Home | > | List of families | > | Asteraceae | > | Lactuca | > | serriola |
Synonyms: | |
Common names: | Prickly lettuce (English) |
Frequency: | Common in urban centres, e.g. Harare, but not generally seen elsewhere |
Status: | Introduced |
Description: |
Erect annual or biennial herb, to 2.5 m with a leafy stem. Leaves sessile, runcinate-pinnate (in ours - f. serriola) or unlobed (f. integrifolia), the lamina often held in a vertical plane. Inflorescence a panicle; flowers small (involucre 6-8 mm long), yellow. Achene 3 mm, with a long beak equalling or exceeding the achene in length. |
Notes: | Two distinct forms of this species are known. Only f. serriola has been recorded for Zimbabwe. The name Compass plant refers to the leaves which are held vertically and tend to be oriented in a north-south direction, hence facing east-west. Papers by Werk and Ehleringer (1984 and 1986) discuss this feature and its implications for the levels of solar radiation, water loss and the species’ reproduction. |
Derivation of specific name: | serriola: in ranks, probably referring to the leaves which are held in two vertical ranks. |
Habitat: | Frequent in disturbed places, often on road verges. |
Altitude range: (metres) | |
Flowering time: | Jul - Oct |
Worldwide distribution: | Native of Europe extending to Siberia and NW China and N Africa. |
Zimbabwe distribution: | W,C,S |
Growth form(s): | |
Endemic status: | |
Red data list status: | |
Insects associated with this species: | |
Spot characters: | Display spot characters for this species |
Images last updated: | Saturday 8 September 2007 |
Literature: |
Mapaura, A. & Timberlake, J. (eds) (2004). A checklist of Zimbabwean vascular plants Southern African Botanical Diversity Network Report No. 33 Sabonet, Pretoria and Harare Page 26. Pope, G.V. (1992). Compositae Flora Zambesiaca 6(1) Pages 204 - 207. (Includes a picture). Prince, S.D. & Carter, R.N. (1977). Prickly lettuce (Lactuca serriola L.) in Britain. Watsonia 11 Pages 331 - 338. (Includes a picture). Setshogo, M.P. (2005). Preliminary checklist of the plants of Botswana. Sabonet Report no. 37. Sabonet, Pretoria and Gaborone Page 35. Werk, K.S. & Ehleringer, J. (1984). Non‐random leaf orientation in Lactuca serriola L. Plant, Cell & Environment 7(2) Pages 81 - 87. Werk, K.S. & Ehleringer, J. (1986). Effect of non‐random leaf orientation on reproduction in Lactuca serriola L. Evolution 40(6) Pages 1334 - 1337. |
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