[Evening Primroses: The Genera Camissonia, Chylismia, Chylismiella, Eremothera, Taraxia and Tetrapteron East of the Cascade Mts. of Oregon and Washington]

Hilgard's Evening-primrose, Hilgard's Suncup

Neoholmgrenia hilgardii

Synonyms: Camissonia hilgardii, Holmgrenia hilgardii, Oenothera andina, Oenothera andina var. hilgardii, Oenothera contorta, Oenothera contorta var. hilgardii, Oenothera hilgardii

Hilgard's evening-primrose observed on balds near the summit of Manashtash Ridge near the Manastash Observatory, southwest of Ellensburg, WA......May 27, 2019.

Hilgard's evening-primrose as seen on the north bank of Douglas Creek in central Washington.

Hilgard's Evening-primrose, Hilgard's Suncup: Neoholmgrenia hilgardii (Synonyms: Camissonia hilgardii, Holmgrenia hilgardii, Oenothera andina, Oenothera andina var. hilgardii, Oenothera hilgardii)

The photo at right shows slender evening-primrose at the Dalles Airport.........6/16/1990.

Characteristics:

Hilgard's evening primrose is a small annual which is sometimes lumped as a variety of obscure evening-primrose, Camissonia andina. Its stems are simple to freely branched, ascending from 3-15 cm high. Its leaves are alternate, linear to linear-spatulate in shape, and 5 to 25 mm long and 0.5 to 2 mm wide.

The yellow flowers are crowded into short, linear-bracteate spikes. The sepals are separately reflexed. The individual petals are yellow, ovate in shape and up to 4.5 mm long. The filaments are short while the anthers are about 0.5 mm long. The style is usually exserted from the floral tube and the stigma is capitate. The fruit is a capsule that is fusiform-lanceolate in shape, wider at the base and tapering gradually to the tip. The capsules are 4-8 mm long.

The similar Camissonia andina has smaller petals, typically up to 1.5 mm long.

Habitat:

Hilgard's evening-primrose may be found in dry fields and on sagebrush scabland from the lowlands into the foothills.

Range:

Hilgard's evening-primrose may be found in central and eastern Washington.

Paul Slichter