Trillium IDs please

[Tiggrx]

I would appreciate some help naming these Trilliums please. The first was photographed at Durham Botanic Gardens, UK and the rest at Howick Hall Garden, Northumberland, UK

Thanks for any help
Aaron

[Greenmanplants]

Aaron,

Good Luck

Identifying Trillium from single photographs that don't show the innards of the flower structure is dubious at best.  Especially as they hybridise fairly easily and if you don't know exactly where they came from...garden origin is likely to have had some influence.

Having said that..
The first and third look to be Trillium kurabayshii, a West Coast trillium often seen under various names such as T. cloropetalum (rubrum or giganteum).  Largely because it was only distinguished in 1975 and there had been lots of collections made before then from this area which also contains T chloropetalum and T angustipetalum.  Suffice  to say, from the large clump, it loooks likely.

The second looks more like T cloropetalum.

You'll need to post another picture for the 4th, when it's in flower.

You would also have a better chance speaking with the people at Durham or Howick Hall.

[Tiggrx]

Thanks for your help. I had a feeling they might be tricky to ID 

[Paul T]

Aaron,

On some lists I have seen experts argue over what a particular Trillium was, and in some cases the "species" comes down to which side of a particular river it grows on.  The sessile species (like in your pics) in particular are apparently a hopeless muddle and hybridise so readily that unless you have a plant that was collected from the wild it becomes very difficult to be sure of a name.  That said, some are easier than others and there are identifiers that can help you at least work out the major influences in the breeding of the plant.  I am NOT one of those who knows them and can help much. 

Good luck with Durham and Howick Halls knowing what they are growing.... that would certainly be the first thing I would be checking if it was me.  The odds are probably pretty good that they won't know for sure either, but you just never know.

All the best.

[Tiggrx]

Just to report back that I have been in contact with the head gardener at Durham Botanic Gardens who was very helpful. He believes that the plant which I photographed there is Trillium ludovicianum (or T. ludovkianum as on their label). Their plants originated from a Ardfearn Nursery in Scotland.

I have attempted to contact Howick Hall, but the e-mail I sent bounced back. I shall try again and let you know any results.

[Afloden]

 My two cents;

  I agree with John on the kurabayshii as the 1st and 3rd, but the second looks like angustipetalum in color, but maybe the petals are too wide, the last looks like a cuneatum. I would not call any of them T. ludovicianum, but do try to key it when it flowers and another picture would be nice also when it is open - see below. Use this key; http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=133668.  This is essentially the same key as in the F. & B. Case book, after all this was written by F. Case.

 As far as hybridization in the eastern species, the sessile species are not promiscuous in the least in the wild (speaking from extensive experience) and the past ten years in my garden. I have yet to see or hear of any man-made hybrids of the eastern NA sessile species. I have come across a few populations that are strange, but not what I would call hybrids. The only Trillium that I suspect is a hybrid, but have yet to confirm, is T. recurvatum "Shari's Flame" which has the petal shape of T. sessile, but the gross morphology of T. recurvatum. Even the new T. oostingii was originally thought to be a hybrid, but all chromosomal and genetic work says otherwise. I am letting nature takes its course with a clump of T. gracile and T. discolor this year both of which opened at the exact same time. In 3 or 4 years I'll know if they hybridized. The T. erectum complex, especially T. rugelii and T. vaseyi are another matter. It is likely that they are so closely related and still in the long process of speciation since the last ice age that they can still be so promiscuous and create outstanding populations with great variation, the T. rugelii dominant in gross morphology, but with color provided by T. vaseyi. The only problem with this is that in two of the "hybrid" populations there are no plants that could be called pure T. vaseyi, but there are pure T. rugelii. Even the genetic markers so far used do not provide enough information. The western species are another matter from what I hear as I have yet to see them all in the wild.

 Aaron Floden
 Knoxville, TN
 UT Herbarium