Cross Section of Wood Log Texture
It is the cross-section of a tree trunk or the tree grain patterns found on tree stumps.

If you are creating a large tree log, this texture may help you fill the ends of your timber.
 
Waxy Tree Trunk Bark Texture
It is a waxy tree trunk. Therefore, its bark has a layer of glossy coating.

If you are building a forest, this texture may increase your tree variations.
Realistic Tree Trunks or Bark Texture
It is a realistic pine tree trunk texture. The tree bark has some peeling effect.

If you are creating natural environment, don't miss this texture.
 
Stylized Tree Trunk or Bark Texture
It is a stylised pine tree trunk texture. The tree bark has the peeling effect.

If you are creating a stylised tree, these PBR maps may suit your need.
Old Wood Planks
These are old wood planks having prominent knots and moss on the tree barks.

The amount of planks, width of gaps, level of edge wear, amount and size of knots, amount of moss, dirt level etc. can be adjusted by the Substance SBSAR file.
Old Wood Texture
It is an old wood material which can be used to texture a wood plank or tree trunk.

The amount of knots, amount of moss, amount of dirt, colour contrast etc. can be managed by the Substance SBSAR file.
Stylized Tree Truck and Bark Texture
It is a tree truck texture. Tree barks and mosses can also be found. It is sort of stylized material.

The SBSAR file allows users to change the colors of the wood and mosses. The quantity of mosses can also be adjusted.
Leaf Vein Texture
It is a leaf vein texture comprised of thicker main veins and thinner side veins.

The SBSAR allows users to control the amount, thickness of the veins, contrast between main and side veins etc.
Leaf Generator
It is a leaf generator. Leaves have loads of variations in nature. Every leaf is unique in the globe.

The most powerful tool is the leaf generator in the format of sbsar. Then you can adjust the parameters to generate desired leaves according to your 3d environment.

Usually, 4-6 types of leaves should be enough to create the randomness in the CG world.

Of course, this leaf generator is absolutely free.
Bamboo Fence Texture
This fencing wall is made of bamboos. The color variation and micro surface is clearly shown. If you want it to be more green, you can adjust the hue.
Birch Tree Bark Texture
It is a tree bark texture. From its horizontal patterns and the peeling, we can tell it is a birch tree.
Tree Bark Texture
It is a tree bark texture. The bark's texture is prominent. It has cracks and bumpy surface. Moss can be found on the bark too.