Mertensia - WikiHQ

Mertensia is a genus of flowering plants in the borage family Boraginaceae. They are perennial herbaceous plants with blue or sometimes white flowers that open from pink-tinged buds. Such a change in flower color is common in Boraginaceae and is caused by changes in soil pH. Mertensia is one of several plants that are commonly called "bluebell". In spite of their common name, the flowers are usually salverform (trumpet-shaped) rather than campanulate (bell-shaped).

Mertensia is native to most of North America and to a large part of Asia from western China to northeastern Russia. Its center of diversity is in the Rocky Mountains. Mertensia is mostly restricted to alpine, subalpine, and montane habitats. Notable exceptions are Mertensia maritima, a maritime plant of Arctic and subarctic coastlines, and Mertensia virginica, which is found from the Appalachian Mountains west to Minnesota, Iowa, and Missouri. The Inuit ate the rhizomes of Mertensia maritima.

Many of the species of Mertensia are hard to distinguish and some are possibly cryptic. Most authors have recognized about 45 species,

Classification

Mertensia is a member of the tribe Cynoglosseae. Its closest relative is the monotypic Eurasian genus Asperugo. These two are probably close to Anoplocaryum, a genus of Central Asia and Siberia. The relationships of Anoplocaryum have never been investigated by cladistic analysis of DNA sequences.

Taxonomy

The type species for Mertensia is M. virginica. Mertensia is divided into two sections: Stenhammaria and Mertensia. Section Stenhammaria consists of the circumboreal M. maritima and 11 of the 12 species from Asia. It is the only species of Mertensia that is native to both Asia and North America. It resembles M. rivularis and might be closer to that species than to the other species of North America. It also resembles M. platyphylla and some authors have placed it in synonymy under Mertensia platyphylla variety platyphylla. It has not yet been sampled in a molecular phylogenetic study.

With the possible exception of M. pilosa, North American Mertensia is a monophyletic group consisting of three clades that are known informally as the Pacific Northwest clade, the Southern Rocky Mountain clade, and the Central Rocky Mountain clade. Albrecht Wilhelm Roth, in 1797, separated what are now M. virginica, M. maritima, and M. sibirica from Pulmonaria to form the genus Mertensia, based on their smaller and differently structured calyx, their different anther position, and the presence of nectar glands on the inner surface of the corolla. Roth described one species as Mertensia pulmonarioides, apparently unaware that Linnaeus had already described it as Pulmonaria virginica. He thus created a superfluous synonym that has been a source of confusion ever since.

Mertensia was named after the German botanist, Franz Carl Mertens.

In the time since Mertensia was erected in 1797, it has been the subject of six major revisions. These, in chronological order, were done by George Don (George Don, the younger (G. Don), not George Don, the elder (Don)), Asa Gray, James Francis Macbride, Per Axel Rydberg, Louis Otho Williams, and Mikhail Grigorevich Popov. The section Stenhammaria was named for the Swedish naturalist and clergyman Christian Stenhammar, who is best known for his work in lichenology. Gray defined the section Stenhammaria as consisting only of the littoral species M. maritima, but in 2014, it was expanded to comprise 12 species. This reclassification has been confirmed by molecular phylogenies which place Pseudomertensia closer to Myosotis than any of the genera that have been sampled so far.

Evolution

In the earlier infrageneric classifications of Mertensia, some of the groups were based on shared "primitive" characters rather than the derived character states that show true phylogenetic relationships. In Mertensia, as elsewhere, such groups have often proved to be paraphyletic. More recently, molecular phylogenetics has greatly clarified the ancestral and derived character states in Mertensia. Some of the traits evolving later have appeared independently as many as seven times.

Ancestral states in Mertensia include short plant height (< 40 cm), long stamens (> 1.5 mm), filaments inserted higher in the corolla, calyces divided at least 2⁄3 of the way to the base, and acute to acuminate calyx lobe apices. Their derived alternatives are greater plant height (> 40 cm), short stamens (< 1.5 mm), filaments attached lower in the corolla, and calyces divided less than halfway to the base, and obtuse calyx lobe apices.

