Gordon Douglas Rowley (1921-2019) was born in London, England. He taught horticultural botany at Reading University. Rowley served as the first president of the British Cactus and Succulent Society from 1983 to 2004. The very popular succulent plant Senecio rowleyanus (String of Pearls) was named after him.
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 proposed to further divide the genus Haworthia into 3 subgenera: Haworthia, Haworthiopsis, and Tulista. He 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 Rafinesque in 1840, but long consigned to synonymy with Haworthia.