I found this Dancing Orchid up on Wireless Hill this morning. Perth, Western Australia.
The Arum Lillies look pretty but they are a serious weed in south west Western Australia. Farming around Forrestdale Lake (about 25 km south of Perth) began in 1893, and in the 1920s sheep and cattle grazing took over from agriculture. During the 1940s the west side of the lake was heavily grazed by livestock, particularly during the dry summers when the lake’s fringing vegetation served as supplementary fodder. As a result, the land on the west side of the lake (pictured here) lacks native understorey plants and is infested with introduced plants such as these arum lillies.