14 Jan Mexican feather grass
Nassella tenuissima
Initially mislabelled and sold as an ornamental in
Australia under the names Elegant Spear Grass,
Pony Tail and Angel’s Hair, Mexican Feather Grass
needs to be prevented from naturalising in Australia.
Family: Poaceae
Origin: South America
Habit: Drooping perennial tussock forming grass which grows in dense
clumps. up to 0.8 m in height.
Leaves: Leaf blades to 0.5 mm wide, tightly rolled and with small
serrations that can be felt when fingers are moved downward
along the blade. Distinguished by hairless nodes, some usually
visible; ligule membranous and hairless, to 2.5 mm long.
Flowers: Seedhead: Young seedheads held among the leaves; mature
seedhead to 25 cm long; glumes purplish in the lower half to 1
cm long; callus bearded. Flowers summer.
Fruit: Lemma to 3 mm long, awn narrow, straight or obscurely twice
bent, 4.5–9 cm long; attached centrally to the top of the lemma.
Roots: Fibrous clump.
Dispersal: Seed spread by water, animals, humans, contaminated soil (earthmoving
equipment, slashers, mowers etc) and as an ornamental.
Control: Hand pull/dig, bag all seed heads. Foliar spray.
This grass is a weed in its native range. If it naturalises in Australia it
potentially has a wider range than Serrated Tussock. Mexican Feather
Grass escaped from cultivation in New Zealand and has become a weed
that is continuing to spread.