The mitochondrial genome of Liriodendron tulipifera. Displayed as a circle, but recognizing that the structure is likely to be much more complex in vivo. Direct (DR) and inverted (IR) repeats longer than 500 bp and with >99% sequence identity are numbered, with arrows denoting their relative orientation. Genes from the same protein complex are similarly colored, introns are white, and plastid-derived sequences are green and unlabeled. Genes shown on the inside and outside of the circle are transcribed clockwise and counter-clockwise, respectively. Potentially functional tRNAs of plastid origin are noted with a “–cp” suffix. Asterisks identify colinear gene clusters inferred to be present in the ancestral angiosperm mitochondrial genome (see Figure 6 and text for more detail). The map was modified from the output of OGDRAW .