1	Leaves alternate or spirally arranged; flowers showy, ± zygomorphic; the style deflexed, at least before the anthers have dehisced; flora tube absent.		(2)
+	Leaves opposite or verticillate, at least below; flowers actinomorphic; the style very rarely reflexed; floral tube 0.5-3 mm long.		(4)
2 (1)	Inflorescence spicate, many flowered; plants tall, erect: seeds smooth, l-1.3 mm long.		1 Epilobium angustifolium
+	Inflorescence leafy, with fewer flowers; plants low-growing, +/- decumbent; seeds papillose, 1.3-2.1 mm long.		(3)
3 (2)	Stems densely strigose; style hairy near the base.		2 Epilobium latifolium subsp. speciosum
+	Stems usually glabrescent; style glabrous.		2 Epilobium latifolium subsp. latifolium
4 (1)	Stigma distinctly four-lobed; stems covered with long spreading hairs.		(5)
+	Stigma entire, clavate to capitate; stems subglabrous or covered with short incurved or gland-tipped hairs.		(6)
5 (4)	Leaves distinctly clasping, petals 6-20 mm long, purplish.		3 Epilobium hirsutum
+	Leaves subsessile but not clasping; petals 3.2-9 mm long, pink.		4 Epilobium parviflorum
6 (4)	Cauline leaves linear or narrowly lanceolate, sub-entire; seeds 1.4-2.2 mm long, with a prominent beak at the chalazal end.		17 Epilobium palustre
+	Cauline leaves narrowly lanceolate to ovate, serrulate; seeds 0.7-1.5 mm long, with short or inconspicuous chalazal beak.		(7)
7 (6)	Flowers 3-4.5 mm long; ovaries white-canescent; seeds with short pellucid beak at chalazal end		18 Epilobium minutiflorum
+	Flowers mostly over 4 mm long, or if less then seeds lacking the chalazal beak; ovaries pubescent or not, but not canescent.		(8)
8 (7)	Stems pubescent all around, without distinct hairy lines running down from the petioles.		(9)
+	Stems not pubescent all around, or if so above, with more or less distinct pubescent lines decurrent from the petioles.		(10)
9 (8)	Pubescence of the stems and inflorescence predominantly strigose or strigillose.		8 Epilobium royleanum
+	Pubescence of stems and inflorescence mostly glandular.		8 Epilobium royleanum forma glandulosum
10 (8)	Leaves narrowly lanceolate, subcoriaceous, coarsely serrulate.		(11)
+	Leaves lanceolate or broader, rarely subcoriaceous, moderately serrulate to subentire.		(13)
11 (10)	Lines decurrent from the petioles strongly strigillose; leaves subsessile; seeds coarsely papillose.		5 Epilobium tetragonum
+	Lines decurrent from the petioles glabrous or sparsely strigillose; leaves evidently petiolate; seeds low papillose or smooth.		(12)
12 (11)	Seeds papillose.		6 Epilobium cylindricum
+	Seeds smooth (foveolate).		7 Epilobium tibetanum
13 (10)	Base of plant with + leafy shoots, ascending or decumbent, clumped and/or basally branched; lacking scales.		(14)
+	Base of plant with fleshy turions that leave scales later, suberect and often strict, at least below.		(17)
14 (13)	Plants low-growing, caespitose, often delicate.		(15)
+	Plants larger, more ascending or suberect.		(16)
15 (14)	Seeds papillose; leaves subsessile; flowers rose purple; plants subglabrous.		13 Epilobium leiophyllum
+	Seeds smooth; leaves petiolate; flowers white or pink; plants strigillose, at least on the inflorescence.		16 Epilobium pseudobscurum
16 (14)	Flowers white; mature pedicels mostly longer than 1 cm; decurrent lines from petioles and inflorescence strigillose.		9 Epilobium amurense subsp. laetum
+	Flowers rose-purple to pink; pedicels mostly less than 1 cm long; stem subglabrous.		8 Epilobium royleanum forma glabrum
17 (13)	Flowers 6-14 mm long; seeds 1.1-1.5 mm long; pedicels mostly less than 5 mm long in fruit.		(18)
+	Flowers mostly less than 6 mm long; seeds less than 1.1 mm long; pedicels 5-20 mm long in fruit.		(19)
18 (17)	Flowers 10-14 mm long; stigma often exserted beyond anthers; leaves ovate, sharply serrulate.		12 Epilobium laxum
+	Flowers less than 10 mm long; stigma surrounded by anthers; leaves elliptic, often narrow, scarcely denticulat		11 Epilobium glaciale
19 (17)	Inflorescence erect; crowded subsessile leaves 1.5-2.5 cm long; plants low-growing, less than 20 cm tall.		15 Epilobium chitralense
+	Inflorescence suberect or nodding, at least in bud; leaves petiolate, mostly longer than 2.5 cm; plants mostly taller than 20 cm.		(20)
20 (19)	Leaves lanceolate, 3-6 cm long; petals 4-6 mm long; seeds coarsely papillose.		10 Epilobium rhynchospermum
+	Leaves narrowly ovate, 1.5-3.5 cm long; petals 3-4.2 mm long; seeds finely papillose.		14 Epilobium aitchisonii