R. S. Williams

1859 – 1945

• Calymperaceae of North America
• Central American mosses
• Colombian mosses, apparently undescribed
• Mosses
• Mosses from the west coast of South America
• Mosses from tropical America
• Mosses of the Canadian Arctic Expedition, 1913-1915
• Mosses of the Philippine and Hawaiian Islands collected by the late John B. Leiberg
• New species from Bolivia
• Philippine mosses
• The genus Desmatodon in North America
• Two new species of grimmia from Montana