Iris giganticaerulea |
Iris savannarum |
|
---|---|---|
giant blue iris |
prairie iris, savanna iris |
|
Rhizomes | green, extensively branched, forming large clumps, 2–4 cm diam., with pale leaf scars. |
greenish, freely branching, forming large, open clumps, 2–2.5 cm diam., fleshy, with fibrous bases of old leaves not covering rhizome but persisting on ringlike scars. |
Stems | 2–3-branched, solid, 10–15(–20+) dm. |
1-branched, solid, 3–10 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. |
basal usually dying back shortly after anthesis, blade bright green, 6–10 dm × 0.8–2 cm, sometimes glaucescent; cauline with blade elongate, linear-attenuate, 15–20 cm, 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. |
1–3-flowered, branch units 1–2-flowered; spathes lanceolate, subequal or unequal, apex acute; outer 8–10 cm, herbaceous, margins scarious; inner 6–9 cm, completely 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. |
perianth blue to blue-violet (white in forma albispiritis); floral tube funnelform, 1.2–1.5 cm; sepals blue or pale violet with flecks of white and lines of deeper blue on either side of ridge, spatulate, elliptic to ovate, 7–8 cm, apex acuminate, ridge yellow, linear, extending to about middle of limb, finely pubescent, claw light green, striated, ribbed, 1–1.2 cm; petals erect or spreading-erect, deep blue, linear to narrowly linear-spatulate, 6–7.5 cm, base abruptly attenuate into claw, claw channeled, green with darker lines, margins pale; ovary bluntly 3-angled, ridged at each angle and on faces between angles; style linear-acute, 5–6 cm; crests ovate, 1–2 cm, margins sharply and irregularly toothed; stigmas broadly 2-lobed, margins crenate; pedicel 1.6–2 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. |
ellipsoid, round in cross section, roundly 6-lobed, with 6 sharp, winglike, equally spaced ridges converging to form stout beak at apex, 6–10 cm, dehiscence loculicidal. |
Seeds | in 2 rows per locule, brown, D-shaped, 8–10 mm wide, very corky. |
in 1 row per locule, brown, circular or uneven, flattened, 8–12 mm diam, very corky. |
2n | = 44. |
= 44. |
Iris giganticaerulea |
Iris savannarum |
|
Phenology | Flowering Mar–Apr. | Flowering late Mar–early Apr. |
Habitat | Shallow water or very wet roadside ditches | Wet ditches, margins of lakes, streams, and swamps |
Distribution |
AL; LA; MS
|
AL; FL; GA
|
Discussion | Iris savannarum has often been included in I. hexagona, but differs in several ways. The capsules of I. hexagona are more obviously hexagonal, with smooth faces alternating with those that have two rounded lobes, whereas the capsules of I. savannarum are more rounded but with six obvious ridges, almost of winglike proportions. Iris hexagona has yellow-green leaves instead of the brighter green of I. savannarum. The leaves of I. savannarum die back after anthesis, while those of I. hexagona remain green. The flowering period of I. savannarum is almost one month earlier than that of I. hexagona in the area where both are known to grow. The sepals of I. savannarum are more acute at the apex than those of I. hexagona. Iris savannarum has been hybridized with Iris fulva to produce I. ×cacique (J. Berry) N. C. Henderson. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 26. | FNA vol. 26, p. 393. |
Parent taxa | Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Hexagonae | Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Hexagonae |
Sibling taxa | ||
Synonyms | I. elephantina, I. hexagona var. giganticaerulea, I. miraculosa | I. albispiritus, I. hexagona var. savannarum, I. kimballiae, I. rivularis |
Name authority | Small: Addisonia 14: 5, plate 451. (1929) | Small: Addisonia 9: 57, plate 317. (1925) |
Web links |