Anthesis is the period during which a
flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
is fully open and functional. It may also refer to the onset of that period.
The onset of anthesis is spectacular in some species. In ''
Banksia
''Banksia'' is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes, and fruiting "cones" and heads. ''Banksias'' range ...
'' species, for example, anthesis involves the extension of the
style
Style is a manner of doing or presenting things and may refer to:
* Architectural style, the features that make a building or structure historically identifiable
* Design, the process of creating something
* Fashion, a prevailing mode of clothing ...
far beyond the upper
perianth
The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla ( petals) or tepals when ...
parts. Anthesis of flowers is sequential within an
inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
, so when the style and perianth are different colours, the result is a striking colour change that gradually sweeps along the inflorescence.
Flowers with
diurnal anthesis generally are brightly colored in order to attract diurnal insects, such as butterflies.
Flowers with
nocturnal anthesis generally are white or less colorful, and as such, they contrast more strongly with the night. These flowers typically attract nocturnal insects including many moth species.
References
Plant physiology
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