About Melocactus zehntneri (Britton & Rose) Luetzelb.
Melocactus zehntneri (Britton & Rose) Luetzelb. is a Turk's turban cactus native to Bahia state, in northeastern Brazil. It also has the synonym scientific names Melocactus giganteus and Cactus zehntneri, and the species name is sometimes written as Melocactus zehnerii. Like other Turk's turban cacti, it has a rounded lower stem that typically bears around eleven vertical ribs and carries out photosynthesis. Above this lower stem sits an elongated capitate inflorescence called a cephalium. This species has an unusually high phyllotaxis ratio of 34/55. The cephalium can grow up to 72 cm (28 in) long, and may hold as many as 16 annual growth rings. This makes it one of the longest-lived inflorescences ever recorded. This species was first discovered in 1968 by Leopoldo Horst and A.F.H. Buining.
