Juncus effusus 'Spiralis' is the ornamental form of common rush, selected for the involuntary corkscrew twist that runs through every stem from base to tip. The stems are the same smooth, cylindrical, leafless green as the straight species, but instead of rising vertically they spiral, each one describing its own loose helix, so that a clump 12 to 18 inches tall reads as something between a plant and an object. Late summer brings yellowish-green to brown flowers in many-flowered cymes, modest blooms that suit the plant's restrained palette, with small capsules following. It grows in zones 5 through 11 and earns its reputation as easy to manage, tolerating sun to partial shade and water over the crown of 1 to 6 inches.

Growing corkscrew rush in a 2-gallon or larger container is the most practical approach, whether on a patio, sunk into a pond margin, or kept as a houseplant with consistently moist soil. Rhizome division is the main propagation method and can get away from a gardener in the open ground, so pot containment is advisable for tidy situations. In warm-winter zones the stems remain evergreen; in cooler climates they yellow and brown in fall and die back before returning. It has no significant pest or disease problems. As a specimen plant beside a water feature or reflected in still water, 'Spiralis' has a visual specificity that the straight-stemmed common rush, useful as it is, simply cannot match.