Salix cinerea

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Salix cinerea
Salix cinerea Habitus in spring Germany.jpg
Salix cinerea subsp. cinerea, Germany
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Malpighiales
Family: Salicaceae
Genus: Salix
Species: S. cinerea
Binomial name
Salix cinerea
L.
Salix cinerea map.png
Green: Salix cinerea subsp. cinerea
Orange: Salix cinerea subsp. oleifolia

Salix cinerea (grey willow; also occasionally grey sallow) is a species of willow native to Europe and western Asia.[1][2]

Salix cinerea seeds on a birch tree branch

It is a deciduous shrub or small tree growing to 4–15 m (13–49 ft) high. The leaves are spirally arranged, 2–9 cm long and 1–3 cm broad (exceptionally up to 16 cm long and 5 cm broad), green above, hairy below, with a crenate margin. The flowers are produced in early spring in catkins 2–5 cm long; it is dioecious with male and female catkins on separate plants. The male catkins are silvery at first, turning yellow when the pollen is released; the female catkins are greenish-grey, maturing in early summer to release the numerous tiny seeds embedded in white cottony down which assists wind dispersal.[1][2]

The two subspecies are:[1][2]

  • S. c. cinerea - central and eastern Europe, western Asia, shrub to 4–6 m (rarely 10 m) tall, with smooth bark, leaves densely hairy below with pale yellow-grey hairs, stipules large, persistent until autumn
  • S. c. oleifolia (Sm.) Macreight (syn. S. atrocinerea Brot.) - western Europe, northwest Africa, shrub or tree to 10–15 m tall, with furrowed bark, leaves thinly hairy below with dark red-brown hairs, stipules small, early deciduous

Some overlap in the distributions (not indicated in the map, right) occurs, with both occurring in a broad band north to south through France, and scattered specimens of S. c. cinerea west to Ireland, western France, and Morocco; scattered specimens of S. c. oleifolia occur east to the Netherlands. Specimens of S. c. oleifolia in southern Scandinavia are planted or naturalised, not native. Intermediate specimens also occur.[1][2]

Ecology[edit]

It usually grows in wetlands. The two subspecies differ slightly in requirements, with S. c. cinerea generally restricted to basic marshland and fen habitats, while S. c. oleifolia is less demanding, occurring in both alkaline marshes and acidic bogs and streamsides.[1]

Invasive species[edit]

S. cinerea is an invasive species in New Zealand and is listed on the National Pest Plant Accord, which means it cannot be sold or distributed.

References[edit]

  1. ^ a b c d e Meikle, R. D. (1984). Willows and Poplars of Great Britain and Ireland. BSBI Handbook No. 4. ISBN 0-901158-07-0.
  2. ^ a b c d Christensen, K. I., & Nielsen, H. (1992). Rust-pil (Salix cinerea subsp. oleifolia) - en overset pil i Danmark og Skandinavien. Dansk Dendrologisk Årsskrift 10: 5-17.