Cirsium Rivulare – Atropurpureum or Plume Thistle – Atropurpureum is a perennial. I remember when Thistles were considered wildflowers and weeds in the garden but in recent years with the introduction of more and more wild flowers in the gardens it has become popular to cultivate thistles. Cirsium Rivulare – Atropurpureum produces purplish maroon color flowers in the summer months rather tall adding a lot of interest to borders. It grows in the sun, moist but well-drained soil and grows to about 5 feet tall. Please keep in mind like any wildflower it will self-seed so you might want to deadhead the flowers.