Iris giganticaerulea |
Iris pumila |
|
---|---|---|
giant blue iris |
dwarf iris |
|
Rhizomes | green, extensively branched, forming large clumps, 2–4 cm diam., with pale leaf scars. |
freely branching, producing dense clumps, 1–1.5 cm diam. |
Stems | 2–3-branched, solid, 10–15(–20+) dm. |
absent or not more than 1 cm. |
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. |
ascending-spreading; blade grayish green, ensiform or slightly falcate, 8–10 cm × 6–15 mm at anthesis, increasing to 15–20 cm in length on innovations after flowering, dying back in autumn, new growth only in spring, glaucous. |
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-flowered, sessile in spathes; spathes 5–10 cm; outer darker green than inner, inner closely shielding floral tube. |
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. |
floral tube with 3 purple stripes in line with midrib of petals, slender, 6–10 cm × 2–3 mm, lifting expanded portion of flower out of spathes; sepals yellow, blue, or purple, with yellowish or bluish beard, often with contrasting spot around beard at base of limb, 4–5 × 1.2–2 cm; petals with darker veins near base, rounded-ovate, broader than sepals, 4–5 × 2.2–2.7 cm, narrowing abruptly to brown-veined claw, apex emarginate; ovary rounded-trigonal, ca. 1 cm × 4–5 mm; style crests triangular, margins serrate distally; stigmas rounded on distal margin, margins entire; pedicel absent. |
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. |
borne on tips of rhizomes at ground level or slightly below, rounded-trigonal, with short portion of dried floral tube forming tip, smooth, 2–3.5 × 1.5–2 cm, dehiscing while green. |
Seeds | in 2 rows per locule, brown, D-shaped, 8–10 mm wide, very corky. |
usually in 2 rows per locule, light brown, subspherical, 3–5 mm diam., wrinkled. |
2n | = 44. |
= 30, 31, 32, 36. |
Iris giganticaerulea |
Iris pumila |
|
Phenology | Flowering Mar–Apr. | Flowering late Mar–mid May. |
Habitat | Shallow water or very wet roadside ditches | Dry, grassy areas |
Distribution |
AL; LA; MS
|
IL; IN; MI; OH; c Europe; e Europe [Introduced in North America] |
Discussion | Iris pumila has been shown to be a natural amphidiploid hybrid between I. pseudopumila Boissier & Heldreich and I. attica Tineo, both 2n = 16. Like many other such hybrids, its range of variability is so extensive that many of its forms have been given specific names. In spite of the variability in color and size, it is now recognized as a distinct species. During the past 50 years, it has been crossed repeatedly with several other species, including I. germanica and its mixed progeny, and this has introduced patterns from the tall-bearded iris into the dwarfs, and vice versa. The ranges of flowering season and plant height are now almost continuous from one extreme to the other, and intermediate groups are now recognized. Iris pumila is widely grown in gardens and often persists for years after cultivation around old dwellings and along roadsides. It is thus extremely difficult to document and map its spontaneous occurrence. Although most, if not all, of the modern dwarf irises are of hybrid parentage, a number of herbarium specimens from the nineteenth century seem to represent wild forms of I. pumila. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 26. | FNA vol. 26, p. 375. |
Parent taxa | Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Hexagonae | Iridaceae > Iris > subg. Iris |
Sibling taxa | ||
Synonyms | I. elephantina, I. hexagona var. giganticaerulea, I. miraculosa | |
Name authority | Small: Addisonia 14: 5, plate 451. (1929) | Linnaeus: Sp. Pl. 1: 38. (1753) |
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