Stylidium repens, the matted triggerplant, is a dicotyledonous plant that belongs to the genus Stylidium. S. repens is endemic to Australia and is found primarily in southwest Western Australia. This species is a creeping or scrambling triggerplant, which can spread over large areas as a tangled mat of stems and aerial roots. The older stems are grey whereas younger stems appear red and have terminal rosettes of small leaves, five mm to one cm in length. When the rains come, new roots and a one to three flowers emerge from the terminal rosettes. This is the only species of triggerplant known to regularly flower twice a year—in autumn and late spring. Pollination, which is typically very specialized in this genus, is achieved with a variety of insects in this species.
Stylidium turbinatum is a dicotyledonous plant that belongs to the genus Stylidium. S. turbinatum is endemic to Australia and is found in the northern part of Western Australia in the Kimberley region and near Darwin in the Northern Territory. This species is an erect annual herb that stands 6–15 cm tall. A 2–5 cm long stem bearing scattered leaves terminate in a tuft of 1–2 cm long upper leaves. Several scapes appear from these terminal tufts. The inflorescence is a raceme, which produces pink flowers whose petals are vertically paired. The hypanthium of this species is turbinate and is one of the distinguishing characteristics used to identify it. The sepals form ribs around the hypanthium, giving it a turbine-like appearance. Seeds of S. turbinatum are pale orange and around 0.2 mm long.
Andersonia is a subgenus of Stylidium that is characterized by a linear hypanthium, recurved mature capsule walls, an erect and persistent septum, and many seeds. This subgenus occurs in areas of tropical northern Australia and into Southeast Asia and was named in honour of William Anderson, the surgeon and naturalist who sailed with James Cook.
Repentes is a section in the subgenus Tolypangium. Repentes is a group of creeping triggerplants known as the locket triggerplants, related to subgenus Nitrangium section Appressae. They possess adpressed stem leaves bearing a small basal spur and uni-flowered inflorescences. Because section Repentes morphologically resembles the other creeping triggerplants in section Appressae, Allen Lowrie et al. (1999) proposed all species in this section be moved to section Appressae and Repentes be placed into synonymy. Juliet Wege (2006), however, argued that these species are morphologically distinct from those in section Appressae, citing trichome and column cunabulum structure as distinctions that separate the sections.
Stylidium rotundifolium is a dicotyledonous plant that belongs to the genus Stylidium. It is an erect annual plant that grows from 4 to 18 cm tall. Obovate or oblanceolate leaves, about 4-17 per plant, form a basal rosette around the compressed stem. The leaves are generally 5–29 mm long and 3–10 mm wide. This species generally has one to ten scapes and cymose inflorescences that are 4–18 cm long. Flowers are pink or white. S. rotundifolium's wide, sporadic distribution ranges from the Kimberley region in Western Australia east to northeastern Queensland with a significant population near Taroom, Queensland. Its typical habitats include damp sandy soils on creekbanks, receding waterholes, or Melaleuca woodlands. It flowers in the southern hemisphere from April to October. S. rotundifolium is most closely related to S. dunlopianum.
Stylidium nominatum is a dicotyledonous plant that belongs to the genus Stylidium. It is an annual plant that grows from 4 to 15 cm tall. The oblanceolate leaves, about 5-15 per plant, form basal rosettes around the stem and are 2.5–9 mm long, 0.5-1.5 mm wide. About 4-11 leaves per plant are also scattered along the stem and are generally 2.3-4.7 mm long and 0.3-0.5 mm wide. Scapes are absent. Inflorescences are 2–6 cm long and produce white flowers that bloom from April to June in the southern hemisphere. S. nominatum is endemic to the northern area of Kakadu National Park and Melville Island in the Northern Territory. Its habitat is recorded as being sandy soils in Melaleuca viridiflora woodlands, bases of sandstone escarpments, and gravelly yellow soil in flat, treeless areas. S. nominatum is most closely related to S. capillare. In his recent revision of the subgenus Andersonia, Anthony Bean (A.R.Bean) noted that there is a large variation recorded in the specimens of this species and more work would need to be done to determine if there's more than one taxon involved with this species. Further evaluation may reveal additional species.
