Grass

[Carey]

We have a grass on our the lawn of the the house we bought in Oct. It has not grown taller than 3", but it expands into squishy bubble like forms in the yard, and grows over everything in a mat form (like throwing a 3" high green shag carpet over the landscape). It is filling in bare spots quite quickly...and has grown over rose stumps, rocks, anything in its' way. The Philipino owner had called this sea grass....but I cannot find a reference to a sea grass that has this form....does this sound familiar to anyone?
Aloha, Carey