Coefficient of Conservatism:
Coefficient of Wetness:
R. W. Smith
Included in A. tricoccum in Michigan Flora.
Rich forests, often on floodplains, but also occasionally in upland oak-hickory and rich deciduous forests of other kinds.
We follow Jones (1979) in separating A. burdickii from A. tricoccum. In the field in leaf, the narrow silvery-green, pale-based leaves of A. burdickii contrast sharply with the broader, bright green, red-based ones of A. tricoccum. Based on Michigan collections, mature leaves of A. burdickii are up to ca. 3.2 cm wide at the widest point, while those of A. tricoccum are usually more than 3 cm wide and collections have been seen with leaves to 9.3 cm wide.
This is a good example of species that are quite distinct in the field and evidently have a distinct biology, but much more difficult to distinguish in herbarium specimens, especially with flowering or fruiting material, which can be virtually impossible to determine. Plants are generally smaller in all their parts, including the bulbs, with shorter flowering stems with fewer flowers, as noted in the key. In Michigan at least, the two species are largely separated by flowering times; A. burdickii flowers in mid- to late June. Allium tricoccum normally has more flowers and blooms from the last few days of June through early August. Doubtless overlooked, and a few ambiguous specimens are from the Upper Peninsula, so the range shown here for A. burdickii may be incomplete.