lady slipper vs slipper orchid

lady slipper and slipper orchid both are nouns.

Word	Noun	Adjective	Verb	Adverb
lady slipper	Yes	No	No	No
slipper orchid	Yes	No	No	No

As nouns, lady slipper and slipper orchid are synonyms defined as:

lady slipper and slipper orchid: any of several chiefly American wildflowers having an inflated pouchlike lip; difficult or impossible to cultivate in the garden

Other synonyms of lady slipper include ladies' slipper, lady's-slipper, lady's slipper, lady-slipper.

lady slipper (noun)	slipper orchid (noun)
any of several chiefly American wildflowers having an inflated pouchlike lip; difficult or impossible to cultivate in the garden	any of several chiefly American wildflowers having an inflated pouchlike lip; difficult or impossible to cultivate in the garden