Herbaceous plant and Sour grass

Herbaceous plant noun - A plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests.

Sour grass and herbaceous plant are semantically related. In some cases you can replace phrase "Sour grass" with "Herbaceous plant", this phrases are similar.

Sour grass noun - Any of certain coarse weedy plants with long taproots, sometimes used as table greens or in folk medicine.

Herbaceous plant and sour grass are semantically related. You can use "Herbaceous plant" instead a noun phrase "Sour grass".