White Cushion Mountain Daisy

Botanical name: Celmisia sessiliflora

Synonyms: Celmisia sessiliflora var. exigua, Celmisia sessiliflora var. pedunculata

Common name(s): White Cushion Mountain Daisy, Cotton Daisy

About:
A distinctive cushion-forming mountain daisy that develops dense silvery-white mats across alpine landscapes. Its tightly packed woolly foliage and stemless white flowers make it one of New Zealand’s most recognisable high-country Celmisia species. Mature plants can form impressive cushions up to a metre across.

Natural habitat:
Montane to alpine grasslands, herbfields, fellfields and rocky outcrops.

Growing environment:
Prefers cool alpine conditions, free-draining moist soil, full sun to light shade and excellent air circulation. Performs best in rock gardens, alpine houses and raised beds. Does not tolerate humidity or prolonged drying out.

Endemic distribution:
Endemic to New Zealand. Widespread throughout the South Island from Nelson to Southland.

Height:
50–100 mm

Width:
Forms dense cushions and patches up to 1 m across.

Flowering:
October–February

Fruiting:
November–April

Uses:
• Alpine gardens
• Rockeries
• Trough gardens
• Native plant collections
• High-country restoration plantings
• Container growing in alpine houses

Appearance:

Growth habit:
A densely branched, cushion-forming subshrub with compact rosettes packed tightly together, creating broad silvery mounds.

Leaves:
Short linear to linear-subulate leaves 10–30 mm long, densely covered on both surfaces with fine white hairs. The rigid foliage gives the entire plant a soft silver-white appearance.

Flowers:
White daisy flowers 10–20 mm across with yellow centres. Flower heads sit almost directly within the foliage, appearing nearly stemless when in bloom.

Fruit:
Produces small wind-dispersed seeds equipped with long white pappus hairs.

Ecology:
A characteristic species of alpine grasslands and fellfields where its dense cushions help reduce moisture loss, trap warmth and provide shelter for small alpine invertebrates. Seeds are dispersed by wind.

Associated habitats:
Alpine grassland, subalpine herbfield, fellfield, rocky outcrops, screes and exposed mountain ridges.

How to grow:
Plant in a cool position with moist but sharply draining soil. Ideal for alpine houses, troughs and south-facing rockeries. Avoid humid climates, heavy soils and drought stress.

Propagation:
Best raised from fresh seed. Can also be propagated from cuttings taken from healthy cushion growth. Keep young plants cool, moist and well ventilated.

Cultural use:
An iconic member of New Zealand’s alpine flora, valued for its remarkable cushion-forming habit and adaptation to harsh mountain environments.

Garden value:
A superb specialist alpine plant that forms striking silver cushions and produces attractive white flowers. Particularly valuable for rock gardens, troughs and alpine collections where its compact growth can be appreciated up close.