slipper orchid vs lady's slipper

slipper orchid and lady's slipper both are nouns.

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

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

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

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

slipper orchid (noun)	lady's slipper (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