Walnut is a kind of walnut plant.

Walnut is a deciduous or semi-evergreen tree or small tree, which has resin and fragrance and is covered by orange-yellow shield-shaped round glands. Buds bare or with bud scales, usually 2-3 overlapping ones born in leaf axils. Leaves alternate or sparsely opposite, without stipules, odd or sparse even pinnate compound leaves; Leaflets are opposite or alternate, with or without petioles, pinnately veined, with serrated edges or sparse entire.

Flower unisexuality, monoecious, wind-borne. Inflorescence unisexual or sparsely bisexual. Male inflorescences are often long inflorescences, solitary or in bundles, born in leaf axils or bud axils; Or born on leafless branchlets, below the terminal female inflorescence, * * * together form a drooping panicle bundle; Or born at the top of the new branch, under the terminal bisexual inflorescence (female inflorescence at the lower end and male inflorescence at the upper end), forming an upright umbrella inflorescence bundle. Male peanuts in leaf axils of 1 indehiscent or 3-lobed bracts; Bracteoles 2 and tepals 1 to 4, attached around the flat receptacle inside the bracts, or without bracteoles and tepals; Stamens 3-40, inserted in receptacle, arranged in multiple whorls 1, filaments extremely short or nonexistent, free or slightly healed at base, anthers hairy or hairless, 2-loculed, longitudinally dehiscent, connective not reaching, or developed but more or less protruding from the top of anthers. Female inflorescence is spike-shaped, terminal, erect, with a small number of female flowers, or pendulous inflorescence, with many female flowers. Female flowers are born in the axils of 1 undivided or 3-lobed bracts, and the bracts leave the ovary or fuse with two bracteoles to attach to the lower end of the ovary, or leave two bracteoles to attach to the lower end of the ovary, or form a pot-shaped involucre with receptacle and bracteoles to attach to the ovary; 2 to 4 perianth segments are attached to the ovary, 2 on each side and 4 on the midline, including both sides; The pistil is 1, which consists of two carpels and the ovary is lower. At first, it is 1, and then the cardinal number is 1 or 2, forming an incomplete 2-chamber or 4-chamber. Style is short, stigma 2-lobed or 4-lobed. Placenta is a short column at the base of ovary, which is free at first and then heals into an incomplete diaphragm. There are 1 upright ovule without suspensor at the top.

Fruit develops from bracteoles and perianth segments or only perianth segments, or from involucre and ovary into drupe-like pseudodrupe or nut-like; Exocarp is fleshy or leathery or membranous, and does not crack or irregularly crack at maturity, or 4 ~ 9 petals crack; Endocarp (stone) is formed by ovary itself, hard and bony, 1 room, and there is an incomplete diaphragm of 1 or 2 bones at the indoor base, thus forming an incomplete 2 or 4 rooms; Endocarp and incomplete diaphragm have or do not have various notches (holes) on the cross section of the wall. The seed is large, completely filling the fruit chamber, with seed coat 1 membranous and no endosperm; Radicle upward, cotyledons hypertrophy, fleshy, usually 2-lobed, base tapering or heart-shaped, embryo small, usually covered by peltate glands.

Physical characteristics of walnut;

Wood properties: Walnut furniture has luster and texture until it is slightly staggered; Thin structure; Soft to medium quality; In strength; Dry shrinkage; Rotary cutting and planing are easy; Paint, adhesive, nailing, dyeing and other properties are good. Slight wear resistance, quick drying and good quality. The density is 640 kg/m3.

Structure: The structure of wood itself is more detailed. In this way, the more delicate wood feels like baby's skin, while some relatively rough wood feels rough like old people's skin and doesn't feel very comfortable. Therefore, walnut furniture itself is very detailed, and many people like it after seeing it.

Strength: Walnut has high strength, which means it is hard. This kind of wood has strong plasticity and is convenient for merchants to process, so some furniture and doors may choose this kind of wood, so there are various products on the market, which have very good performance in the use process, and this property can also improve the service life.

Wood color: Walnut sapwood is white, heartwood is light brown to dark chocolate, with occasional purple and dark stripes. It is possible to provide a plate with deep sapwood after steam treatment or without steam treatment.

Main value

Furniture, cabinets, interior decoration of buildings, advanced joinery products, doors, floors and panels are all ideal materials to match light-colored wood.

Walnut is widely used in Asia, Europe and America. Walnuts can be used to make sporting goods. Walnut has been widely used to make furniture since14th century. One of the reasons why walnuts are popular is their light weight and rich color changes. The heartwood of walnut is usually fawn to brown, and the color and stripes usually change with the origin. Walnuts are usually grayish brown with obvious dark or black stripes, and the color will fade with time.

Machining characteristics

Walnut is easy to process by hand and mechanical tools. Suitable for nailing, auger drilling and gluing. It can be painted and dyed for a long time, and can be polished to a special final effect. Drying is very slow, so care should be taken to avoid reducing the loss after drying in the kiln. Walnut has good dimensional stability and is not easy to deform, so it is a superior material for making furniture.