Biology Reference
In-Depth Information
Fig. 2. Plant phylogenetic tree. Upper scale represents geological periods and time in millions of years ago (mya) according to the
International Commission of Stratigraphy. O, Ordovicean; S, Silurian; D, Devonian; Ca, Carboniferous; P, Permian; T, Triassic; J, Jurassic;
Cr, Cretacic. Vertical bars at right indicate different clades. A, angiosperms; G, gymnosperms. The presence and composition of lignins and
lignin-like compounds are denoted by circles at each branch—green circle: lignin-like compounds; red circle: H
þ
G
þ
S lignins; blue circle:
