Key characteristics

All leafy rushes belong to the family Juncaceae. The genus with most species is Juncus

The name ‘rushes’ is widely applied to plants with a characteristic growth form (see Rushes – I).

This datasheet includes the leafy rushes and the two common species of Luzula, which are not always recognisable as rushes.

• The flower head of leafy rushes appears at the top of the stems. The plants have hairless leaves, except in the genus Luzula – whose species have long hairs especially at the base of the leaves. There are two introduced species, which are relatively common in poor open pastures, and native species found in tussock grassland
• The leafy species of Juncus can be divided into three groups:
  • with tubular leaves with internal cross walls
  • with grass-like leaves, flat or slightly rolled
  • with narrow, wiry leaves

Leafy rushes with tubular leaves with internal cross walls

Juncus acuminatus is an upright, often red-tinged tufted perennial that grows in very damp, little-improved pastures and swampy places, usually lowland, in several parts of the North and South Islands. It is native to North and South America.

• It has short rhizomes and distinct internal partitions just below the inflorescence across the flower stem (only visible by splitting the stem lengthways)
• A very variable flower head with many branches, each with clusters of 6-10 flowers at their ends
• Most widespread and most common of the tubular leaved rushes with internal cross-walls
• Often confused with Juncus articulatus but is more rigidly upright and has obvious partitions in the stem below the flower head. It also has three (not six) stamens, and straw-coloured brown rather than black capsules

Other similar species, also with hollow, tubular leaves, are Juncus canadensis and Juncus microcephalus. Juncus canadensis (tailed-seed rush) has white-tailed seeds and stiff sepals tapering to a sharp point. It is a coarser plant than Juncus acuminatus or Juncus articulatus and lacks reddish colouration on its leaves and stem. It is well-established in Buller and Westland and is also found in isolated places in Canterbury and central North Island, in damp paces and swamps. It was introduced to New Zealand from North America. Juncus microcephalus is taller and stouter than most other species and has flat-topped capsules with a sharp pointed tip, also lacking the obvious partitions in the stem below the flower head. It is loosely or densely tufted, and occurs in wet places and scattered localities throughout the North Island, and in the South Island in Nelson and Canterbury. It originally came from South America.

Juncus articulatus (jointed rush) is a widely occurring and abundant rush with cross-partitions in its round or flattened leaves, and is characterised by its pointed, glossy, dark brown to black capsules that are longer than the tepals (flower parts). Originally from Europe, this species is now found throughout New Zealand in swampy and wet places, including roadside channels and other drains, races, streams and rivers.

• Very variable in size, 6-60 cm high, dark green and often red-tinged
• Flower stems are either erect, or lie along the ground before growing upwards, or flat on the ground and rooting, or very long and floating on water
• Rhizomes are usually short with short internodes but sometimes are long and produce mat-like colonies
• Leaves are round or flattened with 18-25 internal transverse partitions, more or less visible externally but are less obvious than in species like Juncus acuminatus
• Flowers are borne in small, dark clusters of 4-8 at the end of each branch of the inflorescence

Juncus bulbosus (bulbous rush) occurs in swampy places, especially in high rainfall districts throughout New Zealand. It thrives on the pakihi, gumland and other nutrient poor wet soils. It was introduced to New Zealand from Europe and North America.

• Often forms a red-tinged mat-like growth of bristle-like leaves which sometimes occur as tufts at each cluster of flowers in the flower head
• Plants have a distinctive swollen base (like a small onion)
• Leaves are short and bristle-like, or narrow and grass-like in some floating plants, with internal cross walls that are hard to see without splitting these lengthways
• Flower head is variable and may be unbranched with few flowers or branched and open. It may contain only flowers or it may have tufts of bristle-like leaves with or without flowers. There are 2-6 flowers in each cluster

Juncus prismatocarpus can be found in swampy ground throughout the North Island and in a few places in Nelson, Marlborough and Westland in the South Island. The species is native to New Zealand, Japan, China, India, Sri Lanka, Philippines and Australia.

• Plants are tufted, with flower stems 15-60 cm high and 2-5 mm across. The leaves are flattened, with longitudinal internal partitions which can be seen when held up to the light, and incomplete cross partitions
• Flower head is large, open, and often pink in colour, with many 5-22 cm long branches and large flower clusters

Similar species. Juncus ensifolius has distinctly sword-shaped, flat, blue-green leaves which have internal longitudinal and transverse partitions clearly visible from the outside. The stems appear to be winged between the lower nodes and they carry large, black, clustered seed heads. Plants are found in wet swampy places along roadsides and rivers in a few places from Rotorua and Pureora south to Westland and Canterbury. It is native to western North America.

