Weissia controversa
“green-cushioned weissia”
Weissia controversa. May 6, 2011.
Weissia controversa photo by Bob Klips
Weissia controversa in open field in Waldo, Marion County Ohio. April 6, 2011.
Weissia controversa leaf. Note involute margin.
How to recognize green-cushioned weissia: Weissia controversa is a small yellowish-green cushion moss with 1.3-2.3 mm lanceolate leaves that are crispate and spirally contorted when dry, and in-rolled upwards (involute) along the margins. The margins of the leaves of most mosses are either flat and plane, or revolute with margins rolled down toward the back. So spotting the involute margins on Weissia is the first clue toward its naming. The strong midrib extends past the tip of the leaf into 1-5 cells of a point or mucro, and the leaf cells have 4-6 forked papillae. The basal cells are rectangular and yellow or hyaline where the leaf clasps the stem. The species of Weissia are differentiated on the basis of capsule characteristics, leaf shape, strength of mucro and some cell measurements.
Where to find green-cushioned weissia: Weissia controversa occurs on bare soil or rock in disturbed habitats, such as fallow fields, parks, cemeteries, and along woodland paths. It can be seen with mature sporophytes in late fall through spring. It is widespread in Ohio.