Stylidium perizostera is a dicotyledonous plant that belongs to the genus Stylidium. It is an annual plant that grows from 5 to 11 cm tall. The linear leaves, about 8–12 per plant, are mostly in terminal rosettes but with some scattered along the elongate, glabrous stem. The leaves are around 7.5 mm long and 0.4-0.7 mm wide. Petioles are absent. This species produces 1-10 scapes per plant. Inflorescences are around 9 cm long and produce a single white, yellow, and orange flower. S. perizostera is endemic to the Kimberley region in Western Australia and ranges from the Mitchell Plateau to Bigge Island. Its habitat is recorded as being near sandstone outcrops in drainage lines.
Stylidium trichopodum is a dicotyledonous plant that belongs to the genus Stylidium. It is an annual plant that grows from 6 to 20 cm tall. The linear leaves, about 20-200 per plant, are scattered along the elongate, glabrous stems. The leaves are generally 3–9 mm long and 0.2-0.7 mm wide. Petioles are absent. This species produces 1-10 scapes per plant. Inflorescences are 2.6–6 cm long and produce a single yellow or orange flower that blooms in June and July in the southern hemisphere. S. trichopodum is endemic to northern Queensland and is only known from a few populations. Its habitat is recorded as being moist sandy soils on flat or gently sloping terrain, sometimes in areas dominated by Melaleuca species. S. trichopodum is most closely related to S. pedunculatum, though it differs by its much larger flower and its cauline leaves instead of terminal rosettes for S. pedunculatum.
Stylidium aceratum is a dicotyledonous plant that belongs to the genus Stylidium. It occurs within the south west region of Western Australia
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. weeliwolli are annuals. This subgenus appears to be most closely related to the genus Levenhookia, which suggests an ancestral relationship. Centridium was first published by John Lindley in the 1839 publication, A Sketch of the Vegetation of the Swan River Colony. Lindley created this subgenus to distinguish species which did not fit into either of the two other subgenera that had existed at the time. He initially placed Stylidium calcaratum, the newly described Stylidium androsaceum, and Stylidium stipitatum into subgenus Centridium. His description of S. androsaceum turned out to be synonymous with S. calcaratum and S. stipitatum is a synonym of Levenhookia stipitata.
Stylidium ceratophorum is a dicotyledonous plant that belongs to the genus Stylidium. It is an annual plant that is endemic to the Kimberley region of Western Australia and northern parts of the Northern Territory. It attains a height of 12–30 cm with a basal rosette of small leaves. The leaves are petiolate, obovate, or lanceolate and are only 0.2–1 cm long. Solitary scapes are produced that bear golden yellow or orange flowers, 7–9 mm across. Its habitat has been reported as being sandy soils on creek margins in the presence of Stylidium rubriscapum and Stylidium diceratum or in river paperbark stands. S. ceratophorum appears similar to S. diceratum and may be confused with the species since they both have orange flowers. S. ceratophorum's corolla is twice as large as S. diceratum, though, as well as the deeply divided posterior corolla lobes of S. ceratophorum.
Stylidium diceratum is a dicotyledonous plant that belongs to the genus Stylidium. The specific epithet diceratum is Greek for "two horns", referring to the two appendages that are present on the bend of the gynostemium. It is an annual plant that grows from 15 to 35 cm tall. The longer leaves are lanceolate and the shorter ones are spathulate, forming a basal rosettes around the stem. The leaves are around 5–8 mm long and 0.2-2.5 mm wide. Inflorescences are around 6–15 cm long and produce flowers that are orange with dark orange and pink veins and bloom from June to August in their native range. S. diceratum is only known from the type location, which is at creek crossings on the road to Beverley Springs in the Kimberley region of Western Australia. Its habitat is recorded as being sandy soils on creek margins. It grows in the presence of S. ceratophorum, S. rubriscapum, Drosera caduca, D. paradoxa, Byblis liniflora, and Grevillea pteridifolia. S. diceratum is most closely related to S. longicornu, but it can be confused with S. ceratophorum, which also has an orange corolla but twice as large.
Stylidium edentatum is a dicotyledonous plant that belongs to the genus Stylidium. It is an annual plant that grows around 6 cm tall. The elliptical leaves form a basal rosettes around the stem. The leaves are around 0.3-0.8 mm long with recurved margins. Inflorescences are produced on solitary scapes and bear flowers that are white with rose-coloured markings at the base of the corolla lobes and two tooth-shaped throat appendages present. S. edentatum was a previously overlooked species that is related to and appears similar to S. calcaratum and S. ecorne. Allen Lowrie and Sherwin Carlquist described this species in 1989 and argued that if S. ecorne is considered distinct from S. calcaratum, then certainly S. edentatum warrants placement at the species level. It differs from S. calcaratum and S. ecorne by the long petioles on its recurved leaves, and the cuneate, obtuse, and unlobed posterior corolla lobes. They also have a distinctive lateral toothlike appendage at the base of each posterior corolla lobe. S. edentatum is endemic to southwestern Western Australia.
