Cultivar
A cultivar in botany is a type of cultivated plant that has been cultivated for specific properties.
Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, or carefully controlled seed production. Most cultivars arise from purposeful human manipulation, but some originate from wild plants that have distinctive characteristics. (Source: Wikipédia)
Cultivars of the tea plant (Camellia Sinensis (botany)), an evergreen shrub or small tree in the flowering Theaceae family) are generally obtained by cutting and crossing different cultivated varieties of tea.
The Yabukita Cultivar became popular precisely through this process. It was bred in the early 20th century, registered in 1956 and then cultivated widely as tea production boomed in the 1970s and 1980s. Today, it is by far the most common and popular tea plant cultivar in Japan. (Source: Naoki)