Tolypangium is a subgenus

Subgenus

In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...

 of the genus Stylidium that is characterized by ovoid to longish capsules

Capsule (fruit)

In botany a capsule is a type of simple, dry fruit produced by many species of flowering plants. A capsule is a structure composed of two or more carpels that in most cases is dehiscent, i.e. at maturity, it splits apart to release the seeds within. A few capsules are indehiscent, for example...

. This subgenus was part of the earliest taxonomic

Taxonomy

Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 division among the triggerplants (genus Stylidium). Stephan Ladislaus Endlicher

Stephan Ladislaus Endlicher

Stephan Ladislaus Endlicher was an Austrian botanist, numismatist and Sinologist. He was a director of the Botanical Garden of Vienna. He was born in Pressburg and died in Vienna....

 first split the genus into two subgenera in 1838: Tolypangium with is 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

Johannes Mildbraed

Gottfried Wilhelm Johannes Mildbraed was a German botanist that specialized in mosses, ferns, and various spermatophytes. He is well-known for authoring the most current monograph and taxonomic treatment of the family Stylidiaceae in 1908 as part of the unfinished Das Pflanzenreich series. The...

 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

Flora of Australia (series)

The Flora of Australia is a 59 volume series describing the vascular plants, bryophytes and lichens present in Australia and its external territories...

series, Juliet Wege

Juliet Wege

Juliet Ann Wege is an Australian botanist. She graduated in 1992 and gained a PhD at the University of Western Australia in 1999. She currently works as a researcher at the Western Australian Herbarium run by Western Australia's Department of Environment and Conservation...

 will be reviewing and updating the taxonomy of the 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...

.