定義： Tall-herb semi-natural perennial vegetation on disturbed forest edges, nutrient-rich riparian fringes an in forest clearings in the temperate and boreal zones of Eurasia
定義： Of life span, a plant which lives for more than one but less than two years after germination, c.f. annual, ephemeral, perennial, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic.
