Brickellia watsonii, more recently recognized as B. microphylla var. watsonii, is distinguished by its tomentose-puberulent, often gland-dotted indument (contrasted with the villous to glandular-villous indument of var. microphylla), and heads with ca. 18 flowers (versus 15-34 in var. microphylla); such distinctions have proved to be weakly substantiated, at best.