Linaria

Linaria was traditionally placed in the family Scrophulariaceae. Phylogenetic analysis has now placed it in the vastly expanded family Plantaginaceae.

Closely related genera include Nuttallanthus (American toadflaxes, recently split from Linaria), Antirrhinum (snapdragons) and Cymbalaria (ivy-leaved toadflaxes).

Several Linaria species are cultivated as garden plants, and some are regarded as having a weedy habit.

• Common toadflax or butter-and-eggs (Linaria vulgaris), a European species which is widely introduced elsewhere and grows as a common weed in some areas.[1]
• Broomleaf toadflax or Dalmatian toadflax (Linaria genistifolia, syn. L. dalmatica), a native of southeast Europe that has become a weed in parts of North America.[2]
• Purple toadflax (Linaria purpurea), a species native to the Mediterranean region grown as a garden plant for its dark purple or pink flowers. The version with purple flowers can be mistaken for lavender. Spreads readily.
• Pale toadflax (Linaria repens), a species from western Europe similar to L. purpurea, but with paler flowers.
• Alpine toadflax (Linaria alpina), purple flowers with orange (or purple) lobes in the center.
• Moroccan toadflax (Linaria maroccana), the flower has five lobes arranged into two lips with a spur at the end, often purple with white.

The following species are recognised in the genus Linaria:[3]

The members of this genus are known in English as toadflax, a name shared with several related genera. The 'toad' in toadflax may relate to the plants having historically been used to treat bubonic plague, a false link having been drawn between the words 'bubo' and 'Bufo'. The scientific name Linaria means "resembling linum" (flax), which the foliage of some species superficially resembles.

The genus is native to temperate regions of Europe, northern Africa and Asia, with the highest species diversity in the Mediterranean region.

Some Linaria are regarded as noxious weeds. They are likely toxic to livestock, but ruminants generally avoid them.[4]

Linaria species are rich in alkaloids, iridoids, terpenes, phenolic acids and flavonoids.

Vasicine, Vasicinone, 7-hyrdoxyvasicine, Linarinic acid, Choline, Linavuline, Luteolin, Acacetin, Apigenin, Chrysin, Quercetin, Myricetin, Linarioside, Aucubin, Linaride, Iridolinaroside A-D, Iridolinarin A-C are some compounds found in plants of this genus.[5]

Toadflaxes are used as food plants by the larvae of some Lepidoptera species, including the mouse moth (Amphipyra tragopoginis) and the common buckeye (Junonia coenia).

• A Phylogeny of Toadflaxes (Linaria Mill.) Based on Nuclear Internal Transcribed Spacer Sequences: Systematic and Evolutionary Consequences. Mario Fernández-Mazuecos, José Luis Blanco-Pastor, and Pablo Vargas. International Journal of Plant Sciences, Vol. 174, No. 2 (February 2013), pp. 234–249 Published by: The University of Chicago Press, Article DOI: 10.1086/668790
• Vargas P, JA Rosselló, R Oyama, J Güemes. 2004 Molecular evidence for naturalness of genera in the tribe Antirrhineae (Scrophulariaceae) and three independent evolutionary lineages from the New World and the Old. Plant Systematics and Evolution 249:151–172.
• Media related to Linaria at Wikimedia Commons