An adjective used to describe:
a) drawings that are technically accurate representations of all manner of flora and fauna, often annotated with the Latin names, genus and detailing. When attached to a printed fabric, it describes one that represents flora and fauna in a serious, clear and accurate academic manner, as opposed to a looser or painterly drawing.
b) In a less rigid sense, this term may be used to describe prints showing exotic, tropical, floral designs and details with a botanical sense rather than exactitude. These embody the recognisable forms with a degree of artistic license, especially where scale and colour are concerned.
Botanical prints are useful and attractive. I feel they should be shown in their true design, that is flat rather than gathered, e.g. for blinds, wall coverings, to cover screens and to line the insides of cupboards, linen presses, ottomans and small boxes. When gathered curtains spoil the artistry of a beautiful botanical drawing I feel it rather misses the point.