Erigeron sionis var. trilobatus (Maguire ex Cronquist) S.L. Welsh (redirected from: Erigeron proselyticus)
Family: Asteraceae
[Erigeron flagellaris var. trilobatus Maguire ex Cronquist,  more...]
Erigeron sionis var. trilobatus image

Basal leaves: blades (2-)3-5(-11) mm wide, margins usually entire or dentate, rarely deeply lobed. Ray corollas drying pink to dark blue. 2n = 18.

Flowering Jul-Sep. Limestone cliff bases and faces, crevices, ledges, shelves, soil accumulations, talus, limestone gravel, lakeshores, bristlecone pine, spruce-fir-aspen, aspen, limber pine, Engelmann spruce; of conservation concern; 2200-3100 m; Utah.

The leaves of var. sionis tend to be narrower and more deeply lobed than those of var. trilobatus; morphologic intermediacy makes these plants hard to separate even at varietal rank. Differences in habitat and an essentially allopatric distribution, however, suggest that two evolutionary entities are present.

Non-technical Description: Cedar Breaks daisy is a short-lived, taprooted perennial forb that often forms short, stolon-like decumbent branches.  Stems are 1.5-20 cm long and usually pubescent with erect or appressed hairs. Basal leaves are typically 3-5 mm wide and entire to coarsely toothed (rarely lobed) along the margin.  Stem leaves are linear and widely spaced.  Flower heads are usually 4.5-7 mm wide x 3-4.5 mm high and borne on hirsute stalks.  Ray flowers number 20-50 and are white to lilac.  Fruits are sparsely hairy achenes topped by a pappus of long bristles and short scales. Flowering from June-August. (Cronquist 1994, Fertig & Reynolds 2009, Nesom 2006, Welsh et al. 2008).

Similar Species: Zion daisy (Erigeron sionis var. sionis) has smaller flower heads (2-3 mm high) on glabrous branches and narrower basal leaves (1-3 mm wide), often with lobed margins.  Although the two varieties differ in base chromosome number, the distinguishing morphologic features often overlap between populations (Welsh et al. 2008).  Trailing daisy (E. flagellaris) produces longer, leafy stolons and bears nearly leafless erect stems terminating in a single, large flower head 7-13 mm wide (Welsh et al. 2008).

Habitat: Occurs mostly on moist, marly limestone of the red and white members of the Claron Formation often associated with small seeps or steeply V-shaped drainages that accumulate snow or runoff.  Cedar Breaks daisy also occurs at the base of orange Claron limestone cliffs or on alluvial terraces within drainage bottoms(Fertig & Reynolds 2009).

References:  Cronquist, A. 1994.  Volume 5, Asterales. In:  Cronquist, A., A.H. Holmgren, N.H. Holmgren, J.L. Reveal, and P.K. Holmgren, eds. Intermountain Flora, Vascular Plants of the Intermountain West, U.S.A. New York Botanical Garden, Bronx, NY. 496 pp. Fertig, W. and D. N. Reynolds. 2009. Survey of rare plants of Cedar Breaks National Monument: Final Report. Nesom, G. 2006. Flora of North America Editorial Committee. 2006b. Magnoliophyta: Asteridae, part 7: Asteraceae, part 2.  Flora of North America North of Mexico.  Volume 20. Oxford University Press, New York. 666 pp.  Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins.  2008.  A Utah Flora, 2004-2008 summary monograph, fourth edition, revised.  Brigham Young University, Provo, UT.  1019 pp.

Author: Walter Fertig, Moenave Botanical Consulting, Kanab, UT. April 2017