(Map may reflect historical as well as recent sightings)
The rough popcornflower was federally listed as endangered without
critical habitat in January 2000 (US Fish and Wildlife Service
2000). A recovery plan for this species was published on July
Historic Status and Current
Rough popcornflower was probably widespread historically on the
floodplains of the interior valleys of the Umpqua River. Because
it occurs in low-lying areas, seeds were likely dispersed by flood
waters, resulting in a patchy, clumped distribution on the floodplains.
Natural processes such as flooding and fire maintained open, wetland
habitat. Draining of wetlands for urban and agricultural uses
and road and reservoir construction, however, has altered the
original hydrology of the valley to such an extent that the total
area of suitable habitat for this species has been significantly
Description and Life
The rough popcornflower is a member of the borage family (Boraginaceae)
and is an annual herb on drier sites or perennial herb on wetter
sites. It reaches 30-70 cm (1-2 ft) in height and has a fairly
stout stem with widely spreading, coarse, firm hairs on the upper
part. The leaves of the main stem are opposite (paired), and the
inflorescence (flower) is paired and without bracts (small leaf).
The individual flowers are 1-2 mm (0.04-0.08 in) wide and white.
It generally blooms June-July. Rough popcornflower grows in scattered
groups and reproduces largely by insect-aided cross-pollination
and partially by self-pollination. The species is distinguished
from other Plagiobothrys species by its coarse, sparse hairs on
the stem and branches.
Rough popcornflower grows in open, seasonal wetlands in poorly-
drained clay or silty clay loam soils at elevations ranging from
30 to 270 m (100 to 900 ft). The taxon depends on seasonal flooding
and/or fire to maintain open habitat and to limit competition
with invasive native and non-native plant species. This plant
occurs in open microsites within the one-sided sedge (Carex unilateralis)--meadow
barley (Hordeum brachyantherum) community type within interior
valley grasslands. The plant occurs on soils in the Conser Silty
Clay Loam Series (NRCS mapped soil unit SSURGO 44A).
Reasons for Decline
The rough popcornflower is highly threatened by
direct loss of habitat from conversion to urban and agricultural
uses, hydrological alterations, and fire suppression. Other threats
to the species include spring and summer livestock grazing, roadside
mowing, spraying, competition with non-native vegetation, and
Rough popcornflower is endemic to seasonal wetlands in the interior
valley of the Umpqua River in southwestern Oregon. The rough popcornflower
has a narrow range historically, and currently occurs on only
17 habitat patches in Oregon's Umpqua Valley in Douglas County.
The sites are all located within 8 km (5 miles) of one another
and total under 18 hectares (45 acres) in area. Fewer than 7,000
plants are known to exist.
Various USFWS partners are accomplishing recovery of the rough popcornflower: The Oregon Department of Agriculture has over the past 12 years developed a procedure to cultivate, propagate, and outplant rough popcornflower into historically occupied habitat successfully. The Nature Conservancy protects and manages approximately 30 acres of rough popcornflower occupied habitat on a nature preserve. The Oregon Department of Transportation protects and manages two robust rough popcornflower sites adjacent to an interstate highway. Douglas Soil and water Conservation District manages and protects a healthy rough popcornflower population in the Sutherlin, Oregon area. The City of Sutherlin also manages and protects two fenced-in, but happy rough popcornflower patches within the City’s “Festival Grounds." The Bureau of Land Management protects several introduced rough popcornflower patches at the North Bank Habitat Management Area. One patch is so successful that it has expanded in its size to become one of the largest and most vigorous populations.