Lactuca muralis

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Lactuca muralis
Mycelis muralis.jpeg
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Asterales
Family: Asteraceae
Genus: Lactuca
Species: L. muralis
Binomial name
Lactuca muralis
(L.) Gaertn. 1791 not Fresen. 1832
Synonyms[1]
  • Prenanthes muralis L. 1753
  • Lactuca muralis Fresen
  • Mycelis muralis Dumort
  • Cicerbita muralis (L.) Wallr.
  • Phaenopus muralis (L.) Coss. & Germ.

Lactuca muralis (wall lettuce), or Mycelis muralis, is a perennial flowering plant of the genus Lactuca in the tribe dandlion tribe within the daisy family.[2][3]

Its chief characteristic is an open airy clumps of yellow flowers. Each "flower" is actually a composite flower, consisting of 4-5 petal-like flowers (strap or ray flowers), each approximately 5–7 mm in length. There are no disc flowers. Lactuca muralis grows about 2–4 feet tall with the lower leaves pinnately toothed and clasping.

Description[edit]

Mycelis muralis a2.jpg

Lactuca muralis grows from 25 to 150 cm tall, is slender and hairless. It often has purplish stems, and exudes a milky juice.

The lower leaves are lyre shaped, pinnate shaped. The lobes are triangular in shape. The upper leaves are stalkless, smaller and less lobed. All leaves are red tinged.[4]

The achenes are short beaked, spindle shaped and black. The pappus has simple white hairs,[5] the inner longer than the outer.

The flower heads are yellow, small with only 4-5 yellow ray florets.[6] 1 cm wide more or less, on branches 90 degrees to the main stem, in loose panicle.[7] It flowers from June until September.[8]

Distribution and Ecology[edit]

Lactuca muralis is a native of Europe but has invaded shady roadsides, paths and logged areas of the Pacific Northwest.[9] It has become naturalized in parts of Northern Ireland as long ago as 1913.[10]

It can be found in woodlands, especially Beech.[7] It is also found in calcerous soils, and walls.

References[edit]

  1. ^ Tropicos, Lactuca muralis (L.) Gaertn.
  2. ^ Parnell, J. and Curtis, T. 2012. Webb's An Irish Flora. Cork University Press. ISBN 978-185918-4783
  3. ^ Altervista Flora Italiana, Lactuca muralis (L.) Gaertn. includes photos and European distribution map
  4. ^ Blamey, Fitter, Fitter, Marjorie, Richard, Alistair (2003). Wild Flowers of Britain and Ireland. A & C Black - London. pp. 302–303. ISBN 0-7136-5944-0. 
  5. ^ Parnell, J. and Curtis, Y. 2012. Webb's An Irish Flora. Cork University Press. ISBN 978-185918-4783
  6. ^ Sterry, Paul (2006). Complete British Wild Flowers. HarperColins Publishers Ltd. pp. 212–213. ISBN 978-0-00-781484-8. 
  7. ^ a b Webb, D.A., Parnell, J. and Doogue. D. 1996. An Irish Flora. Dundalgan Press (W. Tempest)Ltd. ISBN 0 85221 131 7
  8. ^ Rose, Francis (1981). The Wild Flower Key. Frederick Warne & Co. pp. 390–391. ISBN 0-7232-2419-6. 
  9. ^ Turner and Gustafson, Wildflowers of the Pacific Northwest.
  10. ^ Hackney, P. Ed. 1992. Stewart and Corry's Flora of the North-east of Ireland. Institute of Irish Studies and The Queen's University of Belfast. ISBN 0 85389 446 9(HB)