At present the swamp helmet orchid is known to grow in only one site in New Zealand and that site is in the Waikato. The plant is nationally critical. The area where it grows contains open sedge and wire rush vegetation in wetlands.
It was formerly known in several now drained cane rush dominated wetlands in the Waipa District. Wetland drainage and plant collectors have contributed to the decline of this species. However, a new method of management for the orchid is being undertaken.
Research has shown that the orchid population increases following burning. The Department of Conservation has trialled this method of management which involves helicopter flying a bin into place on the ground and a fire being lit inside the bin. The bin contains the fire so that it doesn’t spread to other areas of the wetlands. The fire removes the taller vegetation so more light is available for the orchid.
The resulting potash provides nutrients which may stimulate the orchid to flower and seed more prolifically. . The orchid seems to need an open habitat to successfully grow and seed. Years ago swamp fowl would have grazed the area and provided sufficient open space for the swamp helmet orchid to flourish.
The orchid is very small and only grows 30 mm tall when flowering. It has a small heart-shaped leaf about the size of a finger nail. A single maroon flower usually grows 8–10 mm tall. Flowering occurs in mid to late spring and the leaf is present from February to December.