Alyssum

Alyssum is an accepted genus in the mustard family, Brassicaceae, with a native range from the Canary Islands and North Africa across temperate Eurasia. Kew’s Plants of the World Online recognizes more than 100 species, and the Royal Horticultural Society describes the genus as including annuals, evergreen perennials and subshrubs ([Kew Plants of the World Online](https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:60433920-2), [RHS Alyssum alyssoides profile](https://www.rhs.org.uk/plants/156191/alyssum-alyssoides/details)). ## What the name covers A generic Alyssum entry does not identify a single garden form. The genus includes plants with different habits and dimensions; RHS describes simple leaves and short racemes of small, four-petalled yellow or white flowers in early summer. Match sun, soil, water, mature size and flowering expectations to the exact species or cultivar before placing it in a design. ## Similar common names “Sweet alyssum,” “sweet Alison” and the old name Alyssum maritimum refer to Lobularia maritima, which RHS treats separately. “Gold dust” is listed under Aurinia saxatilis, formerly called Alyssum saxatile in horticulture. These familiar labels should not be used as interchangeable care guides for Alyssum species ([RHS sweet alyssum profile](https://www.rhs.org.uk/plants/124133/lobularia-maritima/details), [RHS gold dust profile](https://www.rhs.org.uk/plants/1039/alyssum-saxatile/details)). ## Maintenance There is no single pruning or watering schedule for the whole genus. Follow the needs of the identified species, keeping alpine and rock-garden types in conditions suited to their particular habitat.