Stylidium graminifolium
Encyclopedia
Stylidium graminifolium, the grass triggerplant, is a dicotyledon
ous plant
that belongs to the genus
Stylidium (family Stylidiaceae
). This species used to belong to the Stylidium graminifolium complex, but the name was conserved for this single species when two others were split from the complex and introduced as new species in 2001. S. graminifolium is endemic
to Australia
and is one of the Stylidium species with the widest distribution throughout Australia. It is a perennial plant
with grass-like leaves and is easily cultivated. It has been considered to be a carnivorous
or protocarnivorous plant
because it possesses glandular trichome
s underneath the flowers that can trap and digest prey.
. A 15-90 cm (6-36 in) long scape
bearing the racemous
inflorescence
appears in the spring and summer (October through February). The flowers are butterfly shaped and pale or bright pink with petals paired laterally. The calyx
and corolla are both covered in glandular trichome
s. The pollination mechanism involving a sensitive "trigger"--a floral column
, in which the stamen
and style are fused--is unique to the family Stylidiaceae. In S. graminifolium, the column is red and stamens are a greenish color. This species, like most Stylidium species, possesses glandular trichomes underneath the flower and on the scape, which are capable of digesting and absorbing nutrients from prey captured in the sticky mucilage
. This information leads some researchers to believe that the plants are carnivorous
or at the very least protocarnivorous
.
to Victoria
, New South Wales
, and Queensland
over to South Australia
. Its most common habitat is dry sclerophyll
forests with nutrient-poor soil conditions.
when Joseph Banks
and Daniel Solander
joined James Cook
's first voyage to the Pacific Ocean on board the Endeavour
. It was first formally described by Carl Ludwig Willdenow
in 1805. It was again described by Olof Swartz
just two years later in 1807 under the same name. Around the same time, other botanists were considering placing these new species in the new genus Candollea, which would be in the Dilleniaceae
family, but Stylidium was retained as the older nomenclature and placed in its own family, Stylidiaceae.
and varieties were added to what came to be known as the Stylidium graminifolium complex, a group of plants that has been treated as a single species but may have significant morphological differences that require the complex to be split into new species. The complex was formally split into three species in 2001, with S. graminifolium lectotypified
from the collections of Banks and Solander in the 1770s. S. graminifolium sensu stricto is more narrow-leaved and is diploid (2n = 30). The other two species, S. dilatatum and S. armeria
, that used to be included in this complex are tetraploid (2n = 60) and may represent polyploid
speciation
. The three species also represented different habitats and ranges, with S. graminifolium distributed widely in south-eastern continental Australia and Tasmania, S. dilatatum in the subalpine
areas of south-eastern Australia and widely distributed in Tasmania, and S. armeria in the littoral
habitats in Tasmania from Macquarie Harbour
to the Tasman Peninsula
.
S. graminifolium is one of the few Stylidium species commercially available for sale as seed. This species, along with six other triggerplants, was tested for horticultural value and cold hardiness by Douglas Darnowski in the United States from 2000 to 2002. Dr. Darnowski's study concluded that S. graminifolium was able to survive cold temperatures down to -10°C
, making it suitable for growing outside in as low as USDA
hardiness zone
8. Darnowski also postulated that S. graminifoliums attractive floral spikes could be of use in floriculture
and could be used to replace purple loosestrife
in winter and spring arrangements. It has a relatively long flowering period and has somewhat specific conditions for germination, including smoke treatments and higher temperatures to simulate a bushfire, though germination can occur without these conditions. These germination requirements reduce the risk that it will become an invasive species
. It is also able to grow on nutrient-poor soils and withstand significant drought. These attributes increase its potential for floricultural use.
There are two cultivar
s of S. graminifolium, Tiny Trina and Little Saphire, that are tentatively recognized cultivar names by the Royal Horticultural Society
. The epithet Little Saphire is derived from the bright blue foliage that distinguishes this cultivar from the type
species. Tiny Trina has a deeper flower color and leaves that are a darker shade of green with varying leaf blade widths. It also begins to flower later in the season.
Dicotyledon
The dicotyledons, also known as dicots, are a group of flowering plants whose seed typically has two embryonic leaves or cotyledons. There are around 199,350 species within this group...
ous plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
that belongs to the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Stylidium (family Stylidiaceae
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...
). This species used to belong to the Stylidium graminifolium complex, but the name was conserved for this single species when two others were split from the complex and introduced as new species in 2001. S. graminifolium is endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
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...
and is one of the Stylidium species with the widest distribution throughout Australia. It is a perennial plant
Perennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
with grass-like leaves and is easily cultivated. It has been considered to be a carnivorous
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...
or protocarnivorous plant
Protocarnivorous plant
A protocarnivorous plant , according to some definitions, traps and kills insects or other animals but lacks the ability to either directly digest or absorb nutrients from its prey like a carnivorous plant...
because it possesses 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 underneath the flowers that can trap and digest prey.
