MONADENIA or AFRICAN WEED ORCHID
We normally are really happy to spot orchids, but the African weed orchid is not one in that category… ask some of the locals about the spread of these on their properties! The plant invades bushland where other native orchids would usually grow. It is a perennial, with the bits above ground growing annually from tubers which are renewed every year. This means there are often two tubers per plant, and both should be removed when weeding. The green leaves form a rosette, like some native orchids and lilies. The flower spike grows up to 75 cm tall, and appears late spring. When young, it looks something like an asparagus spear, although it is more brown than green. Prolific seed bearers (up to 2.5 million per plant per year!), they spread by seed being carried on the wind, in fur, etc.
See this very good fact sheet from Trees for Life for more details on control: http://www.treesforlife.org.au/sites/www.treesforlife.org.au/files/Monadenia_African%20Weed%20Orchid_Weed%20Profile.pdf