A plate of dogs' teeth, by which I mean bulbs from the Erythronium genus which resemble the molars of a canine. Hence the colloquial name Dog Tooth Violet. The above are E. californicum, a mountain species from that part of the world.

 Presumably a selection from the wild originally because these are referred to as Erythronium californicum 'White Beauty'. Said to be a parent of the cultivar 'Pagoda' which does well in my London garden so hopefully these will too.