Page 137
The serration of the sepals is an important classification key and is often easily noticed on buds just before they open. 'Pink Perfection' has serrated sepals that readily distinguish it from the similar but nonserrated 'Daikoku'. 'Fugenzo' has a distinct serration halfway up the sepals, but not at the base and not at the tip. Prunus Ă—subhirtella and P. pendula mix hairs and teeth at the edge of the sepal. Some garden forms do not show a clear serration, yet they cannot be described as unserrated. Such sepals have only a few teeth and again form a constant cultivar characteristic that helps in classifying cultivars such as 'Washino-o'. Some garden cherries, such as 'Kiku-shidare-zakura' and most other chrysanthemum-flowered forms, show accessory sepals; among the five main sepals are five or more smaller, extra sepals. Calyx Like the sepals, the calyx is a very reliable characteristic for identifying cherries. Its shape may vary among Prunus serrulata cultivars from broad and disk-shaped (as in 'Kikuzakura'), or a more narrow funnel-shape (as in 'Fugenzo'), to a tightly campanulate calyx (as in 'Jo-nioi'). More or less campanulate or funnel-shaped calyxes are found between the extremes. Forms of P. pendula or the closely related P.Ă—subhirtella have an urceolate (pitcher-shaped) calyx, which has a globular base with a narrow cylindrical mouth, widening again at the edge with its five sepals and petals. The urceolate calyx of these cherries is pubescent. The calyx of P. incisa is funnel-shaped and can be so long that it becomes quite tubular. All single-flowered and some semi-double-flowered cultivars have a thickening at the downward end of the calyx where the ovary is attached. This swelling is often lacking in the double-flowered cherries because the ovary is hardly developed; instead of normal pistils there are sometimes leaflike carpels. The swelling makes for a distinct transition from calyx to pedicel, which is a useful classification feature to separate cultivars that show such a swelling from those that lack a swelling and thus do not have a distinct transition between pedicel and calyx. Where the calyx narrows to the pedicel, the surface can be rumpled, as happens with the flowers of 'Pink Perfection'. The calyx of most Prunus serrulata cultivars is glabrous and green with a slight purplish hue. The calyx of 'Takasago' is pubescent like the spring cherries P.Ă—subhirtella and P. pendula. The size of the calyx is given in the