Because of their general vigor and capacity for rapid spread, sow thistles are often considered invasive weeds. Some, in fact, can produce seeds in staggering numbers — as many as 25,000 per plant.

In Erigeron (Asteraceae), diplosporous plants constituted 23% ... Both types of florets were examined in the case that ovule development might be different in the two floret types or, ...

Because of their general vigor and capacity for rapid spread, sow thistles are often considered invasive weeds. Some, in fact, can produce seeds in staggering numbers — as many as 25,000 per plant.

Analysis of self-fertility: seed/floret ratio. Two main factors, population and cross type, had a highly significant effect on seed/floret ratio, as did the cross–population interaction ().The ...