astilbe
Concise Oxford English Dictionary © 2008 Oxford University Press:
astilbe /əˈstɪlbi/
▶noun a plant of the saxifrage family, with plumes of tiny white, pink, or red flowers. [Genus Astilbe.]
– origin mod. L., from Gk a- ‘not’ + stilbē, fem. of stilbos ‘glittering’.
'astilbe' also found in these Oxford entries:

