Flora of North America species comparison

heterogeneous, whitish, cordlike portions 0.1–1.5 dm × 2–4 mm, enlarging to 6–8 mm diam., densely covered with brown, scalelike leaves, roots absent, or torulose with roots borne along entire rhizome.

simple, 5–15 cm.

simple or branched, erect (declining or semierect and obviously zigzag in I. brevicaulis and some of its hybrids), solid or hollow, terete or slightly flattened.

basal with blade light green, ensiform, 0.3–1.5 dm × 0.3–1.3 cm, enlarging to 3.5 dm, glaucous;

cauline 5–9, sheathing, imbricate, blade light green, obovate, 1.3–5 cm, increasing in length, proximal shortest, membranous, apex acute.

basal 3–10, in fan;

blade monofacial (except at base), smooth or ridged, sometimes centrally thickened, veins obscure to prominent;

cauline 0–4 on branched stems, usually similar to basal, subtending each branch, decreasing in length distally, sometimes bracteiform and sheathing stem.

1–2-flowered;

spathes divergent, exposing floral tube, green, lanceolate, 2–2.5 cm, apex acuminate.

rhipidiate, units 1 or more-flowered, spathaceous;

spathes 2, herbaceous with scarious tips, or completely scarious, with or without distinct keel, often persisting and enclosing capsule(s) at maturity.

floral tube pale violet, filiform, 2.5–6.5 cm, expanding somewhat distally to 2.5–4 cm diam.;

sepals widely spreading, blue to violet with yellow or orange longitudinal papillose band at base of blade, obovate, 2–6 × 0.8–2 cm, base gradually attenuate into claw, not crested;

petals erect, arching inward at tip, spatulate, 2–7 × 1–2 cm, base abruptly attenuate into claw;

ovary linear, to 1.3 cm;

styles pale violet, 2.5–4 cm, crests linear-acute, narrow, 0.7 cm;

stigmas rounded, margins entire;

pedicel 1–3 cm, increasing to 25 cm as capsule matures.

lasting 1–4 days, upward-facing, usually somewhat fragrant (odor extremely unpleasant in I. foetidissima), pedicellate or sessile;

perianth epigynous, white, yellow, tan, brown, copper-red, maroon, blue, blue-violet, or purple, often with markings of contrasting colors, differentiated into sepals and petals, actinomorphic, 4–18 cm diam.;

floral tube distal to ovary, terete or occasionally ridged, solid proximally, hollow distally;

sepals 3, spreading or reflexed, expanding either gradually or abruptly from claw into broader limb, with signal of prominent ridge, crest, distinct lines or dots, pubescence, or band of multicellular hairs (beard) along midline of claw and for short distance along midrib of limb;

petals 3, erect, spreading or rarely reflexed, sometimes very reduced and mostly hidden by sepal bases;

stamens opposite sepals, free but appressed to style branches;

style dividing distally into petaloid branches, these arching outward and over stamens and claws of sepals, dividing at apex into 2 rounded or triangular lobes (style crests);

stigma a lip of tissue on adaxial surface of style arm at base of crest;

ovary terete or roundly 3- or 6-angled or -grooved.

capsular, wall papery or becoming dry and hardened, sometimes indehiscent (in I. giganticaerulea).

3-angled with single ridge at each angle, almost hidden in bases of spathes, 1–3.2 × 0.8–1.5 cm, tapering into beak consisting of dried remnant of floral tube.

dark brown, ribbed, 2.8–3.2 mm, lustrous, with small, fleshy aril basally.

4–20, in 1–2 rows per locule, often flattened in contact with others, rounded on outer surface;

seed coat tan to dark brown (red in I. foetidissima), thin, membranous, and smooth, or conspicuously roughened to extensively corky (usually in wetland species), with or without obvious aril.

= uncertain.