She spotted me looking at her plants and invited me to take any flower pods or young seedlingsprouting from the ground. I told this neighbour that I was just admiring the flowers and have no intention of taking any plants from her yard. Anyway, if I wish to, I would definitely ask her permission first.
She then invited me to her backyard to look at her successful planting of some Prosperity flowers of Taiwan origin. I obliged her and noted that she has several pots of these plants that are still very young (less than a foot tall) but already flowering.
I have seen a plant vendor selling these type of plants at the farmers' market. Pretty expensive but his stall draws many interested customers.