Despite its aggressive tendencies, this species (as "lesser celandine") has traditionally been grown in gardens for its showy yellow flowers in spring, together with glossy cordate leaves. F. verna has now become widespread in parts of northeastern states and seems to be increasing southwards. It is abundant in sw. Ohio. In Ky. it has become abundant at several locations in the Louisville (JEFF etc.) and Lexington (FAYE etc.) areas, flowerring in late Feb to early May. Some records from other counties may just be small patches or waifs. But it is now spreading locally within the lower Kentucky River watershed. The species generally occurs in young or disturbed floodplain woods, especially along flashy eutrophic urban streams or in areas that have been intensively browsed during past decades, with reduced native vegetation. It can also extend locally up adjacent slopes into damp shady areas. With deep achoring tubersl, plants are able to withstand spring floods that may wash out taller perennials like Laportea (Masters 2014; and pers. comm.). Native perennials that have significant tolerance of such conditions, and which are often absent in disturbed woods, include Chasmanthium, Elymus spp., Erythronium spp., Enemion, Mertensia, Hydrophyllum canadensis and Rudbeckia laciniata; these might reduce Ficaria if present. Plants are somewhat toxic but may be browsed a little; and there is traditional human use as a cooked greens, dried herb or roasted roots. Segregation of Ficaria from Ranunculus is supported by recent analysis (Paun et al. 2005; W). It can be treated as a monotypic genus with five subspecies, native to Europe but all reportedly escaped into North America; 2n = 16, 24 and 32 (Post et al. 2009). Plants in Louisville, Ky. (JEFF), are probably referable to the largely asexual tetraploid, ssp. verna [= R. ficaria ssp. bulbilifer]. However, this taxon can be difficult to distinguish from the diploid, ssp. fertilis (Lawralrée ex Laegaard) Stace [= R. ficaria ssp. ficaria], which is more restricted to western Europe. Masters (2014) has found an average of about 2 seeds produced per flower in Louisville. More robust plants with basally disposed leaves, named ssp. calthifolia (Reichenb.) Nyman, have also been reported from Ky. (W).