'Climax' is a Prunus cultivar, considered to be a plum.
It was introduced in 1899 by plant breeder Luther Burbank.
He developed a number of cultivars from the hybrid,[2][3] of which 'Climax' was particularly notable for its importance to the fruit shipping industry of California.
The fruit is extremely large and heart-shaped, with yellow flesh that is sweet and very juicy.
The skin is dark red with yellow spots, and somewhat unpleasant in flavour, but peels away easily from the flesh when the fruit is fully ripe.