Levenhookia
Encyclopedia
Levenhookia, also known as the styleworts, is a genus of ten recognized species in the family Stylidiaceae
and is endemic to Australia
. The genus is restricted to Western Australia
almost exclusively with a few exceptions: L. pusilla
' s range extends into South Australia
, L. dubia
' s range extends through South Australia into Victoria
and New South Wales
, L. sonderi
is native only to Victoria, and L. chippendalei
is also found in the Northern Territory
.
All species of Levenhookia possess a sensitive labellum
that performs a similar function to the column
of Stylidium species. The labellum responds to touch and enables the plants to promote cross-pollination and avoid self-pollination. Most species of Levenhookia are ephemeral plant
s that prefer sand heath
habitat. Levenhookia species also possess glandular trichome
s similar to those of its sister genus, Stylidium. While no studies have been done to test Levenhookia for carnivory
, it is plausible that they are carnivorous plants like the related Stylidium species.
The genus is known to be closely related to the genus Stylidium. Specifically, the subgenus
Centridium
is the subgeneric taxonomy in the genus Stylidium that appears to be most closely related to Levenhookia and most suggests an ancestral relationship. Sherwin Carlquist
notes that Levenhookia is most likely a derivative of Stylidium and has relied on outcropping as its mode of evolution. The species in this genus represent a series from L. preissii
, which requires cross pollination for reproduction, to L. dubia, which relies on facultative self-pollination. In an earlier publication, Rica Erickson
described this series in reverse, suggesting that path as the evolutionary sequence. Several species of Stylidium have also been noted to mimic flower morphology of certain Levenhookia species to utilize similar available pollinators. Specifically, S. xanthopis mimics L. leptantha
and S. ecorne
mimics L. pauciflora
.
Three sections have been established and described by Johannes Mildbraed
in 1908 to separate the subgeneric taxonomy in this genus. Section Coleostylis
consists of L. chippendalei, L. preissii, L. stipitata
, and possibly L. octomaculata
, which Erickson described in 1956, noting its affinities with L. stipitata but without placing it in a section. Section Estipitatae
consists of L. dubia, L. leptantha, and L. sonderi, which was considered by Mildbraed to be a variety of L. dubia. Section Levenhookia
consists of L. pusilla and L. pauciflora, though it could also contain L. pulcherrima
, which Carlquist described in 1969 and noted its close association to the other two species in section Levenhookia but neglected to place it within a section. Section Levenhookia was originally described by Mildbraed as section Eulevenhookia, which was later changed to the current section title Levenhookia as an autonym
since it is the type
section.
Stylidiaceae
The family Stylidiaceae is a taxon of dicotyledonous flowering plants. It consists of five genera with over 240 species, most of which are endemic to Australia and New Zealand. Members of Stylidiaceae are typically grass-like herbs or small shrubs and can be perennials or annuals...
and is endemic to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. The genus is restricted to Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
almost exclusively with a few exceptions: L. pusilla
Levenhookia pusilla
Levenhookia pusilla, the midget stylewort or tiny stylewort, is a dicotyledonous plant that belongs to the genus Levenhookia . It is an ephemeral annual that grows about 5 to 6 cm tall with suborbicular to ovate-spathulate leaves. Flowers are pink to white and bloom from September to December...
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
, L. dubia
Levenhookia dubia
Levenhookia dubia, the hairy stylewort, is a dicotyledonous plant that belongs to the genus Levenhookia . It is an ephemeral annual that grows from 2 to 6 cm tall with obovate leaves that are generally 2–5 mm long. Flowers are white and bloom from September to October in its native range....
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
and New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
, L. sonderi
Levenhookia sonderi
Levenhookia sonderi, the slender stylewort, is a dicotyledonous plant that belongs to the genus Levenhookia . It is an ephemeral annual that grows only in Victoria, Australia. L. sonderi is most closely related to L. dubia and it has even been described as a variety of L. dubia in the past...
is native only to Victoria, and L. chippendalei
Levenhookia chippendalei
Levenhookia chippendalei is a dicotyledonous plant that belongs to the genus Levenhookia . It is named after its discoverer, George Chippendale, founder of the Northern Territory Herbarium. It grows from 8 to 18 cm tall with oblanceolate leaves near the base of the plant. The few leaves this...
is also found in the Northern Territory
Northern Territory
The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...