Description
This species is an erect perennial herb with 5-40 cm (2-8 in) long narrow, grass-like leaves that appear from a basal rosetteRosette (botany)
In botany, a rosette is a circular arrangement of leaves, with all the leaves at a single height.Though rosettes usually sit near the soil, their structure is an example of a modified stem.-Function:...
. A 15-90 cm (6-36 in) long scape
Scape (botany)
In botany, scapes are leafless flowering stems that rise from the ground. Scapes can have a single flower or many flowers, depending on the species....
bearing the racemous
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
appears in the spring and summer (October through February). The flowers are butterfly shaped and pale or bright pink with petals paired laterally. The calyx
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
and corolla are both covered in 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. The pollination mechanism involving a sensitive "trigger"--a floral 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....
, in which the stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
and style are fused--is unique to the family Stylidiaceae. In S. graminifolium, the column is red and stamens are a greenish color. This species, like most Stylidium species, possesses glandular trichomes underneath the flower and on the scape, which are capable of digesting and absorbing nutrients from prey captured in the sticky mucilage
Mucilage
Mucilage is a thick, gluey substance produced by most plants and some microorganisms. It is a polar glycoprotein and an exopolysaccharide.It occurs in various parts of nearly all classes of plant, usually in relatively small percentages, and is frequently associated with other substances, such as...
. This information leads some researchers to believe that the plants are carnivorous
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...
or at the very least protocarnivorous
Protocarnivorous plant
A protocarnivorous plant , according to some definitions, traps and kills insects or other animals but lacks the ability to either directly digest or absorb nutrients from its prey like a carnivorous plant...
.
Distribution and habitat
S. graminifolium has one of the widest ranges in the Stylidium genus, extending from TasmaniaTasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
to Victoria
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....
, 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...
, and Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
over to South Australia
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...
. Its most common habitat is dry sclerophyll
Sclerophyll
Sclerophyll is the term for a type of vegetation that has hard leaves and short internodes . The word comes from the Greek sclero and phyllon ....
forests with nutrient-poor soil conditions.
Taxonomy
S. graminifolium was one of only four Stylidium species collected in 1770 from Botany BayBotany Bay
Botany Bay is a bay in Sydney, New South Wales, a few kilometres south of the Sydney central business district. The Cooks River and the Georges River are the two major tributaries that flow into the bay...
when Joseph Banks
Joseph Banks
Sir Joseph Banks, 1st Baronet, GCB, PRS was an English naturalist, botanist and patron of the natural sciences. He took part in Captain James Cook's first great voyage . Banks is credited with the introduction to the Western world of eucalyptus, acacia, mimosa and the genus named after him,...
and Daniel Solander
Daniel Solander
Daniel Carlsson Solander or Daniel Charles Solander was a Swedish naturalist and an apostle of Carl Linnaeus. Solander was the first university educated scientist to set foot on Australian soil.-Biography:...
joined James Cook
James Cook
Captain James Cook, FRS, RN was a British explorer, navigator and cartographer who ultimately rose to the rank of captain in the Royal Navy...
's first voyage to the Pacific Ocean on board the Endeavour
HM Bark Endeavour
HMS Endeavour, also known as HM Bark Endeavour, was a British Royal Navy research vessel commanded by Lieutenant James Cook on his first voyage of discovery, to Australia and New Zealand from 1769 to 1771....
. It was first formally described by Carl Ludwig Willdenow
Carl Ludwig Willdenow
Carl Ludwig Willdenow was a German botanist, pharmacist, and plant taxonomist. He is considered one of the founders of phytogeography, the study of the geographic distribution of plants...
in 1805. It was again described by Olof Swartz
Olof Swartz
Olof Peter Swartz was a Swedish botanist and taxonomist. He is best known for his taxonomic work and studies into pteridophytes...
just two years later in 1807 under the same name. Around the same time, other botanists were considering placing these new species in the new genus Candollea, which would be in the Dilleniaceae
Dilleniaceae
Dilleniaceae is the botanical name for a family of flowering plants. Such a family has been universally recognized by taxonomists. It is known to gardeners for the genus Hibbertia, which contains many commercially valuable garden species....
family, but Stylidium was retained as the older nomenclature and placed in its own family, Stylidiaceae.
