Water Arum vs Knotted Rush - TreeTime.ca

Water Arum vs Knotted Rush

Calla palustris

Juncus nodosus

CUSTOM GROW

NOT AVAILABLE THIS SEASON - MIGHT RETURN

Water Arum
Knotted Rush

Water Arum is a native perennial wetland plant known for its showy white oval sheaths (spathe) that surround a yellow-green, cylindrical flower spike (spadix). It has large, oblong, heart-shaped leaves on stems that rise above the water from shallow, spreading rhizomes. The blossoms are followed in late summer by tiny, pear-shaped fruits that ripen to bright red, adding ornamental interest to wet habitats.

Water Arum provides food for birds and small mammals that eat its berries, and its flowers attract pollinators. It can tolerate cold climates and forms colonies in shallow water and saturated soils. It is well-suited for ecological restoration, riparian planting, naturalisation, and habitat projects in wet and shaded environments.

Knotted Rush is a native perennial wetland plant found growing in marshes, swamps, wet meadows, and along shorelines. It spreads by underground rhizomes to form colonies, which can also help stabilize soils and shorelines.

Its upright, slender stems and small clusters of greenish-brown seed heads add structure to wetland plant communities. Knotted Rush is well-suited to wetland conservation, rain gardens, naturalization, and restoration projects. As a cool-season grower, it grows actively during spring and fall, when temperatures are cooler.

Water Arum Quick Facts

Knotted Rush Quick Facts

Zone: 1b
Zone: 1b
Height: 0.2 m (0.8 ft)
Height: 0.5 m (1.5 ft)
Spread: 0.2 m (0.8 ft)
Spread: 0.2 m (0.5 ft)
Light: shade, partial shade
Light: full sun
Moisture: wet
Moisture: wet
Growth rate: medium
Growth rate: fast
Life span: short
Life span: short
Growth form: colony-forming
Growth form: upright, colony forming
Spreading: rhizomes - medium, seeds - low
Spreading: rhizomes - medium

Toxicity: toxic if ingested

Flowers: white sheath around and yellow spike
Bloom time: spring to summer
Berries: red, in clusters
Hybrid: no
Hybrid: no
Catkins: no
Catkins: no


Native to: AB, BC, SK, MB, ON, QC, NS, NB, NL, YT, NT, PE
Native to: AB, BC, SK, MB, ON, QC, NS, NB, NL, YT, NT, PE
Other Names: bog arum, swamp lily, wild calla, wild dragon