Lactuca canadensis
Encyclopedia
Lactuca canadensis is a species of wild lettuce
known by the common name Canada lettuce, or Canada wild lettuce. It is native to much of North America, especially in eastern regions, but it can be found all across the continent, having been introduced
widely. This is a generally biennial herb in the daisy family
growing from a taproot
to maximum heights between one half and two meters or more. The leaves are deeply lobed and occasionally toothed. The top of the stem bears an inflorescence
with many flower heads
, each up to a centimeter wide when open. The heads have many pale yellow ray florets. The fruit is a dark-colored achene
about half a centimeter long with a white pappus
.
Lactuca
Lactuca, commonly known as lettuce, is a genus of flowering plants in the daisy family Asteraceae. The genus includes about 100 species, distributed worldwide, but mainly in temperate Eurasia....
known by the common name Canada lettuce, or Canada wild lettuce. It is native to much of North America, especially in eastern regions, but it can be found all across the continent, having been introduced
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
widely. This is a generally biennial herb in the daisy family
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
growing from a taproot
Taproot
A taproot is an enlarged, somewhat straight to tapering plant root that grows vertically downward. It forms a center from which other roots sprout laterally.Plants with taproots are difficult to transplant...
to maximum heights between one half and two meters or more. The leaves are deeply lobed and occasionally toothed. The top of the stem bears an inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
with many flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
, each up to a centimeter wide when open. The heads have many pale yellow ray florets. The fruit is a dark-colored achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
about half a centimeter long with a white pappus
Pappus (flower structure)
The pappus is the modified calyx, the part of an individual disk, ray or ligule floret surrounding the base of the corolla, in flower heads of the plant family Asteraceae. The pappus may be composed of bristles , awns, scales, or may be absent. In some species, the pappus is too small to see...
.