(Phones are so handy for subjects like these!)

My lovely chrysogonum virginianum (Green & Gold) ground cover is beginning to rot again. Last year I lost a whole section of it to this mess. Those little beadlike structures puzzle me.

Took a sample to the Cooperative Extension Service and spoke with a Master Gardener, who was puzzled too, and while she was checking out books, I searched the web and found out it's very trouble-free plant except for powdery mildew. Leaves on these plants are perfect - it's the roots that are rotting...one site said it was subject to root rot in areas with poor drainage or too much mulch. Mine have no mulch. Wondering if this is some sort of insect invasion.