Thelocactus (Thelocactus flavus)

Thelocactus
Thelocactus flavus

The form which is called Th. panarottoanus. It is rather a form of Th. tulensis than of Th. conothelos as Anderson is claiming.

There is question mark by the synonym (T. panarottoanus) in Anderson's book on page 658 which means that the ICSG (International Cactaceae Systematics Group) probably hadn't decided on where the synonym should be placed yet at time of publication. Anderson worked closely with the ICSG and Reported the decisions in his book. Did you find this information about the this form being that of T. tulensis in 'The New Cactus Lexicon" (Hunt, 2006)? Or did you find it in a book older than 2001 (Anderson's book)?

The lumper D. Hunt doesn't even mention Th. panarottoanus as synonym in his TNCL!
I came to this 'tulensis var. opinion' by myself (after 2001!) and I still think it is closer than calling it a var of conothelos.
But I rather would like to call it a species of its own anyhow.
Jordi

Since Anderson had a question mark by the T. panarottoanus, which means it was undecided at the time of publishing. And since there is no reference in TNCL, I believe we should back up to the next previous publication.
That would be "Thelocactus flavus - Mosco & Zanovello; Cactus & Co., 3: 20 (1999)".

Cactus-art has gone to great effort to provide accurate information and cite thier references.
http://www.cactus-art.biz/schede/THELOCACTUS/Thelocactus_flavus/THelocactus_flavus/Thelocactus_flavus.htm
They list the synonyms of T. flavus as:
Thelocactus conothelos ssp. flavus
Thelocactus panarottoanus
Thelocactus longispinus
Thelocactus tulensis v. rinconadensis

They have also made a notation that I think is very important, which reads:

"Note: T. flavus is strictly related to T. garciae This species has been well known for a long time and is sometimes listed in catalogues under the name Thelocactus longispinus n. n. which have also been distributed with the field number HK362.
It has always been misidentified as Thelocactus tulensis and considered a yellow flowering form of it. At a glance, flavus resembles tulensis in the epidermis colour and the long central spines, but the relationship stops here.
There are indeed many remarkable differences between the two species. In flavus the areoles bear one or two glands, missing in tulensis; the radial spines are quite different in number and arrangement; the flowers of flavus are yellow with the primary stamens inserted above the receptacle base, while the flowers of tulensis are white to pink with the primary stamens inserted at the base of the receptacle. For the flower morphology and seed micro-morphology, flavus is, instead, referable to the Thelocactus conothelos complex. Thelocactus panarottoanus is the same."

So I recommend that there be a separate entry page for T. flavus with the above listed synonyms, and that this photo be moved to there.

Xeno.

I have read that before and agree with your recommendation.

Jordi