1 Primary inflorescences of spikelets, these consisting of 1-2-many reduced florets, each subtended by 1-2 scales (and also enclosed in a sac or perigynium in Carex in CYPERACEAE), arrayed spirally or distichously, the spikelets then themselves arrayed in various dense or diffuse secondary or tertiary inflorescences; perianth absent, or reduced to chaff, scales, paddles, or bristles.

..2 Leaf sheaths continuous, lacking a split or only irregularly split in age; leaves usually 3-ranked (sometimes reduced to a sheath with a small scale at the summit; stems triangular in ×-section (or roundish), usually with a pith; flowers spirally arrayed in the spikelet (or distichously arrayed, in e.g. Cyperus, Dulichium, Kyllinga); anthers basifixed

..2 Leaf sheaths generally split lengthwise on the side opposite the leaf blade; leaves usually 2-ranked; stems round or flattened in ×-section, usually hollow; flowers distichously arrayed in the spikelet; anthers versatile

1 Primary inflorescences of dense spikes, spadices, heads, glomerules, or a compound corymb of helicoid cymes; perianth present, often very small and variously colored.

....3 Leaves equitant (the leaves distichous, in a fan-like array, e.g. Iris, each leaf clasping the next above in a basal fold, this uniting above so that the main leaf blade, above the basal fold, has only the lower [abaxial] leaf surface visible because of fusion of the ‘upper’ surfaces).

......4 Inflorescence a very densely flowered spike (spadix), appearing lateral, 1 per plant; fresh plant strongly aromatic

......4 Inflorescence either more diffuse, 1 or several per plant, or terminal and cone-like; fresh plant not aromatic.

........5 Inflorescence brownish or tan, spherical, ovoid, or cylindrical, with numerous scale-like bracts arrayed in a cone; flowers individually conspicuous, a single yellow (to white) flower at a time emerging from each of the scales

........5 Inflorescence more diffuse.

..........6 Inflorescence axis and bracts densely lanuginose

..........6 Inflorescence axis and bracts glabrous or inconspicuously pubescent.

............ 7 Inflorescence or flower groups subtended by well-developed, green or scarious spathaceous bracts; inflorescence either a fan-shaped pair of cymes, or seemingly racemose, or solitary

............ 7 Inflorescence or flower groups not subtended by spathes (though individual flowers may be subtended by small green bracts); inflorescence a raceme, panicle, or corymb.

............ ..8 Inflorescence a corymb of helicoid cymes; corolla yellow, densely tomentose; roots bright red (Lachnanthes) or white to brown (Lophiola).

............ ....9 Stamens 3, longer than the (ascending) tepals inner 3 tepals > 2 mm longer than the outer 3 tepals; rhizomes and roots of fresh plants bright red

............ ....9 Stamens 6, shorter than the (recurved) tepals; inner 3 and outer 3 tepals equal in length; rhizomes at roots of fresh plants white to brown

............ ..8 Inflorescence a terminal raceme (the flowers attached to the rachis in groups of 3 or more in Triantha in TOFIELDIACEAE); corolla white, cream, or yellow, glabrous; roots white or brown.

............ ......10 Flowers yellow; capsule loculicidal

............ ......10 Flowers white (yellow in Harperocallis, endemic to FL Panhandle); capsule septicidal

....3 Leaves not equitant, sometimes distichous, upper and lower surfaces both present.

............ ........11 Inflorescence either a linear spike, terminal, the thicker female portion below, the thinner male portion above, or an ovoid, hemispheric, spherical head or glomerule, 1 or several per plant

............ ..........12 Inflorescence a linear spike, terminal, the thicker female portion below, the thinner male portion above

............ ..........12 Inflorescence an ovoid, hemispheric, or spherical head or glomerule, 1 or several per plant.

............ ............ 13 Flowers in a single head terminating an elongate scape; leaves basal (often with 1-2 much smaller leaves or bladeless sheaths on the lower part of the scape); inflorescence white, tan, pale yellow, gray, or blackish, the head usually as broad as or broader than long, involucrate

............ ............ 13 Flowers in multiple heads, not scapose; leaves basal and usually also prominently cauline; inflorescence green, tan, brown, or reddish, the head spherical, not involucrate.

............ ............ ..14 Flowers bisexual, the flowers in various arrays

............ ............ ..14 Flowers unisexual, the male flowers in a terminal head, the female flowers in heads below the male along a usually zigzag stem

............ ........11 Individual flowers solitary or in more diffuse inflorescences; perianth present, at least one whorl petal-like in size, color, and texture.

............ ............ ....15 Flowers bilaterally symmetrical; stamen 1 or 2; tepals 6; perianth often differentiated into a lip and 5 petaloid tepals

............ ............ ....15 Flowers radially symmetrical (sometimes weakly bilaterally symmetrical); stamens 6 (rarely 3); tepals usually 6 (rarely 3), when 6, either undifferentiated (6 tepals) or differentiated into 3 petals and 3 sepals.

