Gordon Douglas Rowley (1921-2019) was born in London, England. He taught horticultural botany at Reading University, and lived in his home ‘Cactusville’ in Reading. He served as the president of the British Cactus and Succulent Society (BCSS), and has several plants named for him including the very popular Senecio rowleyanus (String of Pearls).
In 2013, Rowley published Generic Concepts in the Alooideae (Part 3 and 4) in Alsterworthia International. Based on the earlier genetic studies from Barnabas H. Daru et al, he first proposed to divide the genus into 3 subgenera: Haworthia, Haworthiopsis, and Tulista. Rowley created the name Haworthiopsis based on the ending -opsis from Greek, meaning “appearance”, hence Haworthiopsis means “like Haworthia”. He revived the name Tulista, which was erected by Constantine Samuel Rafinesque in 1840, but long consigned to synonymy with Haworthia.