Stylidium weeliwolli is a dicotyledonous plant that belongs to the genus Stylidium. It occurs in the North West of Western Australia
Stylidium subg. Forsteropsis, as circumscribed by Allen Lowrie and Kevin Kenneally, contains five species of triggerplants from south-western Australia that are characterized by their tightly appressed leaves arranged in a spiral around the stem. This subgenus was originally described by Otto Wilhelm Sonder in 1845 as the genus Forsteropsis.
Stylidium imbricatum, the tile-leaved triggerplant, is a dicotyledonous plant that belongs to the genus Stylidium. It is an herbaceous perennial that grows from 12 to 50 cm tall and has divided stems covered with tile-like leaves that are arranged in a spiral formation around the stem. The ovate-elliptic leaves are basifixed and held closely against the stems. The leaves are around 1.5-1.8 mm long and 0.6-0.8 mm wide. Terminal inflorescences are racemose or spike-like and produce flowers that are reddish violet with laterally-paired lobes and bloom from April to May in their native range. S. imbricatum is only known from south-western Western Australia in Stirling Range National Park and Porongurup National Park south-east to Cheynes Beach. Its habitat is recorded as being sandy or laterite soils in swampy areas, rocky slopes, or heathland. S. imbricatum is distinct within its subgenus because it possesses obovate sepals. Its conservation status has been assessed as secure.
Stylidium leeuwinense is a species that belongs to the genus Stylidium. The specific epithet leeuwinense refers to the Cape Leeuwin region in Western Australia where the type location for this species is. It is an herbaceous perennial that grows from 15 to 60 cm tall and has divided stems covered with tile-like leaves that are arranged in a spiral formation around the stem. The lanceolate leaves are basifixed and held closely against the stems. The leaves are around 2.5-3.5 mm long and 0.5-0.8 mm wide. Terminal inflorescences are racemose or spike-like and produce flowers that are reddish purple with laterally-paired lobes and bloom from February to May in their native range. S. leeuwinense is only known from south-western Western Australia along the coast from Augusta to Denmark. Its habitat is recorded as being black, peat-sand soils in swampy areas or heathland. S. leeuwinense, along with S. preissii, is distinct within its subgenus because it possesses leaves without an apical mucro. It differs from S. preissii by its spike-like racemes.
Stylidium marradongense is a species that belongs to the genus Stylidium. The specific epithet marradongense refers to the Marradong region in Western Australia where the species is located. It is an herbaceous perennial that grows from 15 to 50 cm tall and has divided stems covered with tile-like leaves that are arranged in a spiral formation around the stem. The lanceolate leaves are basifixed and held closely against the stems. The leaves are around 1.5-2.0 mm long and 0.5-0.8 mm wide. Terminal inflorescences are racemose or spike-like and produce flowers that are shades of pink or white with pink at the base of the lobes and bloom from September to November in their native range. S. marradongense is only known from south-western Western Australia from Mount Saddleback to Marradong. Its habitat is recorded as being sandy laterite soils in open jarrah forest with other species such as Banksia grandis, Banksia sessilis, and Persoonia longifolia. S. marradongense is closely associated with S. preissii because they both lack throat appendages. It differs from S. preissii by its spike-like racemes, apical mucro, and conical, capitate stigmas.
Stylidium preissii, the lizard triggerplant, is a species that belongs to the genus Stylidium. It is an herbaceous perennial that grows from 5–18 cm tall and has divided stems covered with tile-like leaves that are arranged in a spiral formation around the stem. The broadly trullate leaves are basifixed and held closely against the stems. The leaves are around 1.9 mm long and 1.0 mm wide. Inflorescences are umbellate racemes and produce flowers that are white, pale pink, or dark pink and bloom from November to December in their native range. S. preissii is only known from south-western Western Australia from Bremer Bay to Israelite Bay with a few populations near Jandakot. Its habitat is recorded as being white sandy soils in open heathland. S. preissii is distinct within its subgenus because it possesses a strap-like gynostemium column with a dilated cunabulum.
Stylidium affine is a species in the genus Stylidium that is endemic to Western Australia.
