- "Soft Rush" redirects here. In inland North America, this usually refers to Interior Rush (J. interior).
Soft rush (Juncus effusus) is a member of the genus Juncus. Native to most continents, and hence also known as Common rush, this plant is found growing in wet areas, such as the purple moor-grass and rush pastures and fen-meadow plant associations in the United Kingdom.
It grows in large clumps about 1.5 meters (5 feet) tall at the water’s edge along streams and ditches, but can be invasive anywhere with moist soil. It is commonly found growing in humus-rich areas like marshes, ditches, fens, and beaver dams.
The stems are smooth cylinders with light pith filling. The yellowish inflorescence appears to emerge from one side of the stem about 20 cm 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 lower leaves are reduced to a brown sheath at the bottom of the stem.
Distinction from other species
J. effusus can be differentiated from the rarer J. pylaei by the number of ridges on the stem. J. effusus has 30 to 40 ridges and J. pylaei has 10 to 20.
Differentiation within the Species
Juncus effusus is divided into no fewer than nine varieties, as listed by the USDA PLANTS website. The list presented there includes the following varieties: the 'lamp rush' varieties brunneus, decipiens, exiguus, gracilis, and solutus; 'common rush' varieties conglomeratus, effusus, and pylaei; and 'Pacific rush' pacificus. Many of these have overlapping distributions in the US. The specific details differentiating these varieties are not presented on the USDA PLANTS website, but attribution to specific botanists is given for each variety.
It is a common plant native in most temperate countries.
In Europe this rush was once used to make rushlights (by soaking the pith in grease), a cheap alternative to candles.
- Peter F.Zika., The native subspecies of Juncus effusus (Juncaceae) in western North America, April 2003, Brittonia pages 150–156.
- C. Michael Hogan, ed. 2010. Juncus Effusus. Encyclopedia of Life.