slipper orchid vs lady-slipper

slipper orchid and lady-slipper both are nouns.

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

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

slipper orchid and lady-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's slipper, lady slipper.

slipper orchid (noun)	lady-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