Mantissa Plantarum Altera (abbreviated Mant. Pl. Alt.) is an illustrated book with botanical descriptions which was edited by the Swedish naturalist Carl Linnaeus in the year 1771.
Mantissa Plantarum Altera was the continuation of Mantissa Plantarum published in 1767 as an appendix to the 12th edition of Systema Naturae.
A gender symbol is a pictogram or glyph used to represent sex and gender, for example in biology and medicine, in genealogy, or in the sociological fields of gender politics, LGBT subculture and identity politics.
In his books Mantissa Plantarum (1767) and Mantissa Plantarum Altera (1771), Carl Linnaeus regularly used the planetary symbols of Mars, Venus and Mercury (♂, ♀ and ☿) for male, female and hermaphroditic (perfect) flowers, respectively. Botanists now use ⚥ for the last.