|A colony of Weissia controversa growing as a low cushion
on landscape fabric around a live oak tree on the campus of
the University of South Florida in Tampa.
short-stemmed shoots, with leaves in a circular arrangement, like a rose), that forms extensive colonies on disturbed soil or sometimes rocks. The leaves are elongate with a strong midrib that extends beyond the tip in a sharp point. It is most distinctive in the margins of the leaves that roll tightly inward onto the upper surface (involute).
|The margins of the long, narrow leaves of
Weissia spp. are distinctively rolled over
the upper surface.
|Leaf cells are compact, roughly circular, on ether side of the
Spore capsules are upright, symmetrical, goblet-shaped, dark brown when mature, and elevated on stalks up to .8 cm in length.
Weissia controversa is found in nearly every state and province in North America, including Greenland, and in Florida it has been well collected south to Manatee and St. Lucie Counties, but also with reports from Miami-Dade County.
Weissia jamaicensis (Mitten) Grout is a related species, with a more tropical and warm-temperate distribution, found in Florida, Georgia, westward to New Mexico, and north to Missouri, but not in the Carolinas. In Florida, it appears to overlap the distribution of W. controversa, but has been much more sparsely collected. It differs in that the tip of the leaf is usually hood-like, and the base of the leaf flares out into broad shoulders.
Weissia ludoviciana and W. muehlenbergiana are found throughout eastern N. America and in north Florida.
From other genera in the Pottiaceae, aside from the involute margins, Weissia species differ in their long, narrow leaves. Tortella species are somewhat similar, but not distinctly involute along their margins except sometimes at the tips. Tortella also differs in the distinct V-shaped region of large, clear cells at the base of the leaf.