Narrowleaf Lyme Grass (Yukon Invasive Species Guide)

Narrowleaf Lyme Grass

Leymus angustus

Description ²

Altai Wild Rye is an Asian dune grass found throughout Mongolia, Siberia and China. In Canada, it is cultivated in many places but was previously only known to occur in the wild in Saskatchewan. This is a tall (100 cm) coarse grass that reproduces mainly by seed and forms dense tussocks from short rhizomes.

Range in Yukon ²

Known from Carcross where it was first reported in 1998. Small patches have been eradicated from the south Klondike Highway. It may have spread to the Alaska Highway and is also known from the BC portion of the Klondike Highway and along the Chilkoot Trail.

Similar Species ²

Sea Lyme Grass (Leymus mollis) and Hairy Lyme Grass (Leymus innovatus) are also large perennial grasses. Sea Lyme Grass is only native to the Yukon coast and has anthers 4-9 mm. Hairy Lyme Grass can be
distinguished by having hairy glumes and anthers 3.5-10 mm whereas Altai Wild Rye has anthers 3–5 mm long; glumes glabrous, sometimes scabrous. Quack Grass (Elymus repens) is widely spread along roadsides and at reclamation projects; often found as a weed in commercial seed.

Ecological Impact ²

It is a dune stabilizing grass that could be a threat to the Carcross Dunes and the animals and plants that depend
on the dune ecosystem. If it spreads along rivers, it could form dense mats that hinder succession and decrease
biodiversity.

Control ²

All known Yukon infestations have been small and have been controlled by pulling prior to the seed maturing. Larger
plants must be dug up; most of the roots are less than 30 cm deep. The seeds of wild rye continue to mature after
pulling. You may put plants into clear garbage bags and then leave them in the sun to kill off the plants and roast the
seeds. Herbicide control may be required in large populations.

For more information visit: Yukon Invasive Species Council

Sources and Credits

More Info

Range Map

iNaturalist.ca Map

Plant	Grass Family (Poaceae)

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