Cinnamon Bells
Gastrodia sesamoides
This native plant, known as Cinnamon Bells (scientific name: Gastrodia sesamoides), is a remarkable species endemic to New Zealand. It is characterized by its unique features, ecological role, and cultural significance. This comprehensive guide provides detailed information on its care, propagation, and importance within the New Zealand ecosystem. Understanding this plant contributes to the appreciation of our rich biodiversity and heritage, and supports conservation efforts for flowers.
Plant Description
Gastrodia sesamoides, commonly known as Cinnamon Bells or Pot-bellied Orchid in New Zealand, and Cinnamon Bells or Common Potato Orchid in Australia, is a fascinating leafless, terrestrial saprophytic orchid. This perennial herb is indigenous to New Zealand and Australia, and has naturalized in South Africa. Lacking chlorophyll, it does not photosynthesize, instead relying entirely on a complex symbiotic relationship with mycorrhizal fungi for its nutritional needs. This unique lifecycle allows it to flourish in diverse habitats from coastal areas to montane regions, often associated with decaying wood and host trees. The plant typically grows up to 1 meter tall, emerging from an underground rhizome that is tuberous, elongated, and swollen, often reaching up to 80 mm long and 30 mm in diameter. This rhizome is characteristically pale pinkish-brown to brownish-black and frequently covered in protective scales. The flowering stem, which is rather brittle when fresh, is thin, fleshy, and brown, ranging from 12 to 75 cm in height, and speckled with small, lighter brown spots. Gastrodia sesamoides produces between 3 and 25 pendulous flowers along its stem. These flowers, mostly unscented or sometimes faintly scented, are distinctive bell-shaped perianths, measuring 10-16 mm long and 4-8 mm wide. Their coloration is usually light brownish or mustard at the base, gradually transitioning to pinkish or pinkish-cream towards the apex, and notably, they are unspotted and smooth externally, but white inside. The lateral sepals are fused almost to the tip of the labellum. The labellum itself, approximately 10 x 4 mm, is white, cream, or yellowish, trilobed, and completely enclosed within the floral tube. The column, nearly as tall as the labellum, contributes to the flower's unique structure. The flowers often release a spicy, cinnamon-like perfume, particularly strong in warmer temperatures, which aids in attracting pollinators like native bees.
Quick Facts
| Scientific Name | Gastrodia sesamoides |
|---|---|
| Height | Up to 1 meter (flowering) |
| Spread | Forms colonies from underground rhizomes |
| Water Needs | Moderate to High |
| Light | Partial to full shade |
| Frost Tolerance | Moderate |
| Salt Tolerance | Moderate |
| Growth Rate | Moderate |
| Lifespan | Perennial |
Climate Best Suited to
Gastrodia sesamoides exhibits a broad climatic tolerance, being indigenous to New Zealand (North Island, Marlborough, and Nelson in the South Island) and Australia (Queensland, NSW, Victoria, Tasmania, South Australia). It has also naturalized in South Africa. This orchid thrives from coastal to montane areas (up to 1000m altitude), indicating adaptability to various temperate zones. Its prevalence in disturbed habitats, coastal wetlands, and gumland scrub suggests it can tolerate a range of conditions, but requires a consistent supply of decaying organic matter and compatible fungi.
Regional Suitability
| City | Climate Suitability |
|---|---|
| Auckland | Suitable (in areas with decaying wood) |
| Wellington | Suitable (in areas with decaying wood) |
| Christchurch | Suitable (in areas with decaying wood) |
| Dunedin | Suitable (in areas with decaying wood) |
| Hamilton | Suitable (in areas with decaying wood) |
Plant Habitat
Gastrodia sesamoides is indigenous to New Zealand (North Island, Marlborough, and Nelson in the South Island) and a wide range of Australian states. It is highly adaptable, thriving in diverse habitats from coastal areas to montane regions (up to 1000m). This orchid is commonly found in disturbed sites, coastal wetlands, associated shrublands, gumland scrub, and open areas along forest margins or in secondary regrowth. Its frequent association with pine bark mulch in plantation forestry and urban environments highlights its ability to colonize modified landscapes, typically where decaying wood and compatible fungi are present.
