Status: Exotic
Synonyms:
Lactuca integrata (Greneir & Godron) A. Nelson
Lactuca scariola Linnaeus, a later variant spelling
Lactuca serriola Linnaeus var. integrata Grenier & Godron
Lactuca serriola Linnaeus forma integrifolia Bogenhard
Lactuca serriola is a tall herb. It has milky juice and yellow ligulate florets.
The leaves are lobed and have small spines. The stems are leafy to the inflorescence
which is highly branched. Unlike Sonchus, the achenes are beaked at the summit. The
inflorescence on Lactuca serriola is longer compared to its width than that of Sonchus.
Lactuca serriola is found in disturbed areas and wasteground.
In Lactuca serriola, the laticifers are confined to a ring of vessels just outside the phloem and inside the epidermis. In other genera, such as Asclepias the laticifers are distributed throughout the stem. On cross section of a stem, the laticifers appear gray or black dots because the milk is opaque to light transmission in light microscopy. The major constituents of Lactuca latex are terpenoids. The latex is highly toxic in many species.
Please click on an image for a larger file.
Lactuca serriola, photo Russ Kleinman, Silver City, July 23, 2007
Lactuca serriola, growth habit, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, July 24, 2010
Lactuca serriola, closeup, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, July 24, 2010
Lactuca serriola, closeup of leaf, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, July 24, 2010
Lactuca serriola, achenes, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, July 24, 2010
Lactuca serriola, 1x macro of beaked achene, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, July 24, 2010
Lactuca serriola, inflorescence, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, August 6, 2010
Lactuca serriola, lateral of inflorescence, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, August 6, 2010
Lactuca serriola, stereoscopic view of stem cross section, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, July 12, 2022
Lactuca serriola, photomicrograph (compound scope) of stem cross section lightly stained with crystal violet, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, July 12, 2022
Lactuca serriola, higher power photomicrograph of stem cross section lightly stained with crystal violet, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, July 12, 2022
Back to the Index