Snapdragon 8 Gen 2

''Antirrhinum'' is a genus of plants commonly known as dragon flowers, snapdragons and dog flower because of the flowers' fancied resemblance to the face of a dragon that opens and closes its mouth when laterally squeezed. They are native to rocky areas of Europe, the United States, Canada, and North Africa. It is widely used as an ornamental plant in borders and as a cut flower.

Description

The Antirrhinum is morphologically diverse, particularly the New World group (''Saerorhinum''). The genus is characterized by personate flowers with an inferior gibbous corolla.

Taxonomy

''Antirrhinum'' used to be treated within the family Scrophulariaceae, but studies of DNA sequences have led to its inclusion in a vastly enlarged family Plantaginaceae, within the tribe Antirrhineae.

Circumscription

The taxonomy of this genus is complex and not yet fully resolved at present. In particular the exact circumscription of the genus, especially the inclusion of the New World species (Saerorhinum), is contentious. The situation is further complicated by the variety of terms in use for infrageneric ranks, especially of the Old World species, that is ''Antirrhinum'', ''sensu stricto'' (e.g. Streptosepalum, Kicksiella, Meonantha).

The USDA Plants Database recognises only two species: '' A. majus'' (the garden snapdragon), the only species naturalised in North America, and ''A. bellidifolium'' (the lilac snapdragon), now considered to be ''Anarrhinum bellidifolium'' (L.) Willd. As of April 2017, The Plant List (Version 1.1) accepts 21 species.

A widely accepted scheme (Thompson 1988) placed 36 species in the genus in three sections. While many botanists accepted this broad circumscription ('' sensu lato''), whose main departure from other classifications was the inclusion of the New World Saerorhinum, others did not, restricting the genus to the Old World. (For a comparison of Thompson with earlier systems, see Oyama and Baum, Table 1.) New species also continue to be discovered (see e.g. Romo ''et al.'', 1995).

In 2004 research into the molecular systematics of this group and related species by Oyama and Baum confirmed that the genus ''sensu lato'' as described by Thompson is monophyletic, provided that one species ('' A. cyathiferum'') is removed to the separate genus ''Pseudorontium'', and the two species of ''Mohavea'' (''Mohavea confertiflora'' and ''M. breviflora'') are included. The species list given here follows these conclusions.

This is the broad circumscription that includes the Old World'' Misopates'' and New World '' Sairocarpus''. By contrast the narrow circumscription (''sensu stricto'') confines the genus to the monophyletic Old World perennial species with a diploid chromosome number of 16, distributed in the Mediterranean basin, approximately 25 species. (Tolety 2011), following the phylogenetic analysis of Vargas ''et al.'' (2004) suggesting they are a distinct group. Both ''Misopates'' and ''Sairocarpus'' are accepted names in ''The Plant List'', and many of the New World species now have ''Sairocarpus'' as their accepted name, rather than ''Antirrhinum''. It has been proposed that many of the New World ''Antirrhinum'' be now considered under ''Sairocarpus'', in the forthcoming ''Flora of North America''.

Infrageneric subdivision

It is widely agreed that this broad group should be subdivided into three or four subgroups, but the level at which this should be done, and exactly which species should be grouped together, remain unclear. Some authors continue to follow Thompson in using a large genus ''Antirrhinum'', which is then divided into several sections; others treat Thompson's genus as a tribe or subtribe, and divide it into several genera. For a comparison of earlier schemes see Mateu-Andrés and de Paco, Table 1 (2005)

If the broad circumscription is accepted, its three sections as described by Thompson are as follows (two Old World, one New):

