This fruit is known as acerola. Though it's not common in Mauritius, the plant actually grows pretty well and the fruit has a unique taste, a Khatta Meetha (bitter/sweet) one. The growing season is summer and the acerolas in the above photos are unripe. On Wikipedia, I've actually learnt that it can also be used to make vodka (#Win) and that the plant is often used as bonsai.Links:1. Tumblr: [link] 2. reddit: [link]