What are stem cells?
Stem cells are cells of organisms that have the peculiarity of being able to divide indefinitely and become as good as any other cell type. The mechanism of infinite sharing is not yet clear, but what is certain is that the environment affects which cell type the cell becomes. They are distinguished by the ontogenetic, individual, age of the organism. The early, embryonic, stem cells can develop into any tissue, the late, adult, stem cells can only develop into specific tissues. Even plants have stem cells, but they also have the ability to regenerate the entire organism.
Where do stem cells come from?
Embryonic stem cells are obtained from the blastocyst. The blastocyst is the accumulated cell accumulation, which occurs approximately from the 5th and 6th development day, and requires 8 weeks to complete, starting from conception. This developmental phase is called embryogenesis. In Germany, the production of embryonic stem cells is banned in so far as it affects or ends the life of the embryo. Importation must be permitted and is only permitted for high-level research purposes. Adult stem cells occur after the development of the embryo in the organism. They have a much less pronounced differentiation potential and can only become specific cells. They are extracted from the blood of donors who undergo the process of stem cell pheresis.
Why are stem cells in cosmetics?
Stem cells have been used for a long time for the treatment of leukemia in particular, but they should also be able to cure many other serious diseases. Plant stem cells are interesting for cosmetics manufacturers. The injection of endogenous stem cells from adipose tissue has been shown, after some tests, to have an anti-aging effect. The plant stem cells, however, offer a number of problems, such as:
→ Stem cells can not last long without very specific circumstances, the shelf life of a product would be only a few days if you're lucky.
→ Whole cells can not be absorbed through the skin.
→ It is not proven that plant stem cells even have a positive effect on humans?
Any research will address the use of adult, or cultured, embryonic stem cells. And even here there were side effects such as tumors or excessive bone growth. 
Conclusion on plant stem cells:
Without serious and reproducible research and studies, plant stem cells are just pretty promises, for expensive prices, without much impact. You pay a lot of money for unclear effects and unknown risks.