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Groupie
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Joined: 10 Aug 2007
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  Quote digger Quote  Post ReplyReply Direct Link To This Post Topic: Classification
    Posted: 29 Nov 2007 at 7:52pm
Question Please could someone give me some insight and guidance . I am reading as much as i can about the subject of classification. As i understand things clematis are classified by species,pruning group and/or flowering times. So far i understand the process GenusClematis species and then cultivar. I am reading a wonderful book by mary Toomey, but I am beginning to get confused.I understand the species name relates to the particular plants origin, ie. C.montana rubens. This tells me the clematis is a montana and the cultivar is "rubens". i looked on a website at clematis i would like to own,but although it was a well know horticultural retailers website, some of the plants were just named Clematis "Danial Deronda" this merely tells me the particular cultivar? why is the species name not made available by the seller? In the book i am reading the clematis are split into "small flowered species and hybrids" and "large flowered species and hybrids". Do all clematis of a particular species flower at the same time of year? ie all montana early in spring? can a species have large floweres cultivars and small flowered cultivars? I have gathered that an integrifolia is a clematis that doesn't twirl it's stems to climb and so needs help, but is the word integrifolia a species? or is it just a word to describe a particular plants habit? I am not sure what the word "atragene" means is this a species?. I have looked in depth at the members section on this website, and  in the section clematis by pruning group, there re many abbreviations in the legend, whilst these are easy to understand and well set out, some names have letters relating to their flowering time only, are these flowering times ie. "Early Large" anything related to the species or are they just a guide to the flowering times? what is confusing me is that I don't know how many species of clematis there are, and i am quite eager to learn how many species there are, I am more confused when i see a clematis labelled "c. "bees jubilee" this only tells me the cultivar and not the species. Would it not be easier to tell us the species as well as the cultivar. Do cultivars from the same species have flowering in different pruning groups? I know some clematis will flower twice in the same season often with the first flower being a big showy double and then late in the season a smaller single flower may occur, but does this mean that all clematis that flower in the season twice are of the same species. I realise that i may well have mis understood something along the way and if so i ask for your patience, many many thanks in anticipation of your much needed help.
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Groupie
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  Quote digger Quote  Post ReplyReply Direct Link To This Post Posted: 29 Nov 2007 at 9:38pm
After doing more reading here and at the rhs i have begun to understand a little more i read the book review on this site and i have ordered the book "the genus clematis" by Magnus Johnson, after reading the review i feel sure that the book will answer most of my questions, except perhaps why some plant suppliers only supply the cultivar name
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  Quote digger Quote  Post ReplyReply Direct Link To This Post Posted: 30 Nov 2007 at 4:30pm
Doing more reading, Does anyone of you know exactly how many species of clematis there is??
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  Quote schristmas Quote  Post ReplyReply Direct Link To This Post Posted: 30 Nov 2007 at 9:26pm
Hello Digger,
 
I will try and answer some of your questions but I do not admit to knowing everything on the subject and I'm sure if I get anything wrong someone will put me right.
 
The area of classification has no definitive answer, many people have their own personal views on the classification of clematis with no one being absolutely sure they have got it correct.
To try and resolve the matter the International Clematis register was produced to try and at least provide some recogniseable stability within the genus but it is by no means set in stone (and the publication admits to this).
The RHS International clematis register broadly defines the existence of two groups (Small-flowered Cultivars and Large-flowered Cultivars). The small-flowered group is broken down into 13 more subgroups consisting of atragene, armandii, cirrhosa, texensis, viorna etc. while the large flowered group consists only of the Early-flowering and Late-flowering large hybrids.
At what point a small flowering plant becomes a large flowering plant can become a bit grey but generally the two groups are easily identifiable.
 
Species are defined as those plants found growing in the wild that have a genetic makeup recogniseably different to anything else. In the wild these species can mutate and when they have mutated to a point that certain recogniseable characteristics are different to the original species then they may be classified as a sub species.
For example C.cirrhosa is a recognised species within the cirrhosa group while C.cirrhosa var. purpurescens is a variety of the species also found growing in the wild. (note how species names are always written in italics with the name starting in lower case). In cultivation these particular plants are sometimes propagated by seed (wild collected or from the garden) and certain characteristics of the resulting offspring may be different to warrant the naming of the plant. This is the point where we get such plants as 'Freckles' and 'Jingle Bells' which are classed as cultivars of their respective species or sub species parents. Here again it should be noted that the cultivar name is written in quotations and starts with a capital letter. It is at this point that quite often only the cultivar name is quoted within documentation without the species prefix that generally accompanies it.
Where two different species are crossed it is the practice to give them a new name but prefixed by an 'X' (multiplication and not the letter x). this is where we get such plants as C. X aromatica and C.X triternata (C.X triternata being a cross between C.flammula and C.viticella which are from different groups within the small flowered types). Like always there are grey areas within this classification such as 'Edward Pritchard' which is also a cross between two different species (C.recta x C.tubulosa) but it was too late to start renaming plants just for the purpose of classification.
The groups within the small flowered clematis are based upon characteristics of the individual plants contained within them. For example the viorna group display nodding urn or bell shaped flowers, with 4 thick re-curving sepals on that years growth and are generally herbaceous in nature. There has always been some discussion as to where some specific species should reside in what group and whether they should have their own group but hopefully you can see the concept.
As to the Early-flowering Large cultivars these are based upon previous cultivars grouped under the category of Patens containing the species C.patens and Fortunei which was based upon a plant introduced from Japan a long time ago but it was not a species in its own right. These plants display large flowers which flower early in the year from last years growth and give a later flowering from new growth. This group has the largest number of members.
The Late-flowering Large category was made up of cultivars from the previously categorised Lanuginosa group containing C.lanuginosa or the Jackmanii group. These have the characteristic of displaying large flowers from the current years growth. 
 
