Evans, A. W. 1921. Taxilejeunea pterogonia and certain allied species. Bulletin of the Torrey Botanical Club 48: 107-136.
Note: Key to the common species; very incomplete.
1. Underleaves small, distant, 3-4 times stem width; perianth with 5 smooth keels near apex … T. obtusangula
1. Underleaves large, contiguous, 6-7 times stem width; perianth with 5 smooth keels near apex … 2.
2. Leaves obliquely spreading (to 50º), asymmetrically broad triangular-ovate; underleaves rounded, U-shaped incision, lobes not overlapping … T. debilis
2. 2. Leaves widely spreading, symmetrically ovate; underleaves with narrow V-shaped incision, lobes often overlapping … 3.
3. Perianth with 5 toothed keels at apex … T. pterigonia
3. Perianth smooth, cylindrical … T. isocalycina