The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

iris de virginie, southern blue flag, Virginia iris

dwarf iris

Rhizomes

many-branched, forming dense clumps, 2–4 cm diam., usually covered with remnants of old leaves;

roots fleshy.

freely branching, producing dense clumps, 1–1.5 cm diam.

Stems

rather weak, often falling over after flowering, solid, usually 1-branched, 5–10 dm.

absent or not more than 1 cm.

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.

ascending-spreading;

blade grayish green, ensiform or slightly falcate, 8–10 cm × 6–15 mm at anthesis, increasing to 15–20 cm in length on innovations after flowering, dying back in autumn, new growth only in spring, glaucous.

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.

1-flowered, sessile in spathes;

spathes 5–10 cm;

outer darker green than inner, inner closely shielding floral tube.

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.

floral tube with 3 purple stripes in line with midrib of petals, slender, 6–10 cm × 2–3 mm, lifting expanded portion of flower out of spathes;

sepals yellow, blue, or purple, with yellowish or bluish beard, often with contrasting spot around beard at base of limb, 4–5 × 1.2–2 cm;

petals with darker veins near base, rounded-ovate, broader than sepals, 4–5 × 2.2–2.7 cm, narrowing abruptly to brown-veined claw, apex emarginate;

ovary rounded-trigonal, ca. 1 cm × 4–5 mm;

style crests triangular, margins serrate distally;

stigmas rounded on distal margin, margins entire;

pedicel absent.

Capsules

ovoid, ellipsoid, or long-cylindric, trigonal or polygonal in cross section, 3–6 × 1–2 cm.

borne on tips of rhizomes at ground level or slightly below, rounded-trigonal, with short portion of dried floral tube forming tip, smooth, 2–3.5 × 1.5–2 cm, dehiscing while green.

Seeds

in 2 rows per locule, pale brown, usually D-shaped, 5–8 mm, pitted, corky.

usually in 2 rows per locule, light brown, subspherical, 3–5 mm diam., wrinkled.

2n

= 70, 72.

= 30, 31, 32, 36.

Iris virginica

Iris pumila

Phenology Flowering May–Jun. Flowering late Mar–mid May.
Habitat Wetlands, margins of lakes and streams Dry, grassy areas
Distribution
from FNA
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
[WildflowerSearch map]
[BONAP county map]
from FNA
IL; IN; MI; OH; c Europe; e Europe [Introduced in North America]
[BONAP county map]
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.)

Iris pumila has been shown to be a natural amphidiploid hybrid between I. pseudopumila Boissier & Heldreich and I. attica Tineo, both 2n = 16. Like many other such hybrids, its range of variability is so extensive that many of its forms have been given specific names. In spite of the variability in color and size, it is now recognized as a distinct species. During the past 50 years, it has been crossed repeatedly with several other species, including I. germanica and its mixed progeny, and this has introduced patterns from the tall-bearded iris into the dwarfs, and vice versa. The ranges of flowering season and plant height are now almost continuous from one extreme to the other, and intermediate groups are now recognized.

Iris pumila is widely grown in gardens and often persists for years after cultivation around old dwellings and along roadsides. It is thus extremely difficult to document and map its spontaneous occurrence. Although most, if not all, of the modern dwarf irises are of hybrid parentage, a number of herbarium specimens from the nineteenth century seem to represent wild forms of I. pumila.

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

Source FNA vol. 26, p. 390. FNA vol. 26, p. 375.
Parent taxa Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Laevigatae Iridaceae > Iris > subg. Iris
Sibling taxa
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. versicolor
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. purdyi, I. savannarum, I. setosa, I. sibirica, I. tenax, I. tenuis, I. tenuissima, I. tridentata, I. verna, I. versicolor, I. virginica
Synonyms I. caroliniana, I. georgiana, I. shrevei, I. virginica var. shrevei
Name authority Linnaeus: Sp. Pl. 1: 39. (1753) Linnaeus: Sp. Pl. 1: 38. (1753)
Web links