Jacobaea aquatica
marsh ragwort
Overview
Jacobaea aquatica is a biennial or short-lived perennial of wet ground in the daisy family, reaching 12-40 inches (30-100 cm) tall. In its first year it forms a rosette of dark green, lyre-shaped leaves; in the second it sends up a branched, often red-flushed stem. The leaves are pinnately lobed with an enlarged terminal lobe, becoming smaller and more deeply cut up the stem. Branches end in a loose, flat-topped cluster of yellow, daisy-like flower heads, each 1-1.2 inches (25-30 mm) across with about 12 to 13 spreading ray florets around a yellow disc. The heads are larger and fewer than those of common ragwort (J. vulgaris), and the cluster is more open. Flowering runs from July to September, after which fluffy, wind-borne seeds are released. It grows in wet meadows, marshes, fens, ditches, and damp pastures on neutral to mildly acid soils that stay moist through summer. All parts contain pyrrolizidine alkaloids that cause cumulative liver damage in horses and cattle, whether the plant is grazed fresh or dried in hay. It spreads by seed and persists where wet grassland is grazed or cut.
Native Range
Native to Europe and western Asia, from the British Isles and Scandinavia south to the Mediterranean. It has been introduced to scattered sites in North America and New Zealand.Suggested Uses
Grown in wet wildflower meadows, pond and ditch margins, and damp conservation grassland for its value to pollinators. It suits naturalistic and wildlife plantings on moist ground. It is unsuited to dry borders, containers, and grazed paddocks where its toxicity to livestock is a concern.How to Identify
Appearance
Size & Dimensions
Height1' - 3'4"
Width/Spread1' - 2'
Reaches mature size in approximately 2 years
Bloom Information
Flower heads open from July to September in loose terminal clusters. Each plant blooms over several weeks, drawing bees, hoverflies, and butterflies to the pollen and nectar. Seeds ripen with a parachute of white hairs and disperse on the wind in late summer and autumn.
Detailed Descriptions
Foliage Description
dark greenGrowing Conditions
Sun Requirements
Requires 4-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight