Shiny Geranium
Geranium lucidum
Washington State Classification
Class B — Control Required (Designated)
Shiny geranium has recently established in Washington and has quickly spread to many counties.
Required control in Region 1 (all western Washington counties)
Quick Reference
Identification
Growth Habit
It is a small, annual or biennial herbaceous plant with basal, lobed, shiny leaves and often times reddish stems with small pink to magenta flowers.
Leaves
Leaves are rounded to kidney-shaped and divided into lobed sections that each have their own 3 lobes at the tip. Leaf blades are 0.4 to 1.6 inches (1 to 4 cm) wide. Leaf stems (petioles) have hairs on one side.
Flowers
It has pink, 5 petal flowers. Each flower has 5 hairless sepals that are somewhat expanded, having longitudinal ridges and small latitudinal wrinkles and bristles tips.
Fruit & Seeds
Seeds are small (2mm) and oval, hairless and reddish with a black projection.
Impact
Shiny geranium has recently established in Washington and has quickly spread to many counties. It is difficult to control as the seeds can germinate when conditions are favorable in a variety of habitats. Originally listed as a Class A noxious weed in 2009, it was reclassified to a Class B noxious weed in 2015.
Ecology & Spread
Habitat
Shiny geranium grows in well-shaded woodlands and forest openings as well as in full to partial sun. It can successfully grow along with herb Robert (Geranium robertianum). Please click here to see a county level distribution map of shiny geranium in Washington.
Spread Mechanisms
Reproduction
Shiny geranium reproduces by seed and has the capability to forcefully eject seeds when ripe.
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Control Methods
Mechanical
- Individual plants and small infestations can easily be controlled by carefully hand-pulling, bagging, and putting in the trash. Make sure to remove its fibrous roots to prevent resprouting. Larger populations can be covered with sheet mulch - ideally overlapping pieces of cardboard covered with a thick layer of woodchips. Make sure to repeatedly monitor and control seedlings before they set seed.