Ptilotus nobilis

Ptilotus nobilis, commonly known as yellow tails, regal foxtail or broad foxtail is a perennial herb of the family Amaranthaceae. It is found across dry interior areas of mainland Australia.

The species was first formally described by English botanist John Lindley in Thomas Mitchell's Three Expeditions into the interior of Eastern Australia in 1838. Lindley gave it the name Trichium nobile. The species was transferred to the genus Ptilotus in 1868 by Victorian Government Botanist Ferdinand von Mueller in the sixth volume of his Fragmenta Phytographiae Australiae. A 2007 genetic study focusing on populations of P. nobilis and the pink-flowered Ptilotus exaltatus found a very close relationship between the two. Ptilotus exaltatus has since been synonymized under P. nobilis subsp. nobilis.

Ptilotus nobilis grows to around 1 metre (39 in) high, with an erect perennial habit. Its spoon-shaped leaves are up to 13 cm (5 in) long, and 5 cm (2 in) wide, arranged alternately along the stems. The flowers rise above the foliage and are cylindrical fuzzy green-yellow spikes up to 22 cm (8.5 in) high and 5 cm (2 in) wide. Plants studied at Cunnamulla in South West Queensland had both purplish and greenish flowerheads; this was a zone of overlap between the P. nobilis and P. exaltatus populations.

Scattered across inland New South Wales, it grows on a range of soils, though prefers more sandy than clayey soils. Habitats include Acacia woodland, mallee, shrubland and grassland.

Ptilotus nobilis subsp. nobilis is listed as "endangered" on the Department of Sustainability and Environment's Advisory List of Rare Or Threatened Plants In Victoria.

Cultivars developed and registered by Dion Harrison and colleagues at the University of Queensland include 'Passion' (an upright form with purple flowerheads), 'Poise' (a two-toned tan and pink flowerhead), and 'Purity' (upright stems and green-yellow flowerheads).