Hooker’s evening primrose (Oenothera elata ssp.) can grow to a height of seven feet – a tall plant in a genus whose members are usually low-growing.
As I understand the current status, Hooker’s evening primrose is now considered one of the many subspecies of Oenothera elata. Previously it was a species unto itself, O. hookeri.
This native biennial or perennial is found throughout the Western United States, mostly in wetland areas. These plants were photographed on the shore of Baum Lake (Shasta County CA).
The first year Hooker’s evening primrose is a basal rosette of leaves. During the second year a stout, reddish, freely branched stem arises from the tap root. The alternate leaves on the stem are lancelike and sessile (no stalk). At the end of the stem is a cluster of flowers. These blooms are large and fragrant with four heart-shaped petals, four sepals, eight stamens with pollen enmeshed in cobwebby threads and a single, long, slender inferior ovary. The fruit contains four chambers each with two rows of seeds. This subspecies has “blisters” at the base of the plant hairs.
Hooker’s evening primrose flowers are yellow and open in the evening. During the day the flowers are closed. As the flowers age and wilt they turn from yellow to orange or a reddish orange color. Pollination, particularly by hawk or Sphinx moths, occurs during the night.
The young roots, leaves and seedpods of Hooker’s evening primrose can be cooked and eaten as a vegetable, although some people object to their mucilaginous texture. Some people use a tea made from the stems and leaves to treat colds, sore throats and gastrointestinal irritations. Oil pressed from the evening primrose seeds is high in gamma linolenic acid (GLA). Clinical studies have shown some success in using Hooker’s evening primrose oil to treat heart and vascular diseases, arthritis, asthma and premenstrual syndrome.
Giant evening primrose and western evening primrose are other common names for Hooker’s evening primrose.
Since the Hooker’s evening primrose flowers were closed during the day when I found them an evening trip to Baum Lake is in order so I can photograph the open flowers.
A post on another evening primrose species is “Tansyleaf Evening Primrose” 02-26-14.