Plant Conservation
Gastrodia sesamoides is generally considered common and widespread throughout much of its New Zealand and Australian range, and is not globally threatened. However, it is classified as "rare" and vulnerable in some regions of South Australia, primarily due to habitat loss and degradation. Its ability to colonize disturbed habitats and associate with various fungi and host trees contributes to its overall resilience, but local populations can be sensitive to significant environmental changes that impact its fungal symbionts.
Growing Requirements
Soil Requirements
Gastrodia sesamoides requires soils rich in decaying organic matter and compatible mycorrhizal fungi. It is frequently found in soils associated with pine bark mulch, gumland scrub, or forest leaf litter. The soil should be consistently damp but well-draining to prevent waterlogging, which can harm its delicate rhizomes and fungal partners. The presence of decaying wood is crucial for its fungal symbionts.
- Rich in decaying organic matter (e.g., pine bark mulch, leaf litter).
- Consistently damp but well-draining.
- Requires compatible mycorrhizal fungi.
Light Requirements
As a leafless, saprophytic orchid, Gastrodia sesamoides does not directly require sunlight for photosynthesis. It typically grows in partial to full shade, often along forest margins, in secondary regrowth, or within gumland scrub. While it can tolerate some light, protection from intense, direct sun is beneficial to maintain the damp conditions it prefers.
- Partial to full shade.
- Does not require direct sunlight for growth.
- Thrives along forest margins and disturbed sites.
Water Requirements
Gastrodia sesamoides needs consistently damp soil conditions, reflecting its preference for wetlands and moist disturbed habitats. The soil should never be allowed to dry out completely, especially during its extended flowering period (August to May in New Zealand). However, it is essential to avoid waterlogging, which can harm its delicate rhizomes and fungal partners; good drainage is necessary even in damp environments.
- Consistently damp soil conditions.
- Avoid drying out completely.
- Good drainage is still essential.
Planting Guide
Cultivating Gastrodia sesamoides, or Cinnamon Bells, is exceptionally challenging for the home gardener due to its complete dependence on a symbiotic relationship with specific mycorrhizal fungi, which are often associated with decaying wood and host trees. It is not a plant that can be easily propagated or maintained in a typical garden setting. While some success has been reported with other Gastrodia species in specialized environments, G. sesamoides is best left undisturbed in its natural habitat. For those dedicated to encouraging its presence, the focus must be on replicating its specific ecological niche. This involves providing a continuously damp, organic-rich soil environment with a good supply of decaying wood (e.g., pine bark mulch, aged timber) to support the necessary fungal networks. The location should offer partial to full shade, mirroring its preference for forest margins, gumland scrub, or secondary regrowth areas. Propagation by home gardeners is generally not successful from seed or cuttings. Attempts to transplant wild specimens are strongly discouraged, as they rarely survive due to the disruption of their delicate fungal associations. The most effective approach for supporting Gastrodia sesamoides is through habitat preservation and restoration, ensuring the presence of its fungal partners and their host trees, and maintaining damp, undisturbed soil conditions. Fire in previous seasons has been noted to enhance flowering.
Ecological Role
Gastrodia sesamoides plays a unique and vital ecological role as a leafless, saprophytic orchid in New Zealand and Australian ecosystems. Its complete dependence on mycorrhizal fungi for nutrients highlights the intricate underground food webs and nutrient cycling processes on the forest floor. The orchid forms a tripartite symbiosis, providing habitat for fungi which, in turn, obtain minerals and sugars from host trees. Its flowers, with their cinnamon-like fragrance, attract native bees, contributing to the pollination of other flora. As an indicator species, its presence suggests a healthy, undisturbed, and organic-rich soil environment.
