(Pale Yellow Iris). A non-native plant of marshes and wet meadows, it is similar to the Blue Flag Iris; the plant grows 1 to 3 foot high on leafless flower stems that branch once. The upper part of the stem forms a spathe covering the ovary of the flower. Flowers are about 4 inches wide, 2 to 3 flowers per stem, that are similar to many beardless iris, on a flower stalk that is shorter than the outer leaves as the large photo below shows. The 3 outward spreading drooping sepals, which surround the true flower, can vary in color, pale yellow being most common, have short claws and are usually purple veined as the photos show in the base area where there is a deeper color patch known as a 'signal'. The petals (called 'standards' in the Iris genus) are smaller than the sepals and curve upward. They are the same color with smooth margins. The style of the fruiting parts in the center of the flower, forms flat petal like branches with spreading crests, that reflex outward atop the base of the sepals and cover the anthers and sigma, providing rain cover for the pollen. The nectar of the plant is in glands at the base of the petals. Fruit: Seed capsules have three chambers with two rows of seeds, which turn dark brown at maturity. The seeds are flat, D shaped and corky and distributed by wind when the capsule opens. Leaves are sword shaped, 20 to 40" long, with a raised mid-rid. Blooms are usually the last half of June. The plant is considered invasive - see notes at bottom of page.

Habitat: The plant spreads via stout rhizomes; it forms clumps as the rhizomes separate. It can grow in a variety of soils with pH ranging from 3.6 to 7.7 and tolerates low oxygen, but it must have full to partial sun and moist conditions. Names: The genus name, Iris, is after the Greek goddess of the rainbow. The species pseudacorus is derived from two Greek words, pseudo, meaning 'false' and Acorus, the Sweet Flag plant; all this meaning that this is a 'false Sweet Flag'. This is due to the rhizomes (and also the leaves after flowering) resembling those of Sweet Flag - another plant of marshes. The author name 'L.' is for Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. Comparison: The other iris in the Garden marsh is Blue Flag, Iris versicolor L. which is a our native marsh iris that is indigenous to the Garden.