Solanum elaeagnifolium

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Silverleaf nightshade
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Subclass: Asteridae Order: Solanales Family: Solanaceae Genus: Solanum Species: S. elaeagnifolium
Binomial name
Solanum elaeagnifolium Cav.

Silverleaf nightshade, Solanum elaeagnifolium, is a common weed of western North America, also found in South America.

It is a perennial 10 cm^[1] to 1 m in height. The stems are covered with short spines, ranging from very few on some plants to very dense on others. Leaves and stems are also covered with downy hairs that lie against and hide the surface, giving a silvery or grayish appearance.^[2]

The leaves are up to 15 cm long and usually only 0.5 to 2.5 cm wide, with shallowly waved edges (one of the distinctions from the closely related Carolina horsenettle, which has wider, more deeply indented leaves). The flowers, appearing from April to August, have five petals united to form a star, ranging from blue to pale lavender or occasionally white; five yellow stamens and a pistil form a projecting center. The plant produces glossy yellow, orange, or red berries that last all winter and may turn brown as they dry.^[2]

Its range is from Kansas south to Louisiana, and west through the Mexican-border states of the United States into Mexico, as well as Uruguay, Argentina, and Chile.^[3] Possibly it originated in North America and was accidentally introduced to South America^[4] or vice-versa.^[3] It can grow in poor soil with very little water. It spreads by rhizomes as well as seeds, and is common in disturbed habitats. Partly because of these characteristics, it is considered a noxious weed in 21 U.S. states and in countries such as Australia, Egypt, Greece, India, Israel, Italy, South Africa, and Zimbabwe.^[4][5] It is toxic to livestock and very hard to control, as rootstocks less than 1 cm long can regenerate into plants.^[6] (However, some eccentric gardeners encourage it as a xeriscape ornamental.)

Habit, unripe berries (green with stripes, center), and previous year's stems and berries (orange, upper left)

The Pima Indians used the berries as a vegetable rennet, and the Kiowa used the seeds together with brain tissue to tan leather.^[4]

Other common names include bull-nettle, prairie-berry, silverleaf-nettle, (white) horse-nettle, silver nightshade, silver-leaf bitter-apple (South Africa), satansbos (in Afrikaans), and trompillo (in Spanish).^[2][3]

[edit] References

1. ^ Theodore F. Niehaus, Charles L. Ripper, and Virginia Savage (1984). A Field Guide to Southwestern and Texas Wildflowers. Houghton Mifflin Company. ISBN 0-395-36640-2. 
2. ^ ^{a b c} Arthur Cronquist, Arthur H. Holmgren, Noel H. Holmgren, James L. Reveal, Patricia K. Holmgren (1984). Intermountain Flora; Vascular Plants of the Intermountain West, U.S.A., vol. 4. Subclass Asteridae (except Asteraceae). The New York Botanical Garden. ISBN 0-231-04120-9. 
3. ^ ^{a b c} GRIN/NPGS Taxonomy Information, accessed 16 June, 2006
4. ^ ^{a b c} Silver Nightshade from the Washington State Noxious Weed Control Board, accessed 16 June, 2006
5. ^ Oregon Invasive Species Action Plan, accessed 16 June, 2006
6. ^ Solanum genus part 2 from the California Department of Food and Agriculture's Encycloweedia, accessed 16 June, 2006