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extreme example is 'Shirotae'. Such serration, called aristate, is an identification aid. Teeth, or bristles, can also have a small gland at the top, which usually can be seen only with a magnifying lens. Most garden forms show a few such glands on the lower half of the leaf blade, but sometimes they are set on the tip of every tooth, up to the top of the leaf. The glands can be white, light pink, or red. It is characteristic of such cherries as 'Choshu-hizakura', 'Najima-zakura', and 'Yae-murasaki-zakura' that all teeth have dark red glands. This has to be ascertained on the young leaves that have only just unfolded; the glands disappear quickly with the expanding of the leaves. The size of the mature (fully developed) leaf is not an identification aid because it is too variable. Moreover, in the flowering season when we are busy studying the flowers, hardly any developed leaves are found. Leaf size is therefore not discussed in the descriptions of the cultivars. Generally, the
Figure 44 Fine, single serration (left) such as seen with leaves of the Japanese mountain cherry (Prunus serrulata var. spontanea), and bristled (aristate) serration (right) as seen with leaves of many Prunus serrulata cultivars.