

NOMENCLATURE
Japanese morning glories come in many different flower and leaf variations. Through history the Japanese have developed a particular sequence for describing the countless combinations of these variations going from leaf colour to flower size. There are some exceptions to this rule however most varieties will follow this sequence.
Leaf Colour
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Leaf Variegation
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Leaf Texture
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Leaf Shape
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Vine Habit
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Flower Colour
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Flower Pattern
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Flower Shape
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Flower Size
Common traits like a normal leaf texture or vine habit are usually not mentioned with exception of leaf shape, which is always mentioned. The flower size is usually only stated for particularly large- or small-sized blooms.
For example the variety pictured (Yuuzuki) below could be described as green, crystal variegated, orthodox leaves, brown, white margined, round blooms.

Sources:
- Kyushu Morning Glories Database | http://mg.biology.kyushu-u.ac.jp/Yoneda_DB/E/menu.html
- The World of Henka-Asagao | ISBN 978-4-89694-993-3 | http://akemimatsui.sakura.ne.jp/englishversion.html
- Elizr | https://elizr.wordpress.com/2011/03/04/descriptive-nomenclature-of-ipomoea-nil/