Helianthemum canadense or Crocanthemum canadense (known as longbranch frostweed, Canada frostweed, frostweed, rock frost, frostplant, or frostwort) is a species of rock-rose (Cistaceae), native to eastern North America.
It is a flowering perennial in height that blooms from May to June for a single day. Each stem normally has a single flower, but rarely can have two. The flower is yellow in color, with five petals and is between 3/4 and inches across. The leaves are covered in hairs and alternate in pattern. The stems are also covered in hairs and are brown or green in color.