The 28 taxa briefly profiled here are not included in the regional chapters. This chapter discusses infraspecific taxa that differ from the type one in only single or minor characters; taxa described as new after the main manuscript was completed; or taxa for which representative photos were unavailable in a required scale.

 

In addition, some taxa with problematic nomenclature or taxonomy warranted more attention than could be given in the regional chapters. Discussions are included for Abies pseudochensiensis (The Kámon Fir), Callitropsis and Xanthocyparis, The Mexican Cypresses, The “Apulco Ravine Pine”, and The Southern North American Stone White Pines (P. flexilis, P. strobiformis, and P. veitchii).