Root

In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. However, roots can also be aerial or aerating (growing up above the ground or especially above water). Furthermore, a stem normally occurring below ground is not exceptional either (see rhizome). Therefore, the root is best defined as the non-leaf, non-nodes bearing parts of the plant's body. However, important internal structural differences between stems and roots exist.

The first root that comes from a plant is called the radicle. The four major functions of roots are 1) absorption of water and inorganic nutrients, 2) anchoring of the plant body to the ground, and supporting it, 3) storage of food and nutrients, 4) vegetative reproduction. In response to the concentration of nutrients, roots also synthesise cytokinin, which acts as a signal as to how fast the shoots can grow. Roots often function in storage of food and nutrients. The roots of most vascular plant species enter into symbiosis with certain fungi to form mycorrhizae, and a large range of other organisms including bacteria also closely associate with roots.

Tree

In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a woody trunk and branches as a way to tower above other plants to compete for sunlight. In looser senses, the taller palms, the tree ferns, bananas and bamboos are also trees. Trees tend to be long-lived, some reaching several thousand years old. The tallest known tree, a coast redwood named Hyperion, stands 115.6 m (379 ft) high. Trees have been in existence for 370 million years. It is estimated that there are just over 3 trillion mature trees in the world.

A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier. Below the ground, the roots branch and spread out widely; they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, the branches divide into smaller branches and shoots. The shoots typically bear leaves, which capture light energy and convert it into sugars by photosynthesis, providing the food for the tree's growth and development. Flowers and fruit may also be present, but some trees, such as conifers, instead have pollen cones and seed cones; others, such as tree ferns, produce spores instead.

Tree Roots

Tree Roots is an oil painting by Vincent van Gogh that he painted in July 1890 when he lived in Auvers-sur-Oise, France. The painting is an example of the double-square canvases that he employed in his last landscapes.

Background

Van Gogh spent the last few months of his life in Auvers-sur-Oise, a small town just north of Paris, after he left an asylum at Saint-Rémy in May 1890. The painting is considered by some to be his last painting before his death late July 1890.

Jan Hulsker considers it the most original of his double-square canvases. The viewer thinks he can identify tree roots and trunks, but is hard put to identify the subject as a whole. Van der Veen and Knapp comment that in this painting, as also in Undergrowth with Two Figures, the painting itself and not the subject is pre-eminent, heralding abstract painting and German expressionism.

As far back as 1882, while at The Hague, van Gogh had made a study of tree roots, Study of a Tree (below), which he had completed at the same time as a larger version (now lost) of Sorrow. In a letter to his brother Theo, van Gogh said that he wanted to express something of life's struggle in these drawings. It is not known whether he had returned to the same thoughts with his 1890 Tree Roots. The letters give no hint and the colours are perhaps too bright for such sombre thoughts.