Arachnothryx gracilis (Hemsl.) Borhidi Arachnothryx gracilis (Hemsl.) Borhidi in Acta Bot. Hung. 28: 69. 1982 sec. Borhidi 2006≡Rondeletia gracilis Hemsl., Diagn. Pl. Nov. Mexic. 3: 53. 1880 syn. sec. Lorence & Taylor 2012