Original: Guavas are plants in the myrtle family ( Myrtaceae ) genus Psidium ( meaning '' pomegranate '' in Latin ) , which contains about 100 species of tropical shrubs and small trees .
Simplified: Guavas are plants in the genus Psidium of the myrtle family ( Myrtaceae ) . There are about 100 species of tropical shrubs and small trees in the genus .