Iris macrosiphon

Common Names

Bowltube Iris, Ground Iris, Long Tubed Iris, Bowl Tube Iris

Summary

Bowltube iris is a California-endemic rhizomatous perennial forming tufted clumps with basal blue-green leaves longer than the short flowering stems, reaching about 0.5–0.6 m tall. Flowers are highly variable in color, ranging from deep indigo blue and purple to cream, white, or yellow, with a long floral tube and bowl-shaped form; bloom occurs in spring and fragrance is described as fruity and sweet. It inhabits sunny grassy slopes, meadows, and open woodlands below 1000 m in California.

Cultivation requires well-drained lime-free soil and positions in full sun to partial shade with regular moisture; it exhibits summer dormancy in dry seasons and can be propagated by seed sown as soon as ripe in a cold frame or by division after flowering; larger clumps can be replanted, and it is also grown as an ornamental plant. Leaves were traditionally used for fiber cordage by Indigenous peoples; edible uses are unrecorded; hardiness is USDA zones 7–10; the plant is generally deer and rabbit resistant.

Lifecycle

Perennial

Height

12-24 inches

Spread

10-12 inches

Hardiness Zones

Zones 7-10

Sunlight Requirements

Ideally full sun. Tolerates partial sun and partial shade.

Soil Type

Loamy, well-drained soil rich in organic matter, lime-free, pH 6.0–8.0

Soil Drainage

Well-drained

Soil pH

6.0-8.0

Bloom Color

Indigo blue to yellow, including lavender, purple, white, and cream

Bloom Time

Spring

Foliage Color

Green to blue-green

Fall Foliage Color

No autumn foliage

Leaf Lifecycle

Deciduous

Growth Rate

Moderate

Seasons of Interest

Spring and Summer

Propagation Methods

Seeds, Division

Attracts Wildlife

Attracts butterflies and other pollinators