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'Multiplex'), a cultivar of varied origin, is also used. One of its parents is the Chinese P. pseudo-cerasus. The triploid 'Mazakura' produces aerial roots and is easily propagated from cuttings. Most garden cherries and all forms of P.Ă—yedoensis are propagated on either of these stocks. Prunus Ă—subhirtella from seed is used in Japan as stock onto which are grafted its cultivars 'Jugatsu-zakura' or 'Autumnalis', the weeping forms of P. pendula, and forms related to the Fuji cherry (P. incisa). Finally, forms related to the Japanese mountain cherry (P. serrulata var. spontanea) are set on seed-grown stock of their parent species. Cultivars are always grafted low on the stock, which only serves as a temporary nurse plant: plants are deeply planted until the propagated cultivar has made its roots. Garden cherries are grown always on their own roots in Japan; for studying tree shapes and growth characteristics unaffected by rootstock influence, one has to visit the collections in their home country. In America and Europe the wild European cherry, the mazzard or gean, Prunus avium Linnaeus, is a perfectly hardy, easily propagated stock for grafting most garden cherries. It gives the grafted cultivar a tree of regular shape with a growth that is more vigorous than the cultivar could show on its own roots (see Arends 1990). Sometimes P. avium stock is grown from seed selected for forestry purposes; it might even be available from individually selected virus-free seed-parent trees. In this case the seed was selected for growth and production, and cherries grafted onto trees from this seed of P. avium seem to be pumped up to an almost unnatural vigor that soon exhausts the tree. This might be desirable for commercial reasons because it quickly gives a salable tree: even an instant standard cherry is obtained when the cultivar is grafted on an established stem. An older 'Kanzan', however, when grafted on a forest-production mazzard stem, looks like a sturdy column that holds a group of slender branches as in a fist. Such a tree image, as we would see in a kindergartner's drawings, might have its appeal to the post-modernist, but it is not very cherrylike, and a slower growing tree that yields a more natural shape is preferred. Weeping cherry cultivars of Prunus pendula can be trained on their own stem with some patience, but grafting on established stems is advised when growing large numbers of plants. Good stems must be selected from among the seed-grown young trees. In the strictest sense, stock grown from seed does not give a uniform nursery product as each plant has its unique characteristics. When a uni-