from Correll & Johnson 'Manual of the Vascular Plants of Texas' 1970; Death year Tweeted from Natural History Museum, London, https://twitter.com/NHM_Botany/status/1436074382552715275 (via Pradit Tinamas, Kasetsart University); Memorial Tribute at: https://drnormanrobson.muchloved.com/ (via John McNeill; E)