Native
Range: South-central Eurasia
History
Yellow
toadflax was introduced to North America as an ornamental plant.
It is still sold today in nurseries and seed catalogs as "Butter
and Eggs" or "Wild Snapdragon". Be aware of what species are included
in wildflower seed mixes, always look on the back of the product
container for a listing of what's included in the mix. If toadflaxes
are listed, PLEASE DO NOT buy that product.
Identification
Yellow
toadflax is a perennial with stems that grow from one to three feet
tall. The pale green leaves are narrow, linear, and pointed at both
ends. Flowers are bright-yellow with an orange center, with a spur
that is approximately as long as the rest of the flower combined.
Flowers occur in clusters near the ends of the stems, becoming more
widely spaced along the stem as the season progresses. Seed capsules
are round, and two-celled. Seeds are small, brown or black, circular,
and surrounded by a notched wing.
Biology
Yellow
toadflax typically emerges around mid-April. Flowering occurs from
May through August, with seeds maturing from July through October.
A mature plant can produce up to 30,000 seeds annually a single
stem has been reported to contain over 5,000 seeds. Seeds can remain
dormant in the soil for up to ten years. Yellow toadflax can reproduce
both by seeds and vegetatively. It can aggressively form colonies
through adventitious buds from creeping root systems.
Habitat
and Distribution
Yellow
toadflax can be found in well-drained, coarse-textured soils but
can also be found in heavier soils as well. Sites where yellow toadflax
can establish include roadsides, riparian areas, dry fields, grainfields,
waste areas, gravel pits, pastures and rangeland, vacant lots, and
railroad yards. In Adams County, yellow toadflax infestations can
be found along the South Platte River, along Clear Creek, and in
various lakes and ponds.
Impacts
From
seed distribution to creeping root systems, yellow toadflax can aggressively
form colonies. These colonies can push out native grasses and other
perennials, thereby altering and simplifying the species composition
of natural communities and reducing forage production for livestock
and wildlife. This in turn reduces rangeland value and can lead to
erosion problems.
