Plantlet

A plantlet is a young or small plant, produced on the leaf margins or the aerial stems of another plant.[1]

Kalanchoe daigremontiana with plantlets on one of the leaves

Chlorophytum comosum "Variegatum" in a hanging basket showing the plantlets

Many plants such as spider plants naturally create stolons with plantlets on the ends as a form of asexual reproduction. Vegetative propagules or clippings of mature plants may form plantlets. An example is mother of thousands. Many plants reproduce by throwing out long shoots or runners that can grow into new plants. Mother of thousands appears to have lost the ability to reproduce sexually and make seeds, but transferred at least part of the embryo-making process to the leaves to make plantlets.