Parnassia, Genus, palustris, Species,
- Genus & species
marsh grass-of-parnassus
Overview
Parnassia palustris is a perennial herb of wet, lime-rich ground, reaching 4-12 inches (10-30 cm) in flower. A basal rosette of heart-shaped, long-stalked leaves 0.4-1.2 inches (1-3 cm) long sits at ground level, while each slender flowering stem carries a single stalkless leaf that clasps the stem near its middle. Stems are unbranched and end in one upward-facing flower. The flowers measure 0.6-1.2 inches (15-30 mm) across and have five white petals marked with translucent green veins. Five pollen-bearing stamens alternate with five sterile staminodes, each divided into 7-15 fringe-like segments tipped with glistening yellow glands that draw small flies and bees. Flowering runs from July to September. The plant grows from a short rhizome and dies back to a resting bud over winter. It occupies fens, calcareous flushes, wet meadows, and damp dune slacks, where soils stay moist and base-rich through summer. P. palustris declines where wetlands are drained or enriched with nutrients, and it establishes poorly in cultivation because it depends on stable groundwater and low competition from taller plants. Despite the common name, it is not a grass and is unrelated to the grass family.
Native Range
Native across the cool temperate and subarctic Northern Hemisphere, including most of Europe, northern and central Asia, and northern North America. In North America it ranges from Alaska and Canada south into the northern United States.Suggested Uses
Grown in bog gardens, pond margins, and damp wildflower areas on calcareous soil. It suits naturalistic plantings where groundwater stays high through summer. It is not suited to dry borders or containers that dry between waterings.How to Identify
Appearance
Size & Dimensions
Height4" - 1'
Width/Spread2" - 6"
Bloom Information
Flowers open from July to September, one per stem, each lasting several days. Plants in northern and upland sites flower toward the later end of this range. After flowering, an egg-shaped capsule forms and splits into four to shed numerous tiny seeds.
Detailed Descriptions
Flower Description
white with green veinsFoliage Description
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