Iris prismatica |
Iris douglasiana |
|
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slender blue iris |
Douglas' iris, mountain iris |
|
Rhizomes | superficial or only slightly buried in peaty soil, cordlike portions usually 1-branched, 40 cm × 2–5 mm, bearing scalelike leaves at nodes; nodal roots absent. |
freely branching, forming large colonies, slender, 0.8–0.9 cm diam., covered with remains of old leaves; roots fibrous. |
Stems | simple or 1–2-branched, 3–8 dm. |
1–4-branched, solid, 1.5–7 dm. |
Leaves | basal with blade slightly ribbed, 3–6 dm × 0.2–0.5 cm; cauline 1–4, erect. |
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 | 1–3-flowered, branch units 1–2-flowered; spathes pale brown, narrowly lanceolate, 2–4 cm, scarious or partially membranaceous. |
(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 pale blue or blue-violet; floral tube 0.2–0.3 cm; sepals pale violet, veined deep violet basally, ovate, 4–5 × 1.3–2 cm, base abruptly attenuate; petals lavender, oblanceolate, 3.5–4.5 × 0.7–1.5 cm; ovary trigonal, sharply angled; style arched, narrow, 2–3 cm, crests divergent, quadrate, 0.5–0.7 cm, margins serrate; stigmas sharply triangular; pedicel somewhat flattened, 3–7 cm, exserted from spathe. |
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 | sharply 3-angled, almost winged, 3–4 × 1.2–1.4 cm, concave faces 6–14 mm wide. |
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 1 row per locule, buff to dark brown, pyriform, with convex sides, 3–4 mm, smooth. |
dark brown, pyriform, wrinkled. |
2n | = 42. |
= 40. |
Iris prismatica |
Iris douglasiana |
|
Phenology | Flowering Apr–Jul. | Flowering Apr–Jun. |
Habitat | Swampy, peaty soil | Open woods, sunny slopes and fields |
Distribution |
AL; CT; DE; GA; KY; MA; MD; ME; NC; NH; NJ; NY; RI; SC; TN; VA
|
CA; OR
|
Discussion | 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. 395. | FNA vol. 26, p. 384. |
Parent taxa | Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Prisimaticae | Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Californicae |
Sibling taxa | ||
Synonyms | 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 | Pursh: Fl. Amer. Sept. 1: 30. (1814) | Herbert G. A. W. Arnott: in W. J. Hooker and G. A. W. Arnott, Bot. Beechey Voy., 395. (1840) |
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