Porella platyphylloidea

Porella platyphylloidea is a large leafy liverwort with an incubous (not to be confused with incubus!) leaf insertion, which is to say its leaves that point forward so that their upper edges overlap the lower edges of the leaves above (like badly installed roof shingles). This was seen Sunday on a walnut branch in southern Ohio.

The foliage of the leafy liverwort Porella platyphylloidea is crazily intricate. The two-ranked lateral leaves are complicate-bilobed (yes, it’s really called that …”complicate”), meaning that they are folded and divided such that different portions of the leaves are visible on the bottom (smaller lobe) versus the top (larger lobe). This is the undersurface of Porella. In addition to the two rows of lateral leaf lobes, there’s a middle row of separate under-leaves. The effect is dizzying.This was seen Sunday on a walnut branch in southern Ohio.