............ ............ ......16 Leaves < 15 mm long, scale-like or linear; leaves cauline.

............ ............ ........17 Leaves (actually cladophylls) clustered, in whorls of (1-) 2-20 (-25); fruit a berry; perianth undifferentiated, of 6 yellow, white, or green tepals

............ ............ ........17 Leaves alternate; fruit a capsule; perianth either differentiated, the 3 petals yellowish-green or maroon, or undifferentiated, the 6 tepals white, blue, or purplish.

............ ............ ..........18 Plants terrestrial, erect; stems and leaves lacking a scaly indumentum; flower solitary, or several to many in heads or racemose cymes; perianth undifferentiated, the 6 tepals white, blue, or purplish

............ ............ ..........18 Plants either epiphytic and pendulous in festoons, or terrestrial, wetland, or aquatic and sprawling; stems and leaves with or without a scaly indumentum; flowers solitary and axillary; perianth differentiated, the 3 petals either yellowish-green or maroon.

............ ............ ............ 19 Plants epiphytic, pendulous in festoons; stems and leaves densely covered by silvery scales; peatls yellowish-green

............ ............ ............ 19 Plants of moist to wet habitats, sprawling or aquatic; stems and leaves not covered by silvery scales; petals maroon

............ ............ ......16 Leaves (at least the larger) > 25 mm long, linear or narrowly lanceolate; leaves basal, basally disposed (or rarely mostly or entirely cauline).

............ ............ ............ ..20 Ovary inferior (or partly inferior; ambiguous taxa keyed both ways).

............ ............ ............ ....21 Inflorescence axillary, a raceme or umbel (or reduced to a single flower); petaloid tepals yellow

............ ............ ............ ....21 Inflorescence terminal; petaloid tepals various (including yellow).

............ ............ ............ ......22 Inflorescence or flower groups subtended by well-developed, green or scarious spathaceous bracts; inflorescence either an umbel, or fan-shaped pair of cymes, or seemingly racemose, or solitary.

............ ............ ............ ........23 Stamens 3; inflorescence either a fan-shaped pair of cymes or seemingly racemose (or rarely solitary (e.g. Crocus)

............ ............ ............ ......22 Inflorescence or flower groups not subtended by spathes (though individual flowers may be subtended by small green bracts; inflorescence a raceme or panicle.

............ ............ ............ ..........24 Leaves fleshy; anthers 12-15 mm long

............ ............ ............ ..........24 Leaves herbaceous; anthers < 5 mm long.

............ ............ ............ ............ 25 Tepals connate into a tube; perianth tube exterior farinose; flowers bisexual, white to bright yellow; inflorescence a raceme

............ ............ ............ ............ 25 Tepals distinct; perianth not farinose; flowers unisexual or bisexual, white, greenish, or creamy; inflorescence a raceme or panicle (raceme of racemes)

............ ............ ............ ..20 Ovary superior (or partly inferior; ambiguous taxa keyed both ways).

............ ............ ............ ............ ..26 Gynoecium of 2 or more pistils, each pistil consisting of 1 carpel and with 1 stigma; [wetland plants].

............ ............ ............ ............ ....27 Inflorescence a terminal raceme, the flowers (fruits) in whorls of 3; perianth differentiated into showy petals and green sepals, the petals white; leaf not differentiated into a sheath and blade separated by a ligule; fruit an aggregate of achenes

............ ............ ............ ............ ....27 Inflorescence a terminal raceme or spike, the flowers (fruits) alternate; perianth not differentiated, consisting of 3 or 6 green or yellow-green tepals; leaf differentiated into an open sheath and blade, with a ligule separating them; fruit an aggregate of achenes or follicles.

............ ............ ............ ............ ......28 Inflorescence ebracteate, with > 10 flowers; leaf without a terminal pore; carpels ascending, appressed to one another

............ ............ ............ ............ ......28 Inflorescence bracteate, with < 10 flowers; leaf with a terminal pore; carpels widely divergent, at nearly right angles to the axis

............ ............ ............ ............ ..26 Gynoecium of 1 pistil, with 2-6 stigmas; [wetland and upland plants].

............ ............ ............ ............ ........29 Leaves strictly or primarily cauline.

............ ............ ............ ............ ..........30 Leaves linear, > 15 cm long, hollow or flat; inflorescence an umbel; fresh plants with an oniony odor

............ ............ ............ ............ ..........30 Leaves linear to lanceolate, < 15 (-30) cm long, flat; inflorescence various, not an umbel; fresh plants without oniony odor.

