Herbaceous plant and Silkweed

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

Silkweed and herbaceous plant are semantically related. In some cases you can replace term "Silkweed" with "Herbaceous plant", this terms are similar.

Silkweed noun - Any of numerous plants of the genus Asclepias having milky juice and pods that split open releasing seeds with downy tufts.

Herbaceous plant and silkweed are semantically related. You can use "Herbaceous plant" instead a noun "Silkweed".