Rough Popcornflower

Plagiobothrys hirtus

Description

The rough popcornflower is an annual herbaceous plant on drier sites, or a perennial herb on wetter sites. It grows as tall as 1-2 ft (30-70 cm) and has a stout stem with coarse, firm, widely spreading hairs on the upper part. The leaves of the main stem are arranged opposite each other in pairs. The inflorescence (floral group) is paired and without bracts (small subtending leaves). The individual flowers are 0.04-0.08 in (1-2 mm) wide and white in color.

Habitat

The rough popcornflower grows in open, seasonal wetlands in poorly-drained clay or silty-clay loam soils. It grows in wet, grassy habitats known as swales, at elevations ranging from 100-890 ft (30-270 m). It appears to be dependent on seasonal flooding and/or fire to maintain its habitat in an open, weakly competitive condition. Annual populations of the rough popcornflower can be quite variable from year to year, depending on environmental conditions, such as the persistence of standing water in the springtime.

Distribution

The rough popcornflower is endemic to the interior valley of the Umpqua River in southwestern Oregon.

Threats

In historical times, the rough popcornflower was probably widespread on the floodplains of the interior valleys of the Umpqua River. However, it was collected only four times between 1887 and 1961, all at sites in Douglas County, Oregon. In fact, it was considered possibly extinct, until it was "re-discovered" in 1983. The principal threats to the rough popcornflower appear to have been grazing by domestic livestock, the draining of wetlands for urban and agricultural uses, flooding of its habitat by the construction of reservoirs, and disturbances associated with road building. In addition, the suppression of wildfires has allowed its habitat to be invaded by more competitive species of woody and herbaceous plants. The rough popcornflower is now limited to 17 isolated patches of habitat in the vicinity of Sutherlin and Yoncalla, Oregon. These habitat patches range in area from 0.1 to 17 acres (0.04-6.9 hectares), with population sizes ranging from 1 to 3,000 plants. The 17 habitat patches are estimated to support a total of about 7,000 plants on a combined area of less than 45 acres (18 hectares). Of the 17 habitat patches, one is 17 acres in area (7 hectares), three are between 5 and 10 acres (2-4 hectares), four are between 1 and 5 acres (0.4-2 hectares), and nine are less than 1 acre (0.4 hectare). The largest known population (3,000 plants) occurs in a habitat patch with an area of 1 acre (4 hectares). Ongoing threats include habitat destruction by conversion to urban or agricultural land-uses, hydrological alterations, fire suppression, livestock grazing, roadside mowing and herbicide spraying, and competition with invasive, non-native plants.

Conservation and Recovery

Three of the occupied habitat patches of the rough popcornflower are owned by the Nature Conservancy and are managed as natural areas. This includes the largest population of the rare plant. The other habitat patches have little or no protective management, and the endangered plant is at great risk of extirpation from development, grazing, farming practices, roadside maintenance, recreational activities, and vandalism. Conservation of the rough popcornflower requires that a larger area of its critical habitat is protected and managed appropriately. This can be done by acquiring private land and setting up ecological reserves, or by negotiating conservation easements with the landowners. The populations of the endangered plant must be monitored in its remaining habitats, and studies made of the environmental factors limiting its spread and abundance.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
(503) 231-6121
http://pacific.fws.gov/

U. S. Fish and Wildlife Service
Oregon Fish and Wildlife Office
2600 S. E. 98th Ave., Suite 100
Portland, Oregon 97266-1398
Telephone: (503) 231-6179
Fax: (503) 231-6195

Reference

U. S. Fish and Wildlife Service. 25 January 2000. "Endangered and Threatened Wildlife and Plants: Endangered Status for the Plant Plagiobothrys hirtus (Rough Popcornflower)." Federal Register 65 (16): 3866-3875.