Scottish Rock Garden Club Forum
Plant Identification => Plant Identification Questions and Answers => Topic started by: cohan on September 16, 2010, 09:30:45 PM
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this plant is growing on my property in a fairly shady break in the woods, in an area that is mowed--it has been there for some years, usually getting mowed over--a half dozen rosettes, stretched in a line several metres long; i marked a couple of the rosettes to mow around the last couple of years, and this one rewarded me by flowering this year..
beyond what you can see in the pics, the rosette especially is fuzzy, both pale and purply, and prickles are rather soft--much more so than C arvense, for example, which is very common here; flowers are also much larger than C arvense, being 2-3 inches across (didn't measure :-[ )
the local candidates seem to be:
1-Cirsium flodmanii- should have single heads at the end of several stems--this had 3 heads at the top of one stem' doesn't seem to have the purpliness
2-Cirsium hookerianum-- looks about right vegetatively, but should have white flowers, not pink-purple
3-C undulatum-wrong habitat and shouldn't be in my area; also single flower heads
4-C vulgare-uncommon weed- again, single flower heads, should be pricklier...
so--another species not listed in my book? (didn't find anything online..) or, a hybrid of the first two? colour variant of numb 2? whatever it is, it is not common in my area, haven't run into it anywhere else, but if it is in this sort of semi shady woodland, thats mostly private land and i wouldnt see it...
if i really dig, i might be able to find a shot of pre-flowering rosette....
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Smart thistle- though I can tell by its accent its not Scottish! ;D
I'll be keen to hear what the Canadians reckon to the ID..... nice looking thistle an no mistake,
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thanks, maggi :) i really like it, though i'm mostly wanting to know whether to encourage it (= native) or keep it in check (=foreign invasive) ..at least i know it didn't invade from scotland!
its just dropped a big blob of seeds (no blowing around, as our weather has been something scots might recognise--cold and wet!) and i have to pick them up for sharing and sowing in one case, disposal in the other!
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i did find some better foliage shots from earlier in the season before the flower stem stretched out fully (btw, i think it was about 50cm tall, i could check if it matters...)
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My goodness, it just gets better, doesn't it? 8)
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it is a cute fuzzy thing, isn't it :)
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i went out and picked up the seed head--which was just a damp dead flower, basically, and brought it inside..there it sat ignored for a while, until i went near the area and noticed a large mass of dry fluffy seeds, with wings extended ready to fly on the slightest breeze-luckily it isn't near the ceiling fan!
anyone want some seed, even though i still don't have a name?
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Handsome is as handsome does and I suspect it could very easily become a major menace. If it's a Canadian native, you're very welcome to it Cohan. Please don't be sending any in this direction. We have more than enough to cope with already. >:(
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Handsome is as handsome does and I suspect it could very easily become a major menace. If it's a Canadian native, you're very welcome to it Cohan. Please don't be sending any in this direction. We have more than enough to cope with already. >:(
lol--same could be said for a great many other plants--especially other asteraceae with fluffy seeds such as this.. this is why i wanted to collect the seeds until i know what it is!
i still haven't been able to pin it down, but the odd thing is that i have seen no others in my area (i certainly don't see all the land around, but obviously common plants crop up repeatedly, and our invasives-in the countryside-are all agricultural weeds, widespread around fields, roadsides and farmyards....)
our prevalent thistle --a very common and problematic weed-is Cirsium arvense-ironically called Canada thistle, when its a european invasive, like most of our problem weeds....
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Cirsium arvense is the bane of my life too and I know it as Californian thistle though my mother always called it Canadian. Most unfair considering its origin.
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Cirsium vulgare? Spear Thistle. Has yellow tipped spines, is downy - biennial... Leaves are deeply pinnately lobed - reckon I can see all those three features in your photos.
See also: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200023702
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i'm not sure, stephen, that's what i was thinking before i started looking into it, and it may be; i don't know how variable the species is--mine just did not seem as prickly as those i see in photos, though, looking more online now, i see some immature rosettes that look more like mine than initially i thought...
the differences i see from images and descriptions:
-C vulgare is described as having longer stiffer spines than C arvense, my mystery thistle is softer than arvense, really just barely prickly, and hairier than most of the images i see of vulgare,including hairy stem (that seems to be variable?)
-C vulgare is said to have single flower heads per stem, whereas mine had a cluster of three;
-bracts on the flowerhead on mine seemed much less spiny than pics of vulgare and the bracted base of the flower head seems larger relative to the 'disc' than on my plant...
however, as i said, i don't know if these characters vary and this is just a variant vulgare, and/or if the several species of Cirsium in the broader region (only arvense is commonly seen here, and it's very common) hybridise??
