“Crassula muscosa var. muscosa” and “Crassula muscosa” is a reference to the same thing?
The addition of “var. mucosa” is redundant correct? But it lets us know there are more then one “var”/variety.
So if a plant has varieties we should be reduntant with “base/parent name” - “Genus species var. variety”
But is no varieties there is no need to be reduntant? - "Genus species
It depends on the scenario. I don’t know much about plant taxonomy, but in animals that would be called the nominate variety. It’s the same as the species in that the original description and types (if present) are the same, but taxonomically the varieties descend from the species and are therefore not the same. Just because there are no varieties on iNat doesn’t mean there aren’t accepted varieties in the literature, but if no varieties are recognized there is no need for a nominate variety.
(it is the same in plants. the differences between animals and all other eukaryotes [at the nomenclatural level, fungi etc. are dealt with in the way that plants are; animals are somewhat the special case] are overwhelmingly minor)
Before joining iNat I rarely (if ever) heard of nominate variety, or nominotypical subspecies etc etc when talking about plants. I think that might be more of a zoological term and wikipedia supports this idea (i.e. for plants I hear the term autonym or type variety). But I think that, from the reading I’ve done, the way botany is being taught means that terms that used to be strictly zoological terms are creeping across. I guess it doesn’t matter because we all know what it means but I thought it worthing mentioning
The nominate variety is a perfectly normal thing in botany, as in zoology.
Basic idea: If you give a plant a subspecies or variety name, you’re doing it because you think that it differs from the original form of the species in some way worth naming. OK. But then what do you call the original form, when you want to distinguish it from the new subspecies/variety? You use the original species name as the subspecies or variety name.
Example: Pinus contorta has two subspecies, Pinus contorta var. contorta, Shore Pine, the coastal form that Eurasian botanists met first, and Pinus contorta var. latifolia, Lodgepole Pine, an inland form Eurasian botanists didn’t meet and describe until later. When you use the name Pinus contorta without specifiying the variety, you may mean you’re talking about the species as a whole or that you’re referring to some form without caring which it is. That’s OK.
Example: A small, eastern bird was described as Setophaga coronata, Myrtle Warbler. Later a similar but slightly different western bird was named Setophaga audoboni, Audubon’s Warbler. They are very similar and it turns out they interbreed in some areas. Therefore, they were merged. Audubon’s Warbler became Setophaga coronata subspecies auduboni. That forced the eastern bird to become Setophaga coronata subsp. coronata. We can identify either form and all hard-to-ID birds of this group as simply Setophaga coronata, the Yellow-rumped Warbler. I for one am glad of that because they can be hard to tell apart.
According to POWO, Crassula muscosa has three named varieties. Crassula muscosa var. muscosa refers to the typical variety (i.e., a distinct taxon closely related to the named varieties).
For example, if someone uploads an observation of Crassula muscosa var. obtusifolia, you might disagree by offering the ID Crassula muscosa var. muscosa. In effect, you are saying that the taxon is “none of the named varieties”.
If a new variety is added (or an existing variety is removed), the meaning of Crassula muscosa var. muscosa is changed. That is, every ID of the typical variety must be reviewed in light of the taxon change.
26.1. The name of any infraspecific taxon that includes the type of the adopted, legitimate name of the species to which it is assigned is to repeat the specific epithet unaltered as its final epithet, not followed by an author citation (see Art. 46). Such names are autonyms (Art. 6.8; see also Art. 7.7).
Ex.1. The variety that includes the type of the name Lobelia spicata Lam. is to be named Lobelia spicata Lam. var. spicata (see also Art. 24 Ex. 5).
Note1.Art. 26.1 applies only to the names of those subordinate taxa that include the type of the adopted name of the species (but see Rec. 26A).
The inclusion of the variety in the name Crassula muscosa var. muscosa is not actually redundant. Crassula muscosa is a species that contains several varieties, one of which is muscosa. Even though that name matches the species epithet, it is on a different taxonomic level.
Let’s consider an interesting example from the animal kingdom. The western lowland gorilla is Gorilla gorilla gorilla. The genus is Gorilla, the species epithet is gorilla, and the subspecies is gorilla. At each taxonomic level, the name distinguishes that taxon from other taxa on the same level, which have other names. The same applies to Crassula muscosa var. muscosa. That name distinguishes it from Crassula muscosa var. accuminata, among several other varieties. Crassula muscosa by itself is a valid name, but it refers to the entire species.
It doesn’t seem a major problem to me, since when the names are cited properly, the context and position of each name in the nomenclature avoids ambiguity concerning the taxonomic level of each. However the concerns expressed above in this discussion are understandable, since there is some confusion connected with this naming system, as the dialog demonstrates.
At the risk of adding to these concerns, following is additional information about the naming of taxa that may be interesting.
In the article Wikipedia: Quercus alba, see the information box on the right that describes its taxonomic classification.
I think it has been said in various ways but this simplification may help:
Crassula muscosa = Crassula muscosa var. muscosa + Crassula muscosa var. obtusifolia + Crassula muscosa var. parvula + Crassula muscosa var. polpodacea
It includes everything in all Crassula muscosa varieties.
Crassula muscosa var. muscosa = Crassula muscosa excluding Crassula muscosa var. obtusifolia, Crassula muscosa var. parvula, and Crassula muscosa var. polpodacea
It is all Crassula muscosa that is not included in any other recognized variety. You would only add var. muscosa if you know it isn’t any of the other varieties.
Yes. The first encountered and named by botanists using our western system of nomenclature. Not necessarily the first evolved. Not necessarily the most typical, either, though the variety that repeats the species name is often called the typical variety.
Example: Black Bamboo is Phyllostachys nigra var. nigra. It’s a mutant form known (only?) from cultivation. Phyllostachys nigra var. henonis is a much more “ordinary” bamboo and probably the ancestral form.
Var. muscosa has the same type specimen as the species, which was described before the other varieties. Var. muscosa is C. muscosa excluding the other varieties, which all have different type specimens and were described later. When other varieties are recognized, var. muscosa is automatically made to have a name that excludes all other varieties. When there are no other varieties recognized, var. muscosa goes away until someone decides to recognize other varieties again. Var. muscosa can mean different things depending on which other varieties are recognized at the time and what names have been lumped into each of the varieties but it always includes the type of the species.