Psidium guajava, the common guava, yellow guava, or lemon guava, is an evergreen shrub or small tree. Widely cultivated in tropical and subtropical regions around the world. Guavas have survived dry summers with no water, although they do best with regular deep watering. It is easily pollinated by insects; when cultivated, it is pollinated mainly by the common honey bee. Various cultivars have white, pink, or red flesh, a few varieties feature red (instead of green or yellow) skin. The fruit, leaf, and bark of guava trees contain medicinal benefits. Guava leaves are the best medicine for ulcers and toothache. Guava fruit contains vitamin C. It also helps the body to grow better and strengthen the bones. It is used for inflammation, diabetes, hypertension, caries, wounds, pain relief, fever, diarrhea, rheumatism, lung diseases, and ulcers. They fight infectious diseases and kill germs.