OENOTHERA. Evening primrose. The Americas. Rugged perennials of quite variable habit, prized for their abundance of broad-petalled, often fragrant flowers during the warmer months. Many open in the evening and close by mid-morning. However, most of the following are day blooming. Sun, reasonably well drained soil, moderate to little watering when established. Hardiness varies.

berlandieri (speciosa). Mexican evening primrose. A carpeting species, useful for ground cover. It travels by short underground rhizomes, eventually covering an area several feet broad. Each seasonal shoot has several narrow, dark green leaves and is tipped by a cluster of large, silvery pink blossoms. It blooms throughout the summer and early fall. The basal leaves are evergreen, at least in milder climates. ‘Siskiyou’ is the name given by California growers to an exceptionally dense, floriferous selection introduced by Siskiyou Rare Plant Nursery in Oregon. ‘Woodside’, selected at Filoli Gardens, is distinguished by nearly white flowers, opening from pink buds. 10^oF or less.

caespitosa. A high desert species of California and the West. It makes tightly clustered crowns of toothed, lance shaped, greyish green leaves. Among these nestle fragrant, broad petalled white flowers. The flowers are nearly 4" across in this selection by Jim Marshall. A good subject for the rock garden, banks and slopes. It needs well drained soil and resents excessive moisture. Probably 0^oF.

missouriensis. A beautiful plant for the rock garden. Several short, prostrate stems radiate from the base, lined with 4" narrow, greyish green leaves. Each stem is tipped by a tight cluster of buds from which brilliant yellow 4" blossoms open successively in summer and fall. ‘Greencourt Lemon’ is distinguished by more silvery leaves and pale yellow flowers. Winter deciduous. Below 0^oF.

odorata. Unlike our other selections, this one is genuinely an “evening” primrose, the flowers opening in late afternoon and closed by midmorning. It forms tight basal clumps, with crowns of narrow, wavy-edged 3-4" leaves, dark green when young and reddening with age. The flower stalks are produced mostly in late spring, though often again in fall. They are held erect, rising to 1' or more to display a succession of large, very fragrant yellow blossoms. Probably 10^oF or less.

rosea. This species makes low mounds 1' or less tall by eventually 2-3' in time. It is closely branched, with slender reddish stems and shiny dark green 1-2" leaves. In summer it bears many rose pink blossoms, about 3/4" across in our material, opening during the day. It should be hardy to 15^oF or less.

tetragona. This species forms permanent clumps of basal rosettes with broad, pointed, shiny 2" leaves, evergreen for us but perhaps winter deciduous in colder climates. Leafy 1-2' blooming stems rise from the rosettes in spring and summer, bearing a wealth of brilliant yellow 1½" blossoms. Probably 0^oF or below.