ABSTRACT
The wild cereals show their strength by invading disturbed habitats such as those caused by weathering, erosion, fire and animal grazing. Wild representatives like Hordeum spontaneum with one seed per spikelet have to rely primarily on variation along the ear which falls apart in triplets. In the thaoudar variant of wild einkorn wheat or in Aegilops kotschyi, the system is even more elaborate but the other way round. The opportunistic strategy of the annual wild cereals made them well fitted for both pathways. Wild oats have demonstrated their ability to spread widely into different climatic zones and daylength regimes. A characteristic of weedy and cultivated derivatives is that man has encouraged them to adapt to even wider climatic regimes. In features where wild and weedy relatives have gradually diverged, the weedy and cultivated forms show coevolution. The weedy types in particular may represent a wide spectrum of patterns adapted to different signals and with different lengths and types of dormancy.
