Helmet orchid and Orchidaceous plant

Helmet orchid noun - Any of numerous orchids of the genus Pterostylis having leaves in a basal rosette and green flowers often striped purple or brown or red with the dorsal sepal incurved to form a hood.

Orchidaceous plant and helmet orchid are semantically related. In some cases you can use "Orchidaceous plant" instead a noun phrase "Helmet orchid".

Orchidaceous plant noun - Any of numerous plants of the orchid family usually having flowers of unusual shapes and beautiful colors.

Helmet orchid and orchidaceous plant are semantically related. Sometimes you can replace phrase "Helmet orchid" with "Orchidaceous plant", this phrases are similar.