Lactuca biennis is a North American species of wild lettuce known by the common names tall blue lettuce and blue wood lettuce. It is widespread across much of the United States and Canada from Alaska and Yukon south as far as California, New Mexico, and Georgia.[2]

Tall blue lettuce

Secure  (NatureServe)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Genus: Lactuca
L. biennis
Binomial name
Lactuca biennis
  • Sonchus biennis Moench 1794
  • Agathyrsus floridanus D.Don
  • Agathyrsus leucophaeus Beck
  • Cicerbita leucophaea Wallr.
  • Cicerbita spicata (Lam.) Beauverd
  • Galathenium multiflorum (DC.) Nutt.
  • Lactuca leucophaea A.Gray
  • Lactuca spicata (Lam.) Kuntze
  • Lactuca spicata Hitchc.
  • Lactuca terrae-novae Fernald
  • Mulgedium leucophaeum DC.
  • Mulgedium spicatum (Lam.) Small
  • Sonchus leucophaeus Willd.
  • Sonchus spicatus Lam.

Lactuca biennis is a biennial herb in the dandelion tribe within the daisy family growing from a taproot to heights anywhere from one half to four meters (20 inches to over 13 feet). There are deeply lobed, toothed leaves all along the stem. The top of the stem bears a multibranched inflorescence with many flower heads. Each head is just over a centimeter (0.4 inches) wide and has many whitish to light blue ray florets but no disc florets. The fruit is a mottled achene about half a centimeter (0.2 inches) long with a brownish pappus.

Lactuca biennis was described botanically in 1794, with the name Sonchus biennis, then transferred to Lactuca in 1940.[3]

References edit

  1. ^ The Plant List, Lactuca biennis (Moench) Fernald
  2. ^ Biota of North America Program 2014 state-level distribution map
  3. ^ "Plant Name Details for '". IPNI. Retrieved November 2, 2009.

External links edit