''Olearia occidentissima'' is a species of flowering plant in the 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 w ...

and 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 elsew ...

to the extreme west of Western Australia. It is an erect or prostrate, wind-pruned shrub with narrowly elliptic leaves that are woolly-hairy on the lower surface, and white, daisy-like

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

Description

''Olearia occidentissima'' is an erect or prostrate, wind-pruned shrub that typically grows up to high, its stems and leaves densely hairy. The leaves are arranged alternately, scattered along the branchlets, narrowly elliptic, mostly long and wide. The upper surface of the leaves is greyish-green and the lower surface covered with woolly hairs. The heads or daisy-like "flowers" are arranged singly on the ends of branches, the leaves grading to the hemispherical

involucre In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

at the base. Each head is in diameter with ten to twelve white or pink ray

florets This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...

, the

ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many grasses (Poaceae) and sedges. A ligule is also a strap-shaped extension of the corolla, such as that of a ...

long, surrounding about 25 disc florets. Flowering occurs in September and the fruit is an

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 ope ...

long, the pappus with about 75 bristles.

Taxonomy

''Olearia occidentissima'' was first formally described in 1990 by

Nicholas Sèan Lander Nicholas Lander is an Australian botanist. References External links * {{DEFAULTSORT:Lander, Nicholas 1948 births Living people Botanists active in Australia 20th-century Australian botanists 21st-century Australian botanists ...

in the journal ''

Nuytsia ''Nuytsia floribunda'' is a hemiparasitic tree found in Western Australia. The species is known locally as moodjar and, more recently, the Christmas tree or Western Australian Christmas tree. The display of intensely bright flowers during the ...

'' from specimens collected by

Alex George Alexander or Alex George may refer to: *Alex George (botanist) (born 1939), Australian botanist * Alexander L. George (1920–2006), American political scientist * Alexander George (philosopher), American philosopher *Alex George (motorcyclist), Sc ...

Dirk Hartog Island A dirk is a long bladed thrusting dagger.Chisholm, Hugh (ed.), ''Dagger'', The Encyclopædia Britannica, 11th ed., Vol. VII, New York, NY: Cambridge University Press (1910), p. 729 Historically, it gained its name from the Highland Dirk (Scot ...

in 1972. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''occidentissima'') means "most westerly", referring to this species having the most westerly distribution of ''Olearia'' species.

Distribution and habitat

This daisy bush grows on shallow soil on coastal limestone cliffs in the Carnarvon and Yalgoo bioregions in the extreme west of Western Australia, including on Dirk Hartog Island and

Francois Peron National Park Francois Peron National Park is a national park on the Peron Peninsula in Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external ...

Conservation status

''Olearia occidentissima'' is listed as " Priority Two" by the Western Australian Government

Department of Biodiversity, Conservation and Attractions The Department of Biodiversity, Conservation and Attractions (DBCA) is the Western Australian government The Government of Western Australia, formally referred to as His Majesty's Government of Western Australia, is the Australian state de ...

, meaning that it is poorly known and from only one or a few locations.

References

{{Taxonbar, from=Q15587265 occidentissima Flora of Western Australia Plants described in 1990