*Section ''Antirrhinum'': 19 Old World species of relatively large flowered perennial plants, including the type species ''Antirrhinum majus'', mostly native to the western Mediterranean region with a focus on the Iberian Peninsula. Chromosomes n=8. (3 subsections: ''Majora'', ''Sicula'', ''Hispanica'')
*Section ''Orontium'': two species, also from the Mediterranean. Chromosome number=8. The species in this section, including the section type species ''Antirrhinum orontium'' (lesser snapdragon) are often treated in the genus ''Misopates''.
*Section ''Saerorhinum'': 15 small flowered New World species, mostly annual plants and mostly native to California, though species are found from Oregon to Baja California Sur and as far east as Utah. Tetraploid (n=15-16). Like other authors, Thompson placed ''A. cyathiferum'' in this section, but Oyama and Baum, following earlier authors, suggest that it should be reclassified in genus ''Pseudorontium'', while ''Mohavea'' should be included. Vargas ''et al.'', strongly recommending segregation of the New World species suggest that the 14 species originally recognised by Sutton (1988) more properly belong to '' Sairocarpus'' (11 species), ''Howelliella'' (1 species), and '' Neogarrhinum'' (2 species). Other authors would also include ''Galvezia glabrata'', ''Galvezia juncea'', ''Galvezia rupicola'' and ''Galvezia speciosa''. None of the names originally allocated to this section are now accepted (see List of Antirrhinum species).

Snapdragons

While ''Antirrhinum majus'' is the plant that is usually meant by the term of "snapdragon" if used on its own, many other species in the genus, and in the family Scrophulariaceae more widely, have common names that include the word "snapdragon". Such as ''Antirrhinum molle'' is known as "dwarf snapdragon" in the UK.

Species

Etymology

The word "antirrhinum" is derived from the Greek ''antirrhinon'' "calf's snout, Antirrhinum Orontium" which in turn is derived from ''anti'' "against, like", and ''rhis'' "nose" ( GEN ''rhinos''); thus, possibly "noselike", possibly referring to the noselike capsule in its mature state.

Ecology

Snapdragons are short-lived perennial plants that survive well in cold seasons but are often replanted each spring and considered annual plants. They do best in full or partial sun, in well-drained soil since their roots are susceptible to rotting (although they do require regular watering). They are classified commercially as a range of heights: ''midget'' or ''dwarf'' (), ''medium'' () and ''tall'' (). Removing the dead flowers, referred to as deadheading, is important to help them to continuously produce beautiful flowers throughout their growing season. They are susceptible to ethylene gas so removing dead flowers and keeping them away from ripe fruits or vegetables also helps them bloom longer. They grow during their peak seasons of April to June and August to October in the Northern Hemisphere. and bloom in a variety of colors ranging from: white, yellow, orange, red, purple, pink and some multicolored patterns.

They are ecologically diverse, particularly the New World species (''Saerorhinum'').

Cultivation

The snapdragon is an important garden plant, widely cultivated from tropical to temperate zones as a bedding, rockery, herbaceous border or container plant. (Tolety 2011) Cultivars have showy white, crimson, or yellow bilabiate flowers (with two lips). It is also important as a model organism in botanical research, and its genome has been studied in detail.

Genetic studies

''Antirrhinum'' is a genus that has been used from the earliest genetic studies of Gregor Mendel and Charles Darwin and was used as a model by Erwin Baur (Tolety 2011). Together with closely related genera, it has become a model organism for the investigation of the genetic basis of plant development, particularly floral development.
The genus is a typical example of incomplete dominance by the red allele with the anthocyanin pigment. Any cross between red-flowered and white-flowered snapdragons, give an intermediate and heterozygous phenotype with pink flowers, that carries both the dominant and recessive alleles.

Several species of ''Antirrhinum'' are self-incompatible, meaning that a plant cannot be fertilised by its own pollen. Self-incompatibility in the genus has been studied since the early 1900s. Self-incompatibility in ''Antirrhinum'' species is controlled gametophytically and shares many important features with self-incompatibility systems in Rosaceae and Solanaceae.

