Grasses (Poaceae)

Grasses or Poaceae are a large family of monocotyledon (ie having only a single seed leaf, vs dicotyledons which have two seed leaves) herbaceous flowering plants that are found globally in a wide range of habitats.

In Marlborough, native grasses can be found from coastal areas above the high tide mark and amongst dune systems right through to alpine tussock grasslands.

Following fires caused by Polynesian settlers, many dry land forest areas regenerated as tussock grassland.

When Europeans arrived centuries later, they found that the native tussock grasses weren’t particularly palatable to stock, so burnt them and replaced them with European grasses.

In some areas such as the Wither Hills, European grasses were poorly suited to providing soil stability resulting in massive erosion.

In spite of the huge growth of viticulture in Marlborough, exotic grasslands account for significantly more land area than vineyards, and exotic and tussock grasslands combined are the most common form of land cover accounting for around 39 percent of land cover in Marlborough.

Some grasses are food crops, with corn and maize produced in Marlborough, although other food crops such as wheat, rye, barley, and oats are not significant crops in the region.

Exotic grasslands for grazing stock cover significant areas of Marlborough, including New Zealand’s largest farm, Molesworth.

Some grasses are major pest species in Marlborough including Chilean needle grass, nasella tussock, couch/twitch, and to a lesser extent pampas grass, bamboo can also be a pest in urban environments, but hasn’t escaped and become naturalised in the wild.

Grasses are mostly wind pollinated, and large areas of pasture grass on the Wither Hills immediately to the south of Blenheim increase problems with hay fever allergies for residents during the active growing season.