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slender blue iris

crested iris, dwarf crested 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.

producing fleshy roots, and 2–8 cordlike branches at apex, cordlike portion 2–3 dm × 1–2 mm, gradually enlarging to 8–12 mm diam., nodes with brown, scalelike leaves and rarely roots.

Stems

simple or 1–2-branched, 3–8 dm.

simple, 2.5–4.5 cm.

Leaves

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

cauline 1–4, erect.

basal 6–8, proximal 2–3 sheathing, blade light brown with darker brown line along midrib at base, falcate, scarious, distal 4–5 not sheathing, blade green or yellowish green, with few, subprominent veins, broadly ensiform, slightly falcate, to 1.5 dm × 1–2.5 cm, enlarging to 4 dm after anthesis;

cauline 2–3, sheathing, proximal very similar to basal leaves, distal 1 or 2 reduced, herbaceous, blade falcate, not inflated.

Inflorescence units

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

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

1–2-flowered;

spathes green, sharply keeled, somewhat inflated, 2–6 cm, unequal, outer shorter than inner.

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.

perianth blue, lilac-purple, or white;

floral tube filiform, widening distally, 4–8 cm, lifting expanded portion of flower out of spathes;

sepals spreading, with 3 parallel, toothed, crested ridges on white signal bordered with purple, tapering gradually into claw, 3–6 × 1.5–2.5 cm, base gradually attenuate, apex rounded, emarginate;

petals spreading, same color as sepals, oblanceolate, 3–4 × 1–2 cm;

ovary triangular, with shallow groove along each face, 0.6–1 cm;

style 1.5 cm, crests narrowly triangular, 6–9 mm;

stigmas oblong, margins entire;

pedicel 0.7–1.8 cm.

Capsules

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

usually enclosed in spathes, oval, sharply triangular, each angle ridged, 1–1.5 cm.

Seeds

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

yellowish brown, 3.2–3.5 mm, smooth, with narrow, white appendage wrapped around seed, 3.4–4 mm, quickly drying upon exposure to air.

2n

= 42.

= 24, 32.

Iris prismatica

Iris cristata

Phenology Flowering Apr–Jul. Flowering Apr–Jul.
Habitat Swampy, peaty soil Rich woods, ravines, bluffs, usually in calcareous 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]
from FNA
AL; AR; DC; GA; IA; IL; IN; KY; MD; MO; MS; NC; OH; OK; PA; SC; TN; VA; WV
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 26, p. 395. FNA vol. 26, p. 377.
Parent taxa Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Prisimaticae Iridaceae > Iris > subg. Limniris > sect. Lophiris
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
I. bracteata, I. brevicaulis, I. chrysophylla, 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. virginica
Synonyms Neubeckia cristata
Name authority Pursh: Fl. Amer. Sept. 1: 30. (1814) Solander ex Aiton: Hort. Kew. 1: 70. (1789)
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