Don't grow it but here is a picture of it on COTW.

Here is a link that might be useful: Bill MacKenzie on COTW

Mine did not have the reddish filaments which I thought would look great with the purple leaf plum.

Lousy pic below but you can barely see the filaments are green....

Here is a link that might be useful: Mine

Didn't realize I had uploaded this one....

Here is a link that might be useful: a better picture

I grew one from seed. Does look like pic on COTW. One single plant covers 6 ft by 6 ft fence. It really quite a show, blooms late August- end of September for my neighbor's actually as I can not grow it in my shady garden. Many clems do well for me but no yellow varieties. I would not say that purple stamens are all that prominent/ it is small flower plant to begin with/ but flowers do look good and colorful en masse. I still might have some seeds if you want any.

Since Bill MacKenzie is a hybrid it won't come true from seed so perhaps that is why Linda's does not have prominent purple stamens. It could be the same for yours BorS (seed grown vs. vegetative reproduction??).

I have grown the species, My Angel, and Helios and to the best of my knowledge they had some coloration to the anthers other than just a creamy yellow. I say to the best of my knowledge since all three were too rambunctious in my garden--My Angel and Helios suckered all over the place and were too invasive for my small garden and tangutica the species seeded itself worse than sweet autumn clematis--so they were all removed from my garden. I have heard others say they are better behaved in their gardens but those people tended to live in areas where the weather on average was colder than in my zone during the summer and especially the winter.

I'm really glad this topic came up, as it's been bothering me in the back of my mind for years and while I've done a bit of research, I still don't have any concrete answers.

It was always my understanding that 'Bill McKenzie' was a named selection of C. orientalis. And if you do a search under that cultivar name, you will typically get a lot of hits referring to it as such. But, you also get about as many referring to it as a tangutica, or often, as belonging to the 'tangutica group'. To take it a bit further, I often encounter those two species names being used interchangeably. My own personal clematis resources refer to them in both ways, so they are little help.

So what's the deal? Are these two species really the same plant? They sure look a lot alike - similar foliage structure, same large, attractive silky seed heads, same yellow flowers, similar rambunctious growth habit. And if they ARE in fact distinctly separate species, to which exactly does Bill belong? BTW, I've also seen 'Helios' labelled as C. orientalis as well. Ditto 'My Angel', although that seems to be a hybrid between orientalis and intricata (according to the patent holder). Can you say "confused"!!?? Does anyone have anything to substantiate or clarify this issue one way or the other?

I have what was originally purchased as C. orientalis 'Bill McKenzie' growing through my apple tree. Because of the above, I'm not at all sure what I have. Irrespective of what species it belongs to, I have also read that Bill is most often available as a seed grown plant so as Miguel notes, there could be a great deal of variability in its appearance. If you look at a selection of Google images, you will see about as many with gold or greenish anthers as you do of those with the maroon or purple tones. I don't have any photos to confirm the coloration of mine in particular but I'm not sure that it makes a huge difference one way or the other......this is not a modest little vine - it grows quite large and while it blooms profusely, the bulk of the blossoms are quite high up in my tree and their bell-like form doesn't allow for easy viewing of the interior. To relate specifically to BorS's situation, once it grows well up into your plum, I doubt you'll have much opportunity to notice the lack of purple anthers......the flowers just don't lend themselves to easy viewing of the interior unless they are down close to eye level. And even then you would have to look up inside the bell to confirm.

Pam, I don't know other than what I have read or seen in books or COTW. COTW refers to it as either tangutica or orientalis 'Bill MacKenzie' but does have its parentage as Tibetana ssp vernayi var vernayi 'Orange Peel' X tangutica indicating to me anyways that it arose as a cross of the two aforementioned clematis.

The Toomey and Leeds Encyclopedia classifies it as being in the tangutica group, its origin being an open-pollinated seedling found by Bill MacKenzie, and then basically says the same for its heritage as that noted on COTW.

Magnus Johnson's The Genus Clematis says that it was once thought to be a cross between C. tangutica and C. tangutica subsp. obtusiuscula. In a rather interesting story related in the book, it is related that the original plant was discovered by MacKenzie as a seedling in the gardens at Waterperry Horticultural School growing between two fully developed plants of clematis orientalis and C. tangutica. (this could at least explain why it is referred to as tangutica by some and orientalis by others).

