Females are known by the slightly acute angle or tooth midway on the ventral margin of the mandible (Fig. 52). Males can be distinguished by the form of the S4, which is strongly truncate and emarginate medially, forming distinct, rounded sublateral lobes (Fig. 60).

In the Nearctic, from Sierra Nevada of California north to British Columbia and Alaska, east through Canada to Nova Scotia and Newfoundland south in the United States to Massachusetts, Michigan, the Black Hills of South Dakota, and mountainous areas of Nevada, Utah, and Colorado. In the Palearctic, Osmia inermis is found from Spain, Italy, and Greece north to the United Kingdom, Norway, Sweden, and Finland, and east through Russia and northern China (Müller, 2010). The related, if not synonymous, species Osmia ishikawai is found in Japan.

Osmia inermis has been recorded nesting under stone or in preexisting cavities in rocks and stones, with cells composed of chewed leaves (Lovell 1909; Müller 2010 and references therein). In the Palearctic, Osmia inermis is polylectic with a preference for Fabaceae (Müller 2010 and references therein); however, in Newfoundland, Canada, the species has been shown to be primarily dependent upon Ericaceae (Hicks 2009).

23 April (1♂, Boulder), 30 July 1955 (1♀, Ottawa); CANADA: ALBERTA, Alberta’s Rockies Region, 21 May 1915 (3♂, Ottawa, 1♂, Logan), 25 May 1892 (1♀, New York), 29 May 1922 (1♂, Ottawa), 6 July 1955 (1♀, Ottawa); Northern Alberta Region, 29 May 1977 (1♀, Logan); BRITISH COLUMBIA, Central Kootenay, 3 June 1906 (1♀, Ottawa), 9 June (1♀, Boulder); Stikine Region, 6 June 1955, 2200 ft (1♂, Ottawa), 17 June 1955, 2200 ft (1♀, Ottawa); Okanagan-Similkameen District, 21 May 1958 (1♂, Ottawa); MANITOBA, Northern Region, 1 July 1927 (1♀, Ottawa), 11 July 1950 (1♀, Ottawa), 29 July 1949 (1♀, Ottawa); Parkland Region, 26 June 1961, 2000 ft (1♀, Ottawa); NEW BRUNSWICK, St. John Co., 9 June 1901 (1♀, Logan), 23 June 1901 (1♀, Ottawa); York Co., 29 May 1918 (1♂, Ottawa); NEWFOUNDLAND AND LABRADOR, Twillingate Islands, 30 May 1951 (13♀, Ottawa); NOVA SCOTIA, Halifax Co., 2 July 1914 (1♀, Ottawa); Hants Co., 4 June 1931, Cornus sp. (1♂, Ottawa), 22 June 1931 (1♀, Ottawa); ONTARIO, Kawartha Lakes, 25 May 1964, Viola adunca (1♂, Ottawa); Lennox and Addington Co., 12 May 1962, Chamaedaphne sp. (1♀, Toronto); Rainy River District, 2 July 1960 (1♀, Ottawa); QUEBEC, Capitale-Nationale Region, 17 May 1914 (2♀, Ottawa), 28 May 1916, Vaccinium sp. (2♀, Ottawa); Nord-du-Québec Region, 4–12 June 1987 (1♀, Ottawa), 12 June–8 July 1987 (1♀, Ottawa), 18 June 1949 (1♂, Ottawa), 14 August 1949 (1♀, Ottawa), 18 August 1949 (4♀, Ottawa), 23 August 1949 (2♀, Ottawa), 2 September 1949 (8♀, Ottawa), 3 September 1949 (1♀, Ottawa); Outaouais Region, 14 May 1916, Vaccinium sp. (1♀, 1♂, Ottawa); YUKON, 26 May 1951 (1♂, Ottawa), 31 May 1951 (2♂, Ottawa), 5 June 1951 (1♂, Ottawa), 12 June 1960, 3500 ft (1♀, Ottawa), 21 June 1949, 5200 ft (1♀, Ottawa), 2 July 1962, 3500 ft (1♀, Ottawa), 10 July 1985 (1♀, Victoria); RUSSIA, Siberia, 3 July 1992 (1♀, Davis), 5 July 1992 (1♀, Davis); SWEDEN: (1♀, Uppsala), 12–19 June 1972 (1 ♀, Uppsala), Jönköping Co., 12 July 1932 (1♀, Logan); Norrbotten Co., (1♂, Uppsala), 25 August 1975 (1♂, Uppsala); USA: ALASKA, Fairbanks North Star Borough, 19 May 1987 (1♀, Davis); Kenai Peninsula, 20 June 1951 (1♀, Ottawa); CALIFORNIA, Madera