International Code of Botanical Nomenclature

(VIENNA CODE)

INTRODUCTION TO THE CACTACEAE SYSTEMATICS

The first sheet lists in order all taxonomic ranks from domain to species, and form.
Ranks in red according to the taxonomic concept Cactusinhabitat Study Project,
* Shared cactusfarm
* Except for the macro-genus Echinopsis:
separate (cactusfarm) in Echinopsis (night-blooming) and Lobivia (day-blooming)

The sheet takes as example:

The second worksheet presents the Cactaceae systematics (from the family to the genus) according to Edward F. Anderson, drafted in a forty-year working group with the IOS

(International Organization for the Study of Succulents).

The book "The Cactus Family" sees the light in 2001, and is the most complete and updated so far known, and developed with the contribution of logical genethical simplification by D. Hunt with "The New Cactus Lexicon" in 2006, and the extraordinary work still in progress in habitat by

Giovanna Anceschi & Alberto Magli : Cactusinhabitat Study Project .

The IOS has adopted as method the analysis of the seeds with electronic scanning microscope, family ties and greater clarity on the definition of species you will have, however, with the analysis and DNA samples of all plants and a natural interpretation of the data thus obtained with a thorough overview of development trends in habitat.

The used double nomenclature, name and synonym, refers, in turn, always to one single taxon

(and photo).

Although completely in agreement with Cactusinhabitat Study Project for the nomenclature of a taxon with ranks genus, species, and (form), however, in the labeling cactusfarm the ranks var. and ssp. are used as syn. for a more precise identification, where the name is not available without the ranks of subspecies and varietas, otherwise it would imply the necessity of publication *:

eg.
Opuntia polyacantha Haworth 1819
syn. Opuntia polyacantha var. rufispina (Engelmann & J.M.Bigelow) L.D.Benson 1969

incl. Opuntia rufispina (nomen nudum, M. Lugnan 2011)*
(forma Gunlock, Washington County, Utah, U.S.A.)

The usefulness of the conservation of the synonym (also interchangeable with the adopted name **) is related to difficulties in ex situ identifying, where it also means losing the name previously used irretrievably lose the "traceability" of the distribution more precisely circumscribed, linked to data found in literature (this is not a theme in situ), after there has been the location of the form in question:

eg.
If by "groups" Opuntia basilaris, macrocentra, macrorhiza, engelmannii, phaeacantha, polyacantha,

the distribution areas are large, for single-forms for species included, the location is more accurate:

eg.
Opuntia engelmannii Salm-Dyck ex Engelmann 1850
syn. Opuntia rastrera F. A. C. Weber 1898
Area : Mexico (Coahuila, Durango, Nuevo Leon, San Luis Potosi, Zacatecas)
min.temp.(tested) -15°C /+5°F

and

Opuntia engelmannii Salm-Dyck ex Engelmann 1850
syn. Opuntia linguiformis Griffiths 1908
area: U.S.A. (C Texas)
min.temp.(tested) -30°C /-22°F

** To reverse name and synonymous is questionable, provided it is clear the relationship, if not the membership of taxa expressed as synonyms for the forms of the group, expressed as the species name.
At this point, for logical and natural simplification, it will be convenient to express as above.
** (Opuntia engelmannii syn. Opuntia aciculata : Opuntia aciculata → Opuntia engelmannii)