I'm pretty sure those are daffodils. They grow from bulbs, which you would need in order to propagate them. The bulbs multiply on their own and will naturalize (spread out) to form a colony after several years.

You might try going back to 'the middle of nowhere' to dig out some of the bulbs after the leaves have begun to die back. If you're lucky, you'll find a larger central bulb with littler bulbs growing around it.. those are your babies, which can be separated from the parent bulb and replanted. (The larger the bulb, the larger the plant it will produce.) Once they have a grown for several seasons, if you dig some of them out, you should be able to obtain more bulbs in the same way. If you can't go back to get bulbs, they are very easy (and inexpensive) to purchase online.

There is also a method called 'scoring', which is supposed to allow for faster propagation, but you'd need a bulb to try that as well.

You cannot propagate daffodils from cuttings. The time to purchase the bulbs is in the fall, where you will see them for sale in all of the big box stores and garden centers. You can also order them on line or from catalogs.

Do not go back to get the bulbs. This is not the time of year to dig and transplant them. Even if it were, they would not produce flowers for you until next year, anyway. A far better idea is to leave them where they are so that others can enjoy them for years to come....and plan on finding a good source of these very popular bulbs elsewhere. There are many, many different kinds to choose from.

you deffinately need the bulbs they are daffodils, i grew up with lots my house. let everyone enjoy the blooms. either wait till they die back to dig them up for next year or perchase them online or at a garden center, they are very cheap and easy to grow.