Nitrogen-Fixing Crops - Peanut, Clover, Alfalfa, Rooibos, Cover Crop, Mucuna Pruriens, Vicia Faba, Lupinus, Fenugreek, Vicia Sativa, Cowpea (Paperback)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 39. Chapters: Alfalfa, Clover, Cover crop, Cowpea, Crotalaria juncea, Fenugreek, Lupinus, Melilotus, Mucuna pruriens, Peanut, Rooibos, Trifolium repens, Vicia faba, Vicia sativa. Excerpt: The peanut, or groundnut (Arachis hypogaea), is a species in the legume or "bean" family (Fabaceae). The peanut was probably first domesticated and cultivated in the valleys of Paraguay. It is an annual herbaceous plant growing 30 to 50 cm (1.0 to 1.6 ft) tall. The leaves are opposite, pinnate with four leaflets (two opposite pairs; no terminal leaflet), each leaflet is 1 to 7 cm ( to 23/4 in) long and 1 to 3 cm ( to 1 inch) broad. The flowers are a typical peaflower in shape, 2 to 4 cm (0.8 to 1.6 in) (3/4 to 11/2 in) across, yellow with reddish veining. Hypogaea means "under the earth"; after pollination, the flower stalk elongates causing it to bend until the ovary touches the ground. Continued stalk growth then pushes the ovary underground where the mature fruit develops into a legume pod, the peanut - a classical example of geocarpy. Pods are 3 to 7 cm (1.2 to 2.8 in) long, containing 1 to 4 seeds. Peanuts are known by many other local names such as earthnuts, ground nuts, goober peas, monkey nuts, pygmy nuts and pig nuts. Despite its name and appearance, the peanut is not a nut, but rather a legume. The domesticated peanut is an amphidiploid or allotetraploid, meaning that it has two sets of chromosomes from two different species, thought to be A. duranensis and A. ipaensis. These likely combined in the wild to form the tetraploid species A. monticola, which gave rise to the domesticated peanut. This domestication might have taken place in Paraguay or Bolivia, where the wildest strains grow today. Many pre-Columbian cultures, such as the Moche, depicted peanuts in their art. Archeologists have dated the oldest specimens to about 7,600 years, found in Peru. Cultivation spread as far as Mesoamerica, where the Spanish conquistadors found the tlalcacahuatl (Nahuatl = "peanut," whence Mexican Spanish, cacahuate and French, cacahuete) being offered for sale in the marketplace of Tenochtitlan (Mexico City). The plant was later spread worldwide by European traders.