rachis

axis of a compound leaf or compound inflorescence

Arachis is a genus of about 70 species of annual and perennial flowering plants in the pea family (Fabaceae), native to South America, and was recently assigned to the informal monophyletic Pterocarpus clade of the Dalbergieae. At least one species, the peanut (Arachis hypogaea), is a major food crop species of global importance; some of the other species are cultivated for food to a small extent in South America. Other species such as A. pintoi are cultivated worldwide as forage and soil conditioner plants, with the leaves providing high-protein feed for grazing livestock and a nitrogen source in agroforestry and permaculture systems. Arachis species, including the peanut, are used as food plants by some Lepidoptera species, including the flame shoulder, nutmeg and turnip moth. https://en.wikipedia.org/wiki/Arachis