Hyptis or Horehound (Hyptis suaveolens)
Hyptis seedpods
Hyptis is declared a Class B (spread to be controlled) and Class C (not to be introduced to the Northern Territory) weed in accordance with the NT Weeds Management Act 2001.
- Hyptis Photo Identification Table (pdf 136Kb)
Hyptis is native to South America, it was first recorded in the Northern Territory (NT) by the explorer Leichhardt in about 1845, indicating it may have been introduced prior to colonisation. Hyptis is now widespread in the Darwin, Katherine, Gulf and Victoria River Districts. It favours disturbed areas such as roadsides and overgrazed areas. Hyptis will grow on most soil types, except those which become waterlogged.
Hyptis can take over improved and native pastures, especially when overgrazed, forming dense thickets. Hyptis is unpalatable to most types of livestock.
The small seeds remain in the spined burr/capsule which can be easily caught and transported by livestock, native animals and human clothing. The capsules can float on water, facilitating waterborne spread. Hyptis can also spread as a contaminant in hay or pasture seed.
The aromatic oils in hyptis make it unpalatable to stock. Care should be taken to stop cattle overgrazing areas with remnant palatable species, as this will provide an opportunity for further hyptis establishment.
Hyptis flower