The more you research the more you realize that the plant's true heritage is really unknown and based on conjecture or assumptions. The book goes on to say that it must be propagated through cuttings to preserve true properties and that the plant easily germinates from seed which has resulted in bad clones often found in nurseries.

I guess the bottom line is that you either love it or not!!! Knowing the parentage is really not a requisite for me for the clematis in my garden. Probably a good thing since I am raising them from seed! ;)

I have 'Helios' and it has never been weedy or seedy. This will be it's third or fourth summer. I can't remember. It is taller than the Bill MacKenzie and it isn't supposed to be.

I'm hoping the one in the plum tree grows taller this year. If not, I'm ripping it out and planting 'Huldine'

I'd like to rip out the plum tree, it always has aphids and fungus. I'm just not a sprayer. DH won't let me though.

Helios wasn't weedy or seedy in my garden either BorS. As I said in my earlier post, it spread out runners in various directions much like My Angel and for that reason it was removed. Tangutica on the hand was weedy and seedy.

I've got no runners either but maybe I haven't given it enough time to show it's true character. I do have heavy clay soil with tree roots where it is planted so that might affect it as well.

Could be BorS. I garden in clay as well but don't have the tree root issues. My Helios had a nice coconuty fragrance. Have you noticed that on your plant?

I did notice that COTW has Helios listed as both tangutica Helios and orientalis Helios just like for Bill MacKenzie.

Here is a link that might be useful: Helios on COTW

I had the oddest experience with this clematis. I planted it, it grew like a wild thing last year, set buds and then the entire clematis turned brown and crispy before it had the first bloom. All the clematis and roses around it were fine. I have no idea what could have happened!

Carol

Wow Carol. That is strange. Did it ever recover or perhaps that is a question better asked later in this season??

I had a similar thing happen with a triternata rubromarginata two years back (it did flower however before it browned out) and it never returned the following year. I know that TRM is finicky about wet winters but this happened during mid summer and like your experience, the surrounding clematis had no issues.

I don't know yet Miguel. I'm still waiting to see if it shows back up :-). It wasn't wilt or anything like it, just brown and crisy almost overnight.

Carol

Yep, that sounds like my TRM summer before last. It didn't return last year at all.

Hi Folks! Major long time since I have visited this forum, looks like it has gotten busier again which is good. I struggled for awhile to obtain the REAL Bill McKenzie and even had a post about that years ago here. I got plants from a number of places and they seemed smaller duller flowered than the descriptions of B.M. I had seen I finally talked to Murray Rosen at Chalk Hill about this and he told me that he had sought to find the real plant too, and that the plants they were selling as B.M. were obtained from England and were vegetatively propagated and not grown from seed. The plant I got from him is large flowered (relatively), golden yellow, very floriferous and very vigorous. I am growing it on a 10' tuteur and it covered it and then some the first season and was covered with flowers. I am sure it can get much bigger, but I prune this to the ground and that's the height of the structure anyway -- it does romp around on adjacent plants some which is nice. Unlike some of the impostors I had, this one does not seem to seed around (prolific seeders is an understatement for the others). I plan to divide it this year and grow it on wire up the side of my brick and stone house. Whatever it is, it is a delightful plant.

As y'all know, Chalk Hill unfortunately went out of business.....

David

Kind of difficult to identify as far as I am concerned since many of the tanguticas/orientalis look way too similar for me. I did have Helios at one time in my garden and its blooms had a definite coconut fragrance to them. That is one thing that you might want to check out.

No coconut fragrance at all. No fragrance of any kind.

Then you can probably rule out Helios as its identity. Like I said previously, unless you have a key and are good at taxonomy, trying to figure out what you have is going to be difficult. It used to drive me crazy when I purchased a clematis that was supposed to be one thing but then it turned out it wasn't. I was upset when I didn't know what I had. Now, if it is something that I like and it gives me joy, that is all that concerns me. The absolute identity is immaterial at this point for me! :0

Seattlesuze, the pic of your mystery yellow clematis has me smitten. Is there any way you would be able to send me some clippings when you prune it? Hope to be able to grow it from a clipping. As no one has been able to identify it, this would be the only way for me to get it. Cost is no object. I am in Zone 7a, Long Island, NY. Please let me know how i could contact you. P.S. what is its bloom season?