noun, plural: pollen-free plants
Flowering plants (angiosperms) are plants that do not produce pollen. Angiosperms may be grouped according to the flowers they produce. Those that bear both male and female flowers are called monoecious plants whereas those that bear either male or female flower are called dioecious plants.
Dioecious angiosperm species are those in which the reproductive structures are on separate plants. This means that a plant bearing male flowers is a male plant whereas the plant bearing female flowers is a female plant. The plant that bears female flowers are those may be regarded as "pollen-free" plants since pollens are produced by male reproductive flower organs. A female flower would bear female reproductive structures, such as pistil and ovary. A male flower, in contrast, would bear male reproductive structures, such as stamen and pollen.
Examples of dioecious plant species are Acer negundo, Baccaurea motleyana, Ceratonia silique, Chionanthus virginicus, Dasiphora fruticosa, Diospyros nigra, Euphorbia obesa, Ginkgo biloba, Hechtia texensis, Juniperus ashei, Laurus nobilis, Macaranga indica, Melicytus lanceolatus, Melicytus ramiflorus, Phytelephas aequatorialis, Pistacia lentiscus, Rhus typhina, Sassafras albidum, Sclerocarya birrea, Siparuna lozaniana, Toxicodendron radicans, and Valeriana edulis.