''Persoonia glaucescens'', commonly known as the Mittagong geebung, is a species of flowering plant in the family

Proteaceae The Proteaceae form a family of flowering plants predominantly distributed in the Southern Hemisphere. The family comprises 83 genera with about 1,660 known species. Together with the Platanaceae and Nelumbonaceae, they make up the order Pro ...

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 New South Wales. It is an erect shrub with smooth bark, hairy young branchlets, lance-shaped leaves with the narrower end towards the base, and yellow flowers. It is the only persoonia in eastern Australia with strongly

glaucous ''Glaucous'' (, ) is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (''Larus hyperboreus''), glaucous-winged gull (''Larus glaucescens''), g ...

leaves.

Description

''Persoonia glaucescens'' is an erect shrub that typically grows to a height of , sometimes to , with smooth bark, brownish red branches and branchlets that are covered with greyish hairs when young. The leaves are narrow spatula-shaped to lance-shaped with the narrower end towards the base, strongly glaucous, especially when young, long, wide and twisted through 90° at the base. The flowers are arranged in groups of up to thirty along a

rachis In biology, a rachis (from the grc, ῥάχις [], "backbone, spine") is a main axis or "shaft". In zoology and microbiology In vertebrates, ''rachis'' can refer to the series of articulated vertebrae, which encase the spinal cord. In this c ...

up to long, each flower on a hairy

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

long. The

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s are yellow, long and sparsely to moderately hairy on the outside. Flowering occurs from January to May and the fruit is a fleshy green

drupe In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or '' pyrena'') of hardened endocarp with a seed (''kernel'') ...

with purple markings, and contain a single seed. This species is the only persoonia in eastern Australia to have strongly glaucous leaves.

Taxonomy

''Persoonia glaucescens'' was first formally described in 1827 by

Kurt Polycarp Joachim Sprengel Kurt Polycarp Joachim Sprengel (3 August 1766 – 15 March 1833) was a German botanist and physician who published an influential multivolume history of medicine, ''Versuch einer pragmatischen Geschichte der Arzneikunde'' (1792–99 in four vol ...

in the 17th edition of ''

Systema Vegetabilium ''Systema Vegetabilium'' (abbreviated as Syst. Veg.) is a book published in four editions, following twelve earlier editions known as '' Systema Naturae''. The first edition, published in 1774 and edited by Johan Andreas Murray is counted as editi ...

'' from an unpublished description by

Franz Sieber Franz Wilhelm Sieber (30 March 1789 – 17 December 1844), was a botanist and collector who travelled to Europe, the Middle East, Southern Africa and Australia. Early life Franz Sieber was born in Prague, Bohemia on 30 March 1789. After 5 ...

. In 1848,

Stephan Endlicher Stephan Ladislaus Endlicher also known as Endlicher István László (24 June 1804, Bratislava (Pozsony) – 28 March 1849, Vienna) was an Austrian botanist, numismatist and Sinologist. He was a director of the Botanical Garden of Vienna. Bio ...

reduced the species to a variety as ''Persoonia lanceolata'' var. ''glaucescens''.

Lawrie Johnson Lawrence Alexander Sidney Johnson FAA, (26 June 1925 – 1 August 1997) known as Lawrie Johnson, was an Australian taxonomic botanist. He worked at the Royal Botanic Gardens, Sydney, for the whole of his professional career, as a botanist (1948� ...

originally thought that '' P. lanceolata'' and the present species grew in separate areas, and gave it the name ''Persoonia'' subsp. B, but more recent fieldwork by

Peter Weston Peter Weston (19 October 1943 – 5 January 2017) was a British science fiction fan from Birmingham, UK. Weston made many contributions in fan writing, fanzine editing, convention-running and in local science fiction clubs. His 1960s pseudonym ...

showed that they do sometimes grow together without appearing to interbreed. As a result, Weston reinstated the name ''P. glaucescens'', publishing the change in the journal '' Telopea''. Within the genus, ''P. glaucescens'' is classified in the ''Lanceolata'' group, a group of 58 closely related species with similar flowers but very different foliage. These species will often

interbreed In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in ...

with each other where two members of the group occur.

Distribution and habitat

Mittagong geebung occurs in small scattered patches in an area bordered by

Buxton Buxton is a spa town in the Borough of High Peak, Derbyshire, England. It is England's highest market town, sited at some above sea level.

to the north and Berrima to the south, having vanished from the vicinities of Thirlmere Lakes and

Fitzroy Falls Fitzroy Falls (postcode: 2577) is a village in the Wingecarribee Shire, located within the Southern Highlands region of New South Wales, Australia. The locality was known as Yarrunga, but was renamed after the waterfall. Waterfall The wat ...

. It grows on clay and gravel soils over laterite on upper slopes and ridges, at altitudes between . It is found in dry sclerophyll eucalypt forest with such trees as red bloodwood (''

Corymbia gummifera ''Corymbia gummifera'', commonly known as red bloodwood, is a species of tree, rarely a mallee, that is endemic to eastern Australia. It has rough, tessellated bark on the trunk and branches, lance-shaped adult leaves, flower buds in groups o ...

''), scribbly gum (''

Eucalyptus sclerophylla ''Eucalyptus sclerophylla'', known as the scribbly gum, is a tree native to eastern Australia. Very similar to the related Scribbly Gum (''E. haemastoma''), a better known tree. The best way of distinguishing the species is the smaller hemisph ...

''), Sydney peppermint ('' E. piperita''), silvertop ash ('' E. sieberi''), narrow-leaved stringybark ('' E. sparsifolia''), grey gum ('' E. punctata'') and, at higher elevations, snow gum ('' E. pauciflora''). The increased light and lack of competing plants means the species adapts preferably to (and can be found on)

road verge A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of ...

Conservation status

''Persoonia glaucescens'' is classified as "vulnerable" under the Australian Government ''

Environment Protection and Biodiversity Conservation Act 1999 The ''Environment Protection and Biodiversity Conservation Act 1999'' (Cth) is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and cultu ...

'' and as "endangered" under the New South Wales Government '' Biodiversity Conservation Act 2016''. The main threats to the species include trail and road maintenance, inappropriate fire regimes and grazing.

References

{{Taxonbar, from=Q7170713 glaucescens Flora of New South Wales Plants described in 1827 Taxa named by Franz Sieber Taxa named by Kurt Polycarp Joachim Sprengel