1a45265a_rigger_Rally_Map_XML_Reference__description
[attribute] scale (optional) [example value] 1 [possible values] a positive number [description] 
The higher the value is set the bigger the vegetation sprite will be displayed. Before version 0.6.3 this value is ignored. Afterwards: Leaving out this attribute defaults to the value "1" for texture scaling.
Trigger Rally Map XML Reference
description