Large quantities of yellow glacier lily roots would be dried for later use or for trade. In addition, Camas used to be an important staple across Southern BC. Access to and the use of camas by Interior communities was made possible through trade from the peoples of what is now northern Washington. Large camas beds on southern Vancouver Island and the Gulf Islands were kept free of invading plants through regular clearing and burning. Traditionally, for the Kwakwaka'wakw village of Haada, trade in root vegetables (springbank clover (Trifolium wormskioldii), silverweed and northern riceroot (Fritillaria camschatcensis) with the Nuxalk and Heiltsuk was an important part of their regional economy. For thousands of years, over 30 types of berries have been harvested in traditional territories of British Columbia from early summer (soapberries, salmonberries, thimbleberries), to late fall (cranberries, crabapples), depending on the berry type and location. Berries were an important part of traditional knowledge. First Nations peoples were shown when the berries were ripe by listening and observing the changes in the animals and plants. The wild rose blooming announced the readiness of sxusem (soapberries) for Nlaka'pamux. The song of Swainson's thrush heralded the ripening of salmonberries for Tlingit, Tsimshian, Haida, Haisla, Oweekeno, Squamish, Nuu-chah-nulth, Ditidaht, and Northern Straits Salish people. Soapberries hold a high place and have a lasting taste memory. Saponins in the soapberries allow them to be whipped up into a frothy 'ice cream' which was traditionally eaten in British Columbia. So-called 'Indian' ice cream has often been mixed in with dried meat, or may be served alone. Soapberries have been mixed with sugar and added to carbonated water as an alternative to pop. Berries contain vitamin C, fibre, and carbohydrates. North Coast: bunchberries, blueberries, cloudberries, cranberries, crowberries (mossberries), currant, gooseberry, blue elderberry, red huckleberry, salmonberry, thimbleberries (Rubus parviflorus), black hawthorn (jam/jelly), crabapple (jam/jelly), oregon grape (jam/jelly), soapberries, strawberry  South Coast: cranberries, red huckleberries, salmonberries, thimbleberries, strawberry, oregon grape (jam/jelly), cherries, currants, blackberries, gooseberries, soapberries, strawberries  Southern interior: blueberries, cranberries, currants, blue huckleberries/bilberry (Vaccinium deliciosum), blue elderberry, soapberries, black raspberry, strawberries  Northern interior: blueberries, cranberries, blue huckleberries/bilberry, crowberries (mossberry), currants, bunchberries, cloudberries.