Bush

Branch/Trunk:   Distribution - 54 Branches Per Segment - 1 / 1 Segments - 10 / 10 Branch Start Angle - 0 Branch End Angle 55 Trunk Thickness - 2 / 14 Branch Thickness - 70 / 90	Tree:   Shape - Default Gravity - 50 Randomness - 70	Foliage:   Shape - Ginkgo (Maiden Hair) Scale - 1 Number of Leaves - 20 Distribution - Spiral	You will need to sink the roots way down into the ground so that you don't see any or much of the trunk. You could also boolean off the roots and trunk that you don't want. You can make a custom material if you want, but many of the preset trunks and leaves materials work great for a bush also!
You can download the Bryce tree preset (.bto) here: bush.bto. To use you will need to have installed the 5.01 Bryce patch. To use the tree ALT-Click on the create tree icon.

Bush 2

Branch/Trunk:   Distribution - 34 Branches Per Segment - 1 / 3 Segments - 7 / 12 Branch Start Angle - 94 Branch End Angle 120 Trunk Thickness - 1 / 54 Branch Thickness - 2 / 33	Tree:   Shape - Mangrove Gravity - 22 Randomness - 70	Foliage:   Shape - Mangrove Scale - 6 Number of Leaves - 20 Distribution - Stacked	You will need to sink the plant to taste.
You can download the Bryce tree preset (.bto) here: bush2.bto. To use you will need to have installed the 5.01 Bryce patch. To use the tree ALT-Click on the create tree icon.