Stylidium uliginosum is a dicotyledonous plant that belongs to the genus Stylidium and is one of the few species in the genus that is not native to Australia. It is an erect annual plant that grows from 4 to 15 cm tall. Obovate or elliptical leaves, about 7-16 per plant, form basal rosettes around compressed stems. The leaves are generally 4.5–11 mm long and 2–4.5 mm wide. This species generally has one to seven scapes and cymose inflorescences that are 4–15 cm long. Flowers are white. S. uliginosum is endemic to Southeast Asia and has a wide distribution, ranging from Thailand to the Guangdong province of southern China. The type location is in Sri Lanka, but it may be extinct there now. Earlier reports list this species as also occurring in Queensland and other parts of Australia, but this was before subsequent revisions revealed those occurrences in Australia were really a different species, S. tenerum, that resembled S. uliginosum. Its typical habitats include sandy, moist soils in open savannah and sandy earth banks at an altitude of less than 200 metres. It flowers from October to March. S. uliginosum is most closely related to S. kunthii and S. tenerum.
Stylidium alsinoides is a dicotyledonous plant that belongs to the genus Stylidium. It is an erect annual plant that grows from 18 to 30 cm tall. Obovate or elliptical leaves, about 20–100 per plant, are scattered along the elongate, glabrous stems. The leaves are generally 5.5–14 mm (0.22–0.55 in) long and 3–8 mm (0.12–0.31 in) wide. The bracts on the inflorescence can be as large as leaves and may be hard to distinguish them except for their growth habit: the leaves are alternate whereas the bracts are opposite.
Stylidium muscicola is a dicotyledonous plant that belongs to the genus Stylidium that was described by Ferdinand von Mueller in 1859. It is an erect annual plant that grows from 5 to 33 cm tall. Obovate or orbicular leaves, about 4-20 per plant, form terminal rosettes with some scattered along the stems. The leaves are generally 6–33 mm long and 5–28 mm wide. This species generally has one to eight scapes and cymose inflorescences that are 3–17 cm long. Flowers are white, pink, or mauve. S. muscicola's native range is concentrated in and around western Kimberley in Western Australia and extends to the northern parts of the Northern Territory and east almost to Queensland. Its typical habitat is a sheltered area along a sandstone ridge in sandy soils that remain moist in the dry seasons. It flowers in the southern hemisphere from February to September.
Stylidium schizanthum is a dicotyledonous plant that belongs to the genus Stylidium that was described by Ferdinand von Mueller in 1859. It is an erect annual plant that grows from 9 to 30 cm tall. Obovate, orbicular, or oblanceolate leaves, about 3-13 per plant, form basal rosettes. The leaves are generally 3.5–23 mm long and 1.5–12 mm wide. This species generally has one to four scapes and cymose inflorescences that are 9–30 cm long. Flowers are white, pink, mauve, or yellow. S. scizanthum's distribution ranges from the Kimberley region in Western Australia through the Northern Territory and into northern Queensland. It has been reported as far south as Mount Surprise and even in southern New Guinea. Its typical habitats are moist sand in Eucalyptus or Melaleuca communities, near creekbanks, or associated with sandstone landscapes. It flowers in the southern hemisphere from February to October. S. schizanthum is closely related to both S. pachyrrhizum and S. lobuliflorum.
Stylidium tenerum, the swamp triggerplant, is a dicotyledonous plant that belongs to the genus Stylidium that was described by Curt Polycarp Joachim Sprengel in 1826. Robert Brown had described this species in 1810 under the name S. tenellum, a name which had already been used for another species in 1805 by Olof Swartz. To add to the confusion, Rica Erickson had described and illustrated this taxon in 1958 under the name S. uliginosum, another currently accepted name for a related species.
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 capillare is a dicotyledonous plant that belongs to the genus Stylidium. It is an annual plant that grows from 6 to 13 cm tall. Obovate or orbicular leaves, about 4-7 per plant, form basal rosettes around the compressed stems. The leaves are generally 1.5–5 mm long and 1–3 mm wide. Petioles are absent. This species usually has one to two scapes per plant and 6–13 cm long inflorescences. Flowers are white and bloom from March to June in the southern hemisphere. S. capillare's distribution ranges from Litchfield National Park in the Northern Territory east to Cooktown Mareeba in northern Queensland, Australia. Its habitat is recorded as being sandy soils in eucalypt woodlands and swampy Melaleuca species communities. S. capillare is most closely related to S. nominatum. Its conservation status has been assessed as secure.
