Rose comprises an outer fleshy layer, the hypanthium, which contains 5–160 "seeds" (technically dry single-seeded fruits called achenes) embedded in a matrix of fine, but stiff, hairs. Rose hips of some species, especially the dog rose ("Rosa canina") and rugosa rose ("Rosa rugosa"), are very rich in vitamin C, among the richest sources of any plant. The hips are eaten by fruit-eating birds such as thrushes and waxwings, which then disperse the seeds in their droppings. Some birds, particularly finches, also eat the seeds. While the sharp objects along a rose stem are commonly called "thorns", they are technically prickles—outgrowths of
Fruit tree forms trunk of less than . This is a traditional and popular form for apple trees. Bush trees are easy to maintain and bear fruit at a young age. Final height is between and , depending on which rootstock is used. Larger than the bush form, with trunks of or more. Standard trees can reach a total height of . They eventually produce high yields but, being large trees, are not easy to maintain. Similar to the bush form, although the main leader shoot is allowed to maintain its dominance, resulting in a pyramidal shape. A variant of the pyramid form