Uses & Significance
Garden Uses
Gastrodia sesamoides is not suitable for conventional garden cultivation due to its saprophytic nature and obligate dependence on specific mycorrhizal fungi associated with decaying wood. It is an orchid best appreciated in its natural habitat, rather than as a horticultural subject.
- Not suitable for conventional garden cultivation.
- Requires specific fungal symbiont associated with decaying wood.
- Best appreciated in its natural habitat.
In Australia, particularly for Indigenous Australians, the tubers of Gastrodia sesamoides held historical significance as a food source. Known as "common potato orchid," its roasted tubers were eaten, and it may have been a principal food for Tasmanian Aborigines. The tubers were often located by observing where bandicoots had scratched the ground, having detected them by scent. While specific Māori uses are not as prominently documented, as an indigenous species in New Zealand, it forms part of the natural heritage valued within Mātauranga Māori.
- Historically a food source for Indigenous Australians (tubers).
- Known as "common potato orchid" in Australia.
- Part of the natural heritage valued in Mātauranga Māori (NZ).
Ecological Value
The ecological value of Gastrodia sesamoides is significant in demonstrating the complex interdependencies within forest ecosystems. Its saprophytic nature, reliant on mycorrhizal fungi and decaying wood, highlights crucial nutrient cycling pathways often unseen. It acts as an indicator of rich, organic soils and healthy fungal networks. The cinnamon-scented flowers attract native bees, contributing to the broader biodiversity and pollination services within its habitats. Its presence is a testament to unique evolutionary adaptations in leafless orchids.
- Contributes to wetland and shrubland biodiversity.
- Forms mycorrhizal associations vital for soil health.
- Provides ground cover and creates microhabitats.
- Part of the pollinator network within its ecosystems.
Cultural Significance
This plant contributes to the rich tapestry of New Zealand's native flora, known collectively as Te Wao Nui a Tāne. While specific traditional uses may vary or be less documented for some smaller species, all native plants are considered taonga (treasures) and possess a mauri (life force).
They are integral to the cultural landscape, featuring in local biodiversity and often indicating the health of the environment.
Landscaping Uses
Gastrodia sesamoides is not a plant for landscaping in the traditional sense due to its highly specialized saprophytic and fungal-dependent lifecycle. Instead, its "landscaping use" is indirect, serving as an indicator of healthy, organic-rich, and undisturbed forest floor environments. Efforts should focus on preserving and restoring its native habitats rather than attempting direct cultivation.
Seasonal Care Calendar
Spring
New flowering stems begin to emerge from the underground rhizomes. Ensure the soil remains consistently damp and rich in decaying organic matter to support the fungal network it relies upon.
- New flowering stems emerge.
- Maintain damp, organic-rich soil conditions.
Summer
This is the peak flowering period (August to May in NZ, Oct-Jan in Australia). The plant relies entirely on its underground fungal symbiont for nutrients; ensure the environment remains stable, moist, and rich in decaying wood. Cinnamon-like fragrance is stronger in warmer temperatures.
- Peak flowering season (August-May in NZ).
- Maintain stable, moist, organic-rich conditions.
- Fragrance is stronger in warm weather.
Autumn
After flowering and seed dispersal, the aerial parts of the orchid will die back, and the plant enters a dormant phase. The underground rhizomes continue their symbiotic relationship with the fungus, drawing nutrients from decaying wood.
- Aerial parts die back.
- Rhizomes remain active underground with fungus.
Winter
The orchid remains dormant underground through winter. The focus should be on protecting its habitat from disturbance, ensuring a healthy supply of decaying wood and a compatible fungal environment.
- Dormant underground.
- Protect habitat from disturbance.
- Ensure presence of decaying wood for fungi.
When to Prune and How Much
Gastrodia sesamoides requires no pruning. Its growth cycle involves the emergence of a flowering stem from an underground rhizome, followed by natural senescence after seed set. Any removal of spent stems should be done carefully to avoid disturbing the delicate forest floor ecosystem and its vital fungal network.
