There are over 400 wild varieties of native clematis, in fact most countries in the temperate regions of the northern hemisphere and to some extent in the southern hemisphere have species of clematis. For example, C. alpina is found in eastern Europe and C. cirrhosa in Mediterranean countries, C. vitalba in Britain, C. montana in India, C. lanuginosa in China, C. patens in Japan, C. aristata in Australia, C. afoliata in New Zealand and C. virginiana in America.
During the 19th century that the stock for the large flowered clematis, which is so admired today was introduced from China, C. lanuginosa for example and C. patens from Japan. The Victorians took to clematis in a big way and the pioneering nursery of Jackmans once held a list of 343. Unfortunately the then little understood disease wilt, decimated the commercial stocks and it was not until after the second world war that nurseries were once more able to pursue serious large scale propagation. However the legacy of the Victorians does live on, many of the popular large flowered clematis available today come from the last century.
Tips on growing clematis can be found at this page and this page.