Cheeseman’s Spider Orchid
Botanical name: Corybas cheesemanii
Synonyms: Corysanthes cheesemanii
Common name(s): Cheeseman’s Spider Orchid, Spurred Helmet Orchid, Helmet Orchid
About:
Cheeseman’s spider orchid is a tiny terrestrial orchid endemic to New Zealand, admired for its remarkable helmet-shaped flowers that appear like small pearls scattered across the forest floor. Growing almost entirely hidden beneath deep leaf litter, it flowers during the cooler months when few other native orchids are in bloom. Its cryptic nature and specialised habitat make it one of New Zealand’s most fascinating woodland orchids.
Natural habitat:
Deep leaf litter in coastal to montane forests and tall scrub, usually in very shady, damp locations beneath kānuka and southern beech forests.
Growing environment:
Requires cool, permanently moist, humus-rich soils in dense shade. Prefers undisturbed leaf litter and sheltered woodland conditions with high humidity.
Endemic distribution:
Endemic to New Zealand. Found on the Three Kings Islands, North Island, South Island and the Chatham Islands.
Height:
Up to 25 mm when flowering; fruiting stems may reach 220 mm.
Width:
1–2 cm
Flowering:
May–September
Fruiting:
November–January
Uses:
• Native woodland restoration
• Conservation plantings
• Native orchid collections
• Forest biodiversity enhancement
• Educational and botanical collections
Appearance:
Growth habit:
A minute, deciduous terrestrial orchid with a single underground tuber connected by long lateral roots. Much of the plant remains buried beneath deep leaf litter, with only the flower emerging during winter.
Leaves:
Produces a single, heart-shaped to rounded leaf measuring 10–20 mm across. The upper surface is pale to bright green while the underside has a silvery-green sheen. In some plants the leaf is greatly reduced and almost completely hidden beneath the leaf litter.
Flowers:
Usually a single flower is produced directly above the leaf. The large hood-like dorsal sepal arches over the flower, forming a distinctive helmet. Flower colour varies from dark pink and maroon to purple-grey, greyish-white with purple flecks or entirely white. The cream to white labellum forms a curved tube with two small downward-pointing spurs hidden beneath the helmet.
Fruit:
Following flowering, an erect cylindrical seed capsule develops on a greatly elongated stem that may reach over 20 cm in height, allowing the tiny dust-like seeds to disperse above the surrounding leaf litter.
Ecology:
This orchid grows almost exclusively within deep, moist leaf litter where it forms specialised relationships with soil fungi essential for germination and survival. Its unusual flowering period provides an important seasonal resource for small forest pollinators.
Associated habitats:
Kānuka forest, southern beech forest, taraire forest, mature mixed podocarp forest, dense scrub and occasionally Douglas fir plantations with deep organic litter.
How to grow:
Extremely difficult to cultivate successfully. Plants should never be removed from the wild. If grown, they require cool, shaded conditions with permanently moist, humus-rich soil and an intact leaf litter layer supporting their natural fungal partners.
Propagation:
Propagation is extremely difficult and relies upon specialised mycorrhizal fungi. Seed germination under natural conditions is slow and should be left to specialist orchid conservation programmes.
Cultural use:
Although not known for widespread traditional use, Cheeseman’s spider orchid is an important component of New Zealand’s native forest biodiversity and represents one of the country’s remarkable terrestrial orchid species.
Garden value:
Rarely cultivated but highly prized by native orchid enthusiasts and botanists. Its extraordinary flowers, hidden woodland lifestyle and winter flowering habit make it one of New Zealand’s most intriguing native orchids.