most of the distribution of the S. carniolicus aggregate	6
6	Rosette leaves deeply (more than half the distance to the midrib) incised, lateral lobes longer than wide, always divided (usually with one or two secondary lobes), adult leaves of eastern (Austrian) populations glabrous, those of western (Italian and Swiss) populations pubescent	S. disjunctus
-	Rosette leaves shallowly lobed (less than half the distance to the midrib) to dentate or rarely almost entire, lateral lobes at most as long as wide, only occasionally with secondary lobes, hairy to slightly tomentose at least when young, older leaves often glabrescent	S. carniolicus