.
All species of Levenhookia possess a sensitive labellum
Labellum
Labellum is the Latin diminutive of labium, meaning lip. These are anatomical terms used descriptively in biology, for example in Entomology and botany.-Botany:...
that performs a similar function to the column
Column (botany)
The column, or technically the gynostemium, is a reproductive structure that can be found in several plant families: Aristolochiaceae, Orchidaceae, and Stylidiaceae....
of Stylidium species. The labellum responds to touch and enables the plants to promote cross-pollination and avoid self-pollination. Most species of Levenhookia are ephemeral plant
Ephemeral Plant
An ephemeral plant is one marked by short life cycles, usually six to eight weeks. The word ephemeral means transitory or quickly fading. In regards to plants, it refers to several distinct growth strategies...
s that prefer sand heath
Heath (habitat)
A heath or heathland is a dwarf-shrub habitat found on mainly low quality acidic soils, characterised by open, low growing woody vegetation, often dominated by plants of the Ericaceae. There are some clear differences between heath and moorland...
habitat. Levenhookia species also possess glandular trichome
Trichome
Trichomes are fine outgrowths or appendages on plants and certain protists. These are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae.- Algal trichomes :...
s similar to those of its sister genus, Stylidium. While no studies have been done to test Levenhookia for carnivory
Carnivorous plant
Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans, typically insects and other arthropods. Carnivorous plants appear adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic...
, it is plausible that they are carnivorous plants like the related Stylidium species.
Evolution and taxonomy
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Centridium
Stylidium subg. Centridium
Stylidium subg. Centridium is a subgenus of Stylidium that is characterized by a globose hypanthium, a stipitate brush-like stigma, and gynostemium mobility not produced by a sensitive hinged torosus but by the movement of a cunabulum. All species with the possible and doubtful exception of S....
is the subgeneric taxonomy in the genus Stylidium that appears to be most closely related to Levenhookia and most suggests an ancestral relationship. Sherwin Carlquist
Sherwin Carlquist
Sherwin Carlquist is an American botanist and photographer. He received his undergraduate degree from the University of California, Berkeley in 1952 and a Ph.D. in botany in 1956, also at Berkeley. Carlquist did a postdoctoral study at Harvard University from 1955 to 1956. After his postdoctoral...
notes that Levenhookia is most likely a derivative of Stylidium and has relied on outcropping as its mode of evolution. The species in this genus represent a series from L. preissii
Levenhookia preissii
Levenhookia preissii, Preiss's stylewort, is a dicotyledonous plant that belongs to the genus Levenhookia . It is an ephemeral annual that grows about 15 cm tall with oblanceolate to linear leaves. Flowers are pink to red and bloom from September to January in its native range. L...
, which requires cross pollination for reproduction, to L. dubia, which relies on facultative self-pollination. In an earlier publication, Rica Erickson
Rica Erickson
Frederica Lucy "Rica" Erickson AM, née Sandilands, was an Australian naturalist, botanical artist, historian, author and teacher. Without any formal scientific training, she wrote extensively on botany and birds, as well as genealogy and general history...
described this series in reverse, suggesting that path as the evolutionary sequence. Several species of Stylidium have also been noted to mimic flower morphology of certain Levenhookia species to utilize similar available pollinators. Specifically, S. xanthopis mimics L. leptantha
Levenhookia leptantha
Levenhookia leptantha, the trumpet stylewort, is a dicotyledonous plant that belongs to the genus Levenhookia . It is an ephemeral annual that grows from 2 to 6 cm tall with ovate to lanceolate leaves that are generally 2–5 mm long. Flowers are pink and bloom from September to October in...
