British distribution: Widespread, frequent.
This is the famous "black rust" or "stem rust" of wheat, though occuring on many grasses.
P. graminis is heteroecious and is widespread on grasses in its uredinial and telial states, when it forms brown (uredinia) or black (telia) stripes on stems and leaf-sheaths. The aecia and spermogonia occur on species of Berberis (barberry) and Mahonia (oregon-grape).
A useful account of P. graminis and other cereal rusts is given by Agrios (1998).
A number of formae speciales have been recognised on different wild and cultivated grass hosts, including f.sp. tritici on wheat (less often barley and rye), f.sp. secalis (= f.sp. hordei?) on barley, rye and some wild species, and f.sp. avenae on cultivated oats and their wild relatives. Wheat has traditionally been most seriously affected crop in Britain, particularly in certain years and in southwestern England, but attack by this rust is often too late in the season to substantially affect crop yields. Nevertheless, in many parts of the country, farmers have eradicated barberry (a shrub) from their hedges in an attempt to control or block infection by this rust.
Wilson & Henderson (1966) noted, however, that f.sp. tritici had not been proven to occur on barberry in Britain and that infection of wheat was generally by wind-blown urediniospores from the continent. Nor is barberry essential to the survival of this rust as it can continue in its uredinial state in the absence of its aecial host.
Note that a number of other rust species occur on cereals and on wild grasses. Their certain identification in the uredinial state is often not easy.
For an explanation of the terms used in this account, go to the profile of the Pucciniales.