T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Linaria vulgaris (Yellow toadflax)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Lamiales
Family: Plantaginaceae
Genus: Linaria
Species: L. vulgaris
Binomial name: Linaria vulgaris
Synonyms: Linaria acutiloba, Linaria linaria
Common names: Yellow toadflax, Butter-and-eggs, Common Toadflax, Greater butter-and-eggs, Flaxweed, Jacob's ladder, Ramsted, Wild snapdragon

Linaria vulgaris is a species of toadflax that is native to most of Europe, northern Asia, the United Kingdom, Spain, east to eastern Siberia and western China. It was first was introduced to New Zealand as an ornamental due to its beautiful yellow and orange snapdragon-like flowers but it has since escaped garden cultivation. In New Zealand, it is now a weed of farmlands, riparian corridors, roadsides, railways and wastelands. It can be found scattered throughout the North Island and in Canterbury and Otago in the South Island.
Linaria vulgaris is a creeping herbaceous perennial that can reach a height of about one metre. The linear to narrow, alternate, soft leaves are pale green and are 2-5cm long. The margin of the leaf blade is entire (has no teeth or lobes). They are often drooping.
The snap-dragon-like flower’s corolla is yellow to pale yellow with an orange bearded throat and yellow spur that is about 1-2cm long in which nectar collect. There are five petals, sepals, or tepals in the flower. The flower contains both male and female organs (hermaphroditic) and requires cross-pollination by heavy insects in order for viable seed production. Seed production for an average individual plant is 30,000 seeds with only about a 10% germination rate under field conditions.
The plant's fruit is an ovate, two-celled, dry, brown capsule that splits open when ripe. It contains dark brown seeds that are small and flat. Each seed has a circular papery wing. is dry and splits open when ripe
Linaria vulgaris is weedy because can form dense populations, mainly through vegetative reproduction from root buds along underground rhizomes. Root fragments as small as 1cm can establish and initiate shoot grow. Dispersal methods are by the transportation of root fragments by machinery and the seeds which attach to the fur of animals, humans and vehicles. Wind and water are also a mechanism of seed dispersal.
Linaria vulgaris can suppress native grasses and compete for soil water resources reducing biodiversity. It also replaces valuable forbs in pasture land reducing the efficiency of livestock grazing; livestock do not prefer the taste of yellow toadflax and it is moderately toxic due to it containing several compounds, including glucosides and the cyanogenic glucoside prunasin. Cattle generally avoid grazing stands of this plant. There is more potential for poisoning when the animals are provided with hay that has a high content of Linaria vulgaris. No definitive records of poisoning are found in the literature.

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/