Stylidium graminifolium complex
After S. graminifolium was discovered and formally described, new formsForm (botany)
In botanical nomenclature, a form is one of the "secondary" taxonomic ranks, below that of variety, which in turn is below that of species; it is an infraspecific taxon...
and varieties were added to what came to be known as the Stylidium graminifolium complex, a group of plants that has been treated as a single species but may have significant morphological differences that require the complex to be split into new species. The complex was formally split into three species in 2001, with S. graminifolium lectotypified
Lectotype
In botanical nomenclature and zoological nomenclature, a lectotype is a kind of name-bearing type. When a species was originally described on the basis of a name-bearing type consisting of multiple specimens, one of those may be designated as the lectotype...
from the collections of Banks and Solander in the 1770s. S. graminifolium sensu stricto is more narrow-leaved and is diploid (2n = 30). The other two species, S. dilatatum and S. armeria
Stylidium armeria
Stylidium armeria, the thrift-leaved triggerplant, is a species of Stylidium that is native to Australia. It is an herbaceous perennial that grows from 50 to 100 cm tall. Narrowly lanceolate to narrowly oblanceolate leaves, about 15-40 mm long, are tufted at the base and are erect to...
, that used to be included in this complex are tetraploid (2n = 60) and may represent polyploid
Polyploidy
Polyploid is a term used to describe cells and organisms containing more than two paired sets of chromosomes. Most eukaryotic species are diploid, meaning they have two sets of chromosomes — one set inherited from each parent. However polyploidy is found in some organisms and is especially common...
speciation
Speciation
Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...
. The three species also represented different habitats and ranges, with S. graminifolium distributed widely in south-eastern continental Australia and Tasmania, S. dilatatum in the subalpine
Subalpine
The subalpine zone is the biotic zone immediately below tree line around the world. Species that occur in this zone depend on the location of the zone on the Earth, for example, Snow Gum in Australia, or Subalpine Larch, Mountain Hemlock and Subalpine Fir in western North America.Trees in the...
areas of south-eastern Australia and widely distributed in Tasmania, and S. armeria in the littoral
Littoral
The littoral zone is that part of a sea, lake or river that is close to the shore. In coastal environments the littoral zone extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged. It always includes this intertidal zone and is often used to...
habitats in Tasmania from Macquarie Harbour
Macquarie Harbour
Macquarie Harbour is a large, shallow, but navigable by shallow draft vessels inlet on the West Coast of Tasmania, Australia.-History:James Kelly wrote in his narrative "First Discovery of Port Davey and Macquarie Harbour" how he sailed from Hobart in a small open five-oared whaleboat to discover...
to the Tasman Peninsula
Tasman Peninsula
Tasman Peninsula is located around by road south-east of Hobart, at the south east corner of Tasmania, Australia.-Description:The Tasman Peninsula lies south and west of Forestier Peninsula, to which it is connected by an isthmus called Eaglehawk Neck...
.
Cultivation
Celsius
Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...
, making it suitable for growing outside in as low as USDA
United States Department of Agriculture
The United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...
hardiness zone
Hardiness zone
A hardiness zone is a geographically defined area in which a specific category of plant life is capable of growing, as defined by climatic conditions, including its ability to withstand the minimum temperatures of the zone...
8. Darnowski also postulated that S. graminifoliums attractive floral spikes could be of use in floriculture
Floriculture
Floriculture, or flower farming, is a discipline of horticulture concerned with the cultivation of flowering and ornamental plants for gardens and for floristry, comprising the floral industry...
and could be used to replace purple loosestrife
Purple loosestrife
Lythrum salicaria is a flowering plant belonging to the family Lythraceae, native to Europe, Asia, northwest Africa, and southeastern Australia. It should not be confused with other plants sharing the name loosestrife that are members of the family Primulaceae...
in winter and spring arrangements. It has a relatively long flowering period and has somewhat specific conditions for germination, including smoke treatments and higher temperatures to simulate a bushfire, though germination can occur without these conditions. These germination requirements reduce the risk that it will become an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
. It is also able to grow on nutrient-poor soils and withstand significant drought. These attributes increase its potential for floricultural use.
There are two cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
s of S. graminifolium, Tiny Trina and Little Saphire, that are tentatively recognized cultivar names by the Royal Horticultural Society
Royal Horticultural Society
The Royal Horticultural Society was founded in 1804 in London, England as the Horticultural Society of London, and gained its present name in a Royal Charter granted in 1861 by Prince Albert...
. The epithet Little Saphire is derived from the bright blue foliage that distinguishes this cultivar from 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...
species. Tiny Trina has a deeper flower color and leaves that are a darker shade of green with varying leaf blade widths. It also begins to flower later in the season.