Polypodium glycyrrhiza Polypodium glycyrrhiza Polypodium glycyrrhiza, commonly known as licorice fern, many-footed fern, and sweet root, is a summer deciduous fern native to western North America, primarily in a narrow strip in southern Alaska, southwestern Yukon Territory, western British Columbia, Washington, Oregon, and California, though two highly disjunct populations are known from Idaho and Arizona. It thrives in a humid climate, prevailing in areas with cool and moist summers and warm and wet winters. "P. glycyrrhiza" can often be found growing on the trunks and branches of winter deciduous trees, particularly bigleaf maple, but is also often found on rocks, logs, and
Selection methods in plant breeding based on mode of reproduction species where normal mode of seed set is through a high degree of cross-pollination have characteristic reproductive features and population structure. Existence of self-sterility, self-incompatibility, imperfect flowers, and mechanical obstructions make the plant dependent upon foreign pollen for normal seed set. Each plant receives a blend of pollen from a large number of individuals each having different genotypes. Such populations are characterized by a high degree of heterozygosity with tremendous free and potential genetic variation, which is maintained in a steady state by free gene flow among individuals within the populations. In the development of hybrid varieties, the aim is