Something spectacular is happening around Wellington – Poor Knights lilies (Raupo taranga; Xeronema callistemon) are bursting into flower!
In contrast to the tiny inconspicuous white flowers typical of many New Zealand endemic plants, Poor Knights lilies have bright red flower spikes that look a little like bottlebrushes. But despite these flamboyant displays Poor Knight’s lilies appear to be undervalued horticulturally compared to the popularity of another of New Zealand’s red flowered plants, the pohutukawa.
Poor Knights lilies only occur naturally on Northland’s Poor Knights Islands and Taranga Island in the Hen and Chickens Group, but are absent from islands between these two sites and the adjacent mainland. Surprisingly this species was only discovered by botanists less that 90 years ago during a Dominion Museum collecting trip. One of the original collections of this plant by its discovers, WRB Oliver and H Hamilton, is a specimen in Te Papa’s herbarium. The herbarium sheet also includes a clipping of a 1925 newspaper article from the Evening Post describing the new discovery.
In the wild this species grows on cliffs and rock outcrops where they can form huge clumps up to four metres across. They are very cold sensitive and can’t tolerate even mild frosts but seem to handle coastal conditions. They are reasonably easy to grow given the right conditions (see propagation techniques for this species) but patience is required as it can take many years before the plants are large enough to begin flowering. Perhaps this is why they aren’t more widely grown.
The Poor Knights lily has no close New Zealand relatives. The only other species in the genus Xeronema is the New Caledonian endemic Xeronema moorei . Together these two species have been placed in their own family, Xeronemataceae.