Plagiognathus alpinus Reuter, 1875e: 56; 1875j: 88. STS: male, female, Austria, Kirschbaumeralpe nr Lienz; MZHF.
Psallus pallidus Reuter, 1880c: 24 (syn. Wagner, 1958j: 325). LT (Kerzhner & Matocq, 1994: 63): female, France, Hautes Pyrénées; MNHN.
Plagiognathus alpinus f. nigrescens Stichel, 1934: 279. For var. β in Reuter, 1883e: 450. Equals f. typica (see Stichel, 1958a: 810).
Plagiognathus alpinus f. simplex Stichel, 1956b: 332. Equals f. pallida (see Stichel, 1958a: 810).