Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Packera quercetorum, Oak Creek Ragwort

Oak Creek Ragwort flowers are large and showy, bright yellow with 15 to 40 or more floral heads per plants. Packera quercetorum Oak Creek Ragