Most (or maybe all) of what I am posting right now are are spines or prickles, not thorns, but I don't really get it, though every few months I read up yet again on the differences. Anyway, these are not questions, and anyone is welcome to post uncomfortable-looking photos here. I am starting with Robinia pseudoacacia, which we mostly see unarmed, though the Vancouver Trees App notes that "the stipules on some stems of Robinia species eventually harden into spines ...". I am posting an old photo of a branch just to show what we usually see. This tree was cut down last year, and the building in the background was fairly new, having replaced the original church that burned down in a fire; now a highrise rental building has replaced that. But around the corner is a seedling that looks like what I will show in my next example. What really got me into this is the few dozen Robinia pseudoacacia seedlings in Queen Elizabeth Park, in several spots at around 20 meters of the old tree. Another tree that I seldom see armed, but has well-armed young growth is Aralia elata. I have not seen prickles on this adult tree at the West End Community Centre. The adult trees on the property of this condominium building have been removed (first photo), and this fine collection of youngsters is long-gone, but they were very impressive. I have recently posted this Colletia sp. in the Fragrance thread, but it certainly also belongs in in this thread, with its hefty spines (actually thorns). [Edited - I wrote "spines" because I read that somewhere, but I have since wondered why not "thorns", and now I see that "thorns" is correct. See posting #9.] Here is a little pond in Devonian Harbour Park, at Coal Harbour just east of Stanley Park. The planting here is doing a good enough job at keeping people out of the pond. The anchor planting is Gunnera manicata, with prickles on the leaves and petioles. Much of the rest of the perimeter of the pond has been planted with mightily-spined Cirsium vulgare. I have room for my favourite rose: Rosa sericea subsp. omeiensis forma pteracantha, winged thorn rose, with the best prickles ever. Never mind that they are not so attractive in the winter - the Vancouver Parks Board cuts them back and they grow fast enough in the summer that they have to trim them mid-season. This is an old photo, maybe one I haven't posted. I'm not sure. These are from a little over a week ago at VanDusen Botanical Garden - this doesn't look like it gets cut down every year, but I have no idea.