''Pteronia'' ("resin daisies") is a genus of
evergreen
In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...
, woody
perennial plant
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
s assigned to 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 ...
with currently 76 described species. Like in almost all Asteraceae, the individual flowers are
5-merous, small and clustered in typical heads, surrounded by an
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 o ...
of
bracts. In ''Pteronia'', the centre of the head is taken by relatively few, yellow,
disc florets
Disk or disc may refer to:
* Disk (mathematics), a geometric shape
* Disk storage
Music
* Disc (band), an American experimental music band
* ''Disk'' (album), a 1995 EP by Moby
Other uses
* Disk (functional analysis), a subset of a vector spac ...
, while a ring of ligulate florets is absent. These florets sit on a common base (or
receptacle).
Taxonomy
A species of Gombos was first described and assigned to the new genus ''Pteronia'' by the famous Swedish naturalist
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...
in the second edition of his groundbreaking
Species Plantarum, the starting point of modern botanical nomenclature, that was published in 1763. He had not seen living plants or
dried herbarium specimens, but based his description on an etching made by the English botanist
Leonard Plukenet
Leonard Plukenet (1641–1706) was an English botanist, Royal Professor of Botany and gardener to Queen Mary.
Biography
Plukenet published ''Phytographia'' (London, 1691–1696) in four parts in which he described and illustrated rare exotic p ...
in 1700. This etching probably represents ''
Pteronia camphorata'', which has been chosen as
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...
of the genus. In 1917,
John Hutchinson and
Edwin Percy Phillips
Edwin Percy Phillips (18 February 1884 – 12 April 1967) was a South African botanist and taxonomist, noted for his monumental work ''The Genera of South African Flowering Plants'' first published in 1926.
Phillips was born in Sea Point, Cap ...
revised the genus and recognised 61 species.
Description
Gombos species are all evergreen, woody perennial plants of high that often contain aromatic substances. It mostly has hairless or variably hairy or
glandular
In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland).
Structure
De ...
, wand-like (or
virgate
The virgate, yardland, or yard of land ( la, virgāta was an English unit of land. Primarily a measure of tax assessment rather than area, the virgate was usually (but not always) reckoned as hide and notionally (but seldom exactly) equa ...
) branches, but sometimes the branches have wider angles (or
divaricate
Divaricate means branching, or having separation or a degree of separation. The angle between branches is wide.
In botany
In botany, the term is often used to describe the branching pattern of plants. Plants are said to be divaricating when the ...
). The leaves are mostly arranged in a cross, in some in a spiral or alternate, and rarely
opposite and may also be hairless, variously hairy and glandular, or have a row of hairs around the margin.
Ecology
Gombos species can mostly be found in dry habitats.
Distribution
The species of ''Pteronia'' can be found in Botswana, Eswatini, Mozambique, Lesotho, Namibia, South Africa, Zambia and Zimbabwe. About 50 species occur in the
Cape Floristic Region, particularly in the
Succulent Karoo and to a lesser extend in the
Nama Karoo
Nama Karoo is a xeric shrubland ecoregion located on the central plateau of South Africa and Namibia. It occupies most of the interior of the western half of South Africa and extends into the southern interior of Namibia.
Climate
The climate t ...
biome
A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...
s. In Namibia 24 species are found.
Species list
It contains the following species:
*''
Pteronia acuminata''
*''
Pteronia acuta''
*''
Pteronia adenocarpa''
*''
Pteronia ambrariifolia''
*''
Pteronia anisata''
*''
Pteronia aspalatha''
*''
Pteronia beckeoides''
*''
Pteronia bolusii''
*''
Pteronia callosa''
*''
Pteronia camphorata''
*''
Pteronia centauroides''
*''
Pteronia ciliata''
*''
Pteronia cinerea''
*''
Pteronia cylindracea''
*''
Pteronia diosmifolia''
*''
Pteronia divaricata''
*''
Pteronia eenii''
*''
Pteronia elata''
*''
Pteronia elongata''
*''
Pteronia empetrifolia''
*''
Pteronia erythrochaeta''
*''
Pteronia fasciculata'', Paraffienbos
*''
Pteronia fastigiata''
*''
Pteronia flexicaulis''
*''
Pteronia foleyi''
*''
Pteronia glabrata''
*''
Pteronia glauca'', Geelboegoekaroo
*''
Pteronia glaucescens''
*''
Pteronia glomerata''
*''
Pteronia gymnocline''
*''
Pteronia heterocarpa''
*''
Pteronia hirsuta''
*''
Pteronia hutchinsoniana''
*''
Pteronia incana'', Asbos
*''
Pteronia inflexa''
*''
Pteronia intermedia''
*''
Pteronia leptospermoides''
*''
Pteronia leucoclada''
*''
Pteronia leucoloma''
*''
Pteronia lucilioides''
*''
Pteronia membranacea''
*''
Pteronia mooreiana''
*''
Pteronia mucronata''
*''
Pteronia oblanceolata''
*''
Pteronia onobromoides'', Boegoebos
*''
Pteronia oppositifolia''
*''
Pteronia ovalifolia''
*''
Pteronia pallens'', Scholtzbos
*''
Pteronia paniculata'', Gombos
*''
Pteronia pillansii''
*''
Pteronia polygalifolia''
*''
Pteronia pomonae''
*''
Pteronia punctata''
*''
Pteronia quinqueflora''
*''
Pteronia rangei''
*''
Pteronia scabra''
*''
Pteronia scariosa''
*''
Pteronia smutsii''
*''
Pteronia sordida''
*''
Pteronia spinulosa''
*''
Pteronia stoehelinoides''
*''
Pteronia stricta''
*''
Pteronia succulenta''
*''
Pteronia tenuifolia''
*''
Pteronia teretifolia''
*''
Pteronia tricephala''
*''
Pteronia uncinata''
*''
Pteronia undulata''
*''
Pteronia unguiculata''
*''
Pteronia utilis''
*''
Pteronia villosa''
*''
Pteronia viscosa''
Gallery
File:Pteronia paniculata - Ashton - b.jpg, '' Pteronia paniculata'' ("Gombos")
File:2 Pteronia pallens - flower detail - Matjiesfontein.jpg, '' Pteronia pallens'' ("Scholtzbos")
File:Pteronia fasciculata - Paraffienbos detail.jpg, '' Pteronia fasciculata'' ("Paraffienbos")
File:Pteronia incana - Asbos detail.jpg, '' Pteronia incana'' ("Asbos")
File:Pteronia uncinata - Kirstenbosch Botanical Gardens 1 - Copy.jpg, '' Pteronia uncinata''
References
{{Taxonbar, from=Q508116
Asteraceae genera
Taxonomy articles created by Polbot