Veld Flower Mystery 1

This little plant grows along the edge of my property in very dry  canopy shade. I am charmed by its pretty, celery-like leaves but have not been able to find any information about it. The flowers are very small, yellow green and well hidden in the foliage. I think they may make a useful ground cover. I have dug up a few and am trying them out in two environments in the garden:  in the shade under some plectranthus, and in full sun. Both areas get occasional watering. I didn't think those in the sun would actually survive - they have remained very low, have yellowish leaves and  are spreading outwards. Those in the shade are leafy and lush, but  I really underestimated the size to which the plectranthus would grow and the poor things are getting swamped.  If anyone recognizes this plant, please let me know what it is called.