Linnaeus's flower clock was a garden plan hypothesized by
Carl Linnaeus that would take advantage of several plants that open or close their flowers at particular times of the day to accurately indicate the time.
According to Linnaeus's autobiographical notes, he discovered and developed the floral clock in 1748. It builds on the fact that there are species of plants that open or close their flowers at set times of day. He proposed the concept in his 1751 publication ''
Philosophia Botanica
''Philosophia Botanica'' ("Botanical Philosophy", ed. 1, Stockholm & Amsterdam, 1751.) was published by the Swedish naturalist and physician Carl Linnaeus (1707–1778) who greatly influenced the development of botanical taxonomy and systematics ...
'', calling it the (). His observations of how plants changed over time are summarised in several publications. ''Calendarium florae'' (the Flower Almanack) describes the seasonal changes in nature and the botanic garden during the year 1755. In ''Somnus plantarum'' (the Sleep of Plants), he describes how different plants prepare for sleep during the night, and in Vernatio arborum he gives an account of the timing of leaf-bud burst in different trees and bushes. He may never have planted such a garden, but the idea was attempted by several
botanical gardens in the early 19th century, with mixed success. Many plants exhibit a strong
circadian rhythm
A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., endogenous) and responds to ...
(see also
Chronobiology
Chronobiology is a field of biology that examines timing processes, including periodic (cyclic) phenomena in living organisms, such as their adaptation to solar- and lunar-related rhythms. These cycles are known as biological rhythms. Chronob ...
), and a few have been observed to open at quite a regular time, but the accuracy of such a clock is diminished because flowering time is affected by weather and seasonal effects. The flowering times recorded by Linnaeus are also subject to differences in daylight due to
latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north ...
: his measurements are based on flowering times in
Uppsala
Uppsala (, or all ending in , ; archaically spelled ''Upsala'') is the county seat of Uppsala County and the fourth-largest city in Sweden, after Stockholm, Gothenburg, and Malmö. It had 177,074 inhabitants in 2019.
Located north of the capi ...
, where he taught and had received his university education.
The plants suggested for use by Linnaeus are given in the table below, ordered by recorded opening time; "-" signifies that data are missing.
Cultural references to the concept
Some 30 years before Linnaeus's birth, such a floral clock may have been described by
Andrew Marvell
Andrew Marvell (; 31 March 1621 – 16 August 1678) was an English metaphysical poet, satirist and politician who sat in the House of Commons at various times between 1659 and 1678. During the Commonwealth period he was a colleague and friend ...
, in his poem "
The Garden" (1678):
How well the skilful gardener drew
Of flow'rs and herbs this dial new;
Where from above the milder sun
Does through a fragrant zodiac run;
And, as it works, th' industrious bee
Computes its time as well as we.
How could such sweet and wholesome hours
Be reckoned but with herbs and flow'rs!
In
Terry Pratchett
Sir Terence David John Pratchett (28 April 1948 – 12 March 2015) was an English humourist, satirist, and author of fantasy novels, especially comical works. He is best known for his ''Discworld'' series of 41 novels.
Pratchett's first no ...
's novel ''
Thief of Time
''Thief of Time'' is a fantasy novel by British writer Terry Pratchett, the 26th book in his ''Discworld'' series. It was the last Discworld novel with a cover by Josh Kirby.
Plot summary
The Auditors hire young clockmaker Jeremy Clockson to b ...
'', a floral clock with the same premise is described. It features fictional flowers that open at night "for the moths", so runs all day.
See also
*
Floral clock
A floral clock, or flower clock, is a large decorative clock with the clock face formed by carpet bedding, usually found in a park or other public recreation area. Most have the mechanism set in the ground under the flowerbed, which is then pla ...
References
{{Reflist
External links
Online text of ''Philosophia Botanica''
Botany