Flowers mostly orchids, poppies, primulas, marigold, daisies and anemones carpet the ground. In the United States, opium poppies and poppy straw are prohibited. Blue poppies do not produce opium. Opium poppies and marijuana are cultivated illegally in the Southern Federal District. There are many types of wildflowers, including rare 'spentzes' or cyclamen and poppies. Not all corn poppies that are available commercially have red flowers. They cultivate great quantities of opium poppies and marihuana around the area. Poppies and opium made their way around the world along the silk road. Wheat, cotton, poppies, melons and grapes were grown in the surrounding fields. The Wa traditionally practiced subsistence agriculture by cultivating rice, peas, beans, poppies and walnuts. Today Flanders Fields is home to tens of thousands of poppies. California poppies are grown near Palmdale. Poppies used as emblems on tombstones symbolize eternal sleep. At the foot of the Gumburanjon mountain blue poppies can be found. Other problems arose because of the Hmong's practice of harvesting poppies.