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

beach-head iris

Rhizomes

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

roots fleshy.

many-branched, producing dense clumps, 3–6 × 1.5–2 cm, covered with remnants of old leaves.

Stems

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

1–2-branched, 1.5–9 dm, exceeding leaves;

branches 1.25–1.5 dm proximal to terminal, but bearing flowers on nearly the same level.

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.

basal with blade green with purple tinge basally, prominently ribbed, ensiform, 0.2–0.45 dm × 1–2 cm, ± glaucous distally;

cauline subtending each lateral branch, blade reduced, 0.5–1.5 dm.

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.

2–3-flowered, lateral units usually 2-flowered;

spathes green flushed with purple, foliaceous, ovate-lanceolate, 2.5–4.5 cm × 5–7 mm, unequal, inner longer than outer, sometimes scarious.

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.

perianth dark blue-violet to red-purple with darker veins;

floral tube ca. 0.7 cm;

sepals 4–6 × 3–5 cm, glabrous, base abruptly attenuate to broad claw with undulate margins;

petals much reduced, 1–2 × 0.3–0.4 cm, widest basally, mostly hidden by bases of outer sepals, apex acuminate, with 3–8 mm bristle;

ovary conspicuously 3-angled, inflated at anthesis, 1.3 cm;

style 2.5 cm, crests overlapping, subquadrate, 0.7 cm, margins incised;

stigmas semicircular, margins entire;

pedicel 2.5–4.5 cm, ± equaling spathes.

Capsules

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

roundly trigonal, 2.5 × 1.3–1.5 cm.

Seeds

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

in 2 rows per locule, light brown, with prominent raphe, D-shaped, 2–3 mm, very smooth.

2n

= 70, 72.

= 34, 36, 38.

Iris virginica

Iris setosa

Phenology Flowering May–Jun. Flowering Jul–Aug.
Habitat Wetlands, margins of lakes and streams Boggy meadows, shores, and dunes
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
AK; BC; YT; e coastal Asia to Japan
[WildflowerSearch map]
[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 setosa was originally described from Siberia; whether our populations are an extension from or were formerly continuous with the Asian ones is not known. Two varieties from Japan, var. hondoensis Honda and var. nasuensis Hara, with 2n = 54 may be triploids.

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

Source FNA vol. 26, p. 390. FNA vol. 26, p. 380.
Parent taxa Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Laevigatae Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Tripetalae
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. pumila, I. purdyi, I. savannarum, 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 I. arctica
Name authority Linnaeus: Sp. Pl. 1: 39. (1753) Pallas ex Link: Jahrb. Gewächsk. 1(3): 71. (1820)
Web links