''Dracophyllum longifolium'', commonly called inaka (from

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the Co ...

), is an upright shrub or small tree in the family

Ericaceae The Ericaceae () are a Family (biology), family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with about 4,250 known species spread acros ...

that is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. ''Dracophyllum longifolium'' grows mostly in the South Island but is found throughout New Zealand from sea level up to . Inaka occurs in open forests where it can grow as high as 12 metres and in

sub-alpine 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 ...

areas it generally reaches .

Description

''Dracophyllum longifolium'' has thin branches that become marked with rings as old leaves die. The needle-like long leaves are wide and up to long with a pointed tip and are often softly coloured from green through to orange and brown. Inaka is a long-lived plant and can survive for up to 220 years. File:Dracophyllum longifolium in Aoraki Mount Cook NP 05.jpg,

Inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

File:Dracophyllum longifolium in Aoraki Mount Cook NP 02.jpg, Adult leaves

Taxonomy

Varieties

This species has the following varieties: * ''Dracophyllum longifolium'' var. ''longifolium'' * ''Dracophyllum longifolium'' var. ''septentrionale''

Phylogeny

In a 1952 supplement of the ''

Transactions and Proceedings of the Royal Society of New Zealand The ''Transactions and Proceedings of the Royal Society of New Zealand'' was a scientific journal and magazine published by the Royal Society of New Zealand. Before 1933 the society was called the New Zealand Institute, and the journal's name ...

,'' New Zealand botanist W. R. B. Oliver published a revised taxonomic arrangement of the genus ''Dracophyllum'' which he had first attempted in 1928. In this supplement he placed ''D. longifolium'' in a group with ''D. oliveri'' within the subgenus ''Oreothemanus''. Oliver, however, conducted his research based purely on morphological characteristics such as growth habit, leaves, and flowers. In 2010 a team of several botanists, including Stephanus Venter, published an article on the genus ''

Dracophyllum ''Dracophyllum'' is a genus of plants belonging to the family Ericaceae, formerly Epacridaceae. There are 61 species in the genus, mostly shrubs, but also cushion plants and trees, found in New Zealand, Australia, Lord Howe Island and New Caledon ...

'' in the

Annals of the Missouri Botanical Garden The ''Annals of the Missouri Botanical Garden'' is a long-established major peer-reviewed journal of botany, established in 1914 by the Missouri Botanical Garden, under the directorship of botanist and phycologist, George Thomas Moore, and still ...

. In it they performed a

cladistic Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...

analysis and produced a

phylogenetic tree A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA. In ...

of the tribe '' Richeeae'' and other species using genetic sequencing. They found that only the subgenus ''Oreothamnus'' as well as the tribe '' Richeeae'' were

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

. The

paraphyly Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

of the genus ''

,'' as well as the

polyphyly A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as homoplasies, which ar ...

of the closely related genus ''

Richea ''Richea'' is a genus of 11 species of flowering plants in the family Ericaceae. Nine of the species are endemic to Tasmania and the other two are endemic to the south-east of the Australian mainland. Species include: *'' Richea acerosa'' (Lin ...

,'' they argued, suggested that a major taxonomic revision was required. Stephanus Venter revised the genus in 2021, merging the genus ''Richea'' into two subgenera, named ''D. subg. Cystanthe'' and ''D. subg.'' ''Dracophylloides'', of ''Dracophyllum.'' Though he noted that because the 2010 study was based on

plastid A plastid is a membrane-bound organelle found in the Cell (biology), cells of plants, algae, and some other eukaryotic organisms. Plastids are considered to be intracellular endosymbiotic cyanobacteria. Examples of plastids include chloroplasts ...

sequence data and did not attain some species with strong enough evidence, the subgenera are instead based on morphological characteristics''.'' ''D. longifolium's'' placement can be summarised in the

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

at right.

Conservation status

In both 2009 and 2012, ''D. longifolium'' var. ''longifolium'' was deemed to be "Not Threatened" under the

New Zealand Threat Classification System The New Zealand Threat Classification System is used by the Department of Conservation to assess conservation priorities of species in New Zealand. The system was developed because the IUCN Red List, a similar conservation status system, had s ...

, and this New Zealand classification was reaffirmed in 2018. However, ''D. longifolium'' var. ''septentrionale'' was classified as "At Risk - Naturally Uncommon" in 2012, and in 2018.

References

{{Taxonbar, from=Q5304666 longifolium Pakihi Flora of the Auckland Islands Endemic flora of New Zealand Trees of New Zealand Plants described in 1819