Prostrate Broom

Botanical name: Carmichaelia appressa
Common name(s): Prostrate broom

About:
A rare and highly distinctive native broom that forms low sprawling mats across coastal sands and gravel. Unlike most brooms, it grows tightly against the ground, creating dense yellow-green mounds of flattened stems. During spring and summer it produces masses of small scented white flowers marked with purple streaks.

Natural habitat:
Stabilised sand dunes, sandy ridges, gravelly sandy loams and coastal sand flats.

Growing environment:
Thrives in full sun and very free-draining soils. Highly tolerant of drought, frost, wind and coastal exposure. Performs best in nutrient-poor sandy or gravelly soils.

Endemic distribution:
Endemic to New Zealand. Restricted to Kaitorete Spit and possibly the mouth of the Rakaia River in Canterbury.

Height:
250–400 mm tall

Width:
1–2 m wide

Flowering:
October – January

Fruiting:
December – May

Uses:

• Coastal restoration
• Rare plant conservation plantings
• Rock gardens
• Dryland gardens
• Retaining wall plantings
• Coastal landscaping
• Habitat restoration
• Low-maintenance groundcover

Appearance:

Growth habit:
A densely branched prostrate shrub forming circular mats pressed closely against the ground.

Leaves:
Leaves are mostly absent on mature plants and reduced to tiny scales. Seedlings and young growth may carry small fleshy leaflets.

Stems:
Flattened yellow-green to light green cladodes (leaf-like stems) form the bulk of the plant and create its distinctive sprawling appearance.

Flowers:
Small scented pea flowers borne in clusters. Flowers are white with purple veins and markings, creating an attractive display over much of the plant.

Fruit:
Produces small brown seed pods containing dark purple-black seeds which often remain attached after the pods split open.

Ecology:
A specialist species of coastal sand and gravel systems where it occupies open, sparsely vegetated habitats. The flowers attract native insects, while the dense growth habit helps stabilise loose sandy soils.

Associated habitats:
Stabilised dunes, sand ridges, coastal gravel flats, sandy shorelines and open coastal herbfields.

How to grow:
Plant in full sun in extremely well-drained sandy or gravelly soil. Avoid rich soils and excessive watering. Particularly well suited to rock gardens, raised beds and coastal landscapes where drainage is excellent.

Propagation:
Readily propagated from seed and hardwood cuttings.

Cultural use:
Part of New Zealand’s unique indigenous broom flora and an important component of the specialised vegetation communities of Kaitorete Spit.

Garden value:
An outstanding ground-hugging native shrub for dry gardens and coastal landscapes. Its unusual mat-forming habit, attractive flowers and ability to thrive in harsh environments make it a valuable feature plant for specialist native collections and restoration projects.