Hymenoxys Species, Prairiedawn, Texas Bitterweed

This is a threatened and endangered species found only in the northern part of Harris and Fort Bend counties in Texas. It is a small annu...Read Moreal member in the sunflower family with yellow disk-shaped flowers occurring in March or April and only attains a height of six inches. This means it is often overlooked.

This plant naturally occurs in between the pimple or mima mounds formed from Pleistocene alluvial deposits on the ancient Katy Prairie. These mima or pimple mounds are like naturally occuring small raised areas having slightly better drainage than the surrounding Katy Prairie which is seasonally/annually classified as a wetlands. This plant is threatened due to massive urban encroachment and the levelling of the ancient Katy Prairie for agricultural interests (primarily rice farming). The plant sets seeds from April to May in the seasonally wet depressions or swales found around the mima or pimple mounds and then dies before the bare lower-lying ground dries and cracks in the summer heat.

Prairiedawn was first discovered and collected near Hockley in northern Harris county, Texas in 1889. Thought to be extinct by 1979, the plant was rediscovered north of Cypress in Harris County by James Kessler.

This plant is currently being grown and preserved at the Mercer Arboretum's Endangered Species Garden in Houston Texas.