If you’re a long-time BPotD reader, you’ll remember that the biogeographical link between plant families of southeast Asia and North America is well-established (see this entry). The distribution across southern Asia into Europe is also understood (and easy enough to imagine). However, the presence of the family in southeastern Africa and Madagascar is a bit of a headscratcher to me. While digging around, I reviewed the paper from the entry on another hamamelid, Disanthus cercidifolius (Li et al. 1999. Phylogenetic relationships of the Hamamelidaceae inferred from sequences of internal transcribed spacers (ITS) of nuclear ribosomal DNA. Am. J. Bot. 86:1027-1037). As it turns out, there is not enough evidence (yet) to clearly understand the biogeography of southern hemisphere Hamamelidaceae, so it remains a puzzle for now.
Botany resource link: The Parasitic Plant Connection by Dr. Dan Nickrent of Southern Illinois University. Scroll down the page for links to pages on parasitic plant families.