German scientist Theodore Vogel (1812–1841) joined an 1841 expedition to the Niger as its chief botanist. He died in the course of the journey, though not before taking extensive notes about the plants that he encountered. His botanical collection and diary were passed to the botanist William Jackson Hooker (1785–1865), who had been appointed as the first full-time director of Kew Gardens in the same year. Hooker edited Vogel's diary and observations and the resulting work, Niger Flora, was published in 1849. Because Vogel's period in West Africa was cut short by his untimely death, much of the work looks at the flora of the places the expedition stopped at along the way – Madeira, Tenerife and the Cape Verde islands, before giving details – including numerous illustrations – about west African plants. The works also includes observations on African flora by other botanists, including Joseph Dalton Hooker, William's son.