Stylidium fissilobum is a dicotyledonous plant that belongs to the genus Stylidium. It is an annual plant that grows from 5 to 50 cm tall. Linear or deltate leaves, about 4-34 per plant, are scattered along the elongate, glabrous stem. The leaves are generally 1–6 mm long and 0.3-0.7 mm wide. Petioles and scapes are absent. Inflorescences are 3–18 cm long. Flowers are pink, white, or mauve and bloom from March to July in the southern hemisphere. S. fissilobum's wide distribution ranges across northern Australia from the western Kimberley region and Northern Territory eastward as far as Mount Surprise in Queensland. Its habitat is recorded as being wet sands at swamp edges in association with grasslands and sedgelands. Due to its weak stem, this species often threads its way through supporting branches and leaves of the dense grass and sedge cover. S. fissilobum is most closely related to S. aquaticum and S. oviflorum. Its conservation status has been assessed as data deficient.
Stylidium section Debilia is a taxonomic rank under Stylidium subgenus Tolypangium. In his 1908 monograph on the family Stylidiaceae, Johannes Mildbraed had established this section as Debiles. In 1999, A.R. Bean published a taxonomic revision of several sections in subgenus Tolypangium in which he renamed the section from Debiles to Debilia.
Stylidium austrocapense is a dicotyledonous plant that belongs to the genus Stylidium. The specific epithet austrocapense refers to this species' native range on the southern part of Cape York Peninsula in Australia. It is an herbaceous annual plant that grows from 9 to 18 cm tall. Oblanceolate or elliptical leaves, about 4-40 per plant, form a basal rosette with stems absent. The leaves are generally 7.5–31 mm long and 2–10 mm wide. This species produces 1-10 scapes per plant that are glandular-hairy. Inflorescences are 9–18 cm long and produce pink or red flowers that bloom from April to July in their native range. S. austrocapense is endemic to the Cape York Peninsula in Queensland, Australia. Its typical habitat has been reported as coarse white sandy soils on low hills or intermittent watercourses. Dominant vegetation in association with its habitat include Eucalyptus tetrodonta, E. clarksoniana, Melaleuca viridiflora, M. nervosa, and Xanthorrhoea johnsonii. S. austrocapense is most closely related to S. multiscapum, but differs by the shorter leaves and absent paracorolla. Its conservation status has been assessed as secure.
Stylidium floribundum is a dicotyledonous plant that belongs to the genus Stylidium. S. floribundum's distribution ranges from the Kimberley region of Western Australia across northern Australia to northwestern Queensland.
Stylidium inaequipetalum, the Ayers Rock triggerplant, is a small herbaceous perennial plant in the genus Stylidium. It grows from 7 to 40 cm tall. Oblanceolate leaves, about 20-100 per plant, form a basal rosette with stems absent. The leaves are generally 15–81 mm long and 2–8 mm wide. This species produces 1-11 scapes per plant. Inflorescences are 7–40 cm long and produce pink flowers with petals all free and blooms almost year-round in their native range. S. inaequipetalum is endemic to the southwestern Northern Territory and Western Australia. Its typical habitat has been reported as sandy soils on sheltered creekbanks or in between rocks. S. inaequipetalum is most closely related to S. floribundum, though it is also closely allied with S. debile.
Stylidium leptorrhizum is a dicotyledonous plant that belongs to the genus Stylidium. It is an herbaceous annual plant that grows from 8 to 25 cm tall. Oblanceolate or elliptical leaves, about 10-20 per plant, form a basal rosette with stems absent. The leaves are generally 14–60 mm long and 3–9.5 mm wide. This species produces 1-3 scapes per plant. Inflorescences are 8–25 cm long and produce pink or mauve flowers that bloom from May to August in their native range. S. leptorrhizum is endemic to the Kimberley region of Western Australia and the Victoria River district of the Northern Territory. Its typical habitat has been reported as sandy soils along creeks or billabongs. S. leptorrhizum is most closely related to S. multiscapum. When reviewing section Debilia, Anthony Bean reduced the recently described S. barrettorum to synonymy with S. leptorrhizum after examining the type specimen.
Stylidium multiscapum is a dicotyledonous plant that belongs to the genus Stylidium. It is an herbaceous annual plant that grows from 10 to 20 cm tall. Oblanceolate leaves, about 8-100 per plant, form a basal rosette with stems absent. The leaves are generally 22–52 mm long and 6.5–8 mm wide. This species produces 1-8 scapes per plant. Inflorescences are 10–20 cm long and produce pink flowers that bloom from May to October in their native range. S. multiscapum's distributions ranges from the eastern Kimberley region of Western Australia through the northern parts of the Northern Territory and into northwestern Queensland. Its typical habitat has been reported as damp sandy soils near creeks or swamps in Eucalyptus-dominated woodlands. S. multiscapum is closely related to S. leptorrhizum.
