Linaria

Linaria is a genus of 150 species of flowering plants, one of several related groups commonly called toadflax. They are annuals and herbaceous perennials, and the largest genus in the Antirrhineae tribe of the plantain family Plantaginaceae.

Linaria
Common toadflax (Linaria vulgaris)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Lamiales
Family:	Plantaginaceae
Tribe:	Antirrhineae
Genus:	Linaria Mill.
Species
See text

Taxonomy

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

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

Cultivation

Several Linaria species are cultivated as garden plants, notably L. alpina (alpine toadflax), L. maroccana (Moroccan toadflax), L. purpurea (purple toadflax) and L. vulgaris (common toadflax).[1]

Species

Linaria aeruginea Linaria algarviana Linaria alpina Linaria amethystea Linaria amoi Linaria angustissima Linaria anticaria Linaria arenaria Linaria arvensis Linaria badalii Linaria biebersteinii Linaria bipartita Linaria bipunctata Linaria bungei Linaria buriatica Linaria caesia Linaria capraria Linaria cavanillesii Linaria chalepensis Linaria clementei Linaria coutinhoi Linaria cretacea Linaria dalmatica (syn. Linaria genistifolia) Linaria debilis Linaria depauperata Linaria diffusa Linaria elegans Linaria farsensis Linaria faucicola Linaria ficalhoana Linaria filicaulis Linaria flava

Linaria glauca Linaria glacialis Linaria glauca Linaria golestaniensis Linaria grandiflora Linaria hellenica Linaria heterophylla Linaria hirta Linaria huteri Linaria incarnata Linaria incompleta Linaria japonica Linaria karajiensis Linaria khorasaniensis Linaria kulabensis Linaria lamarckii Linaria latifolia Linaria laxiflora Linaria lilacina Linaria loeselii Linaria longicalcarata Linaria macroura Linaria maroccana Linaria mazandaraniensis Linaria micrantha Linaria microsepala Linaria nevadensis Linaria nigricans Linaria nivea Linaria oblongifolia Linaria odora Linaria oligantha

Linaria pedunculata Linaria pelisseriana Linaria peloponnesiaca Linaria pinifolia Linaria platycalyx Linaria propinqua Linaria pseudolaxiflora Linaria purpurea Linaria reflexa Linaria repens Linaria reticulata Linaria ricardoi Linaria sabulosa Linaria sagittata Linaria saturejoides Linaria saxatilis Linaria silenifolia Linaria simplex Linaria spartea Linaria supina Linaria thibetica Linaria thymifolia Linaria tonzigii Linaria triornithophora Linaria triphylla Linaria tristis Linaria uralensis Linaria ventricosa Linaria verticillata Linaria viscosa Linaria vulgaris Linaria yunnanensis

Some of the more familiar Linaria include:

• 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.
• 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.
• Pale toadflax (Linaria repens), a species from western Europe similar to L. purpurea, but with paler flowers.

Etymology

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.

Distribution and habitat

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

Ecology

Some Linaria are regarded as noxious weeds. They are likely toxic to livestock, but ruminants generally avoid them.[3]

Chemical Composition

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, Iridolinaroside B, Iridolinaroside C, Iridolinaroside D, Iridolinarin A, Iridolinarin B, Iridolinarin C are some compounds found in plants of this genus.[4]

Uses

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).

Traditional Medicine

L. vulgaris has been used as a medicinal herb.[5]

References

1. Brickell, Christopher, ed. (2008). The Royal Horticultural Society A-Z Encyclopedia of Garden Plants. United Kingdom: Dorling Kindersley. p. 636. ISBN 9781405332965.
2. Dalmatian Toadflax (Linaria dalmatica). National Invasive Species Information Center, United States National Agricultural Library.
3. Sing, S. E. and R. K. Peterson. (2011). Assessing environmental risks for established invasive weeds: Dalmatian (Linaria dalmatica) and yellow (L. vulgaris) toadflax in North America. International Journal of Environmental Research and Public Health 8(7) 2828-53.
4. "Chemical constituents and biological activities of the genus Linaria (Scrophulariaceae)".
5. Duke, J. A. Ethnobotanical uses: Linaria vulgaris. Dr. Duke's Phytochemical and Ethnobotanical Databases.

Bibliography

• 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.