Dusén, ?Ark. Bot. 7, no. 2: 33, pl. 4, 8. 1907?, 1907.

Dusén, ?Ark. Bot. 7, no. 2: 34, pl. 5, 8. 1907?, 1907.

Dusén, ?Ark. Bot. 7(2): 35. 1907?, 1907.