Tofieldiaceae Explained

Tofieldiaceae is a family of flowering plants in the monocot order Alismatales.^[1] The family is divided into four genera, which together comprise 28 known species (Christenhusz & Byng 2016 ^[2]). They are small, herbaceous plants, mostly of arctic and subarctic regions, but a few extend further south, and one genus is endemic to northern South America and Florida. Tofieldia pusilla is sometimes grown as an ornamental.^[3]

William Hudson (1730-1793) named Tofieldia for the British botanist Thomas Tofield (1730–1779).^[4] The family Tofieldiaceae was erected by Armen Takhtajan in 1995.^[5] Molecular phylogenetic studies of DNA sequences have shown it to be the second diverging clade in Alismatales, after the most basal clade, the family Araceae.^[6] Before the segregation of Tofieldiaceae was confirmed by cladistic methods, its genera had usually been assigned to Nartheciaceae,^[7] Liliaceae,^[8] or Melanthiaceae. Tofieldiaceae is recognized by the Angiosperm Phylogeny Group in their APG III system of plant classification.

The circumscription of genera in Tofieldiaceae has been controversial. Many authors do not recognize Triantha as a separate genus from Tofieldia.^{[7] [9] [10]} A few authors have sunk other genera into Tofieldia as well.^[11] 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.

Description

Small herbaceous perennials. Leaves equitant (distichous and overlapping), isobifacial. Inflorescence a raceme. Calyculus present. Tepals free. Fruit a capsule, usually septicidal.

Genera

• Harperocallis McDaniel
• Pleea Michx.
• Tofieldia Huds.
• Triantha (Nutt.) Baker
• †Dicolpopollis ^[12]

Phylogeny

The following phylogenetic tree is based on a DNA paper that was published in 2011,^[13] modified to accommodate the transfer of the species in Isidrogalvia to Harperocallis.

External links

• CRC World Dictionary of Plant Names: R-Z At: Botany & Plant Science At: Life Science At: CRC Press
• Tofieldiaceae at: Plant Names at: IPNI
• Genus List at: Tofieldiaceae at: Alismatales at: Trees at: APweb at: botanical databases at: About Science & Conservation at: Missouri Botanical Garden
• Harperocallis flava and Pleea tenuifolia and Tofieldia and Triantha at: Liliaceae at: Volume 26 at: FNA at: eFloras.org
• NCBI Taxonomy Browser
• links at CSDL, Texas

Notes and References

1. Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. Flowering Plant Families of the World. Firefly Books: Ontario, Canada. (2007). .
2. Christenhusz, M. J. M. . Byng, J. W. . amp . 2016 . The number of known plants species in the world and its annual increase . Phytotaxa . 261 . 201–217 . 10.11646/phytotaxa.261.3.1 . 3 . Magnolia Press . free .
3. [Anthony Huxley]
4. 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).
5. Tofieldiaceae. At: International Plant Names Index. (see External links below).
6. Peter F. Stevens (2001 onwards). "Tofieldiaceae" At: Angiosperm Phylogeny Website. At: Botanical Databases At: Missouri Botanical Garden Website. (see External links below)
7. 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).
8. 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).
9. David J. Mabberley. 2008. Mabberley's Plant-Book third edition (2008). Cambridge University Press: UK.
10. Armen L. Takhtajan (Takhtadzhian). Flowering Plants second edition (2009). Springer Science+Business Media. .
11. Wendy B. Zomlefer. 1997. "The genera of Tofieldiaceae in the southeastern United States". Harvard Papers in Botany. 2:179-194.
12. Tertiary and Late Upper Cretaceous stratigraphy of west border of San Joaquin Valley, north of Panoche Creek, Fresno, Merced and Stanislaus counties, California . 1944 . US Geological Survey.
13. 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.