December in the hills with Barbara Mitcalfe and Chris Horne
In the November 2013 article we described the most commonly occurring NZ cordyline species, tī kōūka. Cordyline is a word of Greek origin meaning a club. It refers to the extraordinarily thick rhizome (swollen root) typical of this genus. In early times, these rhizomes were a staple food for many Māori tribes whose diet was generally deficient in carbohydrates. Unfortunately the high carbohydrate content in cordyline became known to some unscrupulous European whalers in Ōreti, among them a McShane, who cut down all the cabbage trees in the vicinity, boiled and distilled their rhizomes, and produced a wicked rum nicknamed “Chained Lightning”! As a result, local iwi had to move elsewhere to survive, because their previously never-failing stock of tī kōūka had been made into booze.
We now describe Cordyline banksii, tī ngahere, forest cabbage tree. A shrub or small tree, it grows to 4 m tall, usually with several trunks branching from near ground level. The leaves resemble tī kōūka leaves, but are 1-2 m long and 4-8 cm wide, broad at the middle, and with a channelled leaf base. The long panicles (sprays) of very fragrant white flowers, similar to tī kōūka panicles, appear in November-January, producing fleshy, tasty white or blue berries 4-5 mm in diameter.
You’ll find this handsome plant on forest margins in the North and South islands, north and west of the main divide. There are several on the bush edge in the Wainuiomata Valley, just upstream from the Morton Dam and Water Treatment Plant. Cordyline indivisa, tōī, mountain cabbage tree, is called “indivisa” because its massive trunk almost never branches, and can reach to 8-m tall. You can't miss it in montane bush – it is conspicuously different from anything else, with its crown of huge, shiny, dark green leaves shaped like broad swords, 1-2 m long and up to 15 cm wide.
Often partly obscured by the leaves, the spectacular inflorescence is not like that of any other cabbage tree species. Up to 1.5 m long by 30 cm wide, and pendulous, it comprises hundreds of fleshy racemes, densely crowded like ripening bananas overlapping each other, covered with thousands of tiny purple flower buds and scented yellow flowers. Male and female flowers appear in December, and the blue berries are c. 6 mm in diameter. Look for tōī in well-lit places in wet, montane forest, from Great Barrier Island and the Hunua and Coromandel ranges, to Fiordland. Locally there are fine examples beside the 4WD road leading up to Mt Climie, Upper Hutt.
There are two more cordyline species in our NZ flora, C. kaspar and C. pumilio, both of which are found in the Far North, but we shall not describe them here.