- Kingdom: Plantae
- (unranked): Angiosperms
- (unranked): Monocots
- Order: Asparagales
- Family: Iridaceae
- Subfamily: Iridoideae
- Genus: Iris
- Subgenus: Limniris
- Species: I. tenax
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, from white to deep purple. Large, delicate, lavender to deep purple (sometimes white, rarely yellow) flowers, commonly with dark violet veins, grow at top of short stalks in dense clumps. Flowers usually occur singly but sometimes in pairs.
- Leaves: Leaves mostly basal, narrowly linear, up to 4 dm. long and 2-6 mm. broad; cauline leave few, reduced upward.
- Flowers: Lavender or blue to purple, but occasionally white to yellow or pinkish, subtended by a pair of involucral leaves which may be 2 cm. apart; pedicels 1-4 cm. long; perianth parts fused in a tube at the base, the tube 6-10 mm. long; sepals 3, oblanceolate to obovate, 5.5-6.5 cm. long, spreading; petals 3, oblanceolate, 3.5-6 cm. long, erect; style branches 25-30 mm. long with 2 terminal lobes 8-12 mm. long; stigmas triangular; ovary inferior.
- Fruit: Capsule 3-celled, leathery, 25-35 mm. long
Prairies and pastures, open oak and coniferous forests, low elevations
A tincture of the whole plant, or the bulbous stems, is given in the treatment of bilious vomiting and is recommended for treating depression. A fiber from the leaves is used in weaving and making ropes. The fiber is buoyant, strong and durable.