Tōī
Māori names | tī tōī, tōī, tī kapu, tī kupenga, ti-mataku-tai (tī that is afraid of the sea), kuka (old dried leaves of tōī) |
Other common names | mountain cabbage tree, broad-leaved cabbage tree |
Scientific name | Cordyline indivisa |
Family | Laxmanniaceae |
The broad, fibrous leaves of tōī were especially valued in the upland district of the Urewera for making rain capes, as harakeke does not grow naturally in that region. The coarse fibre of tōī is strong and durable. To give extra protection from the rain and cold, overlapping strips of dried tōī leaf were added to the woven underlay.
The bright red/orange midribs are used to plait into waistbands and kete for decorative effect.
Description
Tōī is a smaller, broad-leaved cousin of tī kōuka, found in wet hilly and mountainous regions. The tree bears a majestic single clump of leaves atop a massive, unbranched stem (up to 80-cm diameter) or on sparingly branched stout stems. The leaves are tough, up to 2 m long, and expand from a short leaf stem to 10–25 cm wide around mid-length, before tapering to a blunt point.
The glossy green leaves are pale blue-green underneath, with broad reddish or orange-coloured midribs, and are frequently peppered with large insect-browse holes. The scruffy skirt of dead leaves that hangs below the crown helps protect the stem from cold. The bark is pale, fissured and corky.
There is usually a single large flowering stem that hangs down from the base of the foliage clump (unlike other tī species). Numerous small (7–8 mm long), tubular, white, fleshy, tightly packed flowers are produced in summer. Small bluish berries containing 2-mm-long shiny black seeds develop from midsummer to late autumn.
Distribution and ecology
Tōī is principally restricted to wet mountainous areas from East Cape to Fiordland. Within wetter western districts, it is often found in gullies and valley heads, but also descends to lower elevations where topography allows for a cooler climate. Although still present, it is more local in drier eastern mountains.
A high-light demander, seedlings and mature tōī plants are restricted to well-lit places within forest areas. Mature specimens will die if they become overtopped by taller vegetation.
Pests and disease
Although not classified as a threatened species, the distribution and abundance of tōī is affected by introduced forest herbivores, which have taken a liking to its foliage. Seedling establishment is therefore further restricted to sites that are out of reach of deer and goats. Some northerly populations have been decimated by goats and tōī is presumed extinct on Mt Moehau, Coromandel Peninsula, as a result of goat and livestock browse. Possums threaten the few known tōī plants on Banks Peninsula.
Sudden death of cultivated and some wild specimens has been attributed to the Sudden Decline Syndrome that afflicts tī populations, particularly in the North Island. However, it is still not clear whether tōī really does suffer from this disease.
Propagation
Tōī is easily grown from seed, but requires cool, damp soils and a shady, cool location. Plants are easily grown in cooler parts of the country, but in warm lowland localities few plants reach flowering size before dying. It is occasionally offered by garden centres and specialist native plant nurseries.