[Cal-IPC] Invasive: Cortaderia jubata (jubatagrass) is a large perennial grass (family Poaceae) found along the coast of California and in the Coast Ranges. Jubatagrass favors dunes, bluffs, and disturbed areas, including inland areas where temperatures are moderated by fog. It was introduced as an ornamental plant and for erosion control. Each plume produces up to 100,000 seeds that are widely dispersed by wind and develop without fertilization. Jubatagrass quickly colonizes bare ground, but establishment is generally poor where the seedlings must compete with other grasses or sedges.
Cal-IPC Rating: High (link added by Mary Ann Machi)
[Wikipedia] Northern Andes native, Noxious weed: Cortaderia jubata is a species of grass known by several common names, including purple pampas grass and Andean pampas grass. It is similar to its more widespread relative, the pampas grass Cortaderia selloana, but it can get quite a bit taller, approaching seven meters in height at maximum.
This grass is native to the northern Andes but it is well-known elsewhere as an invasive species noxious weed. This grass has only pistillate parts, that is, all individuals are female. It reproduces by apomixis, in which embryos develop without fertilization.
Description
This pampas grass, Cortaderia jubata, has long, thin, razor-edged leaves forming a large bunch grass tussock from which the eye-catching inflorescences arise. At the top of a stem several meters in height is an inflorescence of plumelike spikelets. These panicles are pink or purplish when new and they gradually turn cream or white. Each inflorescence is packed full of fruits which develop despite the plant's having never been fertilized. Each plant produces millions of seeds per year. They disperse easily by several methods, including wind, water, and soil transport. (link added by Mary Ann Machi)