Cordyline indivisa
Encyclopedia
Cordyline indivisa is a monocot tree endemic to New Zealand, where it has the common name Mountain cabbage tree. It is also known as the Broad-leaved cabbage tree, or Tōī.
Cordyline indivisa occurs from south of Kohukohunui in the Hunua Ranges
and Te Moehau (Coromandel Peninsula) but becomes common only south of Raukumara Ranges and the central Volcanic Plateau. In the South Island
it is widespread and common along the north and western portions of the island, but occurs more locally in the drier eastern regions.
species by its very broad blue-grey leaves, and its smaller, tightly compacted inflorescence which is produced from beneath the foliage. It forms a stout tree up to 8 m tall, with a trunk from 40 to 80 cm in diameter. The stem is usually unbranched, or has very few branches. The leaves are 1 to 2 metres long, and from 10 to 30 cm wide. The foliage, which droops with age, is blue-green and shaped like a broad sword, with a broad and conspicuous midrib which is often tinged red, orange red or golden. The inflorescence is a panicle that arises from the base of the growing points underneath the leaves.
. Since 1987, some species of Cordyline in New Zealand have been affected by a disease called "Sudden Decline", caused by the pathogen
Phytoplasma australiense
. The sudden death of some specimens of C. indivisa in cultivation and in the wild has been attributed to this disease, but it is still not clear if this was in fact the case.
, it can only be grown with great difficulty but few plants survive long enough to flower in lowland areas.
indivisa, a closely related genus from which some species have been reclassified as Cordyline.
Distribution
In the North IslandNorth Island
The North Island is one of the two main islands of New Zealand, separated from the much less populous South Island by Cook Strait. The island is in area, making it the world's 14th-largest island...
Cordyline indivisa occurs from south of Kohukohunui in the Hunua Ranges
Hunua Ranges
The Hunua Ranges form a block of hilly country to the southeast of Auckland in New Zealand's North Island. They cover some 250 square kilometres , containing 178 km² of parkland, and rise to 688 metres at Kohukohunui...
and Te Moehau (Coromandel Peninsula) but becomes common only south of Raukumara Ranges and the central Volcanic Plateau. In the South Island
South Island
The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
it is widespread and common along the north and western portions of the island, but occurs more locally in the drier eastern regions.
Description
C. indivisa is very distinctive. The species can be distinguished from all other CordylineCordyline
Cordyline is a genus of about 15 species of woody monocotyledonous flowering plants in family Asparagaceae, subfamily Lomandroideae. The subfamily has previously been treated as a separate family Laxmanniaceae, or Lomandraceae. Other authors have placed the genus in the Agavaceae...
species by its very broad blue-grey leaves, and its smaller, tightly compacted inflorescence which is produced from beneath the foliage. It forms a stout tree up to 8 m tall, with a trunk from 40 to 80 cm in diameter. The stem is usually unbranched, or has very few branches. The leaves are 1 to 2 metres long, and from 10 to 30 cm wide. The foliage, which droops with age, is blue-green and shaped like a broad sword, with a broad and conspicuous midrib which is often tinged red, orange red or golden. The inflorescence is a panicle that arises from the base of the growing points underneath the leaves.
Conservation
The Mountain cabbage tree is not regarded as threatened. Nonetheless, some northern populations have been greatly reduced by livestock and goats, which are thought to have caused its local extinction on Mount Moehau at the northern tip of the Coromandel PeninsulaCoromandel Peninsula
The Coromandel Peninsula lies in the North Island of New Zealand. It is part of the Waikato Region and Thames-Coromandel District and extends 85 kilometres north from the western end of the Bay of Plenty, forming a natural barrier to protect the Hauraki Gulf and the Firth of Thames in the west...
. Since 1987, some species of Cordyline in New Zealand have been affected by a disease called "Sudden Decline", caused by the pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
Phytoplasma australiense
Phytoplasma
Phytoplasma are specialised bacteria that are obligate parasites of plant phloem tissue and transmitting insects . They were first discovered by scientists in 1967 and were named mycoplasma-like organisms or MLOs. They cannot be cultured in vitro in cell-free media...
. The sudden death of some specimens of C. indivisa in cultivation and in the wild has been attributed to this disease, but it is still not clear if this was in fact the case.
Cultivation
It is a very attractive tree, but it has a tendency to collapse suddenly during high temperatures or in times of water shortage. It prefers cool moist soils, and semi-shade, and is easy to grow in the cooler parts of New Zealand. North of HamiltonHamilton, New Zealand
Hamilton is the centre of New Zealand's fourth largest urban area, and Hamilton City is the country's fourth largest territorial authority. Hamilton is in the Waikato Region of the North Island, approximately south of Auckland...
, it can only be grown with great difficulty but few plants survive long enough to flower in lowland areas.
Momenclature
C. indivisa may be confused with another cabbage tree, Cordyline australis. In particular the popular annual house or ornamental plant, sold under the common name 'Spikes' or 'Dracaena Spikes', an immature form of C australis is incorrectly sold as Cordyline indivisa or DracaenaDracaena (plant)
Dracaena is a genus of about 40 species of trees and succulent shrubs. In the APG III classification system, it is placed in the family Asparagaceae, subfamily Nolinoideae . It has also formerly been separated into the family Dracaenaceae or placed in the Agavaceae...
indivisa, a closely related genus from which some species have been reclassified as Cordyline.