Shoreline Plants  

 
Species: Lysimachia thyrsiflora L., tufted loosestrife
Lysimachia vulgaris L., garden loosestrife
Family: Primulaceae

Tufted loosestrife and garden loosestrife are perennial shoreline plants that can be easily distinguished from other shoreline plants by their leaves and yellow flowers. Tufted loosestrife has willow-like stalkless leaves in an opposite arrangement. The flowers grow in clusters on stalks originating from the leaf bases. Garden loosestrife has leaves on short stalks with an irregular arrangement. The flowers grow at the tip of the plant and from the bases of the upper leaves. Garden loosestrife is a noxious weed in Washington.

Shoreline Plants Icon
Leaf: Tufted loosestrife: the opposite stalkless leaves are several times longer than wide (5-12 cm long), have tiny dark dots, and taper to a pointed tip. Garden loosestrife: the 8-12 cm long leaves may appear opposite, alternate, or in whorls; are on short stalks, have soft hairs beneath; and tiny dark dots.

Stem: Leafy, erect and unbranched. Tufted loosestrife: 20 to 80 cm long and without hair. Garden loosestrife: up to 1 m long with short soft hairs.

Flower: Yellow, 5 petals. Tufted loosestrife: compact bottle-brush like clusters of small flowers originate from lower leaf bases; the petals have small purple dots or streaks. Garden loosestrife: showy flowers 12-15 mm wide in spikes at the plant tip and on stalks from the base of the upper leaves.

Fruit: The egg-shaped capsule contains few seeds.

Root: Roots arise from creeping stems that grow partly or completely underground (rhizomes).

Propagation: Seeds, rhizomes.

Importance of plant: Garden loosestrife is classified as a noxious weed in Washington state. It has been used medicinally in Asia for high blood pressure.

Distribution: Tufted loosestrife: Native to North America and Eurasia. Garden loosestrife: Eurasia, and introduced in North America. In Washington, found in a few locations in eastern and western Washington.

Habitat:  Marshes, shorelines of lakes and ponds. Occasionally along streams.

May be confused with:  Purple loosestrife (Lythrum salicaria)Non-Native Plant  Icon if not blooming, but purple loosestrife has square stems. Another related plant, moneywort (Lysimachia nummularia) also occurs in Washington wetlands, but has smooth round leaves and a trailing growth habit. 

 
(Exotic plant icon for L. vulgaris only)

Photographs: Lysimachia thyrsiflora, Lysimachia vulgaris, Lysimachia vulgaris closeup

Line Drawings: None available 


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