Japanese plant Oshiroi

Hi
I wonder if anyone can tell me more about the plant commonly called 'O-shiroi' because it was once used to make the white cosmetic paste used by geiko ...?

I don't know if there is a plant named Oshiroi but I know it's the name for white makeup powder which used to contain lead or mercury back in the Edo period.

There were mainly four major types of cosmetics in this period; powder, lipstick, eyebrow, and tooth blackening. The powder was called "Oshiroi" in Japanese. Oshiroi was made from mercury or lead. While ordinary citizens used lead as their powder, women of high status used mercury for their powder because the powder which was made from lead was cheaper than the powder which was made from mercury. In this period, most people believed that whitening was very important.

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from History of makeup in Japan - Wikipedia

I remember being introduced to it while studying Japanese at uni, through a, I believe, BBC show case series where they explored various parts of Japanese history. One such episode was about geisha and how a large a number of people had lead poisoning back then due to lead based make-up. It is less than 100 years ago we stopped using lead in makeup in general. And it wasn't just a Japanese phenomenon; this sort of makeup was present in Europe, too. One example being Queen Victoria who covered her small-pox scarred face with white makeup containing lead (which slowly poisoned her).

Some more from Wikipedia. This is the Japanese entry, but you can change language to see the English description.