Lythrum hyssopifolia L.

Nomenclature and Common Names

Lythrum hyssopifolia L. (orthographic variant L. hyssopifolium) is a species of flowering plant in the loosestrife family, commonly known by the common names hyssop loosestrife and grass-poly.

Native Range

This plant is native to Europe.

Introduced Range and Weed Status

It is also found as an introduced species outside its native range across many other regions, including parts of Australia and both eastern and western North America, where it sometimes grows as a weed.

Conservation Status in the United Kingdom

It is considered rare in the United Kingdom, where only occasional isolated populations occur.

Habitat

It most often grows in moist habitats, with examples including marshes, wet agricultural fields, and rice paddies.

Growth Form and Size

It is a mostly upright, branching herb that can be an annual or biennial, and reaches 10 to 60 centimeters (3.9 to 23.6 inches) tall.

Leaf Arrangement

On the plant, oval leaves are arranged oppositely on lower sections, and typically arranged alternately toward the top of the stem.

Leaf Size

These leaves grow up to 3 centimeters (1.2 inches) in length.

Inflorescence and Flower Characteristics

Its inflorescence is a terminal spike of flowers that have pinkish petals up to half a centimeter (¼ inch) long.

Fruit and Seed Characteristics

The fruit it produces is an oval capsule that holds many minute seeds.

Etymology of Specific Epithet

The specific epithet hyssopifolia, a term that appears in many other plant scientific names, translates to "hyssop-leafed".