Okay, now I'm confused again. The petunia seeds sold at the store are small little beige pellets. The seeds I have been collecting from the flowers in my picture are about the size of poppy seeds & black in color. I'd swear they were poppy seeds if I hadn't collected them myself from the plants. I've been gathering the apparent seeds from multiple pods that have developed on the stems. The pods dry to a yellow/brown color. When I open the pod, its full of what I thought were seeds. Is it possible these are also petunia seeds even though they resemble poppy seeds? These flowers are in a container and not close to anything else except the birch tree behind it. Maybe these flowers aren't petunias? I'm confused :(
I agree with Baa. Or they may have "pelletized" them to make them easier to handle - the coating is biodegradeable and simply makes the seed large enough to easily handle, breaking down when it is brought into contact with dirt and water. (I'd still wear gloves when handling the store bought seed, though in case it is a chemical coating :)
Morph, this is just my guess. So many people are familiar with petunia that even very inexperienced gardeners might take a stab at growing it from seed. Unfortunately most beginning gardeners aren't going to be as curious, observant or dexterous as you seem to be - opening a seed packet to discover a tiny amount of microscopic seed could be very confusing and disheartening for a beginner. If it's difficult to germinate in its natural state, that will add to the frustration.
Case in point: I specifically chose flowers with large seeds for my 6 year old daughter to grow in "her" garden this year, so she could easily handle them and they could be directly sowed. As she gets older, I'll expose her to other flower seeds that may need to be started indoors, or handled more carefully.
Ahhhh ~ I see more clearly now... You make it sound so simple & obvious :) I'm just the curious sort so your insight is greatly appreciated! Thanks for taking the time to explain this to me. It will help as my son also becomes more interested in my new hobby. Have a lovely and enjoyable October...