| dbo:abstract
|
- Asterales /æstəˈreɪliːz/ is an order of dicotyledonous flowering plants that includes the large family Asteraceae (or Compositae) known for composite flowers made of florets, and ten families related to the Asteraceae. The order has a cosmopolitan distribution, members are found throughout most of the world including desert and frigid zones, and includes mostly herbaceous species, although a small number of trees and shrubs are also present. Asterales seem to have evolved from one common ancestor, and share characteristics on morphological and biochemical levels. Synapomorphies (a character that is shared by two or more groups through evolutionary development) include the presence in the plants of oligosaccharide inulin, a nutrient storage molecule used instead of starch; and unique stamen morphology. The stamens are usually found around the style, either aggregated densely or fused into a tube, probably an adaptation in association with the plunger (brush; or secondary) pollination that is common among the families of the order, wherein pollen is collected and stored on the length of the pistil. The anthophytes are a grouping of plant taxa bearing flower-like reproductive structures. They were formerly thought to be a clade comprising plants bearing flower-like structures. The group contained the angiosperms - the extant flowering plants, such as roses and grasses - as well as the Gnetales and the extinct Bennettitales. 23,420 species of vascular plant have been recorded in South Africa, making it the sixth most species-rich country in the world and the most species-rich country on the African continent. Of these, 153 species are considered to be threatened. Nine biomes have been described in South Africa: Fynbos, Succulent Karoo, desert, Nama Karoo, grassland, savanna, Albany thickets, the Indian Ocean coastal belt, and forests. The 2018 South African National Biodiversity Institute's National Biodiversity Assessment plant checklist lists 35,130 taxa in the phyla Anthocerotophyta (hornworts (6)), Anthophyta (flowering plants (33534)), Bryophyta (mosses (685)), Cycadophyta (cycads (42)), Lycopodiophyta (Lycophytes(45)), Marchantiophyta (liverworts (376)), Pinophyta (conifers (33)), and Pteridophyta (cryptogams (408)). Five families are represented in the literature. Listed taxa include species, subspecies, varieties, and forms as recorded, some of which have subsequently been allocated to other taxa as synonyms, in which cases the accepted taxon is appended to the listing. Multiple entries under alternative names reflect taxonomic revision over time. (en)
|
