original: Wahlenbergia species have dispersed widely, even to oceanic islands, and there are four species known from the island of St Helena, including the now extinct species W. roxburghii.
simplifications: Wahlenbergia species are found in far away places, even on oceanic islands. There are four species known from the island of St Helena, including the now extinct species W. roxburghii. Wahlenbergia species have spread, even to oceanic islands. There are four species on the island of St Helena, including the now extinct species W. roxburghii. Wahlenbergia species have dispersed widely. Four species are from the island of St Helena, including the now extinct species W. roxburghii. Wahlenbergia species have scattered far, even to oceanic islands. There are four species known from the island of St Helena, including the now extinct species W. roxburghii. Wahlenbergia species have spread out widely, even to oceanic islands. There are four species known from the island of St Helena. That includes the now extinct species W. roxburghii. Wahlenbergia species have dispersed  to the oceanic islands, and there are four species from the island of St Helena, including the now extinct species W. roxburghii. Wahlenbergia species have spread out widely. There are four known species from the island of St. Helena. Wahlenbergia species have spread widely, even to oceanic islands. There are four species known from the island of St Helena, including the extinct species W. roxburghii. Wahlenbergia species have spread out, even to oceanic islands. There are four species known from the island of St Helena. One of the four species is the now extinct, W. roxburghii. Wahlenbergia species have dispersed widely and even to oceanic islands. Four species including the W. Roxburghii (extinct species) are from the island of St Helena.