Uses

In addition to growing the plants for cut flowers, the seeds have been used to extract edible oils, particularly in Russia, while the leaves and flowers have been considered to possess antiphlogistic (anti-inflammatory) properties and have been used in poultices. A green dye has also been extracted from the flowers.Tolety 2011

Gallery

File:Yellow-Snapdragon-Flower(Antirrhinum majus) 08.jpg, Yellow Snapdragon Flower
File:Antirrhinum majus-Flower 01.jpg, Antirrhinum majus Flower
File:Pink Snapdragon Flower-Antirrhinum majus 02.jpg, Pink Snapdragon Flower
File:Yellow-Snapdragon-Flower(Antirrhinum majus) 01.jpg, Yellow Snapdragon Flower
File:Antirrhinum majus-Flower 03.jpg, Antirrhinum majus Flower
File:Pink Snapdragon Flower 02.jpg, Pink Snapdragon Flower
File:White-Snapdragon-Flower(Antirrhinum majus) 05.jpg, White Snapdragon Flower
File:Yellow-Snapdragon-Flower(Antirrhinum majus) 03.jpg, Yellow Snapdragon Flower
File:Antirrhinum majus-Flower 02.jpg, Antirrhinum majus Flower
File:Antirrhinum white.jpg, Variety in Pakistan
File:Antirrhinum-2.jpg, Variety in Pakistan
File:Yellow-Snapdragon-Flower(Antirrhinum majus) 05.jpg, Yellow Snapdragon Flower
File:Pink Snapdragon Flower-Antirrhinum majus 01.jpg, Pink Snapdragon Flower
File:White-Snapdragon-Flower(Antirrhinum majus) 03.jpg, White Snapdragon Flower
File:Yellow-Snapdragon-Flower(Antirrhinum majus) 02.jpg, Yellow Snapdragon Flower
File:Pink Snapdragon Flower 03.jpg, Pink Snapdragon Flower
File:White-Snapdragon-Flower(Antirrhinum majus) 01.jpg, White Snapdragon Flower
File:Antirrhinum majus-Flower 04.jpg, Antirrhinum majus Flower
File:Antirrhinum-3.jpg, Variety in Pakistan
File:Yellow-Snapdragon-Flower(Antirrhinum majus) 04.jpg, Yellow Snapdragon Flower
File:Antirrhinum-4.jpg, Variety in Pakistan
File:Antirrhinum-5.jpg, Variety in Pakistan
File:Yellow-Snapdragon-Flower(Antirrhinum majus) 07.jpg, Yellow Snapdragon Flower
File:Pink Snapdragon Flower 01.jpg, Pink Snapdragon Flower
File:White-Snapdragon-Flower(Antirrhinum majus) 04.jpg, White Snapdragon Flower
File:Yellow-Snapdragon-Flower(Antirrhinum majus) 06.jpg, Yellow Snapdragon Flower
File:Pink Snapdragon Flower-Antirrhinum majus 03.jpg, Pink Snapdragon Flower
File:Antirrhinum-01.jpg, Antirrhinum in Pakistan
File:Antirrhinum majus 6.jpg, Snapdragon cultivar in India

References

Sources

* Sutton, D.A. (1988) A Revision of the Tribe Antirrhineae. Oxford: OUP.
* Rothmaler W. 1956. Taxonomische Monographie der Gattung Antirrhinum. Akademie-Verlag, Berlin, Germany.
*
*

Tolety J, Sane A. ''Antirrhinum '', in Kole C (ed.) Wild Crop Relatives: Genomic and Breeding Resources. Plantation and Ornamental Crops. Springer 2011, pp. 1-14

A. R. Doaigey, K. J. Harkiss. Application of epidermis characters to the taxonomy of European species of Antirrhinum (Schrophulariaceae). Nordic Journal of Botany. Volume 11, Issue 5, pages 513–524, December 1991. DOI: 10.1111/j.1756-1051.1991.tb01258.x

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 Syst Evol 249:151–172.

External links

The Plant ListThe Genus Antirrhinum (Snapdragon): A Flowering Plant Model for Evolution and Development''Antirrhinum majus'' genetic and phenotypic database

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Plantaginaceae genera
Extant Pliocene first appearances
Plant models
Anthocyanins
Taxa named by Carl Linnaeus