Alternative common names:
Grass-poly, small loosestrife, hyssop-leaved loosestrife, lesser loosestrife.
Hyssop loosestrife is a mostly upright, branching annual or biennial herb growing 10-60cm tall. The oval leaves are up to 3cm in length. The inflorescence is a terminal spike with pinkish petals up to 5mm long.
Where does this species come from?Europe.
What is its invasive status in South Africa?NEMBA Category 1b.
Where in South Africa is it a problem?Western Cape.
How does it spread?Primarily introduced as an ornamental. It then spread by seed as well as laterally branching rootstocks.
Why is it a problem?
It degrades natural habitats such as wetlands and riparian areas and reduces biological diversity by outcompeting indigenous vegetation. This affects the entire wetland community of both plants and animals.
What does it look like?
Leaves: Leaves are mostly alternating up the stems, some almost opposite, oval, 0.5-2.5cm long, 1.5-8mm wide, flat and hairless.
Flowers: The inflorescence is a terminal spike of small flowers (less than 5mm across), tubular, pinky-mauve, red, blue or purple, with 4-6 spreading lobes. It flowers in summer.
Fruit/seeds: The fruit is an oval capsule containing many tiny seeds. It produces as many as 2.7 million seeds annually. Their surface is shiny and smooth.
Does the plant have any uses?
Ornamental and herbal.