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Iris douglasiana

Douglas' iris, mountain iris

copper iris

Rhizomes

freely branching, forming large colonies, slender, 0.8–0.9 cm diam., covered with remains of old leaves;

roots fibrous.

compact, greenish brown or sometimes red-tinged, many-branched, with ringlike scars of old leaves, 1.5–2 cm diam.

Stems

1–4-branched, solid, 1.5–7 dm.

simple or sometimes 1–2-branched, solid, 3–9 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 arching distally, blade bright green, lightly ribbed, linear-ensiform, 6–10 dm × 1.5–2.5 cm;

cauline subtending branches, blade 4.5–6 dm.

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 unequal, outer green, 10–12 cm, herbaceous, inner 6–8 cm, partly 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 copper colored or reddish brown (yellow in forma fulvaurea);

floral tube hollow to ovary, 2–2.5 cm;

sepals widely spreading or arching downward, obovate, with 1–3 prominent veins, 4.5–5.5 cm, glabrous, often with lighter yellow basal signal;

petals spreading or declining with sepals, 4–5 × 1.5–2 cm, base gradually attenuate, apex deeply emarginate;

ovary green, hexagonal, 1.5–1.7 cm;

style convex, not keeled, 1.8–2 cm, crests reflexed, rounded-triangular, margins shallowly toothed;

stigmas 2-lobed, lobes pointed, margins entire;

pedicel 2–4 cm.

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.

remaining green even after seeds mature, oblong-elliptic, hexagonal in cross section, with 6 equally spaced ribs, short beak, 4.5–8 × 2.5 cm.

Seeds

dark brown, pyriform, wrinkled.

in 2 rows per locule, irregular, flattened, 10–15 mm, corky.

2n

= 40.

= 42.

Iris douglasiana

Iris fulva

Phenology Flowering Apr–Jun. Flowering Apr–Jun.
Habitat Open woods, sunny slopes and fields Shallow water or low wet areas
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; IL; KY; LA; MO; MS; TN
[WildflowerSearch map]
[BONAP county map]
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.)

Iris fulva hybridizes with I. brevicaulis to produce I. ×fulvala Dykes, which has reddish purple sepals; with I. giganticaerulea to produce I. ×vinicolor Small; and with I. savannarum to produce I. ×cacique (J. Berry) N. C. Henderson.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 26, p. 384. Treatment author: Norlan C. Henderson. FNA vol. 26, p. 392. Treatment author: Norlan C. Henderson.
Parent taxa Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Californicae Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Hexagonae
Sibling taxa
I. bracteata, I. brevicaulis, I. chrysophylla, I. cristata, I. fernaldii, I. fulva, I. germanica, I. giganticaerulea, I. hartwegii, I. hexagona, I. hookeri, I. innominata, I. lacustris, I. longipetala, I. macrosiphon, I. missouriensis, I. munzii, I. orientalis, I. pallida, I. prismatica, I. pseudacorus, I. pumila, I. purdyi, I. savannarum, I. setosa, I. sibirica, I. tenax, I. tenuis, I. tenuissima, I. tridentata, I. verna, I. versicolor, I. virginica
I. bracteata, I. brevicaulis, I. chrysophylla, I. cristata, I. douglasiana, I. fernaldii, I. germanica, I. giganticaerulea, I. hartwegii, I. hexagona, I. hookeri, I. innominata, I. lacustris, I. longipetala, I. macrosiphon, I. missouriensis, I. munzii, I. orientalis, I. pallida, I. prismatica, I. pseudacorus, I. pumila, I. purdyi, I. savannarum, I. setosa, I. sibirica, I. tenax, I. tenuis, I. tenuissima, I. tridentata, I. verna, I. versicolor, I. virginica
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. fulvaurea
Name authority Herbert G. A. W. Arnott: in W. J. Hooker and G. A. W. Arnott, Bot. Beechey Voy., 395. (1840) Ker Gawler: Bot. Mag. 36: plate 1496. (1812)
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