hiː bɪɡˈæn wˈɜːk æt ðə hɜːbˈɛɹiəm ʌvðə ɹˈɔɪəl bətˈænɪk ɡˈɑːɹdənz, kjˈuː ɪn nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi ˈeɪt ænd bɪkˌeɪm hˈɛd ʌv ɪts ˈæfɹɪkən sˈɛkʃən ɪn nˈaɪntiːnhˈʌndɹɪd fˈɪfti nˈaɪn.
He began work at the herbarium of the Royal Botanic Gardens, Kew in 1948 and became head of its African section in 1959.