Tremlett's Bitter is a popular English bittersweet cider variety.
Many growers and nurseries in the USA have taken scionwood from a Tremlett's Bitter tree held at the USDA repository at Geneva, NY. However it has recently been found that this tree was mis-cataloged, and is not the English variety. Although they are both red apples the differences are quite obvious in photos. The Geneva variety has therefore become known as Geneva Tremlett's, and produces a good quality bittersharp juice (whereas the English variety is a bittersweet).