1660s, in zoology, "having separate fingers and toes," from Latin digitatus "having fingers or toes," from digitus "finger" (see digit). In botany, "having deep, radiating divisions, like fingers," by 1788.
Entries linking to digitate
digit n.
late 14c., "numeral below 10," from Latin digitus "finger or toe" (also with secondary meanings relating to counting and numerals), considered to be related to dicere "to say, speak" (from PIE root *deik- "to show," also "pronounce solemnly"). The numerical sense is because numerals under 10 were counted on fingers. The "finger or toe" sense in English is attested from 1640s.