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

slender blue iris

beardless iris

Rhizomes

superficial or only slightly buried in peaty soil, cordlike portions usually 1-branched, 40 cm × 2–5 mm, bearing scalelike leaves at nodes;

nodal roots absent.

Stems

simple or 1–2-branched, 3–8 dm.

Leaves

basal with blade slightly ribbed, 3–6 dm × 0.2–0.5 cm;

cauline 1–4, erect.

Inflorescence units

1–3-flowered, branch units 1–2-flowered;

spathes pale brown, narrowly lanceolate, 2–4 cm, scarious or partially membranaceous.

Flowers

perianth pale blue or blue-violet;

floral tube 0.2–0.3 cm;

sepals pale violet, veined deep violet basally, ovate, 4–5 × 1.3–2 cm, base abruptly attenuate;

petals lavender, oblanceolate, 3.5–4.5 × 0.7–1.5 cm;

ovary trigonal, sharply angled;

style arched, narrow, 2–3 cm, crests divergent, quadrate, 0.5–0.7 cm, margins serrate;

stigmas sharply triangular;

pedicel somewhat flattened, 3–7 cm, exserted from spathe.

Capsules

sharply 3-angled, almost winged, 3–4 × 1.2–1.4 cm, concave faces 6–14 mm wide.

Seeds

in 1 row per locule, buff to dark brown, pyriform, with convex sides, 3–4 mm, smooth.

Sepals

without beard, but with signal of crests or ridges, distinct lines or dots, or a patch of contrasting color

2n

= 42.

Iris prismatica

Iris subg. Limniris

Phenology Flowering Apr–Jul.
Habitat Swampy, peaty soil
Distribution
from FNA
AL; CT; DE; GA; KY; MA; MD; ME; NC; NH; NJ; NY; RI; SC; TN; VA
[WildflowerSearch map]
[BONAP county map]
North America; Eurasia
Discussion

Species ca. 82 (31 in the flora).

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

Source FNA vol. 26, p. 395. FNA vol. 26, p. 377.
Parent taxa Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Prisimaticae Iridaceae > 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. 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
Subordinate taxa
Synonyms I. section Limniris, subg. Limniris
Name authority Pursh: Fl. Amer. Sept. 1: 30. (1814) (Tausch) Spach: Ann. Sci. Nat., Bot., sér. 3, 5: 99. (1846)
Web links