(Nassella tenuissima)
Image: Mexican feather grass, © Molongalo Catchment Group.
What is Mexican feather grass?
Mexican feather grass is a potentially serious weed of pastures, native grasslands and woodlands.
Mexican feather grass is a
declared weed in Tasmania under the Tasmanian Biosecurity Act 2019 and associated Regulations. The importation, sale and distribution of Mexican feather grass are prohibited in Tasmania.
Closely related to serrated tussock, and Chilean needle grass, both Weeds of National Significance(WoNS).
Image: Mexican feather grass in a garden situation, © A Maguire.
How to identify Mexican feather grass
Mexican feather grass leaves are 0.25–0.5 mm wide, up to 60 cm long and tightly rolled with overlapped edges. Leaves roll smoothly between the fingers like a needle, but feel coarse when sliding fingers downwards along the leaf blade. The ligule (a small, thin structure at the base of the leaf blade) is 0.5–2.5 mm long, opaque, papery and smooth.
Flowering stems are up to 70 cm high, round, smooth and hairless, with 2–3 unthickened nodes.
The flower head of Mexican feather grass is 15–25 cm long and green or purplish in colour. An identifying feature of the plant is that the flower head does not detach from the plant and it has a leaf-like sheath that encloses its lower section.
Mexican feather grass seeds are 2–3 mm long and encased by two purple or reddish-brown glumes, 6–10 mm long. Another distinguishing feature is the awn, which is 4.5–9 cm long and attached centrally to the end of the seed.
Mexican feather grass is unpalatable to stock, difficult to control and capable of growing in a variety of climates and soil types. It is able to tolerate prolonged periods of drought and can flourish in areas that are heavily grazed.
Mexican feather grass in Tasmania
Mexican feather grass has been recorded in Tasmania several times as an ornamental or garden plant. Mexican feather grass has also been inadvertently imported to some Australian mainland states for propagation for landscaping purposes.
Mexican feather grass is not naturalised in Tasmania at present.
Image: Mexican feather grass, © Molongalo Catchment Group.
What is the legal status of Mexican feather grass in your area?
The legal responsibilities of landholders and other stakeholders in dealing with Mexican feather grass are laid out in the Mexican feather grass
Statutory Weed Management Plan.
Use
Table 1 (Zone A municipalities) to find out whether this weed occurs in your municipality
What you need to do
If you locate Mexican feather grass anywhere in Tasmania, or if you find a plant that you think could be Mexican feather grass, immediately contact Biosecurity Tasmania on 03 6165 3777 to report this weed.
See Also
Nassella species identification comparison table
|
|
Lobed Needle Grass |
Cane Needle Grass |
Texas Needle Grass |
Chilean Needle Grass |
Serrated Tussock |
|
Status | Introduced, Declared, an Alert List Weed | Introduced, Declared, an Alert List Weed | Introduced, Declared, an Alert List Weed | Introduced, Declared, Weed of National Significance | Introduced, Declared, Weed of National Significance |
|
Form | Tussock | Tussock | Tussock | Tussock | Tussock |
Seed
(outer casing of seed, the 'glume', removed to reveal detail.)
(Click to enlarge image*) | | |
|
|
|
|
'Corona', the collar at seed base | Present | Present | Present | Present | Absent |
|
'Awn', the bristle-like seed tail | 45-85mm double bent firmly fixed to seed coat | 35-40mm Twisted and bent | 35-60mm long Bent twice with 10-20mm to first bend | 25-35mm Straight or double bent Firmly fixed seed coat | 10mm Straight Readily detached from seed coat |
|
'Cleistogenes', or stem seeds | Absent | Present | Present | Present | Absent |
'Ligule', the flap at leaf base
(Click to enlarge image*.)
|
|
|
| | |
|
Overall dimensions | 0.5-1.0m high and 0.3 -0.5m across | to 1m high, to 0.3m across | 1-1.5m high, 0.2 -0.5m across | 1-1.5m high, 0.3 -0.6m across | to 1m high, to 0.6m acros |
* Images in table:
© 2003 Weed Management Guides,
Lobed needle grass,
Chilean needle grass, Serrated tussock, C'wlth Dept of the Env't & Heritage.
© Chilean Needle Grass & Serrated Tussock Ligule photos: Harry Rose (Wikimedia).
|
Important Disclaimer
To the extent permitted by law, the Department of Natural Resources and Environment Tasmania (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using information or material (in part or in whole) contained on this website.