Abstract:North America is one of the important distribution and diversity centers of Angelica (Apiaceae), while the palynologies of these species still have not attracted much attention. In this study, the morphological characteristics of the pollens from 44 populations of 26 species from North America were investigated by the optical microscopy and the scanning electron microscopy, polar axis, equatorial axis length, size index, and ornamentation density were measured and quantitatively defined using SketchUp software. The results shows that: (1) there are four types of pollen shapes as subrectangular, ellipsoidal, hyperretangularb and hyperretangular (equatorial constriction); (2) their polar axis length is 21.1~32.0μm, the equatorial axis length is 10.6~17.1μm, the ratio of polar axis to equatorial axis is 1.5~2.8, and the volume index is 15.8~23.3; (3) the ornamentations on exine walls of pollen equatorial regions includes three types, such as brevistriate baculite cerebroid, lone striate cerebroid, and flaky-like cerebroid, sparsely or densely arranged, and the polar ornamentations of three species turn to smooth; (4) according to the above characteristics of these pollens, a classification system comprising 4-levels, 3-classes and 15-subclasses are suggested herein. In general, the polymorphism of the pollen characteristics of North America Angelica species is lower than that in East Asia; the pollen shape and the types of the equatorial ornamentations of the exine walls are relatively consistent in each species, yet the central pollen protruding, ornamentation types and density, and appendages exhibit a certain intra-specific differences. The study supplies further data of the palynologies of Angelica, and the pollen characteristics will provide significant reference to the classification, identification and the relationships of these species, which are recommended as important supplement for the research on morphological and molecular taxonomy.