Description
Lactuca serriola | Prickly Lettuce
Prickly Lettuce, also commonly known as Wild Lettuce, Milk Thistle (not to be confused with other Milk Thistles), Horse Thistle, Compass Plant, Wild Oplum Lettuce, Tall Lettuce, and Scarole, is a relative of cultivated lettuce that is native to central and southern Europe. Note that ‘Wild Lettuce’ is a common name for several lactucarium-containing plants related to lettuce (Lactuca). (Lac means “milk,” referring to the sap characteristic of this genus.) Although Lactuca serriola is sometimes referred to as Wild Lettuce, it may also refer to:
- Lactuca canadensis (North America)
- Lactuca ludoviciana (NW America)
- Lactuca virosa (Southern Europe)
- Lactuca quercina (Eurasia)
- Lactuca floridana (North America)
Lactuca serriola is an annual or biennial herb that starts out as a basal rosette before it bolts with spreading branches and prickly leaves beneath the midrib and on the margins. Delicate light-yellow flowers bloom briefly before withering by late afternoon each day. The spear-shaped lancelot-shaped leaves clasp onto the stem. Plants are tall and erect, reaching up to 4-5 ft tall, and exude milky sap from the stems. When cut or torn, the plant secretes a milky juice known as lactucarium, which contains lactucin and lactupicrin, sesquiterpene lactones that provide the herbal properties Prickly Lettuce is known for. The plant parts are often processed and ingested for their mild herbal effects.
Similar to Wild Lettuce Lactuca virosa, only shorter and less spreading, and the leaves are more simple, being spear-shaped. L. Serriola is more pleasant to eat than L. virosa, which has a noticeably bitter flavor.
Commonly found growing in fields, banks, along roadsides, ditches, and waste places at elevations below 6500 ft.
Lactuca seeds germinate better with cooler temperatures, so it is recommended to start seeds naturally outdoors in late winter/early spring by lightly covering with soil, or if started indoors, don’t allow temps get too hot.
Type: Annual or biennial
Sun exposure: Full sun to part shade
Mature height: 4-5 ft
Mature width: 1-2 ft
Hardiness zones: 5-9
