Iris tenax

Iris Tenax, Coastal Oregon, April 2015

Single Tenax Iridaceae

Iris tenax is a species of flowering plant in the Iridaceae family, commonly known as the Oregon iris or tough-leaved iris. It is native to the Pacific Northwest of North America, particularly found in the states of Oregon and Washington. Iris tenax is a small to medium-sized iris, characterized by its robust and tenacious leaves, from which its specific epithet "tenax" is derived.

Description

Iris tenax typically grows to a height of 10-40 cm. It has a compact rhizome that produces bright green, sword-shaped leaves. The leaves are stiff and can grow up to 30 cm in length. In spring to early summer, the plant bears flowers that are usually purple or lavender in color, although variations can include shades of blue, pink, and rarely, white. Each stem supports a single flower, which is distinguished by its six lobes: three upright standards and three downward-facing falls, with the falls often showcasing a central yellow or white patch with purple veining.

Habitat and Distribution

This species is adapted to a variety of habitats, from coastal meadows and forest clearings to rocky slopes in the mountainous regions of its native range. Iris tenax thrives in well-drained soils and can often be found in open, sunny locations, although it is also tolerant of partial shade.

Cultivation and Uses

Iris tenax is valued in horticulture for its ornamental beauty and resilience. It is used in garden settings for mass plantings, rock gardens, and borders. The plant prefers well-drained soil and moderate watering, with minimal maintenance required once established. It is also known for its resistance to deer and other herbivores.

In addition to its aesthetic appeal, the Oregon iris has been used by indigenous peoples of the Pacific Northwest for various purposes. The tough leaves were traditionally used for weaving baskets and other items, while the rhizomes were sometimes utilized in herbal medicine.

Conservation

While Iris tenax is not currently listed as endangered, its habitat is threatened by urban expansion, agricultural development, and invasive species. Conservation efforts are focused on habitat preservation and the promotion of native plant gardening to support biodiversity.

Gallery

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See Also

• Iridaceae
• Flora of the Pacific Northwest
• Horticulture
• Conservation biology