1	"Plant with green cylindrical flowering stems having all leaves represented by basal non-green cataphylls, or carrying only 1-2 terete stem-like leaves; inflorescence appearing to be lateral"	2
1	"Plant with numerous leaves, these either flattened, or tubular (with or without internal septa), or filiform; inflorescence terminal or appearing so"	18
2	"Flowering stem with 1-2 terete stem-like leaves; pith continuous and traversed by thin longitudinal woody threads"	"Juncus kraussii"
2	"Flowering stem with basal sheathing cataphylls only; pith continuous or interrupted but without longitudinal woody threads"	3
3	"Pith of stem continuous and uniform although sometimes very loose and spongy"	4
3	"Pith of stem interrupted by small or large lacunae, sometimes very scanty"	11
4	"Stems almost smooth when fresh, striae narrow and close, yellowish or pale to dark green, more-or-less shining"	5
4	"Stems more-or-less strongly ridged (at least below inflorescence), pale-yellowish or grey to blue-green, dull"	8
5	"Stamens 6"	6
5	"Stamens 3-4 (occasionally 6)"	7
6	"Stems 3-8 mm diameter, light yellowish-green, soft; inflorescence branches stout, rigid"	"Juncus pallidus"
6	"Stems 0.75-2 mm diameter (some wider sterile stems sometimes present), dark green, more-or-less wiry; inflorescence branches slender, flexuose"	"Juncus pauciflorus"
7	"Pith firm (continuous or occasionally with a few irregular, small lacunae); primary involucral bract rather short, 2-3 times as long as inflorescence"	"Juncus bassianus"
7	"Pith very loose, spongy; primary involucral bract quarter to a third as long as stem"	"Juncus effusus"
8	"Stems soft (readily indented with finger nail); pith very loose, like cobwebs or honeycomb"	9
8	"Stems hard or wiry; pith continuous but not as above"	10
9	"Inflorescence branches stiff, divaricate, 3-12 cm long, carrying small, capitate flower-clusters; stems yellowish green"	"Juncus vaginatus"
9	"Inflorescence branches short, slender, forming 1-3 loose globular heads c. 1.5 cm diameter, stems bluish green"	"Juncus conglomerataus"
10	"Cataphylls very loosely sheathing; flowers clustered at ends of branches, inflorescence sometimes a compact head"	"Juncus australis"
10	"Cataphylls closely sheathing; flowers spaced more-or-less evenly along branches; branches often numerous diverging like a narrow fan"	"Juncus sarophorus"
11	"Stems smooth, the striae fine and close"	12
11	"Stems prominently ridged (at least below the inflorescence)"	14
12	"Stems wiry, very hard at least in lower half; cataphylls more-or-less closely sheathing only innermost rather loose"	"Juncus astreptus"
12	"Stems relatively soft (may be indented with finger nail); cataphylls loosely sheathing"	13
13	"Outer tepals 2.5-3 mm long, broadly lanceolate, acute; stems 3-8 mm diameter, yellowish green; plant common"	"Juncus procerus"
13	"Outer tepals 1.7-2.3 mm long, lanceolate, acute; stems 1-4 mm diameter, bright green; plant rare"	"Juncus gregiflorus"
14	"Stem filiform with not more than 20 broad longitudinal ridges; plant 15-30 (-60) cm high"	"Juncus filicaulis"
14	"Stem with numerous narrow ridges; plant (30-) 80-120 (220) cm high"	15
15	"Flowers closely clustered at ends of short branches these often condensed into globular heads; pith usually very scanty"	16
15	"Flowers more-or-less evenly spaced along branches also loosely clustered"	17
16	"Cataphylls very loosely sheathing, chestnut-brown below; tepals 2.2-3 mm long; capsule equalling or slightly longer than tepals"	"Juncus australis"
16	"Cataphylls closely appressed, dark red-purple to black below; tepals 1.5-2.2 mm long; capsule longer than tepals"	"Juncus amabilis"
17	"Stems up to 220 cm high, erect at base, spreading above; inflorescence fan-shaped with many slender branches diverging from subtending bract"	"Juncus sarophorus"
17	"Stems 30-80 cm high, erect, rigid; inflorescence a loose cluster with 1-3 bare, elongated branches carrying branchlets with flowers moere-or-less second"	"Juncus subsecundus"
18	"Leaves hollow, terete or flattened laterally, sometimes filiform, comprising 1 or more longitudinal tubes which are transversely septate"	19
