This distinctively pubescent species is widespread on base-rich soils from midwestern regions to the Gulf Coastal Plain. In Ky. it is concentrated in the Bluegrass region, on calcareous uplands of the Mississippian Plateaus, and along some western river bottoms. Unlike related species in the state (in subgenus Swida), drummondii is generally less able to proliferate in damp soils, though patches often occur along well-drained streambanks. Compared to those species, cuttings root much less readily without application of hormones (R. McNiel, pers. comm.). However, the species is easily propagated by transplanting divisions from initial clumps, which often produce running roots. C. drummondii is one of the most suitable native replacements for the alien Lonicera maackii in central Ky., and it has started to spread by seed in restoration projects. Some people, nevertheless, have found the smell of flowers offensive, but there is no published research on volatiles from flowers. There is much variation within drummondii across its range, which deserves further study. Also, introgression can be expected with obliqua, stricta, racemosa and other species (Y, W). C. drummondii can be confused with stricta in Ky., especially based on leaves from the shade, but it tends to be more pubescent. It has distinctly longer hairs on lower leaf surfaces (mostly 0.5-0.7 mm versus 0.2-0.4 mm). These hairs are mostly spreading to erect (versus appressed to curled-up). Pith is generally brownish (versus white). Leaf blades usually have broader shape (ovate versus lance-ovate), with subtruncate bases (versus cuneate). They tend to be larger, on average: (4) 6-15 (18) x 3-9 cm versus 4-12 x 2-7 cm. Fruits are usually white but can be bluish to varied degrees (as in "foemina"). The dubious segregate known as C. priceae Small from dry sites in w. Ky. and w. Tenn. (Sm, F) has been considered to have smaller fruits (3-4 mm wide versus 5-6 mm) and flowers (petals 2.5-4 mm long versus 4.5-6 mm), more scabrous upper leaf surfaces, and more consistently reddish/maroon twigs (versus green/olive to pinkish/reddish-brown). The type of priceae is from WARR (NY), but there are has been virtually no application of this name by botanists even within Ky.