Silver tussock

Description

Poa cita, commonly known as the silver tussock, or wī, which is also the Māori name, is a grass of the family Poaceae that is native to New Zealand. Poa cita was described and named by Elizabeth Edgar in 1986, having previously being named Poa caespitosa. It is endemic to New Zealand and found throughout most of the country, from the Kermadec Islands to Stewart Island / Rakiura and out to the Chatham Islands, but not known from Raglan to Manawatū in the west of the North Island, except on Mount Taranaki. It grows to 0.3–1.0 metres tall, and sometimes hangs as much as 2 metres long down steep banks. It has very fine, narrow leaves, usually 1–1.5 millimetres and up to 2.5 millimetres wide. Leaf width varies through the country, with narrow, needle-like leaves in the central North Island and relatively wide leaves in the northern North Island. Poa is a genus of about 570 species of grasses, native to the temperate regions of both hemispheres. Common names include meadow-grass (mainly in Europe and Asia), bluegrass (mainly in North America), tussock (some New Zealand species), and speargrass. Poa (πόα) is Greek for "fodder". Poa are members of the subfamily Pooideae of the family Poaceae. Bluegrass, which has green leaves, derives its name from the seed heads, which are blue when the plant is allowed to grow to its natural height of two to three feet (0.6 to 0.9 meters). The genus Poa includes both annual and perennial species. Most are monoecious, but a few are dioecious (separate male and female plants). The leaves are narrow, folded or flat, sometimes bristled, and with the basal sheath flattened or sometimes thickened, with a blunt or hooded apex and membranaceous ligule. Many of the species are important pasture plants, used extensively by grazing livestock. Kentucky bluegrass (Poa pratensis) is the most extensively used cool-season grass used in lawns, sports fields, and golf courses in the United States. Annual bluegrass (Poa annua) can sometimes be considered a weed.