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fleur-de-lis, horticultural iris, iris jaune, pale-yellow iris, yellow flag, yellow iris, yellow water iris

prairie iris, savanna iris

Rhizomes

pink, freely branching, producing extensive clumps, 2–3 cm diam., with fibrous remains of old leaves;

roots fleshy.

greenish, freely branching, forming large, open clumps, 2–2.5 cm diam., fleshy, with fibrous bases of old leaves not covering rhizome but persisting on ringlike scars.

Stems

usually 1-branched, solid, 7–15 dm.

1-branched, solid, 3–10 dm.

Leaves

basal deciduous, at first erect, then recurved, blade dark green, with prominent median thickening, 4–10 dm × 2–3 cm, slightly glaucous basally;

cauline equaling inflorescence unit.

basal usually dying back shortly after anthesis, blade bright green, 6–10 dm × 0.8–2 cm, sometimes glaucescent;

cauline with blade elongate, linear-attenuate, 15–20 cm, exceeding flowers.

Inflorescence units

4–12-flowered;

spathes green with brown margins, outer spathe strongly keeled, inner without keel, 6–9 cm, subequal, margins not scarious.

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

spathes lanceolate, subequal or unequal, apex acute;

outer 8–10 cm, herbaceous, margins scarious;

inner 6–9 cm, completely scarious.

Flowers

perianth bright yellow;

floral tube 0.6–0.8 cm, with no constriction into ovary;

sepals bright yellow or cream colored, lanceolate to ovate or suborbiculate, 5–7.5 × 3–4 cm, base abruptly attenuate, claw ca. 1/2 length of limb, signal a darker yellow basal patch limited by short, brown lines;

petals without veining, lanceolate to spatulate, 2–3 cm;

ovary triangular in cross section with concave sides and narrow groove at each angle, 1.5 cm;

style keeled, 3–4 cm, crests spreading, 1–1.2 cm, laciniate at apex;

stigmas rounded with prominent tongue;

pedicel 2.5–7 cm.

perianth blue to blue-violet (white in forma albispiritis);

floral tube funnelform, 1.2–1.5 cm;

sepals blue or pale violet with flecks of white and lines of deeper blue on either side of ridge, spatulate, elliptic to ovate, 7–8 cm, apex acuminate, ridge yellow, linear, extending to about middle of limb, finely pubescent, claw light green, striated, ribbed, 1–1.2 cm;

petals erect or spreading-erect, deep blue, linear to narrowly linear-spatulate, 6–7.5 cm, base abruptly attenuate into claw, claw channeled, green with darker lines, margins pale;

ovary bluntly 3-angled, ridged at each angle and on faces between angles;

style linear-acute, 5–6 cm;

crests ovate, 1–2 cm, margins sharply and irregularly toothed;

stigmas broadly 2-lobed, margins crenate;

pedicel 1.6–2 cm.

Capsules

prismatic to oblong-ovoid, obscurely 3-angled with obvious groove at each angle, 3.5–6 cm, beak 5 mm.

ellipsoid, round in cross section, roundly 6-lobed, with 6 sharp, winglike, equally spaced ridges converging to form stout beak at apex, 6–10 cm, dehiscence loculicidal.

Seeds

D-shaped, flattened, 6–7 mm, corky, lustrous.

in 1 row per locule, brown, circular or uneven, flattened, 8–12 mm diam, very corky.

2n

= 34.

= 44.

Iris pseudacorus

Iris savannarum

Phenology Flowering Apr–Jun. Flowering late Mar–early Apr.
Habitat Swamps, wet shores of rivers and lakes Wet ditches, margins of lakes, streams, and swamps
Distribution
from FNA
AL; AR; CA; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; ME; MS; NC; NH; NY; OH; PA; RI; SC; TN; VA; WA; WV; BC; MB; NB; NF; NS; ON; PE; QC; Eurasia; n Africa [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA
[WildflowerSearch map]
[BONAP county map]
Discussion

Iris savannarum has often been included in I. hexagona, but differs in several ways. The capsules of I. hexagona are more obviously hexagonal, with smooth faces alternating with those that have two rounded lobes, whereas the capsules of I. savannarum are more rounded but with six obvious ridges, almost of winglike proportions. Iris hexagona has yellow-green leaves instead of the brighter green of I. savannarum. The leaves of I. savannarum die back after anthesis, while those of I. hexagona remain green. The flowering period of I. savannarum is almost one month earlier than that of I. hexagona in the area where both are known to grow. The sepals of I. savannarum are more acute at the apex than those of I. hexagona.

Iris savannarum has been hybridized with Iris fulva to produce I. ×cacique (J. Berry) N. C. Henderson.

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

Source FNA vol. 26, p. 390. FNA vol. 26, p. 393.
Parent taxa Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Laevigatae Iridaceae > Iris > subg. Limniris > sect. Limniris > ser. Hexagonae
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. 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. 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. setosa, I. sibirica, I. tenax, I. tenuis, I. tenuissima, I. tridentata, I. verna, I. versicolor, I. virginica
Synonyms I. albispiritus, I. hexagona var. savannarum, I. kimballiae, I. rivularis
Name authority Linnaeus: Sp. Pl. 1: 38. (1753) Small: Addisonia 9: 57, plate 317. (1925)
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