The Kāhili Flower is a member of the Protea family and goes by a number of names including Ha'ikū, Bank's grevillea, Red Silky Oak, and Spider Flower. Interestingly enough, both the words Ha'ikū and Kāhili Flower are Hawaiian and Ha'ikū literally means Kāhili Flower. The word Kāhili means feather standard which refers to the large feather topped staff carried by the kings escorts. A number of plants which have flowers that resemble the shape of the feathers on the staff have Kāhili as a part of their name, including the Kāhili Ginger.
The Kāhili Flower is native to Australia where it is an extremely popular plant for both ornamental as well as ritual use. The plant contains 5-pentadecylresorcinol and tridecylresorcinol that can both cause dermatitis in humans. Because of the reaction the plants secretions have on the skin it was used by the Aboriginal Australians to scarify their bodies.
Dermatitis can result from casual contact such as wearing leis that contain the flower or even contact with sawdust from cutting down a bush or simple gardening. Additionally, Kāhili Flower secretions can cross react with toxicodendron that is found in mango trees.
Kāhili Flower is extremely invasive and is listed with the US State Noxious Weed List as being a noxious weed in 43 states. The shrub grows 10 to 15 feet high and 20 to 25 feet wide and has unusual fingered leaves with extremely beautiful flowers that go from white to yellow to deep red to pink throughout the flower. Small seedpods easily release seeds which quickly grow causing the species to multiply if not kept in check.
When we first encountered this flower and shrub it was on The Great Crack Hike. Suddenly along the trail we encountered a huge expanse of these beautiful trees. We had never seen anything like it before and once we returned we were unable to find out anything using our standard research resources. An Email containing a picture of the plant was dispatched to the botany department at the University of Hawai'i and brought the quick reply that it was indeed the Kāhili Flower.
The shrub was obviously invasive to us, seeing how many there were in this one location, but a large number of them were tipped over. We were curious whether or not this had been done by humans trying to get rid of the plant, or by heavy winds we had recently in a storm. Our conclusions were that this was primarily wind damage as the shrubs were down in a random order (some near the road, some away from the road) and we tried to push a smaller shrub over and it tipped quite easily with just one person shoving. Apparently the roots of this plant have a hard time penetrating the hard lava rock and tend to branch outwards, making even the large, well-established plants easy to uproot and tip over.