White dots instead of trees or grass???

[Terrafied]

So, I'm learning slowly but surely.
Current problem: I have a bunch of grass on my terrain but it won't render. All I see is white dots. I can see the preview bounding boxes but not the grass in the final render. Just dots.
Any ideas??
I tried it with trees too. Then I get small green dots. Are my objects just too small? What settings should I change? 

Here is my scene file and b&w mask layers. I know it's probably something simple but I'm too new at this.

Thanks,

Terrafied

[Henry Blewer]

They may be too small. It depends on the scale of the image map. You might have to use invert shader in the population blend by shader option whih points to the image map shader.

[Oshyan]

Can you post a saved render and/or screenshot of the results from an actual render? It's hard to say what's going on here without seeing an example.

- Oshyan