Montauk daisies were received with no roots.
Do I plant the stems now?
I have been thinking about your Montauk daisies with no roots. I wonder if you mean they are "bare root" plants and not "no root" ones. Bare root plants are dormant plants with no leaves but they have roots. They are great for fall planting. If this is what you have, and I certainly hope so, it is easy to plant them. Soak the roots in warm water for 30 minutes, longer if they seem dry and inflexible. They are then planted out as you would any other plant. Water and mulch with 3-4 inches this first winter. You will see signs of growth next year as the soil starts to warm. https://www.gardeningknowhow.com/garden-how-to/propagation/propgen/bare-root-planting.htm
I wish I had a picture to go from! It sounds like you received a floral bouquet of nippon daisies. They will not survive if planted. Something appears to have gone amiss with your order. Please contact the sender for instructions or refund. You can try to take stem cuttings and root them in water or better yet, in moist sand or potting mix. You don't give your ag zone but for most of us up north, fall planting time has passed with a few exceptions. Montauk daisies go dormant with the first freeze. Here is information on stem cuttings: https://www.gardeningknowhow.com/garden-how-to/projects/rooting-plant-cuttings.htm