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Hartweg's iris, rainbow iris, Sierra iris

blue flag, blue iris, harlequin blueflag, iris versicolore

Rhizomes

creeping, not producing dense clumps, covered with remains of old leaves, slender to moderately thick, 0.5–0.9 cm diam.;

roots fibrous.

pale pinkish white, freely branching, forming large clumps, 1–2.5 cm diam., clothed with remnants of old leaves;

roots fleshy.

Stems

simple, solid, 0.5–3 dm.

1–2-branched, solid, 2–6 dm.

Leaves

basal deciduous, blade pale green, not pink basally, 2–4.5 dm × 0.2–0.6(–1) cm, sometimes glaucous, margins not thickened;

cauline usually 1–several, spreading, sheathing for about 1/2 length, foliaceous, blade not inflated.

basal with blade green to grayish green, often purplish basally, centrally thickened in mature leaves, prominently veined, narrowly ensiform, 1–8 dm × 1–3 cm;

cauline 1–2, blade linear-lanceolate, seldom equaling stem.

Inflorescences/Inflorescence units

1–2(–3)-flowered;

spathes divergent, separated by 1.5–4 cm, linear to linear-lanceolate, unequal, outer 5–11 cm × 4–7 mm, inner 5–6 cm × 2–3 mm, herbaceous, apex acute.

compact, units 2–4-flowered;

spathes never foliaceous, 3–6 cm, unequal, outer shorter than inner, thickly chartaceous to scarious, margins shiny, darker in color.

Flowers

perianth lavender, cream, or pale to deep yellow;

floral tube funnelform, 0.5–1(–1.5) cm;

sepals oblanceolate, 4–7 × 1.4–2 cm, base gradually attenuate;

petals narrowly oblanceolate, 3.5–6 × 0.5–1.1 cm, widest at about 1/2 their length, base abruptly attenuate, claw 1–2 mm wide;

ovary nearly cylindrical, 1–2 cm;

style 1.6–3 cm, crests overlapping, obtusely angled, 0.5–1.1 cm;

stigmas acutely triangular, margins entire;

pedicel 0.5–2.5 cm at anthesis, lengthening to 3.5–7.5 cm at maturity.

perianth violet-blue to rarely white;

floral tube funnelform, constricted above ovary, 1–1.2 cm;

sepals ovate to reniform, 4–7.2 × 1.8–4 cm, base abruptly attenuate, signal a pubescent, greenish or greenish yellow patch surrounded by heavily veined purple on white at base of blade;

petals lanceolate to oblong-lanceolate, 2–5 × 0.5–2 cm, much shorter than sepals, firm, apex rarely emarginate;

ovary rounded-triangular in cross section, somewhat inflated, 0.8–2 cm;

style 3–3.5 cm, base not auriculate, margins entire or toothed, crests reflexed, 0.7–1.5 cm;

stigmas unlobed, triangular or rounded-triangular, margins entire;

pedicel 2–8 cm, frequently exceeding spathe.

Capsules

oblong-oval, 3-angled, tapering abruptly at either end, 2–3 cm.

often persistent over winter, ovoid to oblong-ellipsoid, conspicuously beaked, obtusely triangular in cross section, 1.5–6 cm, tardily dehiscent.

Seeds

brown, irregularly D-shaped, wrinkled.

dark brown, D-shaped, 5–8 mm, shiny, thin, hard, regularly pebbled, not corky.

2n

= 40.

= 108.

Iris hartwegii

Iris versicolor

Phenology Flowering Jun. Flowering May–Jul.
Habitat Yellow-pine forests on sunny or partially shaded slopes Marshy places, along roadsides, shores, and along mountains
Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; MA; MD; ME; MI; MN; NH; NJ; NY; OH; PA; RI; VA; VT; WI; MB; NB; NL; NS; ON; PE; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Plants with pedicels 2.8–4.7 cm, and flowers light purple or bluish violet have been recognized as subsp. australis. Plants having a 3-flowered inflorescence unit, leaves about 1 cm wide, and pale yellow flowers with golden yellow veining have been called subsp. columbiana. Plants having both flowers open at the same time rather than consecutively, pedicels averaging only 1 cm, long narrow style arms and crests, and floral tubes 1.2–1.5 cm have been named subsp. pinetorum.

Iris hartwegii hybridizes with I. douglasiana, I. innominata, I. macrosiphon, I. munzii, I. tenax, and I. tenuissima. It is known from Butte County to Kern County.

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

E. Anderson (1936) showed rather conclusively that Iris versicolor arose as an amphidiploid between I. virginica (n = 35) and I. hookeri (I. setosa var. canadensis) (n = 19). Back-cross hybrids have been produced both ways: I. virginica × I. versicolor producing Iris ×robusta E. S. Anderson, and I. versicolor × I. hookeri producing I. ×sancti-cyri J. Rousseau.

Iris versicolor is becoming a weed in New Brunswick, Prince Edward Island, and Nova Scotia. Livestock will not eat iris foliage, but feed voraciously on the competition, thus giving the irises plenty of room to expand.

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

Source FNA vol. 26, p. 385. FNA vol. 26, p. 390.
Parent taxa Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Californicae Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Laevigatae
Sibling taxa
I. bracteata, I. brevicaulis, I. chrysophylla, I. cristata, I. douglasiana, I. fernaldii, I. fulva, I. germanica, I. giganticaerulea, 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. 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. virginica
Synonyms I. hartwegii subsp. australis, I. hartwegii var. australis, I. hartwegii subsp. columbiana, I. hartwegii subsp. pinetorum, I. pinetorum
Name authority Baker: Gard. Chron., n. s. 6: 323. (1876) Linnaeus: Sp. Pl. 1: 39. (1753)
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