''Raukaua simplex'', commonly known as haumakāroa, is a species of

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

plant in the

Araliaceae The Araliaceae are a family of flowering plants composed of about 43 genera and around 1500 species consisting of primarily woody plants and some herbaceous plants commonly called the ginseng family. The morphology of Araliaceae varies widely ...

family. This species is native to New Zealand. The species occurs in certain lowland,

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

and

subalpine Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

forests from the

Waihou River The Waihou River is located in the northern North Island of New Zealand. Its former name, Thames River, was bestowed by Captain James Cook in November 1769, when he explored of the river from the mouth. An older Māori name was "Wai Kahou Roung ...

southward to

Stewart Island Stewart Island (, ' glowing skies', officially Stewart Island / Rakiura, formerly New Leinster) is New Zealand's third-largest island, located south of the South Island, across Foveaux Strait. It is a roughly triangular island with a la ...

and the

Auckland Islands The Auckland Islands ( Māori: ''Motu Maha'' "Many islands" or ''Maungahuka'' "Snowy mountains") are an archipelago of New Zealand, lying south of the South Island. The main Auckland Island, occupying , is surrounded by smaller Adams Island ...

. An example occurrence in Westland forests includes associates such as ''

Cyathea smithii ''Alsophila smithii'', synonym ''Cyathea smithii'', commonly known as the soft tree fern or kātote, is a species of tree fern from New Zealand. Distribution and ecology The species' natural distribution covers all major islands of New Zealand: ...

'' and ''

Dicksonia squarrosa ''Dicksonia squarrosa'', the New Zealand tree fern, whekī or rough tree fern, is a common tree fern endemic to New Zealand. It has a slender black trunk that is usually surrounded by many dead brown fronds. Description This species has a fas ...

''.

Description

''Raukaua simplex'' grows as a shrub to small tree up to 8m in height. The species exhibits a significant change in appearance (

heteroblasty Heteroblasty is the significant and abrupt change in form and function, that occurs over the lifespan of certain plants. Characteristics affected include internode length and stem structure as well as leaf form, size and arrangement. It should no ...

) between its juvenile and adult form. Juvenile leaves are palmately compound, 3-5 leaflets, and deeply lobed. Adult leaves are simple, with toothed margins.

Taxonomy

''Raukaua simplex'' was first described in 1786 by

Georg Forster Johann George Adam Forster, also known as Georg Forster (; 27 November 1754 – 10 January 1794), was a German geography, geographer, natural history, naturalist, ethnology, ethnologist, travel literature, travel writer, journalist and revol ...

as ''Panax simplex'' in ''Florulae Insularum Australium Prodromus''. Forster, J.G.A. (1786
Florulae Insularum Australium Prodromus 75.
/ref> In 1997, Mitchell, Frodin and Heads redescribed it, assigning it to the genus, ''

Raukaua ''Raukaua'' is a genus of flowering plants in the family Araliaceae. It has an austral distribution, being indigenous to southern Argentina and Chile, as well as New Zealand and the island of Tasmania.David J. Mabberley. 2008. ''Mabberley's Pla ...

'', thus naming it ''Raukaua simplex''.

References

simplex In geometry, a simplex (plural: simplexes or simplices) is a generalization of the notion of a triangle or tetrahedron to arbitrary dimensions. The simplex is so-named because it represents the simplest possible polytope in any given dimension. ...

Flora of New Zealand Flora of the Auckland Islands Plants described in 1786 {{NewZealand-plant-stub