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Cirsium arvense is the bane of my life too and I know it as Californian thistle though my mother always called it Canadian. Most unfair considering its origin.
i like the idea of calling arvense 'california thistle' takes away the blame from us, and makes it seem like we have something more exotic growing here ;)
in gardens here its unlikely to go away, but manageable enough... in some fields its a real problem...no weed bothers me like the d****d buttercup though (not in my garden, but in semi wild pastures etc)
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having spent some time on north american efloras (in spite of not having live flowering plants in front of me to check some things, and not 100% certainty that i have understood some of the terms correctly...) i think Cirsium flodmanii is my best bet; i hesitated at this sp initially, because in my book it seemed yo have only single flower heads, and mine had 3; the eflora says heads borne singly or few, so i think it still is in the running..
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250066371
the dist map in royer and dickinson includes my area, and although described habitat in efloras sounded better for hookerianum, that species is less apt, in having sprouts from a taproot, whereas flodmanii has a horizontal runner root--my plant has a several rosettes spread out along a long line..
compared to photos online, my plant does seem chunkier, in spite of being in a rather shady spot, so perhaps its a variant, or a hybrid-the species notably hybridises with undulatum, which species also seems a pretty good match, though it should be farther south in drier environs....
it does not seem right for C vulgare, in particular looking at the base of the flower head of my plant (involucre; stop me if you catch me using any terms incorrectly ;D the bracts which comprise the exterior of the involucre-- phyllaries-- have a notable whitish ridge (as in flodmanii and hookerianum) a darker area below the ridge (flodmanii), and the spines at the tip of the phyllaries are abruptly (flodmanii) spreading (hookerianum) unlike in vulgare..
oddly, on my fairly extensive rides around the area, i have not seen a single other thistle other than arvense, though of course you would not see them in passing out of flower...
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Cohan, I haven't pored over your photos and description in much detail, but I thought I'd just add the following...
-C vulgare is said to have single flower heads per stem, whereas mine had a cluster of three;
Flora of Alberta disagrees, and says of C. vulgare, "heads usually several".
The F. of A. key also makes the following basic distinction between C. vulgare and the native species - "upper surface of leaves scabrous with appressed spines" (= C. vulgare); "upper surface of leaves not scabrous" (= the 6 native species). From your photos, the upper leaf surfaces look scabrous (rough) but I may be misled...
I can't say I've studied thistles enough to help out particularly, other than to confirm that it is not C. hookerianum, which I do take note of and always enjoy seeing (see links for photos of it):
http://nargs.org/smf/index.php?topic=131.30
http://nargs.org/smf/index.php?topic=361.0
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Cohan, I haven't pored over your photos and description in much detail, but I thought I'd just add the following...
-C vulgare is said to have single flower heads per stem, whereas mine had a cluster of three;
Flora of Alberta disagrees, and says of C. vulgare, "heads usually several".
The F. of A. key also makes the following basic distinction between C. vulgare and the native species - "upper surface of leaves scabrous with appressed spines" (= C. vulgare); "upper surface of leaves not scabrous" (= the 6 native species). From your photos, the upper leaf surfaces look scabrous (rough) but I may be misled...
I can't say I've studied thistles enough to help out particularly, other than to confirm that it is not C. hookerianum, which I do take note of and always enjoy seeing (see links for photos of it):
http://nargs.org/smf/index.php?topic=131.30
http://nargs.org/smf/index.php?topic=361.0
thanks lori, my original impressions of numbers of flower heads were from the (as we know) limited royer/dickinson book; looking at eflora of north america, it seems that isn't much of an identifying character for any of the species involved here, at least, almost were, if not generally multiple, then something like 1-10, or 1 or a few, etc....
as far as scabrous, some of these terms seem so relative, its really hard for me to judge some of them having no other thistles to compare to, other than C arvense..i didn't specifically test for roughness of the surface (i may check--there are probably still overwintering rosettes of those that didn't flower).. i know the overall 'feel' of the plant was more downy than prickly, and eflora mentioned vulgare havinga kind of prickle on the upper leaf surfaces, which i don't think i see on my plant, but again, with no sufficiently close images (let alone live plants) of any other thistles to compare to, i sure wouldn't swear to it...
the involucre, however, as i mentioned above, does not look like vulgare at all, and while not as marked on my plant as some images i have seen, the white ridge on the phyllaries which clearly exists on mine, is not supposed to appear on vulgare; nor does the form of the phyllaries on mine--flat to the involucre, tip spines abruptly spreading outward, seem to match descriptions or images of vulgare..but these things are hard to do from photos, i know, and i may be missing something obvious to someone with more thistle experience....
from what i've seen/read if maps and habitat, it didn't seem hookerianum should appear here, but of course maps have been wrong before, however, this plant is in a habitat more woodland, and moist, than anything else...
what are the rest of the 6 native species, out of curiosity? i didn't find that many species that mention alberta on efloras....
hookerianum, flodmanii, undulatum, drummondii...
