August in the hills with Michele Dickson and Chris Horne
Pseudopanax arboreus, whauwhaupaku, Five-finger
Origin of the botanical names
‘Pseudopanax’ is derived from the Greek words ‘pseudo’ meaning ‘false’, ‘pan’ meaning ‘all’, and ’akos’ meaning ‘remedy’, referring to the medicinal plant ‘ginseng’, which is also in this genus; ‘arboreus’ comes from the Latin word ‘arborescere’ meaning ‘to become a tree’. The Panax genus is a member of the Araliaceae family, commonly called ‘araliads’, with members common in southeast Asia. In Aotearoa the family is represented by twenty-one native species.
Distribution and habitat
P. arboreus is endemic to Aotearoa. It grows on Te Ika a Māui / North Island and Te Waipounamu / South Island, though rare in Central Otago. Look for it in coastal to montane moist broadleaf forest, secondary forest, stream sides and forest margins.
P. arboreus is a small tree up to 8 m tall and a trunk 30 cm in diameter with smooth bark and stout, brittle, spreading branches. It can be epiphytic on other trees and on tree-fern trunks. A feature found in many plants of this family is palmate, compound leaves comprising distinct leaflets spreading from a single point at the top of the leaf stalk/petiole. Five-finger usually has five leaflets / ‘fingers’, sometimes six or seven, from a stalk/petiole 15-20 cm long, each with a stalk/petiolule about 3.5 cm long. The glossy leaflets are 10-20 cm x 4-7 cm, obovate to oblong, slightly leathery, and have coarsely serrate edges. Vein reticulations are visible on both sides of leaflets. Possums relish the petioles, leaving detached leaflets on the forest floor.
Female flowers and male flowers grow on separate plants. The flowers are arranged in compound umbels, arising from single points which develop at the end of stems. The first/primary stalks of the umbel are up to 10 cm long, numbering 8-20, and the secondary numbering 15-20. Each terminal umbel has 15-20 sweet-scented, white to pink-flushed flowers, up to 5 mm diameter. The dark fruits are 5-8 cm diameter, fleshy and somewhat compressed. Each contains 2-3 wrinkled seeds, 3-6 mm long. Flowering is in June to August and fruiting August to February. Birds eat the fruit then spread the seeds.
Māori used the bark green to make skids for hauling canoes and sometimes to make small water vessels, gum from the plant to prevent leakage in joints of water vessels and wood for fashioning a flute taken from a tree growing in exposed conditions. Khaki dyes for wool have been made from ripe berries using an alum mordant, and horses eat the bark.
Where can you find five-finger?
Look for this species in Wellington reserves and patches of bush, and in the Akatarawa, Tararua, Remutaka and Aorangi ranges.