Rolling a leaf between your fingers reveals hidden cross-partitions inside the hollow tube
Jointed rush — the 'joints'.
Nature · Ferns, grasses & other plants
Jointed rush
Native · flowers in summer · wet ground, ditches, dune slacks and pond edges
Juncus articulatus — Juncaceae
Jointed rush is a common, tufted, arching plant of wet pasture, ditches, pond margins and dune slacks, best known for a trick of touch: draw a leaf between finger and thumb and you can feel the cross-partitions inside it like tiny ridges. It is a true flowering plant, although its tiny brown-green flowers are easy to overlook, and it is easily confused with the very similar sharp-flowered rush, with which it hybridises freely.
How to spot them
- ▸Hollow, slightly flattened, dark green leaves with cross-partitions (septa) felt as ridges when rolled between the fingers
- ▸Stems arch up from a low, tufted base
- ▸Open clusters of small brown flowers, with lower branches at an acute angle to the stem
- ▸Shiny, blackish-brown capsules abruptly narrowed to a distinct beak
- ▸Look-alike: sharp-flowered rush has straight, round, upright stems, red-brown flower clusters with branches at right angles and a tapering fruit; the hybrid can be commoner than either parent
How to know it
Arching stems from a tufted base, with shiny black beaked capsules, on wet ground and dune slacks
Jointed rush.
Its species name refers to the joints, or septa, felt along the hollow leaves
Jointed rush — articulatus.
Hybridises with its look-alike sharp-flowered relative, and the hybrid may be commoner than either parent
Jointed rush — Juncus articulatus x acutiflorus.
A flowering plant of the family Juncaceae, not a grass or sedge, with a round stem
Jointed rush — 'Sedges have edges, rushes are round, grasses are hollow right down to the ground.'
Quick-fire facts
- •Leaves are virtually hollow with obvious transverse septa that can be felt as ridges across the leaf (BSBI VC77 account)
- •More prostrate than sharp-flowered rush; the stem arches upwards from a tufted base
- •Capsule shiny black and suddenly narrowed to a clear beak; the sharp-flowered rush capsule tapers to a point
- •Hybridises with sharp-flowered rush, Juncus acutiflorus, and the hybrid can be commoner than either species
- •Rushes belong to Juncaceae; a memory rhyme runs: sedges have edges, rushes are round, grasses are hollow right down to the ground
- •Like all rushes it is a wind-pollinated flowering plant with tiny six-part flowers
- •Common in wet pasture, ditches, pond edges, marshes, and dune slacks across Britain
Drill it — 5 cards
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