- Source: Neoholmgrenia hilgardii
Neoholmgrenia hilgardii is an annual flowering plant in the Onagraceae family with the common name Hildgard's suncup. It is a narrow endemic native to central Washington State. This species was first described as Oenothera hilgardii by Greene, and was transferred to the genus Neoholmgrenia in 2009 by W.L.Wagner & Hoch.
Description
Neoholmgrenia hilgardii is a small annual plant up to 15 cm tall, with a crowded tuft of leaves and yellow flowers atop nearly bare stems, which may be single or grow in a cluster. The linear to narrowly spatulate green leaves are up to 25 mm long and 2 mm wide, but often smaller. Both the stem and the leaves are sparsely covered with fine short appressed hairs. The proportionally-large lemon yellow flowers appear in late spring and have 4 ovate petals up to 5 mm long, born singly on short pedicels. The pedicels arise crowded among the alternate leaves and the flowers usually appear nestled near the foliage. The 8 stamens have bright yellow filaments topped by paler anthers.
The very similar species Neoholmgrenia andina is distinguished mostly by much smaller flowers and has a wider range including Oregon and Idaho.
Range and habitat
Neoholmgrenia hilgardii grows in summer dry areas of the Columbia Plateau at moderate elevations in sparsely vegetated areas and among sagebrush. There is a possible historical record in Multnomah Country, Oregon.