Draft of Linnaeus fil.'s dissertation, which was never defended or published, concerning the clock of plants.
'Horologium plantarum' is a hastily written down unfinished draft of Linnaeus fil.'s dissertation. Its content relies on Linnaeus pater's writings, especially "Calendarium florae" (1756) and 'Regnblomman' (GB-110/LM/LP/BOT/6/7), with some additions by Linnaeus fil. who also gives some glimpses of his parents' lives in Uppsala and at Hammarby.
Undated, but it is known from a letter from P. J. Bergius to E. G. Lidbeck, 13 July 1756 (at LUB), that Linnaeus fil. planned to submit a thesis on the subject in order to qualify for the demonstrator position at the Uppsala botanical garden. Judging by the quotes from the dissertation "Calendarium florae" (1756) and by Bergius's letter, the essay should be dated from 1756 or the following years.

Full title: 'D D | Dissertatio Botanica | sistens | HOROLOGIUM PLANTARUM | quam | Consensu Experient. Facult. Med. | in Reg. Acad. Upsaliensi | sub Praesidio | viri Noblissimi et celeberrimi | D. D CAROLI LINNAEI | S:AE R:AE M:TIS Archiatro | med. et Botan. Profess.'