It also includes three types: loose leaf, erect leaf and ball (that is, three varieties except stem lettuce in botanical classification): 1. Wrinkled leaf lettuce: also known as loose leaf lettuce (loose leaf lettuce).
The main feature of this variety is that it does not knot.
Basal leaves are oval and petioles are long.
The leaf margin is wavy or deeply split, and the leaves are shriveled. The clustered leaves are like big flowers, and the leaf colors are green, yellow-green, light purple and deep purple, which are the main signs to distinguish varieties.
Most of the varieties of wrinkled lettuce have beautiful foliage, bright and colorful colors, and are good materials for decorating meals, with medium quality.
Most of the original varieties of leaf lettuce in China, Guangdong, Changchun, Jilin belong to the variety of leaf lettuce. In recent years, a few other new varieties of leaf lettuce have been introduced, but the planting area is small.
Lettuce crispate
2. Lettuce: also known as lettuce.
The main feature of this variety is that its terminal leaves form a bulb, which is spherical or oblate, similar to the shape of cabbage.
It is mainly eaten by leaf bulbs, and its texture is particularly crisp and tender, which is incomparable to other leaf lettuce varieties.
Lettuce with soft leaves
There are many varieties in this variety, which can be divided into four types according to the texture of leaves: wrinkled lettuce, butterball lettuce, upright lettuce and Latin lettuce (Zhejiang Agricultural University, 1985).
Their characteristics are: (1) lettuce with wrinkled leaves (lettuce with soft leaves) has large bulbs, crisp texture, compact bulbs, green outer leaves and white or light yellow bulbs.
The growth period is about 90 days, which is suitable for open cultivation.
Representative species include the Great Lakes of the United States.
(2) Buttermilk lettuce (crisp-leaf lettuce) has small and loose leaves, wide leaves, slight shrinkage, soft texture and short growth period, which is suitable for protected cultivation.
The representative varieties are Great Boston in the United States.
(3) The bulbous leaves of erect lettuce are conical, the outer leaves are dark green or light green, the middle ribs are thick, the bulbous leaves are slender and light green, and the surface is rough.
(4) Latin lettuce forms loose leaf bulbs (similar to butterball lettuce) with slender leaves (similar to upright head lettuce).
3. Upright Lettuce: Also known as Upright Lettuce.
The main characteristics of this variety are long and narrow leaves, vertical growth, whole or serrated leaves, thick leaves, coarse meat and poor flavor.
This kind of lettuce does not form a leaf ball, but its heart leaves are rolled into a cylinder, which is also called straight lettuce.
Upright lettuce