Also known as
Pennisetum setaceum, African fountain grass, P. ruppellii
Where is it originally from?
What does it look like?
Perennial, clump-forming grass (<1m tall) with deep fibrous roots and short rhizomes that form new plants. Very thin, tough and harsh green leaves, and round, erect, purplish-white stems (<1m tall) support narrow, bristly, purple-brown flowerheads (10-20cm long, 10-20 mm diameter) containing many seeds, each with bristles (20mm).
Are there any similar species?
Other Pennisetum species. Native toetoe and exotic pampas (all Cortaderia and Austroderia species) grow to 2-5 m and have large, fluffy flowerheads.
Why is it weedy?
Rhizomes create dense spreading masses in well-lit sites. Seeds prolifically from two years of age with a seed viability of over 80%. Long-lived, medium to fast growing, and tolerant of many soil types, hot or cold temperatures, drought, wind, salt, damage, and grazing.
How does it spread?
Rhizomes creep outwards and fragments are spread by soil movement and machinery. Seeds are spread via water and by wind for short distances, and also in clothing, animals, pelts.
What damage does it do?
Outcompetes native pioneer species in vulnerable habitats and also invades established plant communities. Has the potential to cause build up of sand and changes in habitat, leading to erosion or flooding elsewhere, and loss of dunelakes and wetlands. It is also a fire hazard and can harbour rats and mice.
Which habitats is it likely to invade?
Bare sand, dunelakes, estuaries, coastline, river systems, low shrubland, dry and disturbed forest, potentially throughout New Zealand.
What can I do to get rid of it?
Don't attempt to control it when mature seed is present as this increases the risk of seed being spread on clothing and so on.
1. Dig out small infestations. Dispose of at refuse transfer station or burn.
2. Spray (spring-summer): glyphosate (15ml/L + penetrant).
3. Slash and spray regrowth (spring-autumn): 520g/L haloxyfop-P-methyl (150ml/10L).
What can I do to stop it coming back?
Rhizomes resprout and seeds germinate in bare sites. Unpalatable to livestock so do not graze to control. Follow up spraying will be needed at least 6-monthly until no further regrowth occurs, so replant the area only with groundcover species that will not be affected by Gallant spraying (that is, no grasses or flaxes).