Stylidium ornatum is a dicotyledonous plant that belongs to the genus Stylidium. It is an herbaceous annual or perennial that grows from 10 to 30 cm tall. Oblanceolate leaves, about 5-25 per plant, form either a basal rosette with stems absent or in terminal rosettes when plant stems are present. The leaves are generally 13–37 mm long and 3–10 mm wide. This species produces 1-4 scapes per plant. Inflorescences are 12–30 cm long and produce pink flowers that bloom all year in their native range. S. ornatum is endemic to Queensland and New South Wales. Its typical habitat has been reported as sandy soils in heathland or "wallum" on waterlogged coastal sands. S. ornatum is closely related to S. debile. Its conservation status has been assessed as secure.
Stylidium paniculatum is a dicotyledonous plant that belongs to the genus Stylidium. It is an herbaceous annual that grows from 10 to 35 cm tall. Oblanceolate or obovate leaves, about 6-30 per plant, form either a basal rosette with stems absent or in terminal rosettes when plant stems are present. The leaves are generally 10–31 mm long and 3–9 mm wide. This species produces one scape per plant. Inflorescences are 10–25 cm long and produce pink flowers that bloom from November to April in their native range. S. paniculatum is endemic to eastern Australia from Dalveen, Queensland to Tenterfield, New South Wales at elevations of 800 to 1000 metres. Its typical habitat has been reported as moist sandy soils on granite substrates along creeks, drains, or low-lying flats. S. paniculatum is closely related to S. debile and was originally described as a variety of S. debile, but raised to the species level by Anthony Bean in 1999. It differs from S. debile by the lack of bracteoles and its paniculate inflorescence. Its conservation status has been assessed as data deficient.
Stylidium semipartitum is a dicotyledonous plant that belongs to the genus Stylidium. It is an herbaceous annual or perennial that grows from 9 to 40 cm tall. Oblanceolate, elliptical, or obovate leaves, about 10-30 per plant, form a terminal rosette with stems present and glandular-hairy. The glandular-hairy leaves are generally 11–68 mm long and 3–21 mm wide. This species produces 1-18 scapes per plant. Inflorescences are 8–30 cm long and produce pink, mauve, or red flowers that bloom from March to August in their native range. S. semipartitum is endemic to the Kimberley region of Western Australia and northern parts of the Northern Territory. Its typical habitat has been reported as either damp sandy soils in eucalypt woodlands, near creeks in the company of Melaleuca species or on sandstone plateaux with Triodia species. S. semipartitum is distinct within section Debilia because it possesses glandular-hairy leaves. Other than that distinctive feature, however, it resembles descriptions of S. leptorrhizum, which is why George Bentham reduced S. semipartitum to a synonym of S. leptorrhizum.
Stylidium velleioides is a species that belongs to the genus Stylidium. The specific epithet velleioides is a reference to how sterile material of this species resembles Velleia spathulata. It is an herbaceous annual that grows from 15 to 30 cm tall. Obovate leaves, about 6-30 per plant, either form a terminal rosette with stems present or a basal rosette when stems are absent. The leaves are generally 8–33 mm long and 3.5–9 mm wide. This species produces 1-3 scapes per plant. Inflorescences are 15–25 cm long and produce pink flowers that bloom from March to November in their native range. S. velleioides is endemic to tropical Queensland from Mount Surprise to St Lawrence. Its typical habitat has been reported as along creekbanks and seepage areas in eucalypt woodlands. S. velleioides is similar to several other species in section Debilia. It, like S. paniculatum, has a paniculate inflorescence, but differs from S. paniculatum by its longer capsules and column. It can also be confused for S. semipartitum, which has glandular-hairy leaves and scapes whereas S. velleioides's leaves and scapes are glabrous. It is also related to S. debile, which has bracteoles present, racemose inflorescences, and shorter columns and posterior petals. In his assessment of the conservation status of this species in 1999, Tony Bean described it as secure.
Stylidium section Lanata is a taxonomic rank under Stylidium subgenus Tolypangium. It was described in 1999 by Anthony Bean. Two of the species in the section were also described by Bean in 1999, but S. eriorhizum was moved from section Debilia to section Lanata. The three species differ from those of section Debilia by their perennial habit, thickened woolly plant bases, indeterminate central rachis of the inflorescence, and larger, spherical seeds that possess a small nipple.
Stylidium eriorhizum is a species that belongs to the genus Stylidium. It is an herbaceous perennial plant that grows from 12 to 25 cm tall. Spathulate to oblanceolate leaves, about 20-100 per plant, form a basal rosette with stems greatly reduced. The leaves are generally 20–60 mm long and 4–10 mm wide. This species produces 1-3 scapes per plant. Inflorescences are 10–23 cm long and produce pink to white flowers that bloom year-round in their native range. S. eriorhizum is endemic to Queensland, where it is widespread from Atherton in the north to Barakula State Forest near Chinchilla in the south. Its typical habitat has been reported as sandy soils in woodlands or heathlands.