At the moment there is generally recognised to be well over 330 different species of clematis.
 
Steve
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  Quote digger Quote  Post ReplyReply Direct Link To This Post Posted: 30 Nov 2007 at 10:16pm
Thank you for your detailed reply steve i do appreciate your time. Is the current trend now to group the plants according to flower type and flowering time? I had no idea that there are over 330 species, I had better not ask how many cultivars:-), I think it would be a good idea for me to get the international clematis register from the RHS, many thanks for your time steve.
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  Quote MMiller Quote  Post ReplyReply Direct Link To This Post Posted: 01 Dec 2007 at 2:32am
Yes, this is a bit of a complex question.  I'll try to continue to elaborate on what Steve said. 

First, for an understanding about cultivars, you can research clematis cultivars easily at the Hull database (http://www.clematis.hull.ac.uk/new-clemlistsearch.cfm).  For instance, you could type in 'Tetrarose' and find out that it's a Montana group that will bloom in the spring.

A simple way of looking at clematis might be a basic grouping. 
  • Montanas that bloom on old wood in the early spring
  • Early Large Flowered Hybrids (LFH) that bloom on old wood in mid spring.  These usually have blood from C. lanuginosa, patens, fortunei, and others.
  • All types that bloom on new wood that are cut down each winter, like those with viticella blood, or viorna group blood.  Some would consider the former large; the latter small.
  • Ones that bloom in the summer on new wood but are not climbers, like integrifolias, tubulosa/heracleifolias, etc. , though the latter do not need to be cut down, they just happen to die off herbaceously in cold climates like mine
  • Ones that bloom late in the summer/autumn; these are usually much smaller-flowered
  • Winter bloomers
Another easy grouping are ones that bloom on old wood (form flower buds on wood grown the previous season) and ones that can develop flower buds on new growth created from spring on.  Pruning types 1 and 2 are old wood, type 3 is new wood.  Some call groups 1, 2 and 3 "A, B and C."

For a more complex grouping, the genus clematis has been divided into these subgenera:
  • Clematis
  • Cheiropsis
  • Flammula
  • Archiclematis
  • Campanella
  • Atragene
  • Tubulosae
  • Pseudoanemone
  • Viorna
Those subgenera are further broken up into sections, such as:
  • Clematis
    • several sections
  • Cheiropsis
    • section Montanae (thus the montanas)
    • others
  • Flammula
    • section Flammula
    • section Viticella
...
  • Viorna
    • section Viorna
Some of these sections are broken down into subsections, like:

  • Viorna
    • section Viorna
      • subsection Viorna
      • subsection Crispa
      • subsection Fuscae
    • section Integrifolia
      • subsection Integrifolia
      • subsection Baldwinii
...etc.

Two books with this information would be Johnson's The Genus Clematis and Grey-Wilson's Clematis, The Genus.

Good luck.




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Groupie
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  Quote digger Quote  Post ReplyReply Direct Link To This Post Posted: 01 Dec 2007 at 8:50am
Thank you for your replies, I shall as you advise visit the link you sent, I have ordered the book by magnus Johnson and I shall look up Grey-Wilsons also. I was beginning to become very confused with regard to species and both replies have been most helpful, thank you.
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  Quote Mariko Quote  Post ReplyReply Direct Link To This Post Posted: 01 Dec 2007 at 10:39pm
I appreciate Mr. Steve and MMiller a kind reply.
Thank you.
Hi Digger, It was good.

Mariko Japan
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  Quote digger Quote  Post ReplyReply Direct Link To This Post Posted: 02 Dec 2007 at 12:01am
Hi Mariko my friend thanks to everyone who is offering me some help, I am grateful to you all, Things can (and do) seem a little overwhelmng at first, but Clematis are the most amazing genus, which is something i think we would all agree upon.
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