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Rare, at risk plant being monitored in Delta

Streambank Lupine is blooming around the community
Rare plant blooming
First found in Delta in 1988, the extremely rare Streambank Lupine continues to bloom in various areas of the community.

A rare, at risk plant is blooming in Delta.

First found in Delta in 1988, the extremely rare Streambank Lupine continues to bloom in various areas of the community.

Delta Climate Action & Environment staff say with only seven known Streambank Lupine populations in Canada, Delta has three of the populations.

“Exact locations of where the plant is in Delta are not being divulged to prevent disturbance of the sites, particularly at this time of year when the plants are flowering, but all three sites in Delta are along the Fraser River corridor,” said Mike Brotherston from the City of Delta.

According to the Federal Species at Risk Act, Streambank lupine is an herbaceous plant that ranges in height from 0.3 to 1.0 m. Although considered a perennial, it appears to be relatively short-lived (often three to five years). Its hollow stems are green to reddish-brown, and are smooth or slightly hairy and branched.

Brotherston said the plant is considered a rare find due to Southwest BC being at the extreme northern range of this species, so it was likely never common.

“The species naturally relies on flooding to transport seeds to new locations. Much of its preferred habitat, gravelly or sandy streambanks, has been lost and/or heavily damaged by human disturbance and invasive species,” he said. “Many juvenile plants have been dying before being able to flower, thus fewer seeds are being produced.

“It is at risk of genetic swamping (hybridization) from invasive lupine species but also inbreeding due to the isolation between the populations. Populations are unable to easily expand from their current range due to lack of available habitat and the plant’s inability to disperse seeds over long distances without relying on flooding.”

Brotherston said staff are unclear how the plant first popped up in Delta.