Rough popcornflower is an herbaceous plant that can grow to be 50-60 cm tall and perennial, or considerably smaller and annual, depending on environmental conditions. The upper stems are distinctly covered with spreading hairs, and the opposite cauline leaves are linear with hairy margins. Flowering stems are spreading, with paired coiled inflorescences containing many 6-10 mm-wide, five-petaled white flowers with yellow centers. Flowers can produce up to four tan- to black-colored nutlets each; due to fruit abortion or lack of pollination, calyces with fewer than four nutlets are often observed. Plants are self-compatible, but require pollination by insects to produce seeds.
Rough popcornflower occurs in shaded, seasonally-wet pools (vernal pools) that dry completely by mid-summer. Requires full sun exposure.
Limiting factors
Habitat loss due to conversion of wetlands to agricultural fields and urban development has adversely affected this species. Fire suppression, invasive plant infestations, and livestock grazing are additional threats. Alterations to hydrologic regimes and competition with exotic weeds threat even protected populations. The species is extremely vulnerable to climate change, particularly due to predicted changes to hydrologic regimes.
Data gaps
Conduct long-term monitoring to establish population trends.
Conservation actions
Avoid herbicide spraying on roadside populations. Work cooperatively with private landowners to maintain rough popcornflower on private land. Acquire land or establish conservation easements on land with quality habitat for population creation projects. Continue monitoring of existing populations. Carefully manage grazing and fence priority sites, if necessary.
Key reference or plan
A U.S. Fish and Wildlife Service Recovery Plan was released for the rough popcornflower in 2003.
Species Status Assessment: https://iris.fws.gov/APPS/ServCat/DownloadFile/219194
