Iris giganticaerulea


Addisonia 14: 5, plate 451. 1929.

Common names: Giant blue iris
Synonyms: Iris elephantina Small Iris hexagona var. giganticaerulea (Small) R. C. Foster Iris miraculosa Small
Treatment appears in FNA Volume 26. Mentioned on page 394.

Rhizomes green, extensively branched, forming large clumps, 2–4 cm diam., with pale leaf scars. Stems 2–3-branched, solid, 10–15(–20+) dm. Leaves: basal 4–6, erect, blade bright green, ensiform, 10–13 dm × 2–3 cm, apex slightly curved; cauline with blade foliaceous, appearing as elongated spathe, 5–6.5 dm × 2–3 cm, not exceeding flowers. Inflorescence units 2–3-flowered, branch units 1–2-flowered; spathes tightly enclosing ovary and pedicel, 15–20 cm, subequal; outer narrowly lanceolate, keeled, margins pale, narrow, inner margins translucent, broad, scarious. Flowers: perianth blue or blue-purple; floral tube tubular-prismatic, 9-ribbed and -grooved, 4–5 cm; sepals blue or blue-purple with white streaks surrounding signal, oval to orbicular-oval, 9.5–11 × 4–5 cm, base abruptly attenuate into claw, apex obtusely angled, signal with raised, yellow, pubescent central ridge, claw green, striate, 4–4.5 × 1–1.2 cm; petals erect or spreading-erect, spatulate, 7–8.5 × 2–3 cm, base cuneate, apex emarginate; ovary bluntly 6-angled, 4–4.5 cm; style blue-violet, keeled, 3.5–4 cm, raised above sepals, crests recurved, 1.5–2 cm, margins sharply and irregularly serrate; stigmas 2-lobed with 2 triangular teeth; pedicel columnar, 3.5–5 cm. Capsules drooping, bright green, ellipsoid, hexagonal in cross section, with 6 broad, rounded lobes, 8–10 × 3 cm, indehiscent; after anthesis, flower stem elongates, arching downward to push capsule into water, where walls are broken down and as funiculus is broken, seed rises to surface. Seeds in 2 rows per locule, brown, D-shaped, 8–10 mm wide, very corky. 2n = 44.

Phenology: Flowering Mar–Apr.
Habitat: Shallow water or very wet roadside ditches


Selected References


Lower Taxa

... more about "Iris giganticaerulea"
Norlan C. Henderson +
Iris subsect. Hexagonae +
Giant blue iris +
Ala. +, La. +  and Miss. +
Shallow water or very wet roadside ditches +
Flowering Mar–Apr. +
Illustrated +  and Endemic +
Iris elephantina +, Iris hexagona var. giganticaerulea +  and Iris miraculosa +
Iris giganticaerulea +
Iris (sect. Limniris) ser. Hexagonae +
species +