[Spikeprimroses and Willowherbs: The Genus Epilobium in the Columbia River Gorge of Oregon and Washington]

Brook Spike-primrose, Brook Willowherb, Stiff Spike-primrose, Torrey's Epilobium, Torrey's Willowherb

Epilobium torreyi

Synonym: Boisduvalia stricta

Flower of brook spike-primrose as seen at Catherine Creek in the Columbia River Gorge......June 3, 2009. Note the numerous spreading hairs on the stem and leaves.

Characteristics:

Stiff spike-primrose is also known as brook spike-primrose. It is an annual wildflower with one to many branched stems arising at the base. The branches when present are closely oriented to the central stem. The herbage is grayish in color due to a dense covering of soft, straight, eglandular hairs. The numerous leaves are linear or narrowly lanceolate with entire to occasionally toothed margins. The leaves range from 1-4 cm long and 1-2.5 mm wide.

The inflorescence ranges from congested to loosely elongated with floral bracts (smaller than the leaves) subtending each flower. The 4 petals are pink or purple with each usually measuring 2 mm long. The tips of each petal is deeply cleft.

Habitat:

Stiff spike-primrose grows along the margins of vernal ponds and streams.

Range:

Stiff spike-primrose may be found from eastern Washington south through Oregon (on both sides of the Cascades) to central California and east to Idaho and Nevada..

In the Columbia River Gorge, it may be found between the elevations of 100'-2000' from Bingen, WA east to Horsethief Lake State Park.

Stiff spike-primrose as seen along the western shoreline of the Deschutes River about one-half mile upstream from its mouth at the Columbia River........July 27, 2011. Note the alternating flowers along the stem, with the flowers well-spaced rather than clustered together as in the other spike-primroses. The stems likewise are much thinner with narrower leaves with this spike-primose compared with the others.

Flower of brook spike-primrose as seen at Catherine Creek.......June 3, 2009. Note the long, slender inferior ovary extending from the leaf axil to the lower base of the petals.

Paul Slichter