Coefficient of Conservatism:
Coefficient of Wetness:
B. S. Walters
Rhamnus frangula of Michigan Flora.
A Eurasian species, locally aggressive and becoming a major pest as a tall shrub in bogs, fens, and other wet habitats, including tamarack and cedar swamps (particularly in disturbed areas as along new power lines and other clearings), thickets along rivers, lake shores, ditches, fencerows; occasionally in drier sites. First collected in Michigan in 1934 in Delta Co. Frequently cultivated, now mostly as fastigiate cultivars ('Columnaris') with normal foliage, but strongly ascending branches, and fern leaf cultivars ('Asplenifolia') with a normal growth habit but a very narrow leaf with an irregular, wavy margin. Occasionally, weedy occurrences will contain variants that suggest their origins from these cultivars.