Great Willow-herb (Epilobium hirsutum)

Great Willow-herb (Epilobium hirsutum), the spontaneous offering of a rootbound tree-cut in the footpath of Nicholson Street, Fitzroy this weekend.

Great Willow-herb is native to Europe and North Africa, where it grows primarily on wetland edges. In North America, where it has grown as a weed since at least the 1890s, it was given the early epithet ‘Apple-pie’ or ‘Cherry-pie’. It has also been introduced to China and South Africa. Although a wetland species, it is known to be somewhat agnostic to soil type and capable of adapting to drier conditions, as seen here.

Great Willow-herb naturalised to Victoria in the second half of the twentieth century, with early list entries from the 1980s for Mornington and the Surf Coast, and formal collections first made in 1996 on the outskirts of both Melbourne (Croydon) and Geelong (Newtown). Presumably introduced to Melbourne as a nursery offering (or contaminating other imported plants), the species has been noted as far west as Ballarat and as far east as the Latrobe Valley. With the exception of a single recording from Canberra in 2008, Great Willow-herb is as yet confined to south central Victoria; it was also recorded for the first time in New Zealand last year, outside of Christchurch.

The photographed plants are small for the species, which grows to a height of up to 2.5 metres; the common name describes both its typical stature and the size of the flowers. Also known in other places as Hairy Willow-herb, Great Willow-herb should not be confused with the similarly named Epilobium hirtigerum (known here as Hairy Willow-herb), one of the ten species of the genus that are indigenous to Victoria.

These plants are unlikely to survive long in this location, exposed as they are to foot traffic from an adjacent tram stop and in heavy competition with a plane tree and a longstanding Agapanthus pile. Whatever their duration, they were remarkable as an insistent and unusual inflorescence from the dry and stony strata of metropolitan pavement.