Chapter 15 Crops

Chapter 15: Crops. Crops originated from all over the world, but primarily from areas close to the tropics (between the equator and 40o N or S). Some important families of flowering plants include: 1. Laurel family (Lauraceae): have no petals but 6 sepals that may resemble petals. They were used in ancient Greece to crown the winners of the Olympic games. Spices such as cinnamon and camphor are in this family, as are avocadoes. 2. Poppy family (Papaveraceae): have milky sap and produce several drugs. Opium poppies are a major cash crops, particularly in Afghanistan. Opium The pain killers Mophine and Codeine are from poppies, as is heroin which was originally sold as a cough suppressant. 3. Mustard family (Brassicaceae): have four petals in the shape of a cross. Apart from mustard, this includes cabbage, broccoli, brussels sprouts and turnip. The wild plant "Shepherd's purse" is in this family. 4. Rose family (Rosaceae): have a cup shaped flower with many stamens. The stems often have prickles. It includes cultivated roses, but also many fruits such as cherries, plums, apricots, apples, pears, strawberries and blackberries. 5. Legumes (Fabaceae): have flowers with a curved keel on the bottom and a large banner petal on top. Cultivated legumes include pea, beans and peanuts. Legumes have special bacteria in their roots that produce nitrate: this was traditionally used in crop rotation. 6. Spurge family (Euphorbiaceae): have separate male and female flowers. Crops include cassava, a staple of tropical areas. Rubber trees are also in this family. 7. Mint family (Lamiaceae): stems are square in cross section. Many herbs like sage, oregano, mint, basil and menthol are in this family. Landscape plants in this group include Coleus. 8. Nightshade family (Solanaceae): have their petals fused into a tube. Many are poisonous, such as deadly nightshade. Crops in this family include tobacco, tomatoes, peppers and potatoes. 9. Pumpkin family (Cucurbitaceae): are vines that have tendrils. Watermelons, pumpkins, squash and cucumbers. 10.Grass family (Poaceae): are wind pollinated, with inconspicuous flowers, and feathery stigmas. This family provides most of our food, either directly as wheat, barley, oats, corn and rice, or indirectly as food for cattle or sheep.