[Deervetches and Bird'sfoot Trefoils: The Genera Acmispon, Hosackia and Lotus in the Cascade Mountains of Oregon and Washington]

Desert Deervetch, Field Lotus, Short-flower Bird's-foot Trefoil, Small-flowered Deer-vetch, Small-flowered Lotus

Acmispon parviflorus

Synonyms: Hosackia parviflora, Lotus micranthus, Lotus parviflora

Desert Deervetch, Field Lotus, Short-flower Bird's-foot Trefoil, Small-flowered Deervetch, Small-flowered Lotus: Acmispon parviflorus (Synonyms: Hosackia parviflora, Lotus micranthus, Lotus parviflora)
Close-up sideview of the flower and leaves of small deervetch as seen along the Atwood Road high above the Labyrinth, central Columbia River Gorge........May 5, 2010.

Characteristics:

Small-flowered deer-vetch is an annual wildflower with prostrate to ascending stems arising 10-30 cm long from a branched base. The leaves and stems are glabrous to sparsely covered with hairs. The 3-5 leaflets are obovate, oblon, or oblanceolate in shape with obtuse to acute tips. The thick leaflet blades measure 6-12 mm long, 2-3 mm wide and can be smoewhat glaucous in color.

The peduncles arise from the leaf axils and measure 3-20 mm long with a single, leaf-like, ternate bract below the single flower. The flowers measure 4-6 mm long and are pale yellow with a reddish tinge. The calyx is about 2 mm long with linear-lanceolate teeth that are typically much shorter than the tube. The fruits are long, glabrous pods measuring 15-20 mm long. The pods are fairly conspicuously constricted between the seeds.


Habitat:

Small-flowered deer-vetch may be found on open slopes and sandy flats from the seashore to the mountains. In the Columbia River Gorge, it is commonly found in grasslands and open woods.


Range:

Small-flowered deer-vetch is primarily found west of the Cascade Mts. to the Pacific Ocean from British Columbia south to California.


Desert Deervetch, Field Lotus, Short-flower Bird's-foot Trefoil, Small-flowered Deervetch, Small-flowered Lotus: Acmispon parviflorus (Synonyms: Hosackia parviflora, Lotus micranthus, Lotus parviflora)

Close-up frontal view of the flower and leaves of small deervetch as seen along the Atwood Road high above the Labyrinth, central Columbia River Gorge.........May 5, 2010.

Desert Deervetch, Field Lotus, Short-flower Bird's-foot Trefoil, Small-flowered Deervetch, Small-flowered Lotus: Acmispon parviflorus (Synonyms: Hosackia parviflora, Lotus micranthus, Lotus parviflora) - Close-up sideview of the flower of Desert Deervetch, Field Lotus, Short-flower Bird's-foot Trefoil, Small-flowered Deervetch, Small-flowered Lotus: Acmispon parviflorus (Synonyms: Hosackia parviflora, Lotus micranthus, Lotus parviflora)

Small deervetch blooming amongst annual grasses at the parking area for Catherine Creek, Klickitat County, WA........May 20, 2011.

Paul Slichter