Red hemp is a dicotyledonous plant. The cotyledons are kidney-shaped, horizontally open when they come out of the ground, and the petiole is short. 5-7d later, the leaf buds are seen at the growth point, and then the true leaves extend out from the lateral side of the cotyledons, which are about 1.5cm long. Leaves alternate, leaf type is divided into two kinds of split leaf and full leaf, cultivated red hemp split leaf type accounted for 60.5%, full leaf type accounted for 39.5%, the wild red hemp is a great part of the split leaf type. Split-leaf type and there are y split leaves and split leaves, the shape of its leaflets are long ovate (such as green skin 3), lanceolate (such as 85-88), pinnately split shape (such as 85-237), nearly ovate (such as 85-133) and so on. The whole leaf shape is ovoid (e.g., K292), suborbicular (e.g., 85-258), and subovate (e.g., 85-152). Leaves are green or dark green, leaf margin serrations are absent (e.g., 85-88), dense (e.g., 85-237), sparse (e.g., 85-210), deep (e.g., 85-247), shallow (e.g., 85-152), etc., and a few varieties of leaf margins are set with purple marks. Palm reticulate veins, leaf vein color mostly light green (e.g., Lapis 3), a few slightly red (e.g., NA128) and purplish red (TA191).
Red hemp leaf type
Leaf size and the number of leaves per plant varies according to varieties, cultivation conditions and growth stages, the maximum peak period of leaf, split-leaf type for the length of 16-22cm, width 20-24cm, full-leaf type for the length of 15-18cm, width 12-15cm, large-leafed varieties such as J-1-113, SD131, C2032, etc.. The number of leaves on a single plant is generally about 100 for medium and late-maturing varieties, and up to 400 when planted sparsely. The number of leaflets in the leaf sequence of cleft-leaved varieties shows regular changes with plant growth. Seedling heart-shaped leaves, 3-lobed mid-birth, after the growth of 5, 7-lobed palmate leaves, mid- and late-birth, the growth of leaves for the 5, 3-lobed palmate leaves, the end of fertility for the lanceolate leaves, but early maturing and extra-early maturing plants in the growth process does not generally appear 7-lobed palmate leaves. The production of "southern seeds planted in the north" varieties, due to the prolongation of the nutrient growth period, the harvest usually does not appear lanceolate leaves. Full-leafed varieties have only heart-shaped and lance-shaped leaves.
The petiole length is 22-30cm for the split-leaf type, 17-28cm for the full-leaf type, and 13-15cm for the short petiole variety. The petiole color is consistent with the stem color, and the colors are green, slightly reddish, light red, red and purple. The angle between the petiole and the stalk is 35° to 60°, and 40° to 50° for cultivated types. The petiole has sparse small spines.
The wild red hemp leaves have more diversity in leaf shape, leaf margin, size, surface, color, etc., generally smaller leaves, darker leaf color, cleft leaf type, table more tomentose, and there are great differences between types.
Leaf shape changes in different fertility stages of the split-leaf type red hemp