''Olearia hectorii'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...

in the daisy family

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae ...

. Its common names include deciduous tree daisy and Hector's tree daisy. It is

endemic Endemism is the state of a species being found 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 found els ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...

, where it is nationally

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

Taxonomy

Members of the genus ''Olearia'', commonly known as daisy-bushes or tree daisies, are found in New Zealand, Australia, and New Guinea. Although originally published under the name ''Olearia hectori'', ''hectorii'' is the correct epithet under the

ICBN The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ...

(ST Louis) Art. 60.11.

Description

''O. hectorii'' is a deciduous shrub or small tree, up to 10 m tall, with reddish stems, furrowed bark, and oppositely-arranged clusters of 2–4 gray-green leaves, 20–50 mm long by 5–20 mm wide. The undersides of the leaves are covered in a silvery

indumentum In biology, an indumentum (Latin, literally: "garment") is a covering of trichomes (fine "hairs") on a plantDavis, Peter Hadland and Heywood, Vernon Hilton (1963) ''Principles of angiosperm taxonomy'' Van Nostrandpage, Princeton, New Jersey, page ...

. As with most other Asteraceae, the tiny flowers are borne in dense clusters known as pseudanthia, which are produced on short, hairy stems from near the leaf

axils A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...

. The florets are pale yellow, and enclosed by pale green, densely hairy

phyllaries In botanical terminology, a phyllary, also known an involucral bract or tegule, is a single bract of the involucre of a composite flower. The involucre is the grouping of bracts together. Phyllaries are reduced leaf-like structures that form one ...

. The seeds are

cypselae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae we ...

, similar in structure to those of

dandelions ''Taraxacum'' () is a large genus of flowering plants in the family Asteraceae, which consists of species commonly known as dandelions. The scientific and hobby study of the genus is known as taraxacology. The genus is native to Eurasia and Nor ...

, consisting of a 1–2 mm

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not op ...

attached to a 3–5 mm feathery pappus.

Ecology

This species is threatened by habitat degradation. It requires open habitat for germination, but this kind of habitat is threatened by introduced flora and grazing animals. ''Olearia hectorii'' is a host of numerous endemic moth species and is known to support at least 23 species, with at least 12 of those species exclusively hosted by this plant. These moths are likely to play an important role in the pollination of the ''O. hectorii''. Species dependent on this plant include the nationally critically endangered '' Stathmopoda campylocha'' and the nationally endangered ''S. albimaculata''.

Conservation status

This plant is now classified 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 some ...

as being Nationally Endangered.

References

{{Taxonbar, from=Q7085998 hectorii Endangered flora of New Zealand Endemic flora of New Zealand Taxonomy articles created by Polbot Taxobox binomials not recognized by IUCN