Please try our next iteration of the Michigan Flora Online here. Beginning on February 1, 2023, michiganflora.net will point to this new site.
The new site offers several benefits over the existing website, including real coordinate mapping, giving a clearer view of the density of documentation as well as more precision about plant distributions and their link to landforms. We will also have the ability to update species pages more regularly, both in terms of new collections and as more existing Michigan specimens are georeferenced. In addition, we have a better photo display, and offer indented keys.
Coefficient of Conservatism:
Coefficient of Wetness:
Polygonum amphibium of Michigan Flora.
Lakes and ponds, permanent or ephemeral; river margins and quiet backwaters, marshes; “terrestrial” forms in drier ground nearby (or after lowering of water levels).
Variety amphibia is native to in the Old World; we have two native intergrading entities sometimes distinguished as varieties, as follows:
(a) var. stipulacea (N. Coleman) H. Hara. Stems prostrate, in water (up to 2 m deep) producing flowering shoots with floating leaves (superficially resembling those of a Potamogeton). Young terrestrial shoots with a ± horizontal green flange at the summit of the ocrea, seldom flowering. (Both types of shoot may be found on a single stem which extends from a terrestrial to an aquatic habitat.) Inflorescence ± ovoid or conic, 1.5–3 (–4) cm long. This variety occurs throughout the state.
(b) var. emersa (Michx.) J. C. Hickman. Stems ± erect, even when in the water. Floating leaves not produced. Ocreae without green flange. Inflorescence ± cylindrical, at least 3–8 cm long. This variety apparently occurs only very rarely north of the Straits of Mackinac in Michigan, though it is common in the southern Lower Peninsula.