In message .com,
texas_gardener writes
Here it is for purchase (I think):

http://tinyurl.com/2wa943


That's a different species of Spiraea. From the picture at the URL it
looks as if it has larger leaves, and a different habit. In particular
the flowers are clustered differently. See

http://www.djroger.com/snowstorm.htm

for a more informative photograph.
--
Stewart Robert Hinsley