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. Most species are free standing or self-supporting, though a few can be climbing or scrambling.
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.
Tolypangium is a subgenus of the genus Stylidium that is characterized by ovoid to longish capsules. This subgenus was part of the earliest taxonomic division among the triggerplants. Stephan Ladislaus Endlicher first split the genus into two subgenera in 1838: Tolypangium with its ovoid capsules and Nitrangium with its linear capsules. Subsequent authors generally followed this classification, which is based almost entirely on the features of the capsule. Recent genetic analysis, combined with an exhaustive morphological comparison, has revealed that the classification defined by Johannes Mildbraed in 1908 is not the most accurate description of how the members of different subgenera and sections are related. As part of the Flora of Australia series, Juliet Wege will be reviewing and updating the taxonomy of the Stylidiaceae.
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 Uniflora is a taxonomic rank under Stylidium subgenus Andersonia. In 2000, A.R. Bean published a taxonomic revision of subgenus Andersonia and established this section to separate these five species based on morphological and cladistic analysis.
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 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 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 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 longissimum is a dicotyledonous plant that belongs to the genus Stylidium. The specific epithet is from the Latin longissimus, which means "very long" and refers to this species' long capsules that can be up to 15 mm long excluding the sepals. The capsules may be the longest in the genus.
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.
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.
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.
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.
