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Thoughts on Epiphyllum naming
Naming based on Cotyledon Classification
- a grower's view point - Grant Bayley
Things you probably know.
There is a plant society club called The Epiphyllum Society of America. They produce a 'Directory of Species and
Hybrids' of epiphyllums.
There are a group of plants we grow called epiphyllums. We even have nurseries that call themselves Epiphyllum Nurseries.
Then we have a group of plants which are named epiphyllums because the taxonomists tell us these are their names.
We 'try' to accommodate these names - Epiphyllum and Disocactus.
So we use the names like epicacti to try and accommodate what the taxonomist tells us to be 'scientifically' correct...
We grow these plants and know more about them than the person who creates their naming system. So what are we doing about the 'correct names'
of these plants?
Waiting for the taxonomists to finally get round to sorting out the naming system so it also works for us as well? Or do we tell them they've
got it all wrong because there basis for naming is, in part, unscientific?
It's time we told the taxonomists that we have a system, based on science and "popular name usage" which works for us, and because we can use
a simple distinguishing feature, we would solve the confusion that continues with these plants and the name arguments that have occurred in the past.
In Scott E. Haselton's book 'Cacti for the
Amateur' Pasadena Abbey Garden Press 1947, he states
"These young plants (cacti) with their variations in seed leaves are more helpful than mature plants in determining the chain in evolutionary
development."
(page 2) And later (page 107) says "Seedlings have scientific value in tracing the evolutionary relationship of the various genera,
since this stage is lost as the plant grows older.
... Thus it will be seen that a careful study of seedlings helps one to learn the various genera and to trace their evolutionary development."
So, scientifically based on cotyledons (that's the seed leaves that emerge from the seed) and using popular name usage, we have to set up
a simple and easy system that works.
Seedlings to the left of the ruler are, at present called, Epiphyllum hookeri, the one to the right are Epiphyllum crenatum.
These seedlings are around the same age.
Check your pea and bean cotyledons and see how differrent they are.... The cotyledon on these two Epiphyllums are too distinction and different to be
classified as the same genera so we propose, using the cotyledons to group plants
into Epiphyllum and Phyllocactus genera. So what other differences do these two groups with different cotyledons have? The large seed leaf type
do not have a juvenile stage in their growth, where as the smaller cotyledon type have a distinct juvenile stage. And what else?
Well, the large cotyledon type have 12 hour lasting flowers, and the other group have 3 day flowering length.... Seed size is different between the
two types .... and there are probably more characteristics, but this will do to start with .... But then the groups generally hybridise with those in the
same cotyledon size and characteristics.
The two names (Epiphyllum and Phyllocactus)
are commonly used internationally and if we use one distinguishing feature (cotyledons) to separate these two group names,
we have a simple and easy naming method.
Because I don't have access to all plants in the epiphyllum and disocactus plants, we give only the names we know that fit the simple
cotyledon criteria used here. Maybe you can help if you have more information to furnish these lists. If cotyledon information is,
at present, not available for all these species, then, then by using the above critera of the length of time the flower is open
(12 hours - phyllocactus - or approximately three days - epiphyllum),
would give a probable indication what the cotyledons would probably look like.
The names are listed old names then new proposed names .
Epiphyllum crenatum = Epiphyllum crenatum
Epiphyllum cooperi = Epiphyllum cooperi
Epiphyllum anguliger = Epiphyllum anguliger
Disocactus speciosus = Epiphyllum speciosus
Disocactus nelsonii = Epiphyllum nelsonii
Disocactus ackermannii = Epiphyllum ackermannii
Disocactus eichlamii = Epiphyllum eichlamii
Disocactus phyllanthoides = Epiphyllum phyllanthoides
Disocactus ackermannii = Epiphyllum ackermannii
Epiphyllum oxypetalum = Phyllocactus oxypetalum
Epiphyllum cartagense = Phyllocactus cartagense
Epiphyllum caudatum = Phyllocactus caudatum
Epiphyllum grandilobum = Phyllocactus grandilobium
Epiphyllum hookeri = Phyllocactus hookeri
Epiphyllum thomasianum = Phyllocactus thomasianum
Epiphyllum pumilum = Phyllocactus pumilum
So you say "not another name change"? Well no, not until the taxonomists recognise that this naming method,
I describe, has more scientific merit that what they have used before!
BUT if we start using these names described in this new naming system,
the taxonomist will have to follow our lead as it has more merit that what they have suggested so far!
Terms used in text.
Cotyledons. The (in this case with Epiphyllum and Phyllocactus) two real leaves that emerge from the seed as it germinates.
These are the only leaves a cacti has and are lost as the cacti grows.
Genera (Genus). The plant naming system is a binomial (two names)
system where a plant generally has a name made up of two words,
the first is the 'genera' = the group name, like 'Epiphyllum' or 'Disocactus'
The second name is the distingushing species name is like 'crenatum' or 'speciosus'. Thus Epiphyllum crenatum or Disocactus speciosus.
Scott E. Haselton. He also wrote a book called "Epiphyllum Handbook" 1946 Abbey Garden Press Pasadena.
His book, today is still the best book written on how to grow Epiphyllums.
And has helped strengthen the use of the term 'epiphyllum' with our three day flowering cacti.
Taxonomist. They are scientists who try putting together a naming system based on information they find at the time.
Information can change with new discoveries and this can lead to the horror of horrors ... name changes!