The Genus Spiraea
White Spiraea: Spiraea betulifolia var. lucida - An erect or ascending shrub to 1 meter high. Leaves egg shaped or elliptical, often toothed midleaf to the tip, and 2-8 cm long. Flowers small and white in a dense, flat-topped inflorescence.
Subalpine Spiraea: Spiraea splendens (formerly Spiraea densiflora) - Shrub to 1 meter in height. Leaves egg-shaped to elliptical and from 2-4 cm long with irregular, coarse teeth. Flowers very small and rose colored in a dense, flat-topped inflorescence.
Douglas' Spiraea, Hardhack, Steeplebush, Western Spiraea: Spiraea douglasii var. douglasii (Synonym: Spiraea douglasii var. roseata) - Shrub to 6 feet. Flowers small, pink, and arranged in dense racemes. Leaves ovate with small serrations. Typically found in wet meadows, or along stream & lake banks.
Menzies' Spiraea: Spiraea douglasii var. menziesii (Synonyms: Spiraea douglasii ssp. menziesii, Spiraea subvillosa, Spirea cuneifolia) -
Pyramid Spiraea: Spiraea x pyramidata (Synonyms: Spiraea betulifolia x douglasii, Spiraea tomentulosa ssp. pyramidata) - Shrub to 1 meter in height. Flowers small, white, and arranged in dense rounded to conical inflorescences. Similar in many aspects to white spiraea except for the pyramidal inflorescence.