Disk water hyssop
Bacopa rotundifolia
Washington State Classification
Monitor List
This plant is on the monitor list - it is not a listed noxious weed in Washington.
Quick Reference
Identification
Growth Habit
This perennial herbaceous plant is native to parts of the United States and Canada but is not native to Washington State. Plants grow in shallow water or stranded in mud when water recedes.
Leaves
Leaves are oppositely arranged on the stems, somewhat rounded with smooth margins and 6 or more veins radiating up from the base.
Flowers
Flowers grow from leaf axils (where leaves connect to the stem), one to two from each axil, on short stalks (6-23 mm). Flowers somewhat bilaterally symmetrical, white, with 5 petals, the petals 4.5 to 9 mm long.
Fruit & Seeds
Fruit is a capsule, spherical to broadly ellipsoid, 3.5 to 5.5 mm long with many small seeds.
Impact
This plant is on the monitor list - it is not a listed noxious weed in Washington. Please contact its sponsor Wesley Glisson at wgli461@ecy.wa.gov with the Department of Ecology to report locations or for more information.
Ecology & Spread
Habitat
Plants grow in ponds, sloughs, swamps, ditches, rivers, aquatic, stranded in mud. Herbarium collections document plants growing in the Umatilla National Wildlife Refuge.
Spread Mechanisms
Reproduction
Plants spread by seed and by rooting stem fragments.
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