# Sanrobertia > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Sanrobertia > Markdown URL: https://mediated.wiki/source/Sanrobertia.md > Source: https://en.wikipedia.org/wiki/Sanrobertia > Source revision: 1304218653 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) ***Sanrobertia*** is a genus of [flowering plants](/source/Flowering_plant) within the subtribe [Symphyotrichinae](/source/Symphyotrichinae) of the family [Asteraceae](/source/Asteraceae). It is [monotypic](/source/Monotypic), meaning there is only one species within the genus. ***Sanrobertia gypsophila*** is a rare [endemic](/source/Endemic) known only from [Nuevo León](/source/Nuevo_Le%C3%B3n), [Mexico](/source/Mexico). ## Description *Sanrobertia gypsophila* is a [perennial](/source/Perennial_plant), [herbaceous plant](/source/Herbaceous_plant) that blooms with lilac rays and yellow disk centers during the months of August through October. It grows from a slender and woody [rhizome](/source/Rhizome),[2] with blue-green [stems](/source/Plant_stem)[3] that reach heights between about 4 and 20 cm (2 and 8 in). The plant has either tiny glands on tiny stalks called *[stipitate glands](/source/Stipitate_gland)* or it may have glands without stalks. These glands are on the upper stems, [leaves](/source/Leaf), and [phyllaries](/source/Phyllary). Most of the plant may be slightly [strigose](/source/Strigose) with very short (0.1–0.5 millimeters[n 1]), [appressed](/source/Appressed), white, and pointed [hairs](/source/Trichomes).[2] ### Leaves Numerous [alternate](/source/Alternate_leaf) and [simple](/source/Simple_leaf) blue-green leaves[3] grow on the stems and branches, and they are usually somewhat clasping at their bases. Their [margins](/source/Leaf_margin) (edges) are [smooth](/source/Entire_leaf), shapes are mostly oblong-lanceolate, and tips are curved slightly outward and covered with a few tiny spines. The single-nerved leaves are without a [stalk](/source/Petiole_(botany)) (known as *[sessile](/source/Sessility_(botany))*) and are small, ranging in lengths from 4 to 7 mm and widths from 1 to 2 mm, being generally even in size and distribution along the stems.[2] ### Flowers The flower heads of *Sanrobertia gypsophila* consist of 12–16 lilac [ray florets](/source/Ray_floret), each about 5–6 mm long and 0.8–1.2 mm wide. These surround a disk of yellow [florets](/source/Disk_floret).[4] ### Chromosomes *Sanrobertia gypsophila* has a [monoploid number](/source/Ploidy#Haploid_and_monoploid) (also called *base number*) of nine [chromosomes](/source/Chromosomes) (***x*** = 9). The species is [diploid](/source/Diploid) with a total chromosome count of 18.[5] ## Taxonomy The [basionym](/source/Basionym) of *Sanrobertia gypsophila* is *Aster gypsophilus* [B.L.Turner](/source/Billie_Lee_Turner_(botanist)), first published in 1974.[6] In 1994, [Guy L. Nesom](/source/Guy_L._Nesom) reclassified it as *Symphyotrichum gypsophilum* (B.L.Turner) G.L.Nesom,[1] even though the chromosome count varied from those species; he wrote that it appeared closely related to the virguloid species in the *[Symphyotrichum](/source/Symphyotrichum)* genus.[5] In 2012, the results of further molecular analyses of *Symphyotrichum* and related species were published by David R. Morgan and Blake Holland which clearly placed it as separate from the *Symphyotrichum* genus.[7] Thus, in 2018, Nesom published it in a [monotypic](/source/Monotypic) genus within the subtribe [Symphyotrichinae](/source/Symphyotrichinae) of the tribe [Astereae](/source/Astereae).[2] The cladogram shows that the genera *[Canadanthus](/source/Canadanthus)*, *[Ampelaster](/source/Ampelaster)*, and *Sanrobertia* are the earliest diverging members of Symphyotrichinae, developing their morphologies prior to the related species in *Symphyotrichum*, *[Almutaster](/source/Almutaster)*, and *[Psilactis](/source/Psilactis)*.[7] ## Distribution and habitat *Sanrobertia gypsophila* is a rare [endemic](/source/Endemic) species known only from [gypsum](/source/Gypsum) flats and llano near *Entronque San Roberto* (San Roberto Junction)[2] in southwestern [Nuevo León](/source/Nuevo_Le%C3%B3n), Mexico, at about 1800–2200 m ft -2.[8] ## Notes 1. To convert [millimeters](/source/Millimeter) to [inches](/source/Inches), divide the number of millimeters by exactly 25.4. ## Citations 1. POWO (2022). 1. Nesom (2018a), p. 1. 1. Turner (1974), p. 123. 1. Nesom (2018a), pp. 1–2. 1. Nesom (2018a), p. 8. 1. IPNI (2022). 1. Morgan & Holland (2012a), p. 828. 1. Nesom (2018a), pp. 2–3. ## References - Nesom, Guy L. (2018a). ["Aster gypsophilus (Asteraceae) segregated as the monotypic genus Sanrobertia"](http://www.phytoneuron.net/2018Phytoneuron/25PhytoN-Sanrobertia.pdf). *Phytoneuron*. **2018-25**: 1–8. [ISSN 2153-733X](https://www.worldcat.org/issn/2153-733X). Retrieved 25 November 2020. - IPNI (2022). 77179517-1. Retrieved 30 October 2022. - Morgan, D.R. & Holland, B. (2012a). "Systematics of Symphyotrichinae (Asteraceae: Astereae): Disagreements Between Two Nuclear Regions Suggest a Complex Evolutionary History". *[Systematic Botany](/source/Systematic_Botany)*. **37** (3): 818–832. [American Society of Plant Taxonomists](/source/American_Society_of_Plant_Taxonomists). [doi:10.1600/036364412X648760](https://doi.org/10.1600/036364412X648760). [JSTOR 41515169](https://www.jstor.org/stable/41515169). [S2CID 84007309](https://api.semanticscholar.org/CorpusID:84007309) - POWO (2022). "*Sanrobertia gypsophila*". 77179517-1. Retrieved 30 October 2022. - Turner, B.L. (26 July 1974). "*Aster gypsophila* (Compositae), a new endemic gypsophile from north-central Mexico". *The Southwestern Naturalist*. **19** (2): 123–125. Austin, Texas: The Southwestern Association of Naturalists. [doi:10.2307/3670271](https://doi.org/10.2307/3670271). [ISSN 0038-4909](https://www.worldcat.org/issn/0038-4909). [JSTOR 3670271](https://www.jstor.org/stable/3670271) --- Adapted from the Wikipedia article [Sanrobertia](https://en.wikipedia.org/wiki/Sanrobertia) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Sanrobertia?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.