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Key to Iris

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1 Plant from an ovoid bulb; [subgenus Xiphium; or genus Xiphion]
1 Plant from short to elongate rhizomes.
  2 Style branches not broad, petaloid, or crested; seeds black, shiny, in a blackberry-like cluster (the seeds exposed at maturity by dehiscence of the papery to chartaceous capsule walls); [genus Belamcanda]
  2 Style branches broad, petaloid, terminating in paired crests; seeds tan to brown, in a capsule.
    3 Sepal "signal" (see above) of multicellular hairs (the “beard”), along the midrib of the claw and the base of the blade; [subgenus Iris; or genus Iris].
      4 Aboveground stem <1 cm tall; floral tubes 6-10 cm long
      4 Aboveground stem 60-120 cm tall; floral tubes 1-2.5 cm long
        5 Spathes scarious, silvery-white; corollas pale blue or pale lilac
        5 Spathes green (or purplish) and herbaceous, with scarious margins; corollas white, blue-violet, or purple.
          6 Corollas white (with yellow or greenish tint near the base); inflorescences simple or slightly branched, the branches hidden with the bracts at anthesis
          6 Corollas blue-violet or purple (very rarely whitish, and then with violet tint near the base; inflorescences visibly branched, the terminal branches extending beyond the bracts at anthesis
    3 Sepal "signal" consisting of contrasting color, ridges, small unicellular hairs, and/or a cockscomb-like crest.
             7 Rhizome branches cord-like, with scale-like leaves, enlarging at the apex to produce vegetative leaves, additional branches, and flowering stems.
               8 Stems 30-80 cm tall; leaves 30-60 cm long, 0.2-0.7 cm wide; cordlike portions of rhizomes to 4 dm long; [of wetlands]; [section Limniris, series Prismaticae; or genus Limniris]
               8 Stems 2-15 cm tall; leaves 10-45 cm long, 0.3-2.5 cm wide; cordlike portions of rhizomes to 2 dm long; [of dry to mesic uplands].
                 9 Sepal "signal" a 3-ridged, toothed crest; leaves 10-25 mm wide, green, falcate; flowers not or only slightly fragrant; rhizomes surficial (one can "pull" them off the ground by gently tugging on the leaves); [generally of mesic and fertile soils]; [section Lophiris; or genus Lophiris]
                 9 Sepal "signal" merely a primarily orange color patch (not a crest); leaves 3-13 mm wide, blue-green, straight or nearly so; flowers strongly fragrant; rhizomes deeply buried (not easily "pulled"); [generally of dry and acid soils]; [section Limniris, series Vernae; or genus Gattenhofia].
                   10 Leaf-bearing offshoots spaced at 0.2-3 cm along the rhizome, thus forming tight to loose clumps of 2 or more leafy, above-ground shoots; rhizomes 2.5-8 mm in diameter, typically irregular, knotty, and contorted, scales not obvious; leaves 5-13 mm wide, with 15-29 veins, usually medium to dark green; leaves typically borne angled to the ground and further arching; capsules 1.7-3.2 cm long; [in and west of the w. Piedmont and Appalachians and extending to the Gulf Coastal Plain in GA, FL, AL, and MS]
                   10 Leaf-bearing shoots spaced at intervals of (5-) 8-15 cm along the rhizome, thus forming colonies with well-spaced, individual, leafy above-ground shoots; rhizomes 1-2.5 mm in diameter, bearing obvious and well-spaced scales; leaves 3-8 mm wide, with 9-19 veins, usually pale or glaucous green; leaves borne rigidly vertical, at 90 degrees to the ground; capsules 1.2-1.8 cm long; [of the Coastal Plain and e. Piedmont, from e. VA to e. GA]
             7 Rhizome branches like the primary rhizome, not as above.
                     11 Petals 1-2 cm long; [section Limniris; series Tripetalae; or genus Limniris]
                       12 Stems hollow; [section Limniris; series Sibirica; or genus Limniris].
                            14 Capsules 3-angled or nearly round in cross-section; [section Limniris; series Laevigatae; or genus Limniris].
                                16 Flowers 8-15 cm in diameter; leaves 0.5-1.5 cm wide; [exotic, cultivated, rarely escaped]
                                16 Flowers 6-8 cm in diameter; leaves 1-4 cm wide; [native].
                                  17 "Signal" a greenish-yellow, papillate patch, surrounded by an area of heavily veined purple-on-white; [of VA northward]
                                    18 Plants to 10 dm tall, usually with 1-2 well-developed branches; capsule 7-11 cm long
                                    18 Plants to 6 dm tall, little or not at all branched; capsule 4-7 cm long
                            14 Capsules 6-angled or ridged in cross-section; [section Limniris, series Hexagonae; or genus Phaeiris].
                                       19 Perianth dull copper or orange-brown (or dark yellow) (fading in nature or drying in the herbarium to a bluish or purplish color); petals spreading or declining
                                       19 Perianth blue-violet (rarely white); petals erect to spreading.
                                           21 Capsules 2.5-3.5 cm long, hexagonal in cross-section, 3 sides flat, the alternating sides with 2 rounded ridges separated by a shallow groove
                                           21 Capsules 6-10 cm long (3.5-7 cm in I. rivularis), slightly to strongly hexagonal in cross-section.
                                               23 Capsules 3.5-7 cm long; sepals ca. 9 cm long; flowers slightly fragrant; [endemic to St. Marys River in se. GA and ne. FL]
                                               23 Capsules (6.5-)8-10 cm long; sepals 9.5-11.5 cm long; flowers strongly musk-scented [FL panhandle w. to e. TX]
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