Mountain Ribbonwood
Botanical name: Hoheria glabrata
Synonyms: None
Common name(s): Mountain ribbonwood, Mountain lacebark
About:
A beautiful deciduous native tree of cool, wet mountain environments, notable for its broad heart-based leaves, masses of large white flowers and golden autumn foliage. Hoheria glabrata is one of the relatively few fully deciduous trees in New Zealand and may reach about 10 m tall, although it often remains smaller and can develop several trunks from near the base.
The foliage is distinctly heteroblastic. Juvenile plants have smaller, more deeply lobed leaves, while mature trees develop much larger ovate leaves with strongly heart-shaped bases and pointed tips. In late summer the branches become covered with conspicuous white flowers, followed by dry winged fruits dispersed by wind.
Natural habitat:
Montane to subalpine environments, particularly in the wetter mountainous regions of the South Island.
It occupies open forest and forest margins, montane scrub, river and stream banks, avalanche paths, slip scars, river fans and other naturally disturbed mountain habitats.
The species is particularly well adapted to cool climates, high rainfall and recurrent disturbance.
Growing environment:
Frost, Sun, Cold, Wind & Damp Soil tolerant. Prefers cool climates with consistently moist soil and good drainage. Dislikes prolonged warmth and high humidity.
Endemic distribution:
Endemic to the South Island of New Zealand.
It occurs predominantly west of the Main Divide but extends eastward into parts of Central Otago, where its range overlaps with the closely related Hoheria lyallii.
Height:
Up to approximately 10 m tall.
Width:
Approximately 4–8 m depending on age, growing conditions and whether the tree develops multiple stems.
Flowering:
February – March
Produces large white flowers, usually solitary or in small clusters of 2–3 from the leaf axils.
Fruiting:
April – July
Produces flattened, dry mericarps with narrow papery wings that assist dispersal by wind.
Uses:
• Specimen tree
• Cool-climate native gardens
• Mountain and high-country restoration
• Riparian planting
• Forest-margin restoration
• Stream-bank planting
• Wildlife and pollinator gardens
• Large native borders
• Seasonal-interest planting
• Traditional fibre source
Appearance:
Growth habit:
A deciduous small tree, usually with an open, spreading crown and sometimes several trunks arising close to ground level.
Young branchlets are initially covered with sparse star-shaped hairs but become progressively smoother with age. Bark is generally pale grey-brown to brown.
The tree loses its foliage during winter, producing fresh green growth again in spring.
Leaves:
Juvenile leaves are approximately 13–50 mm long and 15–30 mm wide, broadly elliptic to almost circular and usually deeply lobed or strongly crenate. Their bases are typically heart-shaped and their tips range from slightly pointed to acute.
Adult leaves are much larger, approximately 36–180 mm long and 25–80 mm wide. They are elliptic to ovate, thin to moderately firm, with a strongly cordate or occasionally nearly truncate base.
The margins are crenate or double-crenate, while the apex is acute to strongly acuminate and may form a conspicuous elongated drip-tip.
Leaves are only sparsely hairy and may become almost completely smooth with maturity.
In autumn the foliage commonly turns yellow before falling.
Flowers:
Flowers are borne singly or in small cymose clusters of 2–3 from the leaf axils.
They are relatively large and conspicuous, with five, occasionally six, broad white petals approximately 13–20 mm long.
The calyx is bell-shaped and densely hairy, with 5–6 triangular lobes.
Numerous white stamens occupy the centre of the flower. The style is characteristically pink, providing a subtle contrast against the white petals, while the anthers may have a purplish appearance.
Fruit:
After flowering, the ovaries develop into clusters of dry mericarps.
Each mericarp has a flattened, broadly elliptic body approximately 4 mm long with a narrow papery wing along much of its outer edge.
The mature seeds are orange-brown, semicircular to triangular and usually separate from the surrounding mericarp when ripe.
The winged fruits are dispersed by wind.
Ecology:
Hoheria glabrata is strongly associated with naturally disturbed montane and subalpine environments.
Avalanche tracks, slips, flood-prone river margins and forest openings provide the high-light conditions in which young trees establish particularly well.
Its relatively rapid growth helps it colonise such disturbed areas, contributing to the recovery of woody vegetation and providing shelter for slower-growing species.
The large summer flowers provide pollen and nectar resources for insects, while the wind-dispersed fruit allows seed to travel into newly disturbed open habitats.
Its deciduous habit is unusual among New Zealand native trees and reflects adaptation to cold mountain winters.
Associated habitats:
Montane forest, subalpine forest margins, open forest, montane scrub, avalanche tracks, slip scars, river terraces, river fans, stream banks, rocky slopes and other cool, disturbed mountain environments.
How to grow:
Best grown in a cool climate with reliable soil moisture.
Plant in full sun or light partial shade in fertile, humus-rich soil that remains damp but does not become stagnant. It performs particularly well beside streams, in cool gullies and in high-rainfall gardens.
The species is very frost hardy and tolerates exposed mountain conditions once established.
It performs poorly in warm, humid climates and may fail to flower satisfactorily where winters are insufficiently cold.
Allow adequate room for the mature crown and root system.
Propagation:
Best propagated from fresh seed.
Collect mature winged fruits and sow promptly into a moist, freely draining propagation medium. Keep seedlings cool and evenly moist.
Young plants develop relatively quickly under favourable conditions and should be gradually exposed to outdoor conditions before planting out.
Seed-grown plants are preferable for restoration because they retain genetic diversity and local provenance.
Cultural use:
The fibrous bark of Hoheria glabrata, like that of the closely related Hoheria lyallii, was likely used by South Island Māori as a source of fibre for textiles, cordage and related purposes.
Lacebark species were valued for the strong, flexible inner bark that could be separated into useful fibrous strips.
Garden value:
One of the finest native trees for cool-climate gardens.
Its combination of fresh spring foliage, masses of white late-summer flowers, yellow autumn colour and bare winter branch structure provides unusually strong seasonal interest for a New Zealand native tree.
It is especially attractive beside streams, in mountain-style gardens and as a specimen tree in cooler parts of the country.
The strongly heart-shaped mature leaves also make it relatively easy to distinguish from Hoheria lyallii, whose foliage is generally more densely hairy and lacks the same strongly cordate leaf base.