232 XYRIDACEAE 
B. Perennial plants : leaves mainly longer than the sheath of the scape. 
Sterile filaments bearded : leaf-blades flat. 
Lateral sepals included. 
Keel or wing of the lateral sepals ciliolate. 
Lateral sepals winged, the wing partially ciliolate, not bearded. 
Sepal-wing narrow, narrower than the sepal-body. 3. X. ambigua. 
Sepal-wing broad, broader than the sepal-body. 4. X. stricta. 
Lateral sepals keeled, the keel mainly ciliolate its entire length, 
bearded at the apex. 5. X. flexuosa. 
Keel or wing of the lateral sepals incised, erose-toothed or lacerate. 
Keel or wing erose-toothed or incised. 
Lateralsepals erested from below the middle or from the base to 
the apex. 6. X. neglecta. 
Lateral sepals crested from above the middle to the apex. 
Scape and leaves not scabro-puberulent. 
Spikes ovoid, oval or globular, 5-15 mm. long at maturity; 
bracts in relatively few series. 
Bracts loosely imbricated in few series, deciduous. 
Bracts closely imbricated in several series, persistent. 
Spikes oblong to conic-oblong, 16-23 mm. long at maturity ; 
bracts numerous and in many series. 
Scape and leaves scabro-puberulent all over. 10. 
Keel or wing lacerate. 
Lateral sepals crested from about the middle, or below it, to the 
aper the crest erect or nearly so. 
Spikes ovoid, 11-15 mm. long ; bracts rounded at the apex. 
Spike acute: lateral sepals with the wing narrow or obsolete 
X. Caroliniana. 
X. communis. 
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X. scabrifolia. 
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near the base: leaves and scape smooth. 11. X. difformis. 
Spike obtuse: lateral sepals with the wing broad to the base, 
leaves and scape rough-margined. 12. X. serotina. 
Spikes oblong or cylindric, 15-30 mm. long; bracts very broad 
and broadly truncate or nearly truncate at the apex. 13. X. platylepis. 
Lateral sepals crested from the base to the apex, the crest spreading 
or partially recurved. 14. X. iridifolia. 
Lateral sepals partially exserted. 
Plants not bulbous at the base, the leaf-bases not greatly dilated. 
Leaves numerous ; blades mostly 1-2 mm. wide at maturity. 15. X. Elliottii. 
Leaves few; blades mostly 5-10 mm. wide at maturity. 
Crest of the lateral sepals of very short erect segments: upper part 
of the scape smooth. 16. X. Smalliana. 
Crest of the lateral sepals of very long spreading segments: upper 
part of the scape rough. l7. X. fimbriata. 
Plants markedly bulbous at the base, the leaf-bases greatly dilated and 
persistent. 
Corolla yellow : upper part of the scape, and the spike green. 18. X. arenicola. 
Corolla white: upper part of the scape, and the spike glaucous or glau- 
. cescent, 19. X. pallescens. 
Sterile filaments glabrous: leaves terete, filiform. 20. X. Baldwiniana. 
1. Xyris brevifdlia Michx. Annual or biennial. Leaves narrowly linear, 2-8 cm. 
long, clustered : scapes solitary or tufted, 8-30 cm. tall, nearly terete, more or less spirally 
twisted : spikes subglobose, 4-6 mm. long; bracts eroded : lateral sepals 3.5-4.5 mm. long, 
the keel smooth or erose-scabrous : petals yellow ; blades obovate, rounded at the apex. 
In low pine lands, North Carolina to Florida. Spring. 
_ 2. Xyris flabelliformis Chapm. Annual or biennial. Leaves linear or narrowly 
linear-lanceolate, 1-2.5 cm. long, spreading in a fan-shaped manner, often curved : scapes 
very slender, 8-30 cm. tall, spirally twisted, nearly terete below, slightly flattened above : 
spikes ovoid or oblong, 4-8 mm. long, usually acute ; bracts entire: lateral sepals 4-5 mm. 
long, the keel ciliate-fringed : corolla yellow. 
In low pine lands, near the coast, Florida and Alabama to Mississippi. Spring. 
3. Xyris ambígua Beyr. Perennial. Leaves linear, 1-4 dm. long, tapering from a 
rather broad base, commonly roughish on the edges : scapes usually solitary, 4-10 dm. tall, 
finely ridged, 2-edged above, the edges often rough : spikes ovoid or oblong-ovoid, 1.5-2.5 
em. long, often acute, compact ; lateral sepals included, 5-8.5 mm. long; wing ciliolate : 
corolla yellow. 
In swamps or open pine lands, North Carolina to Florida and Texas. Summer and fall. 
4. Xyris stricta Chapm. Perennial. Leaves linear or slightly tapering upward, 1-4 
dm. long, quite narrow, smooth-edged, often discolored in drying: scapes often solitary, 
4-10 dm. tall, 2-edged and margined above, the margins rough: spikes narrowly oblong 
or cylindric, 2-3.5 cm. long, compact: lateral sepals 5.5-7 mm. long, included ; wing 
ciliolate the middle to the top: corolla yellow. 
In ponds in pine lands, Florida to Mississippi. Summer and fall. 
5. Xyris flexuósa Muhl. Perennial. Leaves narrowly linear, 5-30 cm. long, acute, 
straight or spirally twisted : scapes 2-6 dm. tall, more or less spirally twisted, nearly terete 
below, 2-edged above, smooth: spikes oval or subglobose, 5-10 mm. long: lateral sepals 
margined, 4-5 mm. long; keel ciliolate and bearded at the apex : corolla yellow. 
In swamps or wet soil, Maine to Minnesota, Georgia and Texas. Summer. 