- No pruning required.
- Allow natural senescence of flowering stems.
Avoid disturbing the forest floor and its critical fungal network and decaying wood.
How to Grow Cinnamon Bells
From Seed
Propagating Gastrodia sesamoides from its minute seeds is extremely challenging due to its obligate symbiotic relationship with specific mycorrhizal fungi, which are often associated with decaying wood. Commercial or home propagation from seed is generally not feasible.
- Seeds are microscopic.
- Requires specific fungal symbiont for germination.
- Primarily for professional propagation in sterile, laboratory conditions.
- Not feasible for typical home cultivation.
Natural reseeding may occur in healthy, undisturbed habitats with decaying wood and compatible fungi.
From Cuttings
Gastrodia sesamoides is a leafless, saprophytic orchid and does not produce stems or leaves suitable for conventional vegetative propagation via cuttings. This method is not applicable to its biology.
- This method is not applicable to Gastrodia sesamoides.
Additional Methods
The plant spreads vegetatively through its underground, tuberous rhizomes, forming colonies in favorable conditions. While direct division can be attempted, it is a delicate process requiring careful handling and ensuring the presence of its fungal partners and decaying organic matter in the replanting site.
- Spreads vegetatively via underground rhizomes.
- Division of rhizomes requires careful handling and specific conditions.
- Focus on habitat preservation for natural spread.
General Propagation Tips (Seeds & Cuttings)
Successful propagation of native New Zealand plants requires attention to detail and patience. When growing from seed, it is essential to start with fresh, viable seeds collected when they are fully mature. Clean the seeds thoroughly to remove any fleshy pulp, which can inhibit germination. Sow the seeds on the surface of a seed-raising mix that is free-draining yet moisture-retentive. A mix of peat and coarse sand or perlite often works well. Cover the seeds lightly with a fine layer of grit or sieved potting mix, or leave them uncovered if they require light to germinate. Keep the trays in a sheltered, shaded spot and maintain consistent humidity; a plastic cover can help but ensure there is adequate ventilation to prevent fungal diseases. Germination can be erratic, sometimes taking several months, so do not discard the trays too early. For vegetative propagation, semi-hardwood cuttings are often the most successful method for shrubby species. Take cuttings in late summer or early autumn, selecting healthy, non-flowering shoots. Trim them to about 10-15 cm in length, making a clean cut just below a node. Remove the lower leaves and dip the cut end in rooting hormone to encourage root development. Insert the cuttings into a propagating mix, ensuring they are firm and stable. Place them in a humid environment, such as a mist unit or a covered frame, out of direct sunlight. Rooting can take anywhere from a few weeks to several months. Once roots have formed, pot the young plants into individual containers and harden them off gradually before planting out. Division is another effective method for clump-forming plants like sedges, grasses, and lilies. This is best done in autumn or early spring when the plant is actively growing. Lift the clump carefully and tease the roots apart, using two garden forks or a sharp knife if the clump is dense. Ensure each division has a good root system and healthy shoots. Replant the divisions immediately, watering them well to settle the soil around the roots. With proper care, these new plants will establish quickly and grow into healthy specimens. By employing these methods, you can successfully expand your collection of native flora and contribute to the preservation of New Zealand's unique botanical heritage.
Pests & Diseases
Gastrodia sesamoides is generally robust against pests and diseases due to its subterranean and saprophytic lifestyle. The main threats are environmental factors, particularly disruption to its symbiotic fungal network, changes in soil moisture (prolonged drought or waterlogging), and the removal of its decaying wood substrate. Maintaining a healthy, undisturbed, organic-rich habitat is crucial for its survival.
Bonus Tip
Gastrodia sesamoides's survival is intrinsically linked to healthy forest ecosystems with a continuous supply of decaying wood and compatible fungi. Supporting indigenous forest regeneration and minimizing soil disturbance are the best "cultivation" practices for this unique orchid.
