Rudolf Jakob Camerarius or Camerer (12 February 1665 – 11 September 1721) was a German botanist and physician.

He is chiefly known for his investigations on the reproductive organs of plants (De sexu plantarum epistola (1694)).

[1] While other botanists, such as John Ray and Nehemiah Grew, had observed that plants seemed to have sex in some form, and guessed that pollen was the male fertilizing agent, it was Camerarius who did experimental work.

His results were reported in the form of a letter (the epistola), and attracted immediate attention, subsequent workers extending his results from the monoecious plants he had studied to dioecious ones as well.

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