Stylidium kunthii 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 8 to 20 cm tall. Obovate, orbicular, or obleanceolate leaves, about 5-15 per plant, form terminal rosettes with some scattered along the stems. The leaves are generally 4–15 mm long and 2–9 mm wide. This species generally has one to five scapes and cymose inflorescences that are 5–14 cm long. Flowers are white or pink. S. kunthii has a wide distribution in Southeast Asia, ranging from eastern India to Myanmar, Bengal, and Vietnam. Its typical habitats include the wet soils of rice fields, natural grasslands, and road cuttings at an altitude of less than 200 metres. It flowers from November to December. S. kunthii is most closely related to S. uliginosum, but differs by the cauline leaves.
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.
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.
Stylidium section Alsinoida is a taxonomic rank under Stylidium subgenus Andersonia. In his 1908 monograph on the family Stylidiaceae, Johannes Mildbraed had established the subgenus Alsinoides for species related to S. alsinoides, which were morphologically similar to species of subgenus Andersonia. In 2000, A.R. Bean published a taxonomic revision of subgenus Andersonia and reduced subgenus Alsinoides to sectional rank, renamed Alsinoida.
Stylidium section Andersonia is a taxonomic rank under Stylidium subgenus Andersonia. In 2000, A.R. Bean published a taxonomic revision of subgenus Andersonia and placed species within sections in the subgenus Andersonia, thus creating this autonym section. It contains 13 species. It is distinguished from the other sections in the subgenus by the inflorescences arising from leafless scapes, emerging from a basal or cauline cluster of broad leaves. The species in this section represent distributions from Southeast Asia, Malesia, tropical Australia, southern Queensland, and northern New South Wales.
Stylidium section Biloba is a taxonomic rank under Stylidium subgenus Andersonia. All the species in this section occur in northern Australia. In 2000, A.R. Bean published a taxonomic revision of subgenus Andersonia and established this section to separate these three species based on morphological and cladistic analysis. Species in this section form a basal rosette or cauline leaves and cymose inflorescences. The column is glabrous and dilated at the distal end.
Stylidium section Tenella is a taxonomic rank in the plant kingdom under Stylidium subgenus Andersonia. In 2000, A.R. Bean published a taxonomic revision of subgenus Andersonia and established this section to separate these eleven species based on morphological and cladistic analysis. This taxonomic rank is named after George Bentham's series Tenellae, which he established in his 1869 treatment of the family Stylidiaceae. Series Tenellae was not used in Johannes Mildbraed's 1908 taxonomic monograph in which he completely revised the subgeneric taxonomy of the genus. Mildbraed's treatment of the genus taxonomy is the general demarcation which has been used in subsequent revisions and additions.
Stylidium tenerrimum is a dicotyledonous plant that belongs to the genus Stylidium. It is an erect annual plant that grows from 4 to 30 cm tall. Linear, oblanceolate, or deltate leaves, about 5-24 per plant, are scattered along the stems. The leaves are generally 1.2-4.8 mm long and 0.3-0.8 mm wide. This species lacks a scape but has cymose inflorescences that are 4–11 cm long. Flowers are white and red. S. tenerrimum is found around Darwin in the Northern Territory of Australia and the Victoria River, though it hasn't been recollected there since the type location was chosen. Its typical habitat is sandy soils that remain moist, associated with grasses and sedges. It flowers in the southern hemisphere from April to August. S. tenerrimum is most closely related to S. alsinoides, though it differs by its asymmetrical petals. In his revision of the subgenus Andersonia in 2000, A.R. Bean placed S. evolutum into synonymy and noted that the type specimen of S. mitrasacmoides was not located and thus the application of this synonym is not certain. Tony Bean assessed this species' conservation status as data deficient in 2000.
Stylidium accedens is a dicotyledonous plant that belongs to the genus Stylidium. S. accedens is found around and northeast of Katherine in the Northern Territory of Australia.