The nutlets and pollen of Mertensia are nearly uniform and consequently, are not of much taxonomic value.

There are no known fossils of Mertensia. A molecular clock analysis has estimated that Mertensia diverged from Asperugo in the late Oligocene or early Miocene. Asperugo and Mertensia do not closely resemble each other morphologically. Being mostly plants of subarctic climates, Mertensia spread southward and to lower elevation during periods of Pleistocene glaciation, then retreated northward and to higher elevation during interglacials. but Mertensia is a conspicuous exception in having most of its species in North America.

Gallery

Mertensia alpina (7977046090).jpg|Alpine bluebells (Mertensia alpina)

Mertensiaarizonica.jpg|Aspen Bluebells (Mertensia arizonica)

Mertensia brevistyla TPrendusi lg.jpg|Short-styled Bluebell (Mertensia brevistyla)

Shot of blue mountain bluebells flowers hanging from a stem mertensia ciliata.jpg|Mountain bell (Mertensia ciliata)

Mertensia franciscana1.jpg|Franciscan bluebells (Mertensia franciscana)

Mertensia lanceolata NPS-1.jpg|Prairie bluebells (Mertensia lanceolata)

Mertensia longiflora 1718.JPG|Long bluebells (Mertensia longiflora)

Mertensia maritima (3701701247).jpg|Oysterplant (Mertensia maritima)

Mertensia oblongifolia flowers (3525613924).jpg|Oblongleaf bluebells (Mertensia oblongifolia)

Tall Bluebells (3816794344).jpg|Tall bluebells (Mertensia paniculata)

Virginia Bluebells at Rocky River.jpg|Virginia bluebells (Mertensia virginica )

</gallery>

References

External links

Mabberley's Plant-book
Mertensia (Search) And Mertensia (Search Exact) At: Names At: Tropicos At: Science and Conservation At: Missouri Botanical Garden
Mertensia Plant Names IPNI
Mertensia Index Nominum Genericorum References NMNH Department of Botany Research and Collections Smithsonian National Museum of Natural History
page 34 page 35 Catalecta Botanica HathiTrust
CRC World Dictionary of Plant Names: M-Q At: Botany & Plant Science At: Life Science At: CRC Press
BHL (Biodiversity Heritage Library):

:* page 135 page 136 Species Plantarum, 1st ed. (1753) At: View Record of title 25 At: Titles by Carl von Linné (1707-1778) Authors BHL

:*Nomenclature of the Virginia bluebell Volume 21, View Book SIDA, contributions to botany BHL

:* page 318 page 372 volume 4 A general history of the dichlamydeous plants Don, George, 1798-1856 authors BHL

:* page 179 page 199 volume 2, part 1 View Book Synoptical flora of North America: Gray, Asa, 1810-1888 authors BHL

:* Louis Otho Williams 1937 volume 24 Annals of the Missouri Botanical Garden titles BHL

:* Asa Gray 1874 volume 10 (New Series volume 2) Proceedings of the American Academy of Arts and Sciences titles BHL

James Francis Macbride 1916
Per Axel Rydberg 1922 Internet Archive
Mertensia At: Species Records for Mertensia At: Mertensia At: List of genera At: Boraginaceae At: List of families At: Families and Genera in GRIN At: Queries At: GRIN taxonomy for plants
Mertensia Boraginaceae Boraginales lamiids asterids Embryophyta Streptophytina Streptophyta Viridiplantae Eukaryota Taxonomy UniProt
Mertensia Boraginaceae Boraginales lamiids asterids Embryophyta Streptophytina Streptophyta Viridiplantae Eukaryota Taxonomy Browser Taxonomy Database Taxonomy NCBI (National Center for Biotechnology Information)
Display Results Hierarchical Report with Plantae and Genus selected Data Access ITIS
Mertensia Boraginaceae Boraginales Magnoliopsida Tracheophyta Plants Global Species
Mertensia Boraginaceae Angiosperms Browse The Plant List
Mertensia Table of families and genera Jepson eFlora
USDA Plants Profile