Heron's bill and Pin grass

Heron's bill noun - Any of various plants of the genus Erodium.

Pin grass and heron's bill are semantically related. In some cases you can replace phrase "Pin grass" with "Heron's bill", this phrases are similar.

Pin grass noun - European weed naturalized in southwestern United States and Mexico having reddish decumbent stems with small fernlike leaves and small deep reddish-lavender flowers followed by slender fruits that stick straight up; often grown for forage.

Heron's bill and pin grass are semantically related. You can use "Heron's bill" instead a noun phrase "Pin grass".