Ordinal level analysis of coxI intron presence among angiosperms. Character state tracing of coxI intron presence (shown in blue) among 45 orders of angiosperms. Numbers listed next to intron-negative orders show the number of families sampled for the coxI intron out of the total currently included within each order. Parasitism is inferred to have evolved 10 times on branches that also are inferred to have the intron (shown by numbers within circles). Only Krameriaceae and Cynomoriaceae do not appear to be associated with intron containing lineages. The probability of 10 origins of parasitism and zero losses of parasitism on branches that have the intron is < 0.001.