Pteridium (family: Dennstaedtiaceae) is a cosmopolitan fern genus comprised of several closely related species that are well differentiated from other genera in the family.
The genera are differentiated based on their chromosome complements.
Recent studies have suggested that further subdivisions are conceivable within Munididae [ 21], with the recognition of a well-differentiated clade including the genera Munida, Cervimunida, and Pleuroncodes and a second clade including the rest of the genera [ 19, 122, 123].
The eggs of the flukes from these genera can be differentiated only by using scanning electron microscopy (SEM).
Except for these few characteristics, the LAO showed significant variation among studied genera, being completely differentiated from the AES in all goo-eaters, except in Tropidodipsas, Sibon, and Atractus in which some of the more posterodorsal fibers tend to share an aponeurosis with the more anteromedial fibers of the AES.
Yet, in most laboratories such in-depth classification is not routinely performed, because these genera cannot be easily differentiated, for example, histopathologically.
The mean percent sequence divergence for rbcL-a ranked sixth, but it exceeded all other loci except ITS1 and trnH-psbA in the percent of genera in which species pairs could be differentiated (69.8%).
This differentiated two major groups, representing the fescue and ryegrass genera.
The proportion of genera in which species in a pair could be differentiated also varied widely among loci (Table 1; Figure 3).
Two measures of the power of a locus to discriminate among species were calculated: 1) percent sequence divergence between pairs of species and 2) the proportion of the 48 genera for which species in a pair could be differentiated.
