Monsonia is a genus of flowering plants in the family Geraniaceae, order Geraniales, distributed across Africa, Western Asia, and East India. The World Checklist of Selected Plant Families recognises approximately 27 species, with the greatest diversity — around 21 species — concentrated in South Africa.
Plants in the genus are herbs or undershrubs, typically growing from a woody rootstock or deep taproot that allows them to persist through dry seasons. The stems are often simple. Leaves are toothed or divided. The flowers are regular and showy, bearing five separate petals with broad, blunt or slightly notched tips. Stamens are arranged in five groups of three, with one stamen in each group slightly longer than the others. The ovary is five-lobed, and the fruit is distinctively beaked — a characteristic shared with related genera in the geranium family.
The genus was named in honour of Lady Anne Monson (1714–1776), an English botanist celebrated for her botanical knowledge and plant-collecting work in the Cape region of South Africa.
Etymology
The genus name Monsonia honours Lady Anne Monson (1714–1776), an English botanist recognised for her botanical knowledge and plant collecting in the Cape region of southern Africa.
Distribution
Monsonia is distributed across Africa, Western Asia, and East India, with approximately 40 species recognised in broader treatments. About 21 of these are native to South Africa, making the Cape region the centre of diversity for the genus.
Taxonomy Notes
The World Checklist of Selected Plant Families accepted 27 species as of July 2020. Monsonia is placed in the family Geraniaceae, order Geraniales. The genus is sometimes treated in a broad or narrow sense depending on authority; GBIF lists 27 accepted descendants under the backbone taxonomy.
