[Taxacom] Euphorbiales/Malpighiales

[michael.heads at yahoo.com]

Dear Colleagues,
 
Why do some authors call the large order including Euphorbia 'Malpighiales' instead of Euphorbiales, when Euphorbiaceae occur just about everywhere and Malpighiaceae are much less common?  
 
Michael Heads

Wellington, New Zealand.

My papers on biogeography are at the Buffalo Museum website: www.sciencebuff.org/research/current-research-activities/john-grehan/evolutionary-biography/panbiogeographic-publications/heads-publications/