Sambal,

"I have found listings for species seed and wonder if it would be a good idea to use them as parents to cross with the hybrids I already have?"

Sometimes under prolonged cultivation a species can lose some of its natural resistance to pests or diseases, or some of its natural hardiness to weather extremes. It can lose some of its genetic diversity. Back crossing to the wild forms can reduce this trend.

It's a good idea to know the chromosome number of your domestic hybrid and to know the chromosome numbers of the wild species you are considering. Crosses between different chromosome numbers are usual sterile. If you are propagating the plant asexually, that isn't a problem.

MM

MM Thanks. But how do you know how many chrosomes a plant has? Is there a list or a database somewhere? There is a heuchera called micranatha Palace Purple that is said to be offered in the trade as both americana and micrantha. Does that mean it is a cross between those two species? I would think that any cross between two species could produce more than one variety of plant? The chromosomes making up Palace Purple must be fixed as I see them for sale everywhere..unless they are vegetatively propagated? The catalog offers the seed as 'palace purple'so I assume that is the plant you will get from growing the seed. On the other hand, I have read that Delphinium Pacific Giant is open pollinated in the field. The plants always look like Pacific Giants. So at what point does a plants characteristcs become fixed? I enjoy your explainations and the conversation that you and DaveMichigan are having. Although much of it is a bit over my head. At present I have one seed tray of Hosta Blue Danube thatis open pollinated. All the babies look the same, which I expected, but the seed leaves aren't as blue as their parent plant. They aren't as green as most of my hostas are either. Since they are selfed, am I to expect much in the way of variation in the babies. SAM

SAM,

"But how do you know how many chromosomes a plant has? Is there a list or a database somewhere?"

There are probably several chromosome databases. The Google search function is a good way to find how many chromosomes a plant species has. For example, this is a Google Advanced Search for heuchera "chromosome number". That search got over 700 "hits".

"There is a heuchera called micranatha Palace Purple that is said to be offered in the trade as both americana and micrantha. Does that mean it is a cross between those two species?"

Not necessarily, although I don't know for sure. My guess is that it has a complex hybrid origin, as many ornamentals that are propagated asexually do. Once again, the Google Advanced Search can be a source of information. Notice that this search for heuchera micrantha Palace Purple goes on for many pages, which you can select from under the Gooooooogle navigator at the bottom of the first page. There is a wealth of information available on the Internet, and Google is possibly the best, but not the only, search engine that can find it for you.

MM