Longer than a short story but shorter than a novel, the form has been the ugly stepchild of the literary world.
The poor novella, it really has had such a bad reputation in literary circles - "unrecognised by academics and publishers", "the ugly duckling of the literary world" - but as this article in the Atlantic I recently read shows, things are starting to change. I know publishers shy away from the novella, I know it is neglected, and also undefined, but I actually love them and think it does have a place in literature. Some great African authors - Sembene Ousmane, Andre Brink, Doris Lessing - have all produced novellas and for me, there's that additional bonus of being able to read a book in a day or less in one sitting :). If you are interested in novellas in general then check out The Art of the Novella and Penguin's Mini-Modern Classics, but here are a few novellas written by African authors.
The money-order with White genesis is a book containing two novellas. In The Money-Order, a man receives a money-order form a relative living in Paris and experiences bureaucratic incompetence and deceit, while the White Genesis tells the tragic tale of incest. Every Day is for The Thief is an account of a Nigerian returning home after many years in the States. The Grandmothers contains four novellas. In The Grandmothers, two childhood friends fall in love with each other's teenage sons, and these passions last for years, until the women end them, vowing a respectable old age. In Victoria and the Staveneys, a poor black woman has a child by a white man from a wealthy family, and she slowly begins to lose her child as she becomes part of this privileged world. The Reason for It traces the birth, faltering, and decline of an ancient culture. A Love Child features a World War II soldier who falls in love on shore leave and is convinced he fathered a child. In Becoming Abigail Abigail is brought as a teenager to London from Nigeria by relatives who attempt to force her into prostitution. Song for Night is the story of a West African boy soldier’s journey through the nightmare landscape of a brutal war in search of his lost platoon. Other Lives - a collection of three novellas - chronicles the lives of three interconnected men in contemporary South Africa. Murder for Profit, The Fatal Payout and Anything for Money all make up Lauri Kubuitsile's detective novellas. Eyes of the Slain Woman is a collection of three novellas exploring grief and the tenacity of human spirit. Adam & Luke, possibly the first gay novella, consists of two separate novellas. In Adam van Eden, the author draws on his personal experience within the church to highlight the damage inherent in fundamentalist condemnation, while According to Luke explores the disruption of a heterosexual marriage.