TaraxacumTaraxacumTaxonomy
The dandelion genus Taraxacum F.H. Wigg. has a complicated taxonomy. Systematic treatments recognise c. 50-250 sexually reproducing and diploid biological species and as many as 2,500 obligately or facultatively asexual, polyploid "microspecies" classified into c. 30-52 sections. Identification of these so-called species is difficult and largely based on obscure characters of the involucral bracts, mature leaves, and the shape of the transition between the seed-bearing part and the beak of the fruit ("cone").
No attempt is made in this key to differentiate between the so-called species of Taraxacum. According to a recent treatment of the genus (Scarlett NH, 2015. Taraxacum. In: Wilson A ed., Flora of Australia Vol. 37, pp. 95-112), there are two native sexual species in Australia as well as several introduced, apomictic, triploid "species" representing at least seven Eurasian sections or species groups. Although the name Taraxacum officinale is often used as a stopgap name for all members of its taxonomic section or even sometimes for all specimens of the genus, apparently none of the plants in Australia belong to this species in the strict sense.
Common name
Dandelion.
Description
Propagule or dispersal unit is the fruit with pappus. Fertile part 2.5-4.5 mm long, 0.6-1 mm wide, in side view widest in upper part (obovoid) or widest in the middle, conspicuously curved, the upper (apical) end narrowing, in cross-section flattened, basal scar (carpopodium) inconspicuous and undifferentiated, central, beak (=thinner sterile stalk between seed and pappus) present, beak length 6-11 mm, wings absent, fruit surface light brown or straw or other, smooth (except at cellular level), with no hairs (glabrous), thickened margin absent, longitudinal ribs present, 5-15, their surfaces smooth or toothed, serrated or scale-like, with no hairs (glabrous).
Pappus type bristles / hairs, pappus elements all +/- similar, up to 3-7 mm long, in several rows, pappus elements numerous, persistent, the individual bristles rough / serrated (barbellate), +/- equal width along length, white / translucent.
Ecology
Perennial rosette herbs, fruits wind-dispersed. Mediterranean to arctic regions, and mountain ranges in warmer regions. Found especially in lawns, grasslands, pastures, wastelands, gardens and urban areas.
Native range
Cosmopolitan.
Introduced range
Cosmopolitan.
Past interceptions (Australia): origins
Canada, United States, Ecuador, Portugal, Spain, United Kingdom, France, Netherlands, Belgium, Germany, Austria, Slovakia, Hungary, South Africa, China, Korea, Japan, Vietnam, Papua New Guinea, New Zealand.
Past interceptions (Australia): commodities
Agricultural machinery, agricultural machinery new and used, container, cut flowers, dried herbs (medicinal), dried spices, grain, machinery and parts new, military equipment, new vehicles, nursery stock, personal effects, sawn timber, timber pallets, used vehicles.