............ ............ ............ ............ ............ 31 Petals < 2 cm long, white, blue, or pink; leaves alternate

............ ............ ............ ............ ............ 31 Petals > 5 cm long, yellow, orange, or red; leaves alternate or whorled

............ ............ ............ ............ ........29 Leaves strictly or primarily basal (the basal leaves persistent, and larger than any stem leaves).

............ ............ ............ ............ ............ ..32 Perianth differentiated into 3 bright pink petals and 3 green sepals

............ ............ ............ ............ ............ ..32 Perianth not differentiated, the 6 segments similar in color, shape, and size, of various colors (sometimes pink).

............ ............ ............ ............ ............ ....33 Tepals brown or green, not at all yellow, white, or otherwise more brightly colored; inflorescence branched and complex

............ ............ ............ ............ ............ ....33 Tepals white, cream, pink, greenish-yellow, yellow, orange, pink, blue, or blue-brown; inflorescence either a terminal umbel, subtended by spathes or bracts, or a terminal raceme or panicle (or a terminal corymb in Ornithogalum in HYACINTHACEAE), not subtended by spathes or bracts.

............ ............ ............ ............ ............ ......34 Inflorescence a terminal umbel, subtended by spathes or bracts; fresh plants with or without an oniony odor

............ ............ ............ ............ ............ ......34 Inflorescence a terminal raceme or panicle (or a terminal corymb in Ornithogalum in HYACINTHACEAE), not subtended by spathes or bracts.

............ ............ ............ ............ ............ ........35 Tepals evidently connate, fused at least basally and sometimes nearly their entire length; filaments adnate to the tepals.

............ ............ ............ ............ ............ ..........36 Tepals 5-8.5 cm long, yellow to orange; anthers dorsifixed (attached near the middle)

............ ............ ............ ............ ............ ..........36 Tepals 0.2-1.0 0.2-1.2 (-2.0) cm long, white, cream, yellow, blue, or blue-brown; anthers basifixed (attached at the base) or dorsifixed (attached at the back).

............ ............ ............ ............ ............ ............ 37 Leaves 4-12 dm long, leathery and somewhat fleshy in texture, erect or ascending

............ ............ ............ ............ ............ ............ 37 Leaves < 4 dm long, herbaceous in texture, erect, ascending, or spreading

............ ............ ............ ............ ............ ............ ..38 Perianth blue or blue-brown, not farinose; leaves 2-7, erect, ascending, or the tips spreading; anthers dorsifixed (attached at the back)

............ ............ ............ ............ ............ ............ ..38 Perianth white, cream, or yellow, farinose-roughened on the outer surface; leaves typically > 8, spreading to slightly ascending (often forming a flattish rosette); anthers basifixed (attached at the bottom)

............ ............ ............ ............ ............ ........35 Tepals completely distinct; filaments free (rarely epitepalous).

............ ............ ............ ............ ............ ............ ....39 Styles 1, lobed only in the upper portion if at all; fruit either loculicidal capsules or berry-like; tepals blue, pink, or white with a broad green central stripe.

............ ............ ............ ............ ............ ............ ......40 Tepals white, with a broad green stripe; inflorescence an umbel or raceme

............ ............ ............ ............ ............ ............ ......40 Tepals blue or pink; inflorescence a raceme

............ ............ ............ ............ ............ ............ ........41 Tepals blue, 7-17 mm long; inflorescence a true raceme

............ ............ ............ ............ ............ ............ ........41 Tepals pink, 3-10 mm long; inflorescence a raceme-like dibotrya

............ ............ ............ ............ ............ ............ ....39 Styles 3, separate to the base; fruit a septicidal capsules (sometimes then also secondarily loculicidal); tepals white, greenish, yellowish, or pink.

............ ............ ............ ............ ............ ............ ..........42 Inflorescence ebracteate, lacking bracts subtending pedicels; tepals pink (Helonias) or white to cream (Chamaelirium).

............ ............ ............ ............ ............ ............ ............ 43 Flowers white to cream; plants dioecious (individual flowers either male or female)

............ ............ ............ ............ ............ ............ ............ 43 Flowers pink; plants hermaphroditic (individual flowers bisexual)

............ ............ ............ ............ ............ ............ ..........42 Inflorescences bracteate, with bracts subtending individual pedicels and (if they are present) branches of the inflorescence; tepals white, greenish-white, or cream.

............ ............ ............ ............ ............ ............ ............ ..44 Leaves narrowly linear, 1-2.5 mm wide, rigid, keeled, and serrulate; stems and leaves strictly glabrous

............ ............ ............ ............ ............ ............ ............ ..44 Leaves linear or oblanceolate (rarely narrowly linear), > 2 mm wide, flexible, unkeeled, and with entire margins; stems and leaves pubescent with hairs or scales (except Amianthium)