spirae

from The Century Dictionary.

• noun A genus of rosaceous plants, type of the Spiræeæ.
• noun A plant of this genus.
• noun The white-flowered shrub Astilbe Japonica, now extensively imported into the United States and propagated under glass, formingone of the chief materials of Easter decorations.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Bot.) A genus of shrubs or perennial herbs including the meadowsweet and the hardhack.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun any rosaceous plant of the genus Spiraea; has sprays of small white or pink flowers
• noun a Japanese shrub that resembles members of the genus Spiraea; widely cultivated in many varieties for its dense panicles of flowers in many colors; often forced by florists for Easter blooming
• noun a dicotyledonous genus of the family Rosaceae