Chionochloa rubra, known commonly as red tussock grass, is a species of tussock grass in the grass family, endemic to New Zealand.
Description
New Zealand has 22 endemic species of Chionochloa, including C. rubra, which has a distinctive appearance from other members in the genus. C. rubra has a long living span, meaning that there is rarely any dead foliage around the plant — giving the species a clean, sleek and vertical look. The plant will grow up to 1–1.2m high in rich moist ground, with seed heads reaching even taller. The leaf blade themselves grow up to 1m long and 1.2mm in diameter, and the plant width itself is 50 cm in diameter (with little rhizomatous spread). There are usually long hairs next to the base of the leaf and prickle-teeth towards the apex that help distinguish it from other Chionochloa species. There is also rows of short hairs at the base of the leaf. However, in dry habitat conditions such as dry clay soil the plant struggles to grow and may only grow to 90 cm high, causing possible confusion for other species of Chionochloa. Therefore, environment should be taken into account for identification purposes. Depending on the subspecies, the tawny leaves' colour ranges from a beautiful greenish tone to its more dominant rustic colour of bronze or red. Because of this, some may consider it to be one of the most aesthetically pleasing tussocks, as green and red are known as complementary colours. In general, C. rubra is a tall brown reddish plant with slender leaves that clump together forming its classic arc shape.
C. rubra has been found to display the unusual phenomenon of producing many seeds in response to decreased seed predation. In contrast, it was found to have a lower seed production at higher predation rate areas. Red tussocks seeds annually at low alpine areas, differs from other Chionochloa sp. Red tussocks mast seeding at higher altitudes. An explanation for these changes is that red tussocks do not have pronounced altitudinal ecotypes, seed predators satiation and mast seeding being ineffective at lower altitudes.
Distribution and habitat
C. rubra is endemic to New Zealand. It is dispersed from the central volcanic fields and Huiarau Range to Stewart Island, and from the lower area of the penalpine belt to sea level in south of New Zealand.
Habitat
There are two different types of tussock-grassland, the one where commonly small tussock-grasses dominate, called: “Low tussock-grassland”, and other where generally larger tussocks dominate, called “Tall tussock-grassland." Red tussock (C. rubra) is distributed in general in Tall tussock-grassland, and covers most of the pumice-scoria soil located on the volcanic plateau at the altitude between 900 and 1200 m. Places associated with wetlands will be changed by the red tussock, because other species cannot tolerate the diminution of light environment due to the master seeding and dense growing habit of red tussock.
Red tussock (C. rubra) is a most adaptable vegetation which will grow in the exposed and windy environment. It can tolerate low-nutritious, and also can grow in relatively wet or dry soil conditions. It is harsh enough to use one individual specimen plant however, if space allowed, would be better for planted several as a group. Red tussock (Chionochloa rubra) is a useful vegetation for helping to reestablish wildlife habitat, especially useful as a buffer plant around wetland areas. While C. rubra can be slow growing and prefers more cooler, wet and less humid climates. Though once established it is very resistant plan and can take plenty of abuse due to its hardy texture.
Ecology
C. rubra plant's seeds are dispersed with the use of gravity and the wind. Nature is the plants main pollinating agent with very little use of invertebrates or mammals as pollinating agents. Mass seeding is used as the main technique to prevent seed loss by predators (which are hard to satisfy due to their big appetite) and other competitor plants. Mass seeding is the production of a large quantity of seeds that are released all at once over a large area. It usually takes the plant a few years to produce enough seed to carry out the process. This form of spreading is particularly more prominent in the Takahe Valley in the Southland of New Zealand. Statistics and studies have shown that the mean annual loss ranges from 10–33% during a four-year studies in the Takahe Valley. So if not for mass seeding the plant would not be able to be successful as it is. The seed is dropped on well drained and moist soil where starts to grow. It flowers during the summer season from October to December and grows fruits all around from November to May.