April in the hills with Barbara Mitcalfe and Chris Horne
Geniostoma ligustrifolium var. ligustrifolium; hangehange
Tramping in the bush in early Spring, have you ever wondered which plant was producing a delicate, unmistakably almond perfume? The origin of that lovely perfume is hangehange, a small, commonly-occurring understorey tree or shrub which is often found at the bush margin but can grow to c. 6 m or more. It has opposite pairs of glossy, pale green leaves, even paler underneath, with prominent veins underneath as well. Some people mistake them for coprosma leaves but hangehange's are much softer in texture than any coprosma leaves, and have no obvious domatia (breathing pores) on the underside. Broadly ovate in shape, they can reach to c. 9 cm long and c. 5 cm wide, narrowing abruptly to an extended, pointed apex.
The perfume emanates from dense clusters of little green flowers, about finger-nail size, dangling from stalks that encircle the leaf axils at regular intervals along the slender, brittle twigs. Some flowers are female and some are hermaphrodite. Each has five petals, turned back like collars around the domed centre. After the flowers are pollinated, the seeds develop inside sharply-pointed green capsules which later turn black and split open, but stay hinged at the base, looking remarkably like wide-open birds' beaks holding the seeds.
Sometimes referred to as NZ privet, hangehange is a NZ endemic, the only NZ member of the numerous, worldwide Loganiaceae family. The genus Geniostoma has about 35 other members, scattered from Madagascar to Mauritius and Australia. In NZ, it usually grows in rocky, well-lit, lowland sites, from the Three Kings, down to the north of the South Island. Often prolific in the understorey, it is frequently overlooked but is a most useful plant. Read on ......
Recently I read in Murdoch Riley's Māori Healing and Herbal that hangehange foliage was used extensively by Māori as a food - for example there is a record from 1883 describing the leaves being used to wrap - and enhance the flavour of - food items for steaming in the umu. When in the bush last month I sampled a few leaves raw, and was agreeably surprised to find them very much like lettuce. The taste is not strong, but refreshing, so I have added hangehange to my list of native foliage which is readily available to munch as sandwich greens. You might like to try them yourself? The nectar is favoured by birds such as tūī, korimako, hihi and possibly waxeyes. It produces a delicious honey.
Hangehange leaves have rongoa (medicinal) uses, often having been used, with tītoki oil, as an ointment applied locally for skin infections. Murdoch Riley writes that Māori used the wood, to generate fire, but does not explain whether it was used like kaikōmako, (as the hard component), or like māhoe, (the soft component). Trampers will find the dead twigs useful as kindling. Māori weavers used the bark to produce a black dye, and in modern times, by using mordants, textile workers have produced not only black, but grey, purple and blue dyes from the leaves and fruit.