Stylidium divergens is a dicotyledonous plant that belongs to the genus Stylidium that was described as a new species in 2000. The specific epithet divergens means diverging or separating, referring to the widely spreading posterior petals. It is an erect annual plant that grows from 7 to 27 cm tall. Obovate, orbicular, or elliptical leaves, about 2-6 per plant, form a basal rosette. The leaves are generally 4–21 mm long and 3–5 mm wide. This species generally has one to six scapes and cymose inflorescences that are 4–24 cm long. Flowers are white or mauve. S. divergens is endemic to Kakadu National Park in the Northern Territory of Australia. Its typical habitats are sandstone slopes and gullies. It flowers in the southern hemisphere in April. S. divergens is most closely related to S. accedens. Its conservation status has been assessed as data deficient.
Stylidium ensatum is a dicotyledonous plant that belongs to the genus Stylidium that was described as a new species by A.R. Bean in 2000, though the taxon had been noted by Rica Erickson in her discussion of S. muscicola variation in 1958. The specific epithet ensatum is from the Latin ensatus, meaning sword-like, which refers to the shape of the floral throat appendages of this species. It is an erect annual plant that grows from 14 to 22 cm tall. Obovate or orbicular leaves, about 6-17 per plant, are scattered along the stems. The leaves are generally 7–12 mm long, 5.5–12 mm wide, and lack petioles. This species generally has one to three scapes and cymose inflorescences that are 8–16 cm long. Flowers are pink or mauve. S. ensatum is endemic to the area around Darwin in the Northern Territory of Australia. Its habitat has been reported as being a "Melaleuca viridiflora-Lophostemon lactifluus forest with damp peaty soil." It flowers in the southern hemisphere from June to July. S. ensatum is most closely related to S. muscicola. Its conservation status has been assessed as data deficient.
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 stenophyllum is a dicotyledonous plant that belongs to the genus Stylidium that was described by A.R. Bean in 2000. It is an erect annual plant that grows from 30 to 40 cm tall. Linear leaves, about 7-25 per plant, are scattered along the stems. The leaves are generally 36–86 mm long and 1.5-2.5 mm wide. This species generally has three to four scapes and cymose inflorescences that are 28–39 cm long. Flowers are white or pink. S. stenophyllum is endemic to the far northeastern Northern Territory of Australia and is only known from the type location. It has only been recorded from one sandstone monolith known as a beehive formation where less than 100 clumps of plants survive at the concentration of about 10 individual plants per clump. For this reason, A.R. Bean suggested a vulnerable conservation status. However it currently appears on neither the IUCN Red List nor the EPBC Act list of threatened flora.
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 aquaticum is a dicotyledonous plant that belongs to the genus Stylidium. The specific epithet aquaticum refers to this species' typical habitat. It is an annual plant that grows from 18 to 30 cm tall. Linear leaves, about 20-100 per plant, are scattered along the elongate, glabrous stem. The leaves are generally 1.7–11 mm long and 0.1-0.3 mm wide. Petioles and scapes are absent. Inflorescences are 3–8 cm long. Flowers are pink or white. S. aquaticum is only known from its type location in northwestern Northern Territory of Australia. Its habitat is recorded as being a Melaleuca viridiflora swamp, growing in shallow water at a depth of around 7 cm. It flowers in the southern hemisphere in May. S. aquaticum is most closely related to S. fissilobum but differs mostly in the leaf shape. Its conservation status has been assessed as data deficient.
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 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 ericksoniae is a dicotyledonous plant that belongs to the genus Stylidium. It is an annual plant that grows from 6 to 15 cm tall. The linear or deltate leaves, about 20-100 per plant, are mostly in terminal rosettes but with some scattered along the elongate stem. The leaves are generally 4.0–9.5 mm (0.16–0.37 in) long and 0.6–1.1 mm (0.024–0.043 in) wide. Petioles are absent. This species produces 1–20 scapes per plant. Inflorescences are 5–11 cm (2.0–4.3 in) long and produces a single pink or mauve flower that blooms from March to August in the southern hemisphere. S. ericksoniae is endemic to the northern areas of the Northern Territory of Australia. Its habitat is recorded as being damp sand near sandstone rocks or on swampy drainage channels. It's been found in association with Micraira and Pandanus species. S. ericksoniae is most closely associated with S. pedunculatum. Its conservation status has been assessed as data deficient.
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.