18	"Leaves flattened or deeply grooved (sometimes very slender), hollow or solid towards the apex but not septate"	29
19	"Leaves unitubular having transverse septa extending across whole width of the leaf"	20
19	"Leaves with 2 or more longitudinal tubes having transverse septa across the individual tubes"	28
20	"Stems and leaves filiform; inflorescence of 1-2 (-4) heads with 1-6 flowers in each"	21
20	"Stems and leaves moderately stout; inflorescence a cymose panicle with heads of 3-20 flowers"	23
21	"Stamens 3"	"Juncus ratkowskyanus"
21	"Stamens 6"	22
22	"Capsule 1 1/3 times to twice as long as tepals, tapering gradually to a beak; inner tepals often slightly shorter than outer ones"	"Juncus sandwithii"
22	"Capsule only slighter longer than tepals, rather abruptly contracted to a conspicuous beak; inner tepals often slightly longer than outer ones"	"Juncus curtisiae"
23	"Stems spreading or decumbent or prostrate, often rooting; capsules very dark brown to black, shining"	"Juncus articulatus"
23	"Stems erect; capsules brown or reddish-brown"	24
24	"Stamens 3"	"Juncus acuminatus"
24	"Stamens 6"	25
25	"Capsule as long as or shorter than tepals, broadly trigonous-ovoid or obovoid, the top depressed, shortly mucronate; plant rare"	"Juncus microcephalus"
25	"Capsule as long as or longer than tepals, narrowly trigonous-ovoid, tapered to an obtuse, or acute, or acuminate apex"	26
26	"Leaves usually more-or-less curved; tepals 2-2.5 (-3) mm long; capsule longer than tepals"	"Juncus acutiflorus"
26	"Leaves stiffly erect; tepals 3.5-5 mm long; capsule as long as or conspicuously longer than tepals"	27
27	"Tepals 4-5 mm long; capsule as long as tepals; plant widespread and frequent"	"Juncus holoschoenus"
27	"Tepals 3·5-4·5 mm long; capsule conspicuously longer than tepals; plant rare"	"Juncus fockei"
28	"Leaves filiform, deeply channelled between 2 longitudinal tubes; inflorescence often producing bulbils developing small leafy shoots in place of flowers"	"Juncus bulbosus"
28	"Leaves moderately stout, more-or-less flattened but with more than 2 longitudinal tubes"	"Juncus prismatocarpus"
29	"Plant annual"	30
29	"Plant perennial"	31
30	"Flowers in 1 (-2) terminal heads; leaves all radical"	"Juncus capitatus"
30	"Flowers usually solitary and distant along upper sides of branches of panicle, sometimes in clusters of 2-6; leaves radical and cauline"	"Juncus bufonius"
31	"Tepals broadly lanceolate, 4-5 mm long, outer surfaces scaberulous"	"Juncus falcatus"
31	"Tepals glabrous, not as above"	32
32	"Leaves with blades hard, rigid, narrow-subulate, deeply channelled, 8-15 cm long, spreading and sharply recurved above erect, closely-packed sheathing bases"	"Juncus squarrosus"
32	"Leaves not hard as above"	33
33	"Margins of leaf-sheath membranous, their upper ends prolonged forming lobes or auricles"	34
33	"Margins of leaf-sheath membranous, their upper ends narrowed, gradually merging into margins of leaf-blade"	35
34	"Plant tufted, rootstock short; tepals 3.5-4 mm long, lanceolate, long-acute"	"Juncus tenuis"
34	"Plant with long, slender rhizomes; tepals 4.5-5 mm long, lanceolate, acute"	"Juncus revolutus"
35	"Involucral bracts scarious or leafy but not or scarcely longer than inflorescence"	36
35	"Involucral bracts leafy, erect, conspicuous, one or more twice as long as inflorescence or longer"	37
36	"Leaf-blades grass-like, flat, apex obtuse or mucronate in young leaves, plant common in disturbed ground"	"Juncus planifolius"
36	"Leaf-blades coriaceous, upper part of blade linear-subulate becoming solid below blunt apex; plant subalpine, reaching sea level in the south-west"	"Juncus antarcticus"
37	"Outer tepals 2.5-3 mm long, slightly shorter than inner ones, acute or mucronate; capsule as long as or somewhat longer than tepals, mucronate"	"Juncus caespiticius"
37	"Outer tepals 3-3.5 mm long, slightly longer than inner ones, aristate-acuminate, the arista black, c. 0.4 mm long; capsule shorter than tepals, rostrate"	"Juncus indescriptus"