Prostrate Snowberry

Botanical name: Gaultheria macrostigma
Synonyms: Pernettya macrostigma; Gaultheria depressa var. microphylla
Common name(s): Prostrate Snowberry, Large-stigma Snowberry

About:
Prostrate Snowberry is a small evergreen upland shrub with wiry, interlacing branches, narrow leathery leaves and colourful berry-like fruit. It usually grows as a low, tangled mat but may occasionally form a compact bush approaching 1 m tall.

Its white to pinkish bell-shaped flowers are followed by pale pink, deep pink, red or occasionally whitish fruit. The combination of fine foliage, bristly twigs and conspicuous fruit makes it an attractive component of New Zealand’s montane and subalpine vegetation.

Natural habitat:
Occurs in montane to subalpine grasslands, open shrublands, forest margins, rocky places and other exposed upland habitats.

It commonly occupies freely draining slopes, rocky outcrops and open ground where taller vegetation is sparse. Plants may grow through tussock or amongst low alpine shrubs, with their stems spreading across the soil surface and between stones.

Growing environment:
Prefers full sun or partial shade in cool conditions with acidic, humus-rich and freely draining soil.

It tolerates severe frost, wind and exposed upland environments. Reliable moisture is beneficial during establishment, but prolonged waterlogging and hot, humid conditions should be avoided.

Endemic distribution:
Endemic to New Zealand.

Found in montane and subalpine districts of the North and South Islands.

Height:
Usually 10–50 cm, occasionally forming a bush up to approximately 1 m tall

Width:
Approximately 50 cm–1.5 m, spreading through long, interlacing stems

Flowering:
Spring–summer

Fruiting:
Summer–autumn

Uses:
• Alpine and rock gardens
• Native ground cover
• Subalpine restoration
• Tussock and shrubland planting
• Wildlife gardens
• Erosion control on rocky slopes
• Botanical collections
• Edible berry planting

Appearance:
Growth habit:
A low, sprawling evergreen shrub with flexible, much-branched stems that commonly form tangled mats.

Stems may occasionally root where they contact the ground, helping the plant spread across rocky or gravelly substrates. In sheltered situations it may become more upright and bush-like.

Stems:
Branches are slender, wiry and frequently interlaced.

Young branchlets are moderately hairy and bear scattered long, weak, bristle-like hairs. Older stems become woody and are often partially hidden beneath the foliage.

Leaves:
Leaves are alternately arranged, rather widely spaced and generally 6–15 mm long and 1–3 mm wide.

They are narrow, linear to narrowly elliptic, thick and leathery. The margins are often strongly recurved or rolled under and usually bear several small teeth on each side, sometimes arranged in opposite pairs.

Some teeth may terminate in fine bristle-like points. The foliage varies from dark green to olive, bronze or brownish-green, particularly in cold and exposed conditions.

Flowers:
Small bell-shaped flowers are produced singly from the leaf axils on short stalks.

They are usually white but may be flushed pale pink. Fine hairs may occur within the corolla, while the calyx lobes have conspicuously fringed margins.

The flowers are comparatively small and may be partly concealed amongst the narrow foliage.

Fruit:
The fruit is rounded, berry-like and approximately 5–6 mm wide.

It is typically pale to deep pink but may vary from whitish through red. The fleshy outer portion surrounds the seed-bearing capsule and has a distinctly lobed appearance.

The fruit is edible, although its flavour and abundance can vary between individual plants.

Seeds:
Each fruit contains numerous small seeds.

The fleshy fruit is eaten by native birds, lizards and invertebrates, which assist with dispersal. Fruit falling beneath the parent shrub may also establish in nearby open ground.

Ecology:
Prostrate Snowberry contributes low, protective cover within upland grasslands, rocky shrublands and subalpine communities.

Its interlacing stems help protect shallow soils from erosion and provide shelter for native insects, spiders and small reptiles. Flowers supply nectar and pollen to upland insects, while the fruit provides seasonal food for ground-dwelling and fruit-eating fauna.

Its tolerance of frost, wind and nutrient-poor acidic soils allows it to persist in exposed habitats where taller woody plants grow poorly.

Associated habitats:
Montane grasslands, subalpine shrublands, tussock country, rocky outcrops, scree margins, forest edges and open upland slopes.

Associated species may include snow tussocks, Celmisia, Dracophyllum, Coprosma, native brooms, small hebes, Raoulia and other native snowberries.

How to grow:
Plant in full sun or light shade in acidic, humus-rich and freely draining soil.

A gritty mixture containing pumice, coarse sand, fine bark and leaf mould is suitable for alpine gardens and containers. Keep evenly moist while establishing but avoid saturated soil.

Provide good air movement and protect from prolonged summer heat in warmer districts. Plants generally require little pruning beyond removing dead growth or lightly trimming stems that spread beyond their allotted area.

Propagation:
Propagation may be achieved from fresh seed, semi-hardwood cuttings or naturally layered stems.

Clean ripe fruit from the seed and sow onto the surface of an acidic, free-draining propagation mix. Keep cool, lightly shaded and consistently moist, as germination may be slow.

Cuttings taken from firm young shoots during late summer provide a useful way of retaining compact growth and desirable fruit colour.

Cultural use:
Specific traditional Māori uses for Gaultheria macrostigma are not well documented.

The edible fruit may have been gathered locally, as were the fruits of several other native snowberries. Claims of medicinal use should not be assumed from unrelated overseas Gaultheria species.

The species name macrostigma means “large stigma”, referring to the prominent pollen-receptive structure within the flower.

Garden value:
Prostrate Snowberry is an attractive evergreen shrub for alpine gardens, rockeries, raised banks and cool naturalistic landscapes.

Its tangled habit, fine dark foliage, delicate bell-shaped flowers and pink to red fruit provide subtle year-round interest. It combines particularly well with native tussocks, mountain daisies, small hebes and other upland shrubs.

It performs best in cool, acidic and sharply drained conditions that resemble its natural montane and subalpine habitat.