Iris douglasiana |
Iris tenax |
|
---|---|---|
Douglas' iris, mountain iris |
Oregon flag, Oregon iris, tough-leaf iris |
|
Rhizomes | freely branching, forming large colonies, slender, 0.8–0.9 cm diam., covered with remains of old leaves; roots fibrous. |
many-branched, not creeping, forming dense clumps, slender, 0.3–0.8 cm diam.; roots fibrous. |
Stems | 1–4-branched, solid, 1.5–7 dm. |
simple, somewhat angular, solid, 1.5–2.7 dm. |
Leaves | 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. |
basal somewhat lax, overtopping stem, blade light green, paling to pink or straw color basally, finely ribbed, linear-acute to linear, ensiform, 4.5 dm × 0.5 cm, margins not thickened; cauline 1–3, sheathing for 1/2 length then spreading, foliaceous, blade linear-lanceolate, not inflated, narrow, reduced, to 15 cm. |
Inflorescence units | (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. |
1–2-flowered; spathes distant basally by 3 cm in some cases, keeled, linear-lanceolate to lanceolate-acuminate, 5–7 cm × 2–4 mm, unequal, outer longer than inner, herbaceous, margins scarious. |
Flowers | 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. |
perianth color variable, purple, pink, lavender, cream, yellow, or rarely white; floral tube funnelform, 0.6–2 cm; sepals veined with color of limb, obovate, 5.8–6 × 1.6–2 cm, base gradually attenuate into white claw with slight yellow ridge, apex emarginate to bluntly rounded; petals same color as sepals, not prominently veined, lanceolate to oblanceolate, 5 × 1 cm; ovary 1–2 cm, slightly wider distally, base very gradually attenuate; style 2.2–3.2 cm, crests subquadrate, 8–12 mm, margins crenate or incised; stigmas triangular, margins entire; pedicel 1–5 cm, longer in second flower (when present) than in first. |
Capsules | 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. |
oblong, triangular in cross section, prominently ribbed, beaked, 3–5 cm. |
Seeds | dark brown, pyriform, wrinkled. |
brown, D-shaped to irregular, wrinkled. |
2n | = 40. |
|
Iris douglasiana |
Iris tenax |
|
Phenology | Flowering Apr–Jun. | Flowering Jun–Aug. |
Habitat | Open woods, sunny slopes and fields | Dry soils in fields and open woods |
Distribution |
CA; OR
|
CA; OR; WA
|
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.) |
Plants described as subsp. klamathensis differ from others of the species in having floral tubes 11–20 mm instead of 6–10 mm, style crests somewhat longer and narrower, and flower color and markings more like those of Iris bracteata or I. innominata. The latter species has an even longer floral tube, 15–30 mm, which could be evidence of introgression. Hybrids are known to occur in the area common to both species, in Douglas County, Oregon. Iris tenax hybridizes with I. bracteata, I. chrysophylla, I. douglasiana, I. hartwegii, I. innominata, I. macrosiphon, I. purdyi, and I. tenuissima. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 26, p. 384. | FNA vol. 26, p. 383. |
Parent taxa | ||
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 | I. gormanii, I. tenax var. gormanii, I. tenax subsp. klamathensis |
Name authority | Herbert G. A. W. Arnott: in W. J. Hooker and G. A. W. Arnott, Bot. Beechey Voy., 395. (1840) | Douglas ex Lindley: Edwards’s Bot. Reg. 15: plate 1218. (1829) |
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