Chara2, Gloriosa tubers do contain plenty of colchicine, but it can be tricky getting the dosage right. According to the following review, 20 grams of tubers contains 60 milligrams of colchicine. If you do use colchicine, look for sports as well as polyploids. Sometimes chromosome doubled cells will revert to the original chromosome number by dividing again. The resulting cells probably won't be exactly like the originals. This is especially useful when working with sterile hybrids. For instance, a sterile diploid hybrid treated with colchicine can produce both tetraploid shoots, and diploid "sports" that may just as interesting. I have added this info and links to some articles on colchicine use Karl Review: Croaking on a crocus 02 February 1991 From New Scientist Print Edition. JULIE JOHNSON Toxicity of Houseplants by David G Spoerke Jr and Susan C Smolinske, CRC Press, Boca Raton, pp 244, $124.95/100 Pounds. Hours after cooking and eating a meal of sweet potatoes, a 28-year-old woman developed classic symptoms of poisoning. Four days later she was dead. She had mistakenly eaten tubers of the glory lily plant (Gloriosa superba), native to Africa and Asia but also grown as a houseplant in the US. Two years earlier, a 16-year-old girl died after eating 12 flowers from Colchicum autumnale, or autumn crocus. Just half a flower might have proved fatal. Both plants contain the poison colchicine (acetyltrimethylcolchicinic acid), which damages blood vessels and nerves, and stops cell division. A fatal dose of colchicine lies somewhere between 7 and 60 milligrams, not much considering that a dried seed of C autumnale can contain up to 3.5 milligrams, while as little as 20 grams of G superba tubers provide 60 milligrams. Here is a link that might be useful: Chemicals in Plant Breeding

They would be genetically identical. Cuttings can be much quicker. The red-leaf Cordyline is a cutting, from about 2 months ago.

You can tell whether the plant is tissue cultured or natural division by looking at the roots. Here are some pictorial examples of "naturally divided Itohs" Below is a picture of Callie's Memory Itoh root. Whether it's 3 eyes or many eyes, it will take a few years before I can get a flower out of this small size root. A good size Garden Treasure Itoh root with eyes on both ends of the root planted last September. I got 2 flowers out of it already. I probably could have cut the root in in the middle and created 2 plants. A large Hillary Itoh peony root left, and a "pencil" size Yellow Crown Itoh right. It is not only the number of eyes that matters, but also the root size! Figureon 2-3 years before I see the first flower on Yellow Crown. I've received both of these roots from the same supplier this spring. A decent size Border Charm Itoh planted this spring. So, these are the shapes of "natural" Itoh peonies. Let's look at the root geometry of tissued cultured Itoh peony roots. I've received 5 small size Itoh peonies from Lesjardinsosiris, Quebec in2014. The roots are "rounded", with a stem. This stem will be developed into a trunk where the eyes will appear. I have never seen an eye growing out of a tuber in a tissued cultured Itoh root. A developing tissued cultured Itoh with eyes, and a trunk forming, and "round" shape roots/tubers. Here is a failed attempt of splitting a tissue cultured Sequested Sunshine Itoh peony, The picture shows the trunk and peony tree roots. Refer to http://forums.gardenweb.com/discussions/2081041/itoh-peony-trade?n=14 thread for more details. I put the plant back, but it will be several years before this plant is fully recovered and producing a mass of flowers again. Here is a picture showing how this plant looks today. It has one flower and one bud on it. If I have a choice between a tissue cultured Itoh and a naturally divided one, and the price is the same, I'll pick the one that is naturally divided because it is easier to divide down the road.

A few thoughts from a non-professional. The "process" takes at least two years before you should be buying anything at the retail level. No reputable dealer should sell you what the trade calls TC liners (or starters), which is what the process has produced after about 1 year. But it happens. The reasons TC fails for a cultivar likely fall into two classes: plants where isolation of bud tissue is difficult (some plants are simply finicky; I suspect Midnight Oil may be one) and plants where the buds do not reproduce with a high percentage of "true to type" offspring. Sometimes that's for variability in variegation (such as 'Goodness Gracious') and for oddity in form (those with "congested" central veins like 'Stitch in Time' can be a problem, I believe). Streakers are a special case for this, of course, as the instability generally leads to the whole gamut of possibilities in variegation. I was pretty shocked when 'Ice Age Trail' actually went to market as a TC plant, but I guess they figured they could still sell all those 'Big Daddy's. As to what goes into TC, the market is a bit odd right now, as it's all pretty much shopped out to production labs based on demand. Walter's Gardens, once one of the big daddies in generating new hostas, doesn't have much of an internal development program any more, but they still produce old-school hostas for the wholesale market. Mark Zilis's newest incarnation does TC for a few partners (Solberg, Avent, maybe some others). Rob Mortko sold his retail business, in theory so he could focus more on the lab/TC side, producing for retailers like Josh Spece, perhaps in direct collaboration with hybridizers (e.g. Don Dean). Other hybridizers and retailers work out production directly with smaller TC shops. The Europeans have their own routes, but then only get their new plants into the US in small batches. All of this makes the yay/nay question interesting. If a retailer sees (or finds) a plant they want to sell, then they have to make it happen. I think no one wants to see a repeat of what happened at the end of the Q and Z days, where Mark was, frankly, producing a whole lot of new cultivars of little merit. We'll be stuck for a while, though in the situation where North American and European producers/growers discover identical (or near-identical) sports coming out of TC and then registering/producing/releasing both. Hybridizers face an increasingly narrow market in finding truly novel, garden-worthy plants to release, and an uphill battle in getting someone to produce/sell them. For interest, this could be the best quick on-line reference for TC in hostas: http://www.plantsgalore.com/care/hostas/Hosta-propagation-TC.htm