Dieteria

Dieteria canescens var. aristata. (synonyms include Machaeranthera canescens var. aristata, M. rigida, and Aster canescens var. aristatus). Strikingly different from var. canescens. Upper branches contain numerous bracteate leaves. The mid and distal leaf blades are linear-lanceolate .Sept. 24, 2010, Colorado River drainage, Professor Valley, Grand Co., Utah, elev. approx. 3,980 ft.

Dieteria canescens var. aristata. (synonyms include Machaeranthera canescens var. aristata, M. rigida, and Aster canescens var. aristatus). In addition to the upper branches containing numerous bracteate leaves, the erect stems are stipitate-glandular. The leaves are mostly glabrous however.Sept. 24, 2010, Colorado River drainage, Professor Valley, Grand Co., Utah, elev. approx. 3,980 ft.

This appears to most closely match Dieteria canescens var. aristata. (synonyms include Machaeranthera canescens var. aristata, M. rigida, and Aster canescens var. aristatus). Strikingly different from var. canescens. Upper branches contain numerous bracteate leaves. Native forb, annual or biennial.Sept. 24, 2010, Colorado River drainage, Professor Valley, Grand Co., Utah, elev. approx. 3,980 ft.

California, United States

Dieteria canescens var. leucanthemifolia (syn. Machaeranthera canescens var. leucanthemifolia) growing mainly with weeds despite the fact that this area was not close to any developments at this time, and was accessible only via a bumpy dirt road.The species complex is also referred to as Hoary-aster or Hoary aster (but they are not true asters). This variety in Utah only occurs in mainly the central-southern and southwestern part of the state.Usually plants of this species would not start to bloom until later in the year, but this variety is known to bloom in June (even earlier however when this was taken)earlier) plus this is nearing its lowest elevation, and it had been as I recall dry.The area where this plant was growing was nowhere near any development in 2004, but now in 2012 is either within or on the fringe of a large business park.May 1, 2004, Price City Hills, Washington, County, Utah, elev. approx. 2870 ft. Growing with the ever present non-native weed in the area, Red Brome.

Tucson Arizona, Oct 30, 2009 by side of road

This appears to very closely match what Dr. Stanley Welsh refers to as  Machaeranthera canescens var. monticola (which Welsh refers to as "Bracteate aster" and which he earlier moved from the species level to var. latifolia under "canescens" however it is not clear whether that it is even a proper synonym for this entity despite its inclusion as such by some sources). Note the glabrous leaves and broad involucral bracts. The taxon grows at montane elevations where it is also thought to be perennial (compared to the typically biennial habit of var. canescens). Notice also the relatively few ray flowers (although that has not been described as a characteristic of this entity).While Cronquist included this entity under var. canescens, he noted that it was a seemingly distinctive phase and that taxonomic recognition might be appropriate. FNA on the other hand, while not even including this name as synonym, apparently lumps it into Dieteria canescens var. canescens. At the very least it should have included "monticola" as a synonym or referenced it in some way; again and again I find FNA too often involves less complete and scholarly work than taxonomists primarily focusing on the Intermountain West, and frequently (but certainly not always) those authors often have little field experience in our area. So no one resource can be blindly followed or considered to be authoritative.No combination involving the specific epithet "monticola" has been made with Dieteria. So this may remain something that could slip through the cracks until more detailed studies are conducted. Genetic work is needed to figure out this complex.Cronquist alluded to these plants as being similar to M. commixta (treated earlier by Welsh as var. commixta under M. canescens, and by FNA as Dieteria bigloveii var. commixta, but "commixta" does not occur as far north in Utah as this location and has longer involucral bracts and its leaves tend to be more entire and lanceolate to oblanceolate shaped compared to the mostly linear leaves of var. canescens. Welsh currently recognizes M. commixta (but indicates that it could still just as easily be included as a variety under "canescens") and separately from "monticola." September 5, 2011, Wasatch Plateau, Huntington Canyon, near Huntington Creek, northwestern corner of Emery County, Utah at approx. 7,190 ft. elev.

Dieteria bigelovii var. commixta (syn. Machaeranthera bigelovii var. commixta, Machaeranthera commixta).As treated by FNA, distribution of this taxon is limited to the Utah Plateaus in southern Utah.Aug. 9, 2003, Ashdown Gorge Wilderness Area, Iron County, Utah, elev. approx. 10,440 ft.