Iris virginica |
Iris douglasiana |
|
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iris de virginie, southern blue flag, Virginia iris |
Douglas' iris, mountain iris |
|
Rhizomes | many-branched, forming dense clumps, 2–4 cm diam., usually covered with remnants of old leaves; roots fleshy. |
freely branching, forming large colonies, slender, 0.8–0.9 cm diam., covered with remains of old leaves; roots fibrous. |
Stems | rather weak, often falling over after flowering, solid, usually 1-branched, 5–10 dm. |
1–4-branched, solid, 1.5–7 dm. |
Leaves | basal erect or often flexible, blade gray-green to bright green, buff to purplish basally, with several prominent ribs in mature leaves, linear-ensiform, 6–8 dm × 2.5–3 cm, apex acute. |
basal with blade yellow-green, occasionally darker green, sometimes flushed pink or red basally, prominently ribbed, linear, 4.5–10 dm × 2 cm, apex acute; cauline 1–3, reduced. |
Inflorescence units | 2–3-flowered, branch units 1–2-flowered; spathes compact, often with brown striations, ridged, unequal, outer 3–8 cm, inner 8–14 cm, firm, herbaceous. |
(2–)3-flowered, branch units 2–3-flowered; spathes opposite or separated, divergent, green, sometimes flushed purple basally, lanceolate-acuminate, 6–12 cm × 7–12 mm. |
Flowers | perianth lavender to violet, rarely white; floral tube constricted above ovary, 1–2 cm; sepals spreading and arched, pale blue to purple with darker blue or purple lines, obovate to oval, 4–8.4 × 1.6–4 cm, base abruptly attenuate, claw green in median, bordered by yellow ground with blue or purple lines, yellow extending onto base of limb as finely pubescent signal patch; petals oblong-lanceolate to oblong-spatulate, 3–7 × 1–3 cm, claw greenish yellow with blue or purplish lines, apex often emarginate; ovary trigonal, 1.3–3.8 cm; style inwardly auriculate at convergences, 3–4.5 cm, crests reflexed, 0.7–2 cm; stigmas unlobed, with prominent triangular tongues, margins entire; pedicel 2.5–8 cm. |
perianth deep red-purple, lavender, gray-blue, cream, or white, with gold signal and blue or purple veins; floral tube 1.5–2.8 cm, usually widening to bowl shape at base of flower; sepals oblanceolate to obovate, 5–9 × 1.4–3 cm, base gradually attenuate, apex obtusely rounded; petals oblanceolate, 4.5–7 × 0.9–1.8 cm, base attenuate to narrow claw; ovary elliptic-oval, sharply triangular in cross section, 3–4 cm; style 1.7–3.5 cm; crests overlapping, subquadrate, 1–2 cm, margins coarsely toothed; stigmas triangular; pedicel 2–5 cm. |
Capsules | ovoid, ellipsoid, or long-cylindric, trigonal or polygonal in cross section, 3–6 × 1–2 cm. |
sharply triangular in cross section with ridge at each angle, tapering at both ends, remnant of floral tube forming tip at apex, 2.5–5 cm. |
Seeds | in 2 rows per locule, pale brown, usually D-shaped, 5–8 mm, pitted, corky. |
dark brown, pyriform, wrinkled. |
2n | = 70, 72. |
= 40. |
Iris virginica |
Iris douglasiana |
|
Phenology | Flowering May–Jun. | Flowering Apr–Jun. |
Habitat | Wetlands, margins of lakes and streams | Open woods, sunny slopes and fields |
Distribution |
AL; AR; DC; FL; GA; IA; IL; IN; KS; KY; LA; MD; MI; MN; MO; MS; NC; NE; NY; OH; OK; PA; SC; TN; TX; VA; WI; WV; ON; QC
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CA; OR
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Discussion | Plants of Iris virginica from the southeastern and south-central states having stems 2–3-branched and seldom falling to the ground after flowering, and with capsules long-cylindric have been recognized as var. shrevei. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
R. C. Foster (1937) named several varieties of Iris douglasiana, about which L. W. Lenz (1954) said, “This is a widespread and extremely variable species whose total variability is being increased due to introgressive hybridization between it and other species with which it has come into contact. Well marked and distinct geographic races cannot be detected; however, pronounced variations are to be found within a single population. For these reasons no attempt is made here to segregate taxa within such a polymorphic species.” Iris douglasiana hybridizes with I. bracteata, I. chrysophylla, I. fernaldii, I. hartwegii, I. innominata, I. macrosiphon, I. munzii, I. purdyi, I. tenax, and I. tenuissima. The natural hybrid between I. douglasiana and I. innominata has been designated as Iris ×thompsonii R. C. Foster and the garden hybrid as Iris ×aureonympha E. H. English. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 26, p. 390. | FNA vol. 26, p. 384. |
Parent taxa | Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Laevigatae | Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Californicae |
Sibling taxa | ||
Synonyms | I. caroliniana, I. georgiana, I. shrevei, I. virginica var. shrevei | I. beecheyana, I. douglasiana var. alpha, I. douglasiana var. altissima, I. douglasiana var. beecheyana, I. douglasiana var. bracteata, I. douglasiana var. major, I. douglasiana var. mendocinensis, I. douglasiana var. nuda, I. douglasiana var. oregonensis, I. watsoniana |
Name authority | Linnaeus: Sp. Pl. 1: 39. (1753) | Herbert G. A. W. Arnott: in W. J. Hooker and G. A. W. Arnott, Bot. Beechey Voy., 395. (1840) |
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