Aestivation (botany)
Aestivation or estivation, refers to the positional arrangement of the parts of a flower within a flower bud before it has opened. Aestivation is also sometimes referred to as praefoliation or prefoliation, but these terms may also mean vernation: the arrangement of leaves within a vegetative bud.
Aestivation can be an important taxonomic diagnostic; for example Malvaceae flower buds have valvate sepals, with the exception of the genera Fremontodendron and Chiranthodendron, which have sometimes been misplaced as a result.
The terms used to describe aestivation are the same as those used to describe leaf vernation.[1] Classes of aestivation include:
- imbricate - overlapping
- contorted or twisted - every petal or sepal is outside its neighbour on one margin, and inside its neighbour on the other margin
- cochleate - spirally twisted
- contortiplicate - contorted and also plicate
- quincuncial - with five parts, where two petals or sepals are outside all others, two inside all others, and the fifth is outside on one margin and inside on the other
- contorted or twisted - every petal or sepal is outside its neighbour on one margin, and inside its neighbour on the other margin
- crumpled
- decussate
- induplicate - folded inwards
- open - petals or sepals do not overlap or even touch each other
- reduplicate - folded outwards
- valvate - margins of adjacent petals or sepals touch each other without overlapping.
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Lilac (Syringa vulgaris), valvate aestivation
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Phlox (Phlox paniculata), contorted aestivation
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Vinca minor, contorted aestivation
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Ipomoea, contortiplicate aestivation
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The corolla of Merremia tuberosa was contortiplicate in the bud
References [edit]
- ^ Hickey, M.; King, C. (2001). The Cambridge Illustrated Glossary of Botanical Terms. Cambridge: Cambridge University Press,.
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