Important wild species in the collection are H. bulbosum and H. murinum. Other wild species included are: H. vulgare subsp. spontaneum, H. pusillum, H. chilense, H. cordobense, H. stenostachys, H. comosum, H. jubatum, H. lechleri, H. procerum, H. depressum, H. marinum, H. bogdani, H. brevisubulatum and one unknown wild Hordeum species. The majority of the cultivated H. vulgare material, 2156 accessions, are spring types, 48 are intermediate types and 374 accessions are winter barleys. The intermediate types were mainly collected in Pakistan at altitudes of around 2000 meter, during the joint Pakistan-Netherlands expedition (Hashmi et al. 1981).
The H. vulgare material is divided in 1525 landraces, 440 cultivars, 442 numbers of breeding material and 166 accessions with an unknown population type.
Between 1953 and 1981 1330 landraces were collected in several countries located in the centre of diversity of Hordeum, such as Iran, India, Nepal, Pakistan and Ethiopia. The barley collection includes only a limited number of landraces from Europe (N=49), and these are mainly from South European countries. Only four old Dutch landraces, cultivated before 1890, are present. The names of these landraces are: Maartsche gerst, zesrijige uit Wijlre, Terschelling tweerijige en Vierrijige Blauwkaf. The majority of the 439 cultivars are from Europe (N=348), including 78 from the Netherlands. The 442 accessions classified as research material are mainly from European and North American origin.