Dandya is a genus of cormous plants from across northern and southwestern Mexico in the Milla clade of Themidaceae. This clade includes Behria, Bessera, Jaimehintonia, Milla, and Petronymphe. The flowers can be white, lavender-blue, and mauve.
Dandya thadhowardii grows in rocky terrain and dry hillsides in full sun or shade among cacti and thorny trees in Guerrero and Michoacan. It breaks dormancy and flowers soon after the first rains of summer. Flowers look much like Dodecatheon in form, growing in umbels of small pendant flowers that are white, keeled with a green line, with anthers touching to form a tiny birdcage surrounding a small bright green ovary.