Tofieldiaceae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s in the

monocot Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are flowering plants whose seeds contain only one Embryo#Plant embryos, embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but ...

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Alismatales The Alismatales (alismatids) are an order of flowering plants including about 4,500 species. Plants assigned to this order are mostly tropical or aquatic. Some grow in fresh water, some in marine habitats. Perhaps the most important food cro ...

.Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant Families of the World''. Firefly Books: Ontario, Canada. (2007). . The family is divided into four

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

, which together comprise 28 known

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

(Christenhusz & Byng 2016 ). They are small,

herbaceous plant Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition o ...

s, mostly of

arctic The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( ...

and

subarctic The subarctic zone is a region in the Northern Hemisphere immediately south of the true Arctic, north of hemiboreal regions and covering much of Alaska, Canada, Iceland, the north of Fennoscandia, Northwestern Russia, Siberia, and the Cair ...

regions, but a few extend further south, and one genus is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to northern

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

and

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

. '' Tofieldia pusilla'' is sometimes grown as an ornamental. Anthony Huxley, Mark Griffiths, and Margot Levy (1992). ''The New Royal Horticultural Society Dictionary of Gardening''. The Macmillan Press,Limited: London. The Stockton Press: New York. (set). William Hudson (1730-1793) named ''Tofieldia'' for the British botanist Thomas Tofield (1730–1779).Umberto Quattrocchi. 2000. ''CRC World Dictionary of Plant Names'' volume IV. CRC Press: Boca Raton; New York; Washington,DC;, USA. London, UK. (set). (see ''External links'' below). The family Tofieldiaceae was erected by

Armen Takhtajan Armen Leonovich Takhtajan or Takhtajian (; surname also transliterated Takhtadjan, Takhtadzhi︠a︡n or Takhtadzhian, pronounced takh-tuh-JAHN; 10 June 1910 – 13 November 2009), was a Soviet- Armenian botanist, one of the most important fi ...

in 1995.Tofieldiaceae. At: International Plant Names Index. (see ''External links'' below).

Molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

studies of

DNA sequence A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nu ...

s have shown it to be the second diverging clade in Alismatales, after the most basal clade, the family

Araceae The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe (or leaf-like bract). Also ...

.Peter F. Stevens (2001 onwards). "Tofieldiaceae" At: Angiosperm Phylogeny Website. At: Botanical Databases At: Missouri Botanical Garden Website. (see ''External links'' below) Before the

segregation Segregation may refer to: Separation of people * Geographical segregation, rates of two or more populations which are not homogenous throughout a defined space * School segregation * Housing segregation * Racial segregation, separation of human ...

of Tofieldiaceae was confirmed by

cladistic Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...

methods, its genera had usually been assigned to Nartheciaceae,Minoru N. Tamura. 1998. "Nartheciaceae" pages ??. In: Klaus Kubitzki (general editor) with Klaus Kubitzki, Herbert F.J. Huber, Paula J. Rudall, Peter F. Stevens, and Thomas Stützel (volume editors). ''The Families and Genera of Vascular Plants'' volume III. Springer-Verlag: Berlin;Heidelberg, Germany. (vol. III).

Liliaceae The lily family, Liliaceae, consists of about 15 genera and 610 species of flowering plants within the order Liliales. They are monocotyledonous, perennial, herbaceous, often bulbous geophytes. Plants in this family have evolved with a fai ...

,Frederick H. Utech, Loran C. Anderson, and John C. Packer. 2002. pages 5-6. In: "Liliaceae". pages ??. In: Flora of North America Editorial Committee. ''Flora of North America'' vol. 26. Oxford University Press: UK. (vol. 22). (see ''External links'' below). or

Melanthiaceae Melanthiaceae, also called the bunchflower family, is a family (biology), family of flowering plant, flowering herbaceous perennial plants native to the Northern Hemisphere. Along with many other lilioid monocots, early authors considered member ...

. Tofieldiaceae is recognized by the

Angiosperm Phylogeny Group The Angiosperm Phylogeny Group (APG) is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships disc ...

in their

APG III system The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy being developed by the Angiosperm Phylogeny Group (APG). Published in 2009, it was superseded in 2016 by a f ...

of plant classification. The

circumscription Circumscription may refer to: * Circumscribed circle * Circumscription (logic) *Circumscription (taxonomy) * Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthr ...

of genera in Tofieldiaceae has been controversial. Many authors do not recognize ''Triantha'' as a separate genus from ''Tofieldia''.David J. Mabberley. 2008. ''Mabberley's Plant-Book'' third edition (2008). Cambridge University Press: UK. Armen L. Takhtajan (Takhtadzhian). ''Flowering Plants'' second edition (2009). Springer Science+Business Media. . A few authors have sunk other genera into ''Tofieldia'' as well.Wendy B. Zomlefer. 1997. "The genera of Tofieldiaceae in the southeastern United States". ''Harvard Papers in Botany''. 2:179-194. A phylogenetic analysis, based on two nuclear genes and ten chloroplast genes, has confirmed that all five of the genera are monophyletic and that ''Triantha'' and ''Tofieldia'' are close

sister taxa In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

Description

Small herbaceous perennials.

Leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

equitant (

distichous In botany, phyllotaxis () or phyllotaxy is the arrangement of leaves on a plant stem. Phyllotactic spirals form a distinctive class of patterns in nature. Leaf arrangement The basic arrangements of leaves on a stem are opposite and alternat ...

and overlapping), isobifacial.

Inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

raceme A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...

. Calyculus present.

Tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s free.

Fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

a capsule, usually septicidal.

Genera

*'' Harperocallis'' McDaniel *'' Pleea'' Michx. *'' Tofieldia'' Huds. *'' Triantha'' ( Nutt.)

Baker A baker is a tradesperson who baking, bakes and sometimes Sales, sells breads and other products made of flour by using an oven or other concentrated heat source. The place where a baker works is called a bakery. History Ancient histo ...

*†'' Dicolpopollis''

Phylogeny

The following

phylogenetic tree A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA. In ...

is based on a DNA paper that was published in 2011,Hiroshi Azuma and Hiroshi Tobe. 2011. "Molecular phylogenetic analyses of Tofieldiaceae (Alismatales): family circumscription and intergeneric relationships". ''Journal of Plant Research'' 124(3):349-357. modified to accommodate the transfer of the species in ''Isidrogalvia'' to ''Harperocallis''.

Description

Genera

Phylogeny

References

External links