and S. ecorne
Stylidium ecorne
Stylidium ecorne is a dicotyledonous plant that belongs to the genus Stylidium . It is an annual plant that grows from 5 to 12 cm tall. It has pale or bright pink flowers and occurs in swampy areas.- Taxonomy :S...
mimics L. pauciflora
Levenhookia pauciflora
Levenhookia pauciflora, the deceptive stylewort, is a dicotyledonous plant that belongs to the genus Levenhookia . It is an ephemeral annual that grows from 5 to 10 cm tall with ovate to suborbicular leaves. Flowers are white and bloom from September to November in its native range. L...
.
Three sections have been established and described by Johannes Mildbraed
Johannes Mildbraed
Gottfried Wilhelm Johannes Mildbraed was a German botanist that specialized in mosses, ferns, and various spermatophytes. He is well-known for authoring the most current monograph and taxonomic treatment of the family Stylidiaceae in 1908 as part of the unfinished Das Pflanzenreich series. The...
in 1908 to separate the subgeneric taxonomy in this genus. Section Coleostylis
Levenhookia sect. Coleostylis
Levenhookia sect. Coleostylis is a section of four recognized species in the family Stylidiaceae. It was established and described by Johannes Mildbraed in 1908 to separate the subgeneric taxonomy in the genus Levenhookia. Mildbraed originally placed L. preissii and L. stipitata in this section. L...
consists of L. chippendalei, L. preissii, L. stipitata
Levenhookia stipitata
Levenhookia stipitata, the common stylewort, is a dicotyledonous plant that belongs to the genus Levenhookia . It is an ephemeral annual that grows about 7 to 10 cm tall with oblanceolate to linear leaves. Flowers are pink and bloom from August to January in its native range. L...
, and possibly L. octomaculata
Levenhookia octomaculata
Levenhookia octomaculata, the dotted stylewort or eight-spotted stylewort, is a dicotyledonous plant that belongs to the genus Levenhookia . The specific epithet octomaculata refers to the eight red dots this plant produces on each flower. It is an ephemeral annual that grows from 4 to 10 cm...
, which Erickson described in 1956, noting its affinities with L. stipitata but without placing it in a section. Section Estipitatae
Levenhookia sect. Estipitatae
Levenhookia sect. Estipitatae is a section of two to three recognized species in the family Stylidiaceae. It was established and described by Johannes Mildbraed in 1908 to separate the subgeneric taxonomy in the genus Levenhookia. Mildbraed originally placed L. dubia and L. leptantha in this...
consists of L. dubia, L. leptantha, and L. sonderi, which was considered by Mildbraed to be a variety of L. dubia. Section Levenhookia
Levenhookia sect. Levenhookia
Levenhookia sect. Levenhookia is a section of two to three recognized species in the family Stylidiaceae. Section Levenhookia was originally described by Mildbraed as section Eulevenhookia, which was later changed to the current section title Levenhookia as an autonym since it is the type section....
consists of L. pusilla and L. pauciflora, though it could also contain L. pulcherrima
Levenhookia pulcherrima
Levenhookia pulcherrima, the beautiful stylewort is a dicotyledonous plant that belongs to the genus Levenhookia . It is an ephemeral annual that grows on average from 7 to 8 cm tall. Lower leaves are spathulate while upper leaves are oblanceolate and up to 1.8 cm long. Stems and older...
, which Carlquist described in 1969 and noted its close association to the other two species in section Levenhookia but neglected to place it within a section. Section Levenhookia was originally described by Mildbraed as section Eulevenhookia, which was later changed to the current section title Levenhookia as an autonym
Autonym (botany)
In botanical nomenclature, autonyms are automatically created names, as regulated by the International Code of Botanical Nomenclature . Autonyms are cited without an author. Relevant provisions are in articles 6.8, 22.1-3 and 26.1-3....
since it is the type
Biological type
In biology, a type is one particular specimen of an organism to which the scientific name of that organism is formally attached...
section.