3.1 DNA extraction and PCR amplification from herbarium and
contemporary samples
A total of 186 samples from twelve states in the U.S. (n=130), four
states in Mexico (n=13), three Central American countries (n=13), four
South American countries (n=6), four Caribbean Islands (n=16), Germany
(n=3), India (n=3) and The Philippines (n=2) were sequenced and analyzed
as noted above. There were varying levels of success for the
amplification of each genetic locus among the samples. This was
particularly the case for many of the herbarium samples, some of which
were more than 100 years old. The ITS region was the most successfully
amplified and sequenced, with 168 sequences generated. Whereas 91
sequences were generated for the LSU locus (Table 1).