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giant blue iris

Fernald's iris

Rhizomes

green, extensively branched, forming large clumps, 2–4 cm diam., with pale leaf scars.

many-branched, producing dense clumps, compact, slender, ca. 0.6 cm diam., base covered with remains of old leaves;

roots fibrous.

Stems

2–3-branched, solid, 10–15(–20+) dm.

simple, solid, 2–4 dm.

Leaves

basal 4–6, erect, blade bright green, ensiform, 10–13 dm × 2–3 cm, apex slightly curved;

cauline with blade foliaceous, appearing as elongated spathe, 5–6.5 dm × 2–3 cm, not exceeding flowers.

basal with blade gray-green, usually brilliantly colored basally, drying to unusual gray-green, veins fairly prominent, to 4 dm × 0.7–0.8 cm, often quite glaucous, margins not thickened;

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

Inflorescence units

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

spathes tightly enclosing ovary and pedicel, 15–20 cm, subequal;

outer narrowly lanceolate, keeled, margins pale, narrow, inner margins translucent, broad, scarious.

2-flowered;

spathes opposite, connivent, often flushed red basally, broadly lanceolate, 5–9 cm × 6–11 mm, subequal.

Flowers

perianth blue or blue-purple;

floral tube tubular-prismatic, 9-ribbed and -grooved, 4–5 cm;

sepals blue or blue-purple with white streaks surrounding signal, oval to orbicular-oval, 9.5–11 × 4–5 cm, base abruptly attenuate into claw, apex obtusely angled, signal with raised, yellow, pubescent central ridge, claw green, striate, 4–4.5 × 1–1.2 cm;

petals erect or spreading-erect, spatulate, 7–8.5 × 2–3 cm, base cuneate, apex emarginate;

ovary bluntly 6-angled, 4–4.5 cm;

style blue-violet, keeled, 3.5–4 cm, raised above sepals, crests recurved, 1.5–2 cm, margins sharply and irregularly serrate;

stigmas 2-lobed with 2 triangular teeth;

pedicel columnar, 3.5–5 cm.

perianth pale creamy yellow with gold or gray veins;

floral tube funnelform, 3–6.2 cm, spreading apically to form wide throat;

sepals horizontally spreading, claw with deep yellow median line, oblanceolate to spatulate, 4.5–7 × 1–2 cm, base gradually attenuate into broad claw;

petals narrowly oblanceolate, 4.3–6 × 0.6–1.4 cm, base gradually attenuate into narrow claw;

ovary elliptical, nearly circular in cross section, 1.5–2.3 cm;

style 2.2–3 cm, crests divergent, linear to narrowly oblong, 1–1.7 cm;

stigmas triangular, margins entire;

pedicel 0.9–2.2 cm at anthesis.

Capsules

drooping, bright green, ellipsoid, hexagonal in cross section, with 6 broad, rounded lobes, 8–10 × 3 cm, indehiscent;

after anthesis, flower stem elongates, arching downward to push capsule into water, where walls are broken down and as funiculus is broken, seed rises to surface.

oblong, roundly trigonal, distinctly beaked, 2.5–3.5 cm.

Seeds

in 2 rows per locule, brown, D-shaped, 8–10 mm wide, very corky.

dark brown, wrinkled.

2n

= 44.

= 40.

Iris giganticaerulea

Iris fernaldii

Phenology Flowering Mar–Apr. Flowering Apr–Jul.
Habitat Shallow water or very wet roadside ditches Mixed evergreen forest
Distribution
from FNA
AL; LA; MS
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
Discussion

Iris fernaldii hybridizes with I. douglasiana, I. innominata, and I. macrosiphon.

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

Source FNA vol. 26. FNA vol. 26, p. 387.
Parent taxa Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Hexagonae Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Californicae
Sibling taxa
I. bracteata, I. brevicaulis, I. chrysophylla, I. cristata, I. douglasiana, I. fernaldii, I. fulva, I. germanica, 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
I. bracteata, I. brevicaulis, I. chrysophylla, I. cristata, I. douglasiana, 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 I. elephantina, I. hexagona var. giganticaerulea, I. miraculosa
Name authority Small: Addisonia 14: 5, plate 451. (1929) R. C. Foster: Iridis Sp. Nov., 1. (1938)
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