Peonies, which grow on herbaceous plants or trees, provide decades of glorious color to the home landscape. In shades of white, pink, red and purple, peonies thrive in cooler weather. Peonies need little more than full to partial sun and well-draining soil for optimal flower production. The North Carolina Cooperative Extension Service notes that the shape of the bloom classifies herbaceous peonies.
Single Peony Varieties
Single peonies are comprised of one or more rows of large guard petals which surround the reproductive parts of the flower, including the stamen, anthers and pistil. Popular single bloom varieties include America, Color Magnet, Karl Rosenfeld and Requiem.
Semi-Double Peony Varieties
Semi-double peonies have several rows of guard petals that open, in full bloom, to expose the reproductive parts, including the center crown and its cone-shaped seed pods. Popular semi-double peonies include Abalone Pearl, Circus Circus and Garden Treasure.
Double Peony Varieties
Double peony varieties have row upon row of compact petals that completely cover the crown and seed pods of the bloom. Heartland Peony Society notes that the stamen and stigma transform into petals, thus leaving no sign of their existence in double peony blooms. Adonis, Candy Hearts, Elsa Sass and Lord Cavin are just a few favorite double peony cultivars.
Anemone Peony Varieties
Anemone peonies are similar to Japanese peonies, with enlarged guard petals; however, anemone peonies do not possess anthers, while their filaments and stamens more closely resemble narrow, straight petals. Burma Midnight, Luella Shaylor and Showgirl are just a few examples that showcase the anemone form.
Japanese Peony Varieties
Japanese peonies sport several rows of enlarged guard petals that open to reveal a center mound of stamens which appear as small fringe-like petals. Japanese peony cultivars include Beautiful Senorita, Carrara, Cora Stubbs and Gypsy Rose.