Most commonly, gourds are the product of the species Lagenaria siceraria (the calabash or African bottle gourd), native to Africa, and at a very early date spread throughout the world by human migrations. This species may be the oldest plant domesticated by humans.
Gourds can be used as a number of things, including bowls or bottles. Gourds are also used as resonating chambers on certain musical instruments including the berimbau and many other stringed instruments and drums. Instruments of this type are fairly common to the Caribbean. Gourds are also used as a tool for sipping yerba mate by means of a bombilla, in Chile, Uruguay, Argentina, Paraguay and Brazil, where it is called "cuia" (kOOya). Birdhouse gourds are commonly used in southern USA for group housing for purple martins, which reputedly help control mosquitoes. "Gourd" can also refer to the live fruit before it is dried, or to the entire plant that produces that fruit.
Day-blooming gourds are pollinated in the same way as squash, and commercial plantings should have bee hives supplied. Night blooming gourds are pollinated by moths, which are normally present in adequate supply unless they are drawn off by night lights in the area.
Gourds were the earliest plant species domesticated by humans and were originally used by man as containers or vessels before clay or stone pottery, and is sometimes referred to as "nature's pottery". The original and evolutional shape of clay pottery is thought to have been modeled on the shape of certain gourd varieties.
Recent DNA analyses of bottle gourds found at several sites throughout the Americas has resolved a long-standing mystery, as well as adding evidence establishing the early date of domestication of the bottle gourd plant. As the bottle gourd is native to Africa and not the Americas, archeologists previous to the analyses could only speculate that it had probably floated across the Atlantic. But upon examining the DNA, they found that the American samples most closely matched the varieties of the African bottle gourd found in Asia, not Africa. It was thus concluded that the bottle gourd had been deliberately brought by early Asian migrants to the Americas, at a time pre-dating the domestication of plants for food anywhere on Earth.
In addition to utilitarian uses, gourds have seen other functions throughout history in various cultures. Very early specimens of squash shells discovered (for example, in Peru) indicate the use of squashes as means of recording events of the time. In North America, the carving of pumpkins and some other squashes into Jack-o-Lanterns is a popular cultural activity during Halloween.
Generally, gourds are used more for utilitarian uses than for food. Only a few varieties are harvested for consumption, mostly in Asia. The shell of the gourd, when dried, has a wooden appearance. Gourd "wood" is essentially cellulose that has no grain, varying in thickness from paper-thin to well over an inch. Drying gourds, which takes months in some cases, causes the internal contents (seeds and fruit matter) to dry out completely, although seeds are often still capable of germination. For the uninitiated, cutting open a dried gourd (with a craft knife or miniature jig-saw) can present hazards; the resulting dust is extremely fine and can cause respiratory problems, and requires adequate protection. A bitter taste or smell is typically evident when opening a gourd that is not completely dry inside.
It has also been found that gourd skins were used to replace missing portions of skulls in Neolithic times as part of surgery. This is seen as evidence of prostheses made of very fine gold sheet and gourd skins, which were inserted in the skull under the skin or to cover the hole left by the operation.
The harder outer surface lends the gourd to a wide variety of creative appeals, including carving, pyrography, sculpture, basketry, masks, musical instruments, and more. A growing following has emerged in the United States and other Western countries for Gourd art and craft-related purposes. There are many different types of decorative gourds. They include spoon gourds, spoon bicolor, orange warted, and striped pear. The spoon gourd ripens from the top to the bottom. A baby spoon gourd is green and as it grows it changes color. A yellow color overlaps the green and creates a two colored gourd. For decorative purposes the harvester can harvest the gourd early, when it has two colors.
White gourd juice is also a common beverage retailed in China and Chinese outlets outside China. It has a unique, smokey taste.