Taxonomic novelties in the genus Spiraea (Rosaceae)

Roman Businský

with 4 figures

Key words: Rosaceae, Spiraea, new combinations, new natural hybrids, Spiraea ×exspectata hybr. nova, Spiraea ×mollissima hybr. nova, S. ×chionobia hybr. nova, Spiraea ×notha new from nature.

Summary
Businský R. 2025. Taxonomic novelties in the genus Spiraea (Rosaceae). – Phyton (Horn, Austria) 64–65: 75–84, with 4 figures.

Five typified species names of the genus Spiraea are relegated to the rank of variety and newly combined with appropriate species names as follows: Spiraea alpina var. tianschanica, S. anomala var. laeta, S. aquilegiifolia var. chailarensis, S. brahuica var. pilosa, and S. hirsuta var. turczaninowii. Moreover, Spiraea beauverdiana var. stevenii is newly combined as S. betulifolia var. stevenii. Three new natural interspecific hybrids are described: Spiraea ×exspectata (S. alba × S. lucida) from Alberta, Canada; Spiraea ×mollissima (S. cana × S. media) from Bosnia, formerly misinterpreted as Spiraea mollis K. Koch & C. D. Bouché; S. ×chionobia (S. schneideriana × S. lasiocarpa) from southwestern China. Spiraea ×notha (S. corymbosa × S. latifolia), previously known only from cultivation, was found documented by a herbarium specimen from nature in Virginia, USA.