Atrichum angustatum (Brid.) Bruch & Schimp - Lesser Smoothcap Moss


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Atrichum angustatum - (image 1 of 6)



Family: Polytrichaceae


Open, disturbed, often sandy soils, e.g. dry bare mounds in woods, on road banks, poor lawns.




Newfoundland to Manitoba, south to the Gulf of Mexico; also found in Europe and Asia.


Plants 1-2 cm high. Leaves undulate, toothed at back of lamina and costa, bordered, doubly serrate, more or less concave near the tip; lamellae restricted to the costa, more or less wavy, 5-14 cells high, obscuring as much as half of the upper third of the leaf; upper leaf cells 9-19 um wide, thick-walled, more or less isodiametric. Capsules cylindric, not angled; calyptra naked.


The generic name Atrichum refers to the lack of long hairs covering the calyptra, unlike mosses in the genus Polytrichum (haircap mosses). According to Crum, A. undulatum is a diploid or triploid expression of A. angustatum, with the two therefore forming a haploid-diploid species pair. The antheridia of A. augustatum are said to be produced one year and archegonia in the next year.


Crum, H. 2004. Mosses of the Great Lakes Forest, 4th ed.

The University of Michigan Herbarium. Ann Arbor, MI




Michael Hough 2010