Ray's system, starting with his Cambridge catalogue, began with the division between the imperfect or lower plants (Cryptogams), and perfect ("planta perfecta") higher plants (Seed plants). The latter he divided by life forms, e.g. trees ("arbores"), shrubs ("frutices"), subshrubs ("suffrutices") and herbaceous plants ("herbae") and lastly grouping them by common characteristics. The trees he divided into 8 groups, e.g. "Pomiferae" (including apple and pear). The shrubs he placed in 2 groups, "Spinosi" (Berberis etc.) and "Non Spinosi" (Jasmine etc.). The subshrubs formed a single group and the herbs into 21 groups.