Pale Alyssum, Pale Madwort, Small Alison, Small Alyssum: Alyssum alyssoides (Synonym: Alyssum calycinum)- Sepals persist as the fruits mature. Silicles with numerous minute, appressed, star-like hairs barely visible with a hand lens.
Desert Alyssum: Alyssum desertorum (Synonym: Alyssum desertorum var. desertorum) - Sepals typically drop off soon after flowering. Silicles glabrous. Mature pedicels ascending to spreading.
Small Alyssum: Alyssum minus ssp. micranthum (Synonyms: Alyssum minus var. micranthum, Alyssum parviflorum var. micranthum, Alyssum minus ssp. micranthum, Alyssum minus, Alyssum parviflorum) - Sepals typically drop off soon after flowering. Silicles with large, non-appressed, star-like hairs easily seen with a hand lens. Mature pedicels spreading or at right angles to the stem.