Books by P. van Royen
The alpine flora of New Guinea
The alpine flora of New Guinea
The orchids of the high mounta
The orchids of the high mountains of New Guinea
The genus Rubus (Rosaceae) in
The genus Rubus (Rosaceae) in New Guinea
Sertulum Papuanum
Sertulum Papuanum
Provisional list of families a
Provisional list of families and genera found in New Guinea and surrounding islands (Gymnospermae, Angiospermae)
De botanische expeditie 1954-1
De botanische expeditie 1954-1955 in Nieuw Guinea
Eriandra, a new genus of Polyg
Eriandra, a new genus of Polygalaceae from New Guinea
The podostemaceae of the New W
The podostemaceae of the New World