Co., 19 July 2004, 3315 m, Phyllodoce breweri (1♂, Logan); Mariposa Co., 15 June 2004, 3024 m (3♂, Logan), Phyllodoce breweri (1♂, Logan), 3215 m (1♂, Logan), 23 June 2004, 3112 m (1♂, Logan), 4 July 2004, 2860 m (1♀, Logan), 2847 m, Horkelia tridentata (1♀, Logan), 14 July 2005, 3112 m, (2♂, Logan), Phyllodoce breweri (1♂, Logan), 16 July 2004, 2944 m, Phyllodoce breweri (1♀, Logan), 14 August 2004, 3189 m, (1♀, Logan), 1 August 2005, 3189 m, (1♂, Logan); Shasta Co., 30 July 1947, 7000 ft (1♀, Logan), Tuolumne Co., 14 July 2004, 3049 m (1♀, Logan), 3114 m (1♂, Logan), Phyllodoce breweri (2♀, Logan), 15 July 2004, 3215 m, (3♂, Logan), Phyllodoce breweri (1♀, Logan), 17 July 2005, 3215 m (2♂, Logan), 28 July 2006, 3215 m, Arenaria kingii var. glabrescens (1♀, Logan), Eriogonum incanum (1♀, Logan), Phyllodoce breweri (1♀, Logan); COLORADO, Boulder Co., 18 June 1940 (1♀, Boulder), 20 June 1940 (1♀, Boulder), 27 June 1939 (1♀, Boulder), 8 July 1940 (1♀, Boulder); Grand Co., 22 June 1976 (1♀, Boulder); Larimer Co., 19 June (1♀, Boulder), 25 July (1♀, Boulder); Mesa Co., 10 July 1938 (1♀, Boulder); Routt Co., 21 May 1964, 8500 ft, Erythronuim sp. (1♂, Boulder); Summit Co., 29 July 1961, 11700 (1♂, Ottawa); IDAHO, Bear Lake Co., 10 August 1972 (1♀, Logan); Lemhi Co., 20 July 1963 (2♀, Moscow); MAINE, Knox Co., 28 May 1962, Vaccinium angustifolium (1♂, St. Charles); MASSACHUSETTS, Barnstable Co., 16 May 1914 (1♂, Logan); MICHIGAN, Alger Co., 23 May 1982, Vaccinium sp. (1♂, St. Charles), 29 May 1991, Vaccinium angustifolium (2♀, St. Charles); Marquette Co., 25 May 1983, Vaccinium angustifolium (1♂, St. Charles), 9 June 1985, Gaylussacia sp. (1♀, St. Charles), 21 June 1984 (1♀, St. Charles); MONTANA, Carbon Co., 10 July 1963, 5900 ft, Melilotus sp. (6♀, Boulder), 12 July 1963, 5900 ft, Melilotus sp. (1♀, Boulder), 28 July 1975 (1♀, Boulder); Gallatin Co., 1 May 1927 (1♀, Logan), 24 June 2008 (1♂, Logan); NEVADA, Elko Co., 9 July 1979 (1♂, Logan), 19 July 1975, 9500 ft (1♂, Logan-TG), 21 July 1976, 9600 ft (2♂, Logan-TG); OREGON, Baker Co., 15 July 1930, 7100 ft (1♀, Corvallis); Wallowa Co., 26 July 1929, 7500 ft (1♀, Corvallis); SOUTH DAKOTA, Custer Co., 20 June 1955, Trifolium repens (1♀, St. Charles); UTAH, Cache Co., 7 June 1962, (1♀, Logan), 18 June 1948, Wyethia sp (2♂, Logan), 30 June 1976, Penstemon leonardi (1♀, Logan), 4 July 1947, Ranunculus acriformis var. montanensis (1♀, 1♂, Logan), 5 July 1981, 8500 ft (1♀, Logan-TG), 17 July 1995, 8200–8600 ft, Penstemon sp. (2♀, Logan), 25 July 1971 (1♂, Logan), 28 July 1975, Penstemon cyananthus (1♀, Logan); 1 August 1965 (1♀, Logan), 4 August 1975, Potentilla fruticosa (1♀, Logan); Grand Co., 8 June 1963 (1♂, Logan); Sanpete Co., 25 June 1990, 10760 ft, Astragalus montii (1♂, Logan); Weber Co., 13 July 1950 (1♂, Logan); WASHINGTON, King Co. (1♀, 4♂, Boulder); WYOMING, Big Horn Co., 6 August 2000, 8975 ft, Machaeranthera sp. (1♀, Boulder); Carbon Co., 31 May 1972 (1♂, Boulder); Fremont Co., 10 June 1955 (1♀, Logan), 29 June 1990, 11000–12000 ft (2♂, Logan); Johnson Co., 22 July 1998 (1♀, Logan); Sheridan Co., 26 June 1986 (1♀, Ottawa); Sublette Co., 20 July 1959 (2♀, Logan); Teton Co., July 1937 (1♀, Logan), 4 July 1983, 6700 ft, Hedysarum boreale (1♀, Logan), 13 July 1983, 6700 ft, Hedysarum boreale (1♀, Logan); 17 July 1983, 6700 ft, Hedysarum boreale (1♀, Logan).