The names and pictures of various leaves are as follows:

1. Ginkgo leaves

2. Maple leaves?

3. Elm leaves

4. Flat hazel leaf?

5. Lidou leaf

6. Cotinus

7. Lilac

8. Small-leaf poplar

9. Big-leaf poplar?

10. Oshima cherry

11. Topopodium tomentosa

12 , hawthorn leaves

13. creeper

14. pearl plum?

15. fuchsia leaves

16. elm leaf plum

17. Silk crabapple

18. Big-leaf boxwood

19. Red-leaf barberry

20. Forsythia leaves

The composition of leaves

A complete leaf consists of the following three parts:

Leaves - mostly broad and flat, suitable for receiving sunlight.

Petiole - supports the leaf and connects the leaf to the stem.

Stipules - protect young leaves. (Some plants have no stipules, and the stipules of some plants fall off very early.)

Veins

The veins of varying thicknesses that cover the leaves are called veins. There are two types of leaf veins:

Reticular veins - the leaf veins are intertwined to form a network. The leaves of most dicots have reticulated veins.

Parallel veins - leaf veins do not intersect with each other and are generally parallel. Most monocot leaves have parallel veins.

Types of leaves

Leaves can be divided into two types according to the number of leaves on the petiole:

Single leaves - only one leaf on each petiole. There is a blade.

Compound leaves - each petiole has many leaflets.

Shape of leaves

Oval: Shaped like an ellipse, with the widest middle and rounded tips and bases, such as camphor tree, rubber tree, mignonette, tea tree, black jujube tree, and cherry tree. Leaves of grass.

Heart-shaped: Shaped like a heart, with a wide, round and slightly concave base and a tapered apex, such as the leaves of sweet potato, morning glory, redbud, and hemp. If the heart shape is inverted, it is called an inverted heart shape, such as the small leaves of wood sorrel.

Palm-shaped: The leaves have three or five lobes, forming deep notches, and are shaped like a palm, such as the leaves of cotton, castor, grape, maple, and sycamore.

Fan-shaped: shaped like an unfolded folding fan, with a wide and rounded top, narrowing toward the base, like a ginkgo leaf.

Rhombus: The leaves are in an equilateral square shape, such as the leaves of rhombus and tallow tree.

Lanceolate: Also called lanceolate, the leaf base is wider, the apex is tapered, the length is about 3-4 times the width, such as peach, willow, bamboo leaves, if it is lanceolate Inverted, called oblanceolate, like the leaves of a small tiller.

Oval: shaped like a chicken egg, with a round and wide lower part and a slightly narrow upper part, like the leaves of mulberry and sunflower. If the oval is inverted, it is called obovate, such as the leaflets of magnolia and peanuts.

Round: shaped like a disk, with length and width nearly equal, such as nasturtium leaves

Needle-shaped: leaves as slender as needles, such as tabula rasa, masson pine, and whitebark pine of leaves.

Scale: shaped like scales, like the leaves of Platycladus orientalis.

Spoon-shaped: shaped like a spoon, with a rounded tip and narrowing toward the base, such as cabbage and plantain leaves.

Triangle: The base is wide and flat, and the three sides are nearly equal, such as buckwheat leaves.

The role of leaves

Leaves are the main organs of plants for photosynthesis and nutrient production. Release oxygen, provide food, and protect humans from wind and sun.

Leaves turn red: This is due to the increase in anthocyanins, and acidic leaves will turn red. There are "maple leaves, black cypress leaves, persimmon leaves" and so on.

Leaves turn yellow: This is because the chlorophyll is destroyed, leaving only lutein. Common ones include "laurel leaves, ginkgo leaves, poplar leaves, sycamore leaves", etc.