Liatris is a genus of about 50 species of perennial plants. These prairie wildflowers have spiky or feathery flowers and long narrow leaves growing up along the stem. Liatris flower is actually a cluster of many small flowers that appear to be one flower. The plant grows up to 150 cm (5 ft) in height. Liatris will grow best in sandy or loamy soil, with a pH between 5.5 and 7.5. Plant Liatris in tough soil conditions with good drainage.