Monographs Details: Plagiothecium
Authority: Buck, William R. 1987. Bryostephane Steereana: A Collection of Bryological Papers Presented to William Campbell Steere On The Occasion of His 80th Birthday. Mem. New York Bot. Gard. 45: 1-749.
Discussion:In general, the seven species of Plagiothecium have unicellular spores, ranging in size from 9-14 µm, which are either green, yellow or brown, They are apparently thin-walled, as evidenced by their collapse upon air-drying, and they never germinate precociously. The spores appear to be atreme (i.e., without a distinct aperture), spherical or rarely ovoid and apolar (i.e., poles or polar regions cannot be distinguished) with sculpturing uniform or irregular over the spore surface. The omamentation is either gemmate or branched-baculate, the elements covered with high-conic to rounded papillae. The size of the elements varies from 0.2-0.7 µm in diameter and aboui 0.2-0.6 µm in height. The spore surface between the gemmate or branched-baculate elements appears to be smooth or sometimes minutely roughened or granulose.