T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Juncus effuses (Soft rush)

Kingdom: Plantae
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Juncaceae
Genus: Juncus
Species: J. effusus
Binomial name: Juncus effuses
Subordinate taxa: Juncus effuses var. effusus
Synonyms: Juncus communis, Juncus luxurians
Common names: Soft rush, Leafless rush

Juncus effuses is a perennial herbaceous flowering plant species in the family Juncaceae. It was originally from Europe, Africa, Asia and South America and it is now naturalised in New Zealand. It is widespread and common throughout New Zealand. It is an invasive weed of damp pastures and a wide range of other humus-rich areas like marshes, ditches. It is the most widespread of the leafless rushes in New Zealand.

Juncus effuses is an upright clump-forming leafless rush with soft, smooth, tubular, shiny, dark-green to yellow-green stems that grow up to 1.2 tall. The stems taper from the base to their tip. The stems are easily broken or compressed between finger and thumb. When the stem is split lengthways the spongy, light pith is continuous without holes. It is often grazed to the base.
A yellowish inflorescence appears during spring to early summer. It emerges from one side of the stem about 20 centimetres from the top. In fact, the stem ends there; the top part is the bract, that continues with only a slight colour-band marking it from the stem. The inflorescence is an open clustered flowerhead made up of many light brown flowers/capsules (fruit). The seeds are spread by animals, water or contaminated machinery. It displaces our native rushes.

A cross-section of a stem with continuous pith

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0