Mostly mat- or cushion- forming, evergreen, semi-evergreen or deciduous perennials, biennials and annuals. Most varieties grown are evergreen and perennial. Great variance in leaf shape and form, producing flat, star-shaped or cup-shaped flowers singly, in cymes, racemes or panicles. Rosettes of monocarpic forms die after flowering and replaced by offsets. Suitable for rock gardens, mixed borders and woodland gardens. All forms mainly require sun or shade, moderately fertile, moist free draining soil.