Iris douglasiana, the Douglas iris, is a common wildflower of the coastal regions of Northern and Central California and southern Oregon in the United States. It grows mainly at lower elevations, below 100 m, though it is occasionally found at heights of up to 1000 m. It is most common in grasslands near the coast. Consumption may cause severe discomfort. This is a typical beardless iris of subgenus Limniris, series Californicae, growing from a rhizome that is typically less than a centimeter in diameter. Its leaves are about 2 cm wide. The flowers, appearing from April to June, are usually a purplish-blue, though occasionally white or yellow flowers are found. Two or three flowers are found on each stem, which is of variable height, ranging from 15 - 80 cm tall.

Taxonomy

It was first described by 19th century botanist David Douglas in Monterey, California. It was first published by the british botanist William Herbert in 'Bot. Beechey Voy.' 9 on page 395 in 1840. Several varieties have been recognized, for example Iris douglasiana var. altissima and Iris douglasiana var. oregonensis, but the species is highly variable and the varieties may not be well enough defined to be of much practical use. The Douglas iris hybridizes freely with several other species; its natural hybrid with I. innominata has been designated as Iris ×thompsonii, and the garden hybrid with the same species as Iris ×aureonympha. This plant has gained the Royal Horticultural Society's Award of Garden Merit.