Senna artemisioides, commonly known as silver cassia,[2][3][4] is a species of flowering plant in the family Fabaceae and is endemic to Australia, where it is found in all mainland states and territories. It is a small, woody shrub with silver-green leaves and yellow flowers.
Senna artemisioides is a small shrub 1–3 m (3 ft 3 in – 9 ft 10 in) high with grey-green or silvery mostly pinnate leaves, leaflets in pairs of one to eight, variable, 2–4 cm (0.79–1.57 in) long, equal or increasing in size from the leaf base and sessile. The flowers are borne in clusters in leaf axils on a peduncle about 15 mm (0.59 in) long, 1.5 cm (0.59 in) in diameter, petals yellow, 4–10 mm (0.16–0.39 in) long, pedicel about 10 mm (0.39 in) long and the sepals 6–8 mm (0.24–0.31 in) long and greenish. Flowering occurs from April to November and the fruit is a linear-shaped pod 5–10 cm (2.0–3.9 in) long, 8–15 mm (0.31–0.59 in) wide, smooth, flattened and straight.[2][5]
This species was first described in 1825 by Augustin Pyramus de Candolle, who gave it the name Cassia artemisioides in his Prodromus Systematis Naturalis Regni Vegetabilis,[6] from an unpublished description by Charles Gaudichaud-Beaupré of specimens collected by Charles Fraser.[7] In 1989 Barbara Rae Randell raised the genus Senna in the Journal of the Adelaide Botanic Gardens, and transferred C. artemisioides to the new genus as S. artemisioides.[8][9] The Latin specific epithet (artemisioides) means "resembling Artemisia", a different group of plants often known as wormwood.[10]
Senna artemisioides is known as wormwood senna in the U.K.,[11] and as silver senna in the U.S., where it is an introduced species.[12][13]
As of May 2023, the names of six subspecies of S. artemisioides are accepted by the Australian Plant Census:
Four hybrid subspecies are also recognised by the Australian Plant Census:
A further two supspecies are named, but as of May 2023, not formally described:
Silver cassia is endemic to Australia, occurring in all mainland states and territories, and has ben introduced to California, the Canary Islands, Cyprus, India, Iraq, Spain and Zimbabwe.[13]
S. artemisioides is a recognized larval food plant for several species of butterfly and moth, including the small grass yellow, icilius blue, twig looper, blotched satin moth and bag-shelter moth.[60][61][62] Seed dispersal is aided by ants which eat the arils.[63]
Senna artemisioides adapts to a wide range of climatic conditions, but is susceptible to frost, especially when young. It prefers dry, well-drained sites with full sun. As an ornamental plant, it is propagated readily from seed, which should first be briefly immersed in boiling water.[64]
This species has gained the Royal Horticultural Society's Award of Garden Merit.[11][65]
Subsp. filifolia in Currawinya National Park
Subsp. helmsii in West MacDonnell National Park
Subsp. oligophylla near Winton
Subsp. quadrifaria near Kata Tjuta
Subsp. × artemisioides in the Australian National Botanic Gardens
Subsp. × coriacea in South Australia
Subsp. x petiolaris between Narrandera and Morundah
Subsp. x sturtii South of Leigh Creek
Senna artemisioides, commonly known as silver cassia, is a species of flowering plant in the family Fabaceae and is endemic to Australia, where it is found in all mainland states and territories. It is a small, woody shrub with silver-green leaves and yellow flowers.
