Perennial flowering plants on the other hand develop a seed pod on the base of its flower and there are several seeds in it. The seeds are much more substantial. They are hard, and are round or oval.

with a Description of Commonly Occurring Weed Seeds and a Guide to Their Identification. By S. T. Parkinson G. Smith. Pp. 105 + xxxviii plates. (London and Ashford (Kent): Headley Bros ...