1	Corolla lobes fimbriate at base	G. acuta
–	Corolla lobes glabrous at base	2
2	Nectaries above the middle of corolla tube	3
–	Nectaries at the base of corolla tube	4
3	Plant 12–40 cm tall, nectaries close to the throat of corolla tube, seeds 1.2–1.6 mm in diameter	G. macrosperma
–	Plant 1–4 cm tall, nectaries just above the middle of corolla tube, seeds 0.7–0.8 mm in diameter	G. pygmaea
4	Margin and midvein of calyx lobe blackish	G. azurea
–	Calyx not as above	5
5	Stem densely purple pilose	G. gentianoides
–	Stem glabrous (sometimes sparsely pilose in G. moorcroftiana)	6
6	Flowers often angled, corolla tube 3–4 times longer than lobe	G. angustiflora
–	Flowers not angled, corolla tube 1–3 time(s) longer than lobe	7
7	Corolla lobes apically obtuse or round	8
–	Corolla lobes apically mucronate	9
8	Flowers 5-merous, stem leaf blades linear	G. moorcroftiana
–	Flowers 4-merous, stem leaf blades spatulate to oblong-spatulate	G. arenaria
9	Corolla lobes densely papillate outside	G. anomala
–	Corolla lobes glabrous outside	10
10	Corolla 7–20 mm long, terminal ones ca. 20 mm, lobes 3–7 mm	G. stoliczkae
–	Corolla 4–10 mm long, terminal ones up to 10 mm, lobes ca. 2 mm	G. sibirica