This article was published in The Fringe, July 2013
NZ Cucumber - Mawhai
Mawhai is neither the world's most popular vegetable, nor a commonly known native plant. It is a rare plant considered to be a relict from what was once a more widespread population prior to human disturbance.
This recently named species was previously lumped into a complex of related forms named Sicyos australis. Recent research shows there are three species in the South-West Pacific, two of which occur in New Zealand. We share Sicyos australis with the eastern coastline of Australia, while the newly named endemic species, Sicyos mawhai, was confined to the eastern coast and islands of the North Island and also Marlborough. However, due to pest animals, diseases (including introduced cucumber mosaic viruses), and the destruction of its habitat, it has now disappeared from most mainland sites.
Sicyos australis can still be found scrambling over the stone walls at the Otuataua stone fields at the end of Ihumatao Quarry Road in Mangere. To find the real mawhai in the wild you would need to visit one the outer Hauraki Gulf Islands where it is perhaps starting to recolonise areas lost over the last century or two.
Although it is clearly a relation to the common garden cucumber, mawhai is definitely not for eating. The green fruit are very small, less than a pea in diameter and covered in very sharp penetrating bristles. The white flowers are also much smaller than a normal cucumber flower. Like the garden variety, the male flowers are on long stalks, while the female flowers and consequently the fruit, snuggle close to the main stem. Being a curcubit, the vine has strong, twining tendrils that are most efficient at grasping support on any adjacent twig, lifting the rapidly growing vine high into surrounding vegetation.
Mawahi is frost tender but the seed germinates as soon as temperatures start to warm, so it gets an early start with a long growing season, resulting in a far-flung vine by the end of autumn. The myriad fruit set lots of seed which can lie dormant until the worst of winter is over.
Grow mawhai in a sunny warm position with rich soil and it will transform your garden into a tropical-looking paradise with its bold foliage and clinging tendrils. You will think the Amazon has come to you, as well it might as mawhai's close relatives are mostly South American vines.