Short-stemmed Geranium

Botanical name: Geranium brevicaule
Synonyms: Geranium sessiliflorum subsp. novae-zelandiae var. novae-zelandiae; Geranium sessiliflorum var. glabrum; Geranium sessiliflorum var. maculatum
Common name(s): Short-stemmed Geranium, Native Geranium

About:
A compact, low-growing native geranium with persistent basal rosettes, a stout rootstock and delicate pink, white or occasionally deeper pink flowers. Geranium brevicaule is highly variable in foliage colour, with plants ranging from fresh green to purple, bronze or green mottled with purple-brown markings.

Its very short flowering stems and persistent rosette habit make it quite unlike most other native and introduced geraniums in New Zealand. It is well adapted to open, exposed habitats and occurs from the coast to subalpine areas.

Natural habitat:
Occurs in open ground from coastal environments to about 1,200 m elevation.

Typical habitats include short and tall tussock grassland, frost flats, clay pans, freshly deposited alluvium, river flats and rocky outcrops.

It favours places with low competition, good light and freely draining or periodically disturbed soils.

Growing environment:
Best in full sun and a dry to moderately moist, free-draining soil.

It tolerates frost, exposure, wind and relatively poor soils, making it well suited to rock gardens, dry native borders and alpine-style plantings.

Avoid heavy, waterlogged soils and excessive shade.

Endemic distribution:
Indigenous to New Zealand and also present in south-eastern Australia and Tasmania.

In New Zealand it occurs on the North, South and Stewart Islands, with its North Island distribution mainly south of Auckland.

Height:
Approximately 2.5–15.5 cm

Width:
Approximately 10–25 cm

Flowering:
Year round

Flowers may be deep pink, pale pink or white.

Fruiting:
Year round

Uses:
• Rock gardens
• Alpine gardens
• Dry native borders
• Container growing
• Open ground restoration
• Tussock grassland planting
• Gravel gardens
• Specialist native plant collections
• Colour-form selection for ornamental use

Appearance:
Growth habit:
A compact perennial herb with a stout rootstock and persistent basal rosettes.

The flowering stems are extremely short, usually shorter than the leaves, giving the plant a tight, low-growing appearance.

Plants may remain as small individual rosettes or gradually form compact multi-crowned clumps.

Leaves:
Leaves are borne in a persistent basal rosette and are approximately 8–26 mm long and 9–32 mm wide.

The leaf blade is polygonal to broadly rounded in outline and deeply divided into five to seven segments.

Each segment is broadly triangular and may be further shallowly toothed or lobed.

The foliage is softly hairy with appressed, non-glandular hairs.

Colour varies considerably between plants. Forms may be green, grey-green, purple or green mottled with purple or brown. These colour differences are genetically based and can persist in cultivation.

Leaf stalks may reach approximately 13 cm long and are covered in short, backward-pointing or appressed hairs.

Flowers:
Flowers are usually borne singly on slender stalks.

The flowering stalks are generally short relative to the basal leaves, which is one of the best features for recognising this species.

Sepals are approximately 4–6 mm long, lance-shaped and softly hairy.

Petals are approximately 3–6.5 mm long, entire, without a distinct claw, and range from deep pink through pale pink to white.

The anthers and filaments are yellowish.

Fruit:
The fruit is approximately 8–18 mm long and develops the characteristic elongated beak of the geranium family.

The individual mericarps are approximately 2–4 mm long, brownish and softly hairy.

At maturity the fruit separates explosively, throwing the seeds away from the parent plant.

Seeds:
Seeds are approximately 1.5–2.8 mm long and finely reticulate.

Unlike several related geraniums, the seeds are smooth rather than strongly ridged or roughened.

Dispersal occurs by ballistic projection when the mature fruit opens, with wind potentially moving the small seeds farther.

Ecology:
Geranium brevicaule is an open-ground species adapted to habitats that experience exposure, disturbance and seasonal dryness.

Its low rosette form reduces wind exposure and allows it to survive in frost flats, alpine grassland and exposed rocky areas.

The persistent basal foliage enables plants to retain a compact growth point close to the soil surface, while the stout rootstock helps them survive harsh seasonal conditions.

The species is variable across its range, and some forms may represent distinct local races that have not yet been fully resolved taxonomically.

Associated habitats:
Short tussock grassland, tall tussock grassland, frost flats, clay pans, river terraces, recent alluvium, rocky outcrops, gravelly ground and open subalpine vegetation.

It may occur with native grasses, small sedges, alpine herbs, bidibids, native buttercups and other low-growing species adapted to exposed ground.

How to grow:
An easy native geranium to cultivate in the right conditions.

Plant in full sun with excellent drainage. A gritty soil containing pumice, coarse sand or fine gravel is ideal.

Keep moderately moist during establishment, then allow the soil to dry somewhat between waterings.

Avoid rich fertiliser and heavy organic soils, as these can encourage soft growth and reduce the plant’s compact form.

It is particularly suitable for pots, troughs and rock gardens where drainage can be controlled.

Colourful forms with purple or mottled foliage are especially attractive in cultivation.

Propagation:
Easily propagated from fresh seed.

Collect seed as the fruits mature but before they have fully released their contents.

Sow into a fine, free-draining seed mix and cover lightly.

Keep moist but not saturated and provide bright light.

Seedlings are generally straightforward to grow and may show considerable variation in leaf colour and markings.

Because colour forms have a genetic basis, selective propagation can maintain and develop attractive ornamental strains.

Cultural use:
No specific traditional Māori uses are widely documented for Geranium brevicaule.

The species is nevertheless part of the native open-ground and tussock flora of Aotearoa.

The name brevicaule means “short-stemmed”, referring to the characteristically short flowering stems that remain close to the basal rosette.

Garden value:
A highly attractive and underused native herb for rock gardens, troughs, dry borders and alpine-style plantings.

Its compact form, fine divided foliage and variable colour make it ornamental even when not in flower.

Plants with purple, bronze or mottled foliage are particularly distinctive and have strong potential for horticultural selection.

The ability to flower and fruit throughout the year adds further interest, while its tolerance of frost, exposure and dry, free-draining soils makes it a useful low-maintenance option for difficult sunny sites.