Leafy rushes with grass-like leaves and no cross walls

Juncus planifolius is an upright, tufted perennial, with grass-like leaves. It can be found throughout New Zealand in higher rainfall areas, on shady cuttings, about springs or seepages, along ditch banks and in roadside water channels. It is native to New Zealand, Australia, South America and Hawaii.

• Flower stems are 15-75 cm high, longer than the leaves
• Leaves all arise from the base of the stem and are flat, up to 8 mm wide, soft, green or reddish-tinged in colour
• Flower head is variable in size with few or many branches radiating like the spokes of an umbrella
• Flowers are crowded in round clusters at the ends of the branches

Similar species. Juncus caespiticius is also native and similar in its grass-like form but differs in its inwardly rolled leaves and compact, globose heads. It is found throughout New Zealand in lowland swamps or brackish ground, being a common weed of drain banks and races in Canterbury. Juncus lomatophyllus (broad-leaved rush) is also a grass-like perennial, only found on the West Coast of the South Island. Its flower stems are longer than the bright green often red-tinged leaves, which are very broad, being 6-15 mm across. It is locally common in swampy places and sometimes in damp pastures. It is native to South Africa.

Leafy rushes with narrow, wiry leaves and no cross walls

Juncus bufonius (toad rush) is a very common weed of cultivated land, pathways, and lawns. This is probably the most widely distributed and abundant of the introduced species in New Zealand. It occurs throughout the country from sea level to about 1200 m. The tiny seeds are dispersed by animals, footwear, tools, wind and water, and can be found in huge numbers in some cultivated soils. Its fibrous roots make the plant easy to pull from the ground. The species occurs throughout the world, especially in the north and south temperate zones.

• A very variable annual tufted rush, between 2.5 and 45 cm high, usually light green but tinged with red in dry situations
• Flower stems may or may not branch near the base but are branched higher up to form the inflorescence
• Plants have few leaves, mostly at the base of the plant and these are bristle-like, channelled and have no auricles
• Flower head is variable in size and shape and often makes up as much as two-thirds of the length of the plant
• Flowers are not stalked and are single or in clusters of between two and seven

Juncus tenuis is a wiry leaved rush forming stiff tufts to 60cm high. Native to North and South America, it now occurs throughout New Zealand in damp or dry places and is sometimes a problem in pastures. Since it is tolerant of treading and has sticky seeds that help its spread, it is commonly found along paths and tracks, shingle drives, farmyards, gateways and along road verges. It sometimes forms colonies along the shoulders of sealed or shingle roads. It can be confused with Juncus bufonius, but plants are not easily pulled from the soils, the tufts are denser and have basal leaves, and the flower heads are less than one third of the plant height.

• Flower stems are 20-60 cm high
• Leaves are in dense grassy clumps at the base of the flower stems and are tough, slender and shorter than the flower stems, usually flat, green or reddish, with two large, prominent, papery auricles at the junction of leaf and sheath. These auricles are 2-4 times as long as they are broad, and are slightly pointed
• Flower head is at the top of the stem, very variable in size, with unequal branches, the longest up to 12 cm
• Flowers are stalkless, borne singly or in clusters of 2-3 along the branches

Luzula species are grass-like, with flower stalks less than 1 m tall, flowers at the top of the stems, and have hairy leaves especially near the leaf bases. Additionally, the capsules of Luzula contain three seeds, whereas Juncus capsules contain numerous dust-like seed. There are 20 native species in New Zealand, mostly found in forest or upland rocky or grassy locations and may be found in tussock land. There are four introduced species but only two of these are commonly found.

Luzula multiflora (wood rush) is grass-like, tufted, with the leaves usually having long white hairs on their margins, especially towards the base. This species is found in poor and reverting pastures in the North Island and in a few places in the South Island. It can form dense, low-growing colonies on damp gully bottoms and can invade lawns.

• Plants are often found in poor, reverting pastures, especially in damp places
• Bright green leaves are 2-3 mm wide, shorter than the flower stems, soft and limp, with blunt tips and long silky hairs on the margins of the lower halves. At the mouth of the leaf sheath is a thick tuft of white hairs. The leaves have minute marginal teeth.
• Flower stems are 20-30 cm high, and the flower heads are umbel-like with a central cluster and 3-10-flowered lateral clusters.

Luzula congesta is similar, grass-like, and also has minute teeth and long soft hairs along the margins of the leaves, and a tuft of long hairs at the mouth of the leaf sheath. Its flower head consists of a large rounded or lobed head, often more than 1 cm in diameter, with a large central cluster occasionally with 1 or occasionally 3 smaller clusters on long stalks. This species is found in second-class and reverting pastures, often on damp ground.