Glory Lily Gloriosa superba
The name of this plant gives an indication of why it was once a popular garden plant – its showy flowers were considered pretty “glorious” before its weed potential was understood. Long escaped from gardens, it is now known to be a terrible pest in coastal areas. It has an ability to form dense carpets in coastal ecosystems, clambering up and over native vegetation, gripping other plants with its distinctive tendril-tipped leaves, and reaching up to four metres in length/height. Every part of the plant is highly toxic to humans and other mammals, but birds can and do eat the fruit and spread the seeds.
On the Midcoast we are in the Northern part of the “Regional Priority-Eradication” zone – eradication is already considered impossible North from the Port Macquarie area, with the North Coast area zoned “Regional Priority – Containment”.
This plant dies off in winter and comes back in late Spring/early Summer. It is up and flowering now in local hotspots. We have known infestations around Nine Mile Beach at Tuncurry and on Leon Island in Wallis Lake, it has been spotted out at Caffrey’s Flat, Diamond Beach and Old Bar, and there are recent reports of it making an appearance in the Coomba area.
Control is difficult, as it forms deep, highly toxic, highly resilient tubers, which are very, very tricky to effectively dig out. Chemical treatments often require repeat doses in subsequent seasons. The most efficient treatment is typically spot spraying with a “hot mix” of 2% Glyphosate, 1.5g/10L Metsulfuron Methyl, and a spray sticker like Alcohol Alkoxylate or an Organosilicone penetrant like “Pulse”. This mix will destroy just about any plant that receives a decent dose, so off-target damage can be significant without great care. Local experiments have shown stem scrape application of neat Glyphosate to also be effective – very gentle handling is required as stems can be easily broken; both sides of the stem should get a long scrape, and the growing tip/s of the plant is also dripped with neat poison.
If you think you have seen this plant, please get a good photograph and notify the MidCoast Council Weed Biosecurity team at weeds@midcoast.nsw.gov.au
For more information see NSW Weedwise.