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Bransford, W.D. and Dolphia

Iris tenax

Iris tenax Douglas ex Lindl.

Toughleaf Iris, Tough-leaf Iris, Oregon Iris

Iridaceae (Iris Family)

Synonym(s):

USDA Symbol: IRTE

USDA Native Status: L48 (N)

A tufted perennial with narrow, grass-like leaves and showy flowers on thin, wand-like stems to 14 in. tall. Leaves slightly exceed the flower stem in height. The flower of this species shows considerable variation in color. Large, delicate, lavender to deep purple to cream to yellow (rarely white) flowers, commonly with dark violet veins, grow at top of short stalks in dense clumps of leaves. Flowers usually occur singly but sometimes in pairs.

In the Willamette Valley of Oregon these handsome flowers provide brilliant color displays along highways. Tenax, Latin for "tenacious," refers to the tough leaves; Native Americans used fibers from the edges of the leaves of some western species to make strong, pliable rope and cord.

From the Image Gallery

2 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Fruit Type: Capsule
Size Notes: Up to about 14 inches tall.
Leaf: Yellow-Green

Bloom Information

Bloom Color: White , Pink , Yellow , Purple
Bloom Time: Apr , May , Jun

Distribution

USA: CA , OR , WA
Canada: BC
Native Distribution: S.w. WA, s. to s.w. OR; intermittent to n. CA as var. klamathensis
Native Habitat: Open prairies; logged land; open areas in oak & conifer forests

Growing Conditions

Water Use: Medium
Light Requirement: Part Shade
Soil Moisture: Dry
CaCO3 Tolerance: Medium
Soil Description: Drier, well-drained soils.
Conditions Comments: Good rock garden plant. Does not spread quickly, but will form large clumps.

Benefit

Use Wildlife: Hummingbirds
Warning: Some Iris species are known to be poisonous to humans and animals if eaten (especially the rhizome, or root), and it is likely that all irises contain toxins. Plant juices can cause blisters on the skin. POISONOUS PARTS: Rhizomes (thickened roots) and rootstocks, fresh or dry. Minor skin irritation when touched, low toxicity if ingested. Symptoms include nausea, vomiting, abdominal pain, diarrhea, elevated temperature following ingestion; skin irritation upon contact with seeds, rootstock, or cell sap. Toxic Principle: Irisin, iridin, or irisine. (Poisonous Plants of N.C.)
Conspicuous Flowers: yes
Attracts: Hummingbirds

Propagation

Seed Collection: Easily collected from the large capsules.
Commercially Avail: yes

Find Seed or Plants

Find seed sources for this species at the Native Seed Network.

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is on display at the following locations:

Native Seed Network - Corvallis, OR

Bibliography

Bibref 928 - 100 easy-to-grow native plants for Canadian gardens (2005) Johnson, L.; A. Leyerle

Search More Titles in Bibliography

Web Reference

Webref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Additional resources

USDA: Find Iris tenax in USDA Plants
FNA: Find Iris tenax in the Flora of North America (if available)
Google: Search Google for Iris tenax

Metadata

Record Modified: 2023-02-14
Research By: TWC Staff

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