Please try our next iteration of the Michigan Flora Online here. Beginning on February 1, 2023, 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.


1. Sporangia borne in the axils of regular leaves, not in strobili; stems bearing flattened, two-lobed gemmae that fall off and serve in vegetative reproduction.


1. Sporangia always born in terminal, differentiated strobili; gemmae absent.

2. Sporophylls (bracts subtending sporangia) green, leaf-like; erect branches with soft, herbaceous leaves, deciduous, unbranched (rarely forked) and always bearing terminal strobili; horizontal stems leafy, attached to substrate surface and rooting at frequent intervals.


2. Sporophylls yellowish, scale-like; sterile erect or ascending branches often present, these sometimes branched, all branches with evergreen, leathery leaves; horizontal stems either deeply buried or ± on the surface and rooting at irregular intervals.

3. Strobili sessile.

4. Leaves of sterile branches opposite and in ranks of 4, the branches ±square in cross-section.

Diphasiastrum alpinum

4. Leaves of sterile branches in 5 or more ranks, the branches plus leaves flattened to rounded in cross-section.

5. Aerial stems simple or occasionally forked once with ascending branching; horizontal stems at the ground surface; strobilus one per upright shoot.


5. Aerial stems much branched and “tree-like,” with the branches often spreading; strobili usually several per upright shoot.


3. Strobili elevated on distinct peduncles.

6. Leaves spreading, lanceolate, acuminate and ending in a whitish, hair-like bristle.


6. Leaves appressed, partially fused with the stem, ± scale-like, in opposite pairs, the tips acute to acuminate, but lacking a whitish bristle.

Diphasiastrum (in part)


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. January 29, 2023.