I have this too. I thought it was Rhodohypoxis bauerii but maybe that's the other one which has pink flowers?
Rhodohypoxis grow from small bulbs (corms?) and they multiply incredibly. Each plant produces about 5 new bulbs for next year so the pots get full pretty quick and you have plenty to sell or give away.
Just in case you would like to see more of them please find a link to facebook pages of a Czech bonsai guy who has quite large collection of different cultivars. btw he makes great shohin bonsai. One of his tree has been published in the latest cataloque of Gafu_ten exhibition