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CALTHA palustris

Image of Caltha palustris

James H. Schutte

Family

Ranunculaceae

Botanical Name

CALTHA palustris

Plant Common Name

Cowslip, Golden Marsh Marigold, Kingcup

Special Notice

This entry has yet to be reviewed and approved by L2G editors.

General Description

Brightening the streambanks or bogs in midspring with showy yellow buttercup flowers, marsh marigold is a lovely woodland wildflower. A deciduous, mounding aquatic perennial, it is native to the northern half of North America from Alaska to Newfoundland south to Iowa and North Carolina.

The thick, spreading, hollow stems carry lush green heart-shaped leaves with dull jagged teeth. In mid- to late spring, the branching stems bear small loose clusters of bright yellow flowers that are waxy. Shaped like a cup (and not like a true marigold), the blossom has five petals and a rounded tuft of golden yellow anthers that carry the pollen. The dry fruits with red seeds that follow are relished by birds.

Grow marsh marigold in partial to full shade in acidic soils that are wet or shallowly underwater. Plants may receive more sunlight in spring while overstory trees have not yet leafed out or if growing in still water. Protect this perennial from winds. Rhizomes (underground stems) or fresh seeds can be ways to increase this plant in a lanscape. Use it as a lovely accent or clumped mass in a moist woodland hollow or stream shoal, in a bog garden or in the mixed border provided the soil very becomes dry, especially in the summer. A double-flowering form (extra petaled flowers) is 'Flore Pleno'.

Leaves and fruits can irritate some people's skin when handled, neither should be eaten. There are health concerns regarding this plant, for more information go to: http://www.ces.ncsu.edu/depts/hort/consumer/poison/Calthpa.htm

Characteristics

  • AHS Heat Zone

    7 - 1

  • USDA Hardiness Zone

    3 - 7

  • Sunset Zone

    A1, A2, A3, 1a, 1b, 2a, 2b, 3a, 3b, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24

  • Plant Type

    Perennial

  • Sun Exposure

    Partial Sun, Partial Shade, Full Shade

  • Height

    4"-16" / 10.2cm - 40.6cm

  • Width

    12"-18" / 30.5cm - 45.7cm

  • Bloom Time

    Spring

  • Native To

    North America, United States, Northeastern United States, Mid-Atlantic United States, Southeastern United States, North-Central United States, Central United States, Alaska, Canada

Growing Conditions

  • Soil pH

    Acidic

  • Soil Drainage

    Poorly Drained

  • Soil type

    Clay, Loam, Sand

  • Tolerances

    Wet Site

  • Growth Rate

    Medium

  • Water Requirements

    Average Water, Ample Water

  • Habit

    Cushion/Mound-forming

  • Seasonal Interest

    Spring

Ornamental Features

  • Flower Interest

    Showy

  • Flower Color

    Yellow

  • Fruit Color

    Green

  • Foliage Color (Spring)

    Green, Light Green

  • Foliage Color (Summer)

    Green

  • Foliage Color (Fall)

    Green

  • Fragrant Flowers

    No

  • Fragrant Fruit

    No

  • Fragrant Foliage

    No

  • Bark or Stem Fragrant

    No

  • Flower Petal Number

    Single

  • Repeat Bloomer

    No

  • Showy Fruit

    No

  • Edible Fruit

    No

  • Showy Foliage

    Yes

  • Foliage Texture

    Medium

  • Foliage Sheen

    Glossy

  • Evergreen

    No

  • Showy Bark

    No

Special Characteristics

  • Usage

    Bog Garden, Feature Plant, Groundcover, Wildflower

  • Sharp or Has Thorns

    No

  • Invasive

    No

  • Attracts

    Butterflies

  • Self-Sowing

    Yes