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Diuris sulphurea
tiger orchid
Overview
Diuris sulphurea is a terrestrial, tuberous orchid growing 20-60 cm (8-24 in) tall from underground tubers. Two or three narrow grass-like leaves rise from the base. Each slender stem carries two to six flowers 2-3.5 cm (0.8-1.4 in) across, bright yellow and marked with two prominent dark brown to blackish blotches at the base of the upright petals. Two narrow lateral sepals hang downward and cross beneath the flower. Flowering occurs in spring and early summer, after which the plant dies back to the tuber for summer dormancy. The species grows in grassland, grassy woodland, and open forest in seasonally moist soils. Like other terrestrial orchids it associates with soil fungi that aid germination. Limitation: the plant is dormant and invisible for much of the year and is hard to cultivate because of its fungal associations.
Native Range
Eastern and southeastern Australia, including Queensland, New South Wales, the Australian Capital Territory, Victoria, Tasmania, and South Australia. It grows in grassland, grassy woodland, and open forest that is moist in winter and dry in summer.Suggested Uses
Grown by terrestrial-orchid enthusiasts in pots under a summer-dry regime, and conserved in grassland and woodland habitat. It suits undisturbed native grassland more than general garden beds.How to Identify
Appearance
Size & Dimensions
Height8" - 2'
Width/Spread2" - 6"
Bloom Information
Detailed Descriptions
Flower Description
yellow with brown markingsFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 4-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grows in seasonally moist, well-drained soils in full sun to light shade, with a wet growing season and a dry summer dormancy. The tubers need to dry out over summer and rot in constantly wet soil. It depends on specific soil fungi, which makes it slow and hard to establish outside its habitat. Water is supplied by seasonal rain during growth and withheld in dormancy. Plants tolerate frost while dormant. The species is rarely cultivated and usually left undisturbed in the wild.Pruning
No pruning is needed. The above-ground stem and leaves wither after flowering as the plant enters summer dormancy. Spent stems can be removed once dry.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons