Studies on the inflorescence of wild oats (Avena fatua)

Abstract

Some observations and experiments were carried out on inflorescences of wild oats, Avenafatua L. (Poaceae). Results of these studies indicate that the distal spikelets are initiated and mature earlier than those in the proximal positions. In each spikelet, the primary floret matures earlier than the secondary floret. However, the less mature secondary floret drops from the spikelet sooner. The awn in mature florets is geniculate and shows a characteristic twisting movement depending on the availability of moisture in the atmosphere. The movement of awns results in periodic dislodging of mature florets from spikelets. The basipetal maturity of spikelets in the panicle, the acropetal maturity of florets in each spikelet, and the premature separation of florets aided by the awn movement produce caryopses of variable maturity and are of considerable significance in the reproductive biology of wild oats.