General Species Description
- Purple loosestrife is a highly invasive introduced plant that can reproduce by seed, runners, and stem clippings. It is a rhizomatous, perennial herb. Plants can grow to be 2 m tall. Plant stems become woody with age. The stems are more or less square. Blooms from August to September.
Leaves
- Leaves are mostly opposite, occasionally alternate, attached directly to the stem. They are lance-shaped, pointed, slightly hairy, notched at the base, 3-10 cm long.
Inflorescence/Flowers
- The inflorescence is a dense elongated terminal spike. The flowers are a showy purple color. Each flower is fused into a tube terminating in five lobes, 5-10 mm long. There are many stamen and may occur in three different lengths.
Fruits
- This plant fruits woody capsules, small and numerous.
Habitat
- The purple loosestrife likes areas along pond or lake margins. The preference is for a very wet to damp habitat. It actually prefers a few inches of inundation and is often found associated with other species that prefer the same, like the common cattail (Typha latifolia) and the hardstem bulrush (Scirpus acutus) and the softstem bulrush (Scirpus tabernaemontanii)