The dynamics of clonal dispersal and regenerative activity of Veronica filiformis J.E. Smith

Abstract

The absence of capacity for sexual reproduction does not hinder the rapid expansion of the invasive range of the alien species Veronica filiformis J.E. Smith (Plantaginaceae). Lawn mowing or raking causes the fragmentation of shoots and accelerates vegetative reproduction of V. filiformis. The clone diameter of this species was shown to increase up to 25 times during the growing season, whereas the number of internodes increased by a factor of 1000–2000. Slender speedwell expanded from the site of initial introduction (Moscow, Russia) at the speed of 4 km/year in the northern direction and at a speed of 10 km/year in the southern direction. Illumination of the site had a more pronounced effect on the regenerative capacity of the species than the age of root-forming shoots. Invasion of meadow and forest fringe communities by this species was registered in recent decades. The high speed of expansion of the secondary distribution range, the displacement of native species, and the direct damage to lawns caused by this plant allow for the assignment of an invasive species status to V. filiformis and justify the control over the dispersal of this species.