Post a new (useful) comment about a plant. Where do I do that?
Cultivar, Trade name, Series in the photo posting form. I have no idea what to put on these blocks because most of my plants were trades with friends or wild seed harvesting. The only plants I purchase are vegetable seedlings and even with those I do not know where I would have seen that information at the nursery.

Also, how would one know if a comment is new and ore useful?

I know these are newbie questions, but then, I am new.

to ATP Jennifer!
Let's talk about comments first. Click on my link & then scroll down the page until you're past all the photos. That's where you will see the comments for that plant.
Hardy Hibiscus (Hibiscus moscheutos)
You can post your own comment by scrolling down to the bottom of the page where you will see a box that says:

Adding Actions:
In that box you will see your choices, one of which is post a comment.

There is also these same options off to the left side of where the plant data is so there are 2 places on each plant page where you can access the ability to add comments, data, photos, etc....

If you don't know the cultivar then you have 2 choices. 1) would be to post it in the ID forum along with photos & info. & see if a cultivar ID can be had
2) You can add your info., photos, comments to the generic parent plant entry such as this one for Hibiscus:
Hibiscus

Thank you for the hearty welcome! Now, back to cultivars, I do not see how my wild seed could have a "cultivar", perhaps but I just go out on nature walks and take seeds from plants I like. Most of my flowers are annual seeding plants. I harvest seed as they become ready and save them for the next spring planting, IE: what possible cultivar is there for buttercups or regular field daises. Sure enough, my poppy type plants and my columbine, may have had a cultivar but if they did, the seeds were deposited by birds, community compost or some such and are now growing wild. My asters are the same story.

In the cases in which plants would not be likely to have a cultivar name, you can post your photos in the appropriate generic entry for the genus, or the entry for the species if you happen to know the genus and species.

And welcome to ATP.

Okay, I understand what you're saying. So since you don't know the cultivars then you put them in either the parent plant entry or the generic plant entry. Let's do some examples.
Let's say your asters. You only know they are asters. So you go to the plant database & type in aster, click this is the page you get:
http://garden.org/plants/searc...
Now, you see on the upper right there? That box that says "view all plants in the genus aster"? Click on that. And you end up here:
http://garden.org/plants/brows...
Now look at the top entry there. It says Asters (Aster). That would be where you want to put your asters of unknown heritage. That is a generic listing for Asters.

Now let's look at your Columbine. Again, type Columbine into the database search & this is the page you get:
http://garden.org/plants/searc...
Look at the top entry there. It simply says Columbines (Aquilegia) -- that is the generic entry for Columbines that you don't know the cultivar of. You put your Columbines there.

Jennifer -- Welcome to ATP, and I hope the above info was helpful to you! (If not, please don't be hesitant to ask for clarification -- the site is pretty easy to use once you've used it, maybe not so much at first...)

Jennifer, if you're going on nature walks & collecting seed then likely you are collecting seeds from native plants. Many of those can be ID'd. I found several sites that you can use for reference:
http://www.ontariowildflowers....

http://www.nativeplants.ca

http://www.natureconservancy.c...

And again I will mention our plant ID forum.
http://garden.org/forums/view/...
We have some people who are super at ID'ing plants so give them a shot at ones you don't know.

ZuZu, Thanks for the welcome!
Where do I find the generic entry form. The only form I have seen is the standard add a plant to the data base?

O.K. I think I'm getting a handle on the subject now. In fact, I think I'll do most of my posting on the ID forum for a bit and see how that works out. Thank you for all the help. I had been to those sites you linked and it really did not enlighten me so much. I think I may be a bit dense where the academics of flowers are concerned. But people love to photograph my front gardens so I must be doing all right low down in the dirt.

I think I confused you unnecessarily. There is no generic entry form. I meant the main entry for the genus. As Ann explained, if you know your plant is a columbine, you'd post the photo in the generic entry for columbines (Aquilegia),

Columbines (Aquilegia)

but if you knew that it was Aquilegia vulgaris, you'd post it in the species entry.

Columbine (Aquilegia vulgaris)

Jennifer you're going to do fine. It takes a little while to learn the site & navigation but you'll get the hang of it. I always tell people to RELAX. I think a lot of times people look too hard for navigation. I know I do on an unfamiliar site & then I will suddenly realize what I was looking for was staring me right in the face. That's when I have one of those palm slap to the forehead moments.

When you post on the ID forum, it will be much easier to get an ID if you post photos of all portions of the plant & add a little explanation as well.

AND you can always ask questions. We're really a friendly, helpful bunch here so don't be shy.

Nope, I'm still an idiot! I added a submission to the data base (add a plant) for which I have pictures of both plant and seed head but could see no place to upload the photo. (I just know I'm going to wear you people out! ) How do I post a photo?

When you propose the addition of a new plant, you have to wait for the proposal to be appproved. In this case, you proposed the addition of Ranunculus acris, but it's already in the database, so I declined your proposal and sent you a link to the entry.

This is the link I sent you:

Meadow Buttercup (Ranunculus acris)

Open the link and scroll down below the plant data and the photos that are already there. Click on "Upload a photo."