garden lettuce
Family
AsteraceaeScientific Name
Lactuca sativaSynonyms (former Scientific Names):
Lactuca scariola var. integrata
Habit
Lactuca sativa is an upright non-woody herb. It can reach a height of 3ft.
Leaves
The leaves are arranged in a basal rosette. They are typically about 15cm long and green. The leaf edges are usually entire (no lobes).
Identifying Characteristics
There are many different cultivars of Garden lettuce due to its ability to be a food crop. These different cultivate may have different characteristics (stiff or lobed leaves). Unlike other members of the Lactuca genus, the mid ribs of Latuca sativa are usually not prickly. Like other members of the Lactuca genus it emits a milky sap.
Flower Seed Head
The flowers are usually yellow, sometimes with a streak of purple. If grown as a crop you do not want the plant to flower or "bolt" because this usually means the crop will have a bitter or undesirable taste.
Seed Fruit
Seed heads are achenes (small dry fruits with one seed that do not split open). They have white beaks that attach to the achenes.
Where Found
While it can be considered a weed, it is commonly a crop planted for food.
Growth Habit
upright and nonwoody
Thorns or Spines
not present
Approximate Flower Diameter
Varies:
pencil,
dime,
nickle
Dominant Flower Color
yellow
Flower Symmetry
radial symmetery
Leaf Hairs
no hairs
Leaf Shape
oval
Leaf Arrangement
rosette
Leaf Margin
entire
Leaf Structure
simple
Leaf Stalk
none
Stem Hairs
no hairs
Stem Cross Section
round or oval
Milky Sap
present
Root Structure
taproot
Life Cycle
winter annual
Ochrea
not present
Plant Type
Herb