''Petrophile macrostachya'' is a species of flowering plant in the family Proteaceae 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 else ...

to southwestern Western Australia. It is an erect shrub with prickly,

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

or lobed leaves, and oblong or cylindrical heads of

glabrous Glabrousness (from the Latin '' glaber'' meaning "bald", "hairless", "shaved", "smooth") is the technical term for a lack of hair, down, setae, trichomes or other such covering. A glabrous surface may be a natural characteristic of all or part of ...

yellow to cream-coloured flowers.

Description

''Petrophile macrostachya'' is an erect, compact shrub that typically grows to a height of and has hairy grey branchlets that become glabrous with age. The leaves are pinnate or deeply divided, long on a petiole long, with between nine and seventeen prickly

pinnae The auricle or auricula is the visible part of the ear that is outside the head. It is also called the pinna (Latin for "wing" or " fin", plural pinnae), a term that is used more in zoology. Structure The diagram shows the shape and location ...

or lobes up to long. The flowers are arranged on the ends of branchlets or in leaf axils in

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

, cylindrical heads long, with overlapping, egg-shaped involucral bracts at the base. The flowers are about long, yellow to cream-coloured and glabrous. Flowering occurs from July to November and the fruit is a

nut Nut often refers to: * Nut (fruit), fruit composed of a hard shell and a seed, or a collective noun for dry and edible fruits or seeds * Nut (hardware), fastener used with a bolt Nut or Nuts may also refer to: Arts, entertainment, and media Co ...

, fused with others in an oval to cylindrical head up to long.

Taxonomy

''Petrophile macrostachya'' was first formally described in 1830 by Robert Brown in the '' Supplementum'' to his ''

Prodromus Florae Novae Hollandiae et Insulae Van Diemen ''Prodromus Florae Novae Hollandiae et Insulae Van Diemen'' (Prodromus of the Flora of New Holland and Van Diemen's Land) is a flora of Australia written by botanist Robert Brown and published in 1810. Often referred to as ''Prodromus Flora Novae ...

'' from material collected by Charles Fraser near the Swan River in 1827. The specific epithet (''macrostachya'') means "long flower spike".

Distribution and habitat

''Petrophile macrostachya'' grows in heath, shrubland and woodland from the

Kalbarri National Park Kalbarri National Park is located north of Perth, in the Mid West region of Western Australia. The major geographical features of the park include the Murchison River gorge which runs for nearly on the lower reaches of the Murchison River. Sp ...

to near Gingin in the

Avon Wheatbelt The Avon Wheatbelt is a bioregion in Western Australia. It has an area of . It is considered part of the larger Southwest Australia savanna ecoregion. Geography The Avon Wheatbelt bioregion is mostly a gently undulating landscape with low reli ...

Geraldton Sandplains Geraldton (Wajarri: ''Jambinu'', Wilunyu: ''Jambinbirri'') is a coastal city in the Mid West region of the Australian state of Western Australia, north of the state capital, Perth. At June 2018, Geraldton had an urban population of 37,648. ...

Jarrah Forest Jarrah forest is tall open forest in which the dominant overstory tree is ''Eucalyptus marginata'' (jarrah). The ecosystem occurs only in the Southwest Botanical Province of Western Australia. It is most common in the biogeographic region named i ...

and Swan Coastal Plain biogeographic regions.

Conservation status

This petrophile is classified as "not threatened" by the Western Australian Government

Department of Parks and Wildlife The Department of Parks and Wildlife (DPaW) was the department of the Government of Western Australia responsible for managing lands described in the ''Conservation and Land Management Act 1984'' and implementing the state's conservation and e ...

References

{{Taxonbar, from=Q7179054 macrostachys Eudicots of Western Australia Proteales of Australia Taxa named by Robert Brown (botanist, born 1773) Plants described in 1830