guava are also a kind of berry fruit on those plants. there are many kinds of guavas. the most common guava is the apple guava ("psidium guajava"): it is so common that the word 'guava' usually refers to this species. red guavas are called maroonguava. in 100 g of guava are 200 mg of vitamin c, which means that guavas have five times more vitamin c than oranges.