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ok, of course i didn't get good photos of the involucre and phyllaries, not realising that was important..lol--it may take me several years to get the right images of some plants....
but here is the best i have, the detail on the smaller head is clearer--note the white ridge, dark, bent phyllary tip spine, which as far as i can tell, are not typical of C vulgare..
even clearer than in my photo is this image of C undulatum from saskatchewan -not the same as mine, probably, but similar phyllaries, distinct from vulgare, in the second link...
http://em.ca/garden/native/nat_Cirsium%20undulatum.html
http://www.discoverlife.org/mp/20p?see=I_HLV151&res=640
also a close-up of a cauline leaf of mine, i've been peering at it, and trying to find web images to compare to, but simply can't say if this is what they call 'scabrous with (i assume they mean -due to-) appressed spines' i'd need to see a good image of each to know... leaf texture on mine does not seem different to me than images online of other natives, but again, i could easily be wrong looking at web pics.....my feeling again, was that this plant is more fuzzy than prickly, but i can't compare it to anything but arvense, which is much pricklier....
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There's a nice clear photo of the leaves now (your second photo, immediately above).
From eFlora of N. A. (which also says, by the way, "heads many" for C. vulgare):
"Native to Eurasia, Cirsium vulgare is the only thistle in North America with bristlelike spines borne on the adaxial leaf faces. These structures are variously described in the literature as trichomes ("spreading hirsute," "scabrous-hispid," "coarsely hispid," "rigid, rather pungent setae," "prickly-hairy"), prickles, or spines ("setose-spinulose," "appressed and dense spines")."
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200023702
"Adaxial" leaf surfaces = upper leaf surfaces
I dunno... as I said in the disclaimer ;), I don't know much about thistles... but, based on the above (which corroborates the F. of A. key), I think your thistle is pointing to C. vulgare... ?
Here's a closeup of the lower leaves of C. hookerianum, for comparison... said not to be scabrous, lacking appressed spines, in F. of A.. I think this photo shows a clear difference, which may be what the F. of A. key was trying to get across. The leaves near the inflorescence on C. hookerianum become woolly, with tangled hairs, but not spiny (second photo).
Oh, and the other 2 native thistles are C. foliosum and C. scariosum.
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There's a nice clear photo of the leaves now (your second photo, immediately above).
From eFlora of N. A. (which also says, by the way, "heads many" for C. vulgare):
"Native to Eurasia, Cirsium vulgare is the only thistle in North America with bristlelike spines borne on the adaxial leaf faces. These structures are variously described in the literature as trichomes ("spreading hirsute," "scabrous-hispid," "coarsely hispid," "rigid, rather pungent setae," "prickly-hairy"), prickles, or spines ("setose-spinulose," "appressed and dense spines")."
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200023702
"Adaxial" leaf surfaces = upper leaf surfaces
I dunno... as I said in the disclaimer ;), I don't know much about thistles... but, based on the above (which corroborates the F. of A. key), I think your thistle is pointing to C. vulgare... ?
Here's a closeup of the lower leaves of C. hookerianum, for comparison... said not to be scabrous, lacking appressed spines, in F. of A.. I think this photo shows a clear difference, which may be what the F. of A. key was trying to get across. The leaves near the inflorescence on C. hookerianum become woolly, with tangled hairs, but not spiny (second photo).
Oh, and the other 2 native thistles are C. foliosum and C. scariosum.
tks, lori--i had already read the section of eflora you quote, and obviously saw my own pics ;D but i had not been able to decide, based on available information, whether the 'hairs' in my photo were the sort of spines they are talking about; they are also not appressed, though i think there was a qualifier in the full text which said 'more or less' so if not at all falls withing more or less...lol
--i need to go out and see if there are some leaves on plants that did not flower and feel to see if those hairs are in fact bristly/spiny(i remember overall the plant did not feel very spiny, but i imagine this is a matter of degree relative to other species..)..if so, then vulgare it may well be.....
there would remain, however, the issue of the white ridges on the phyllaries, and outward spine tips on phyllaries which do not match vulgare according to the same eflora; they also mention numbers of series of phyllaries, which seem low on my plant--though it would seem that could be affected by growing conditions--i.e.--a cold year, shady conditions might lead to smaller flower heads which could have fewer ranks of phyllaries? of course then we are into wild speculation on my part....lol
there are also characters based on the seeds, which i am working on absorbing as well, since i have a great pile of those safely bagged... in case its vulgare, i didn't want them floating about-though its clearly no important weed in my area (amazing enough, given the number of seeds from one plant!)..
i clearly spent too much time reading about thistles yesterday--i had species names floating around in my dreams last night ;) its been a good exercise, brushing up on some botanical terms and getting myself wrapped around some of those used especially in Asteraceae..
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well, i just managed to remember, while i was collecting branches for kindling, to look for immature rosettes, and managed to find one among the fallen leaves..
on the broader immature leaves, the hairs/bristles/spines were easier to look at, even with the naked eye (i'll still try to get a photo for a macro view)--and while very small and not prickly, they were much more appressed than on the cauline leaf in the prev photo, and could certainly be said to give a scabrous feel to the leaf, lacking still any other leaves to rub for comparison ;D
-so that does look like C vulgare, which still leaves me wondering about the out of place phyllary/involucre characters ??? maybe i have misread/understood the glutinous ridge on the phyllaries- which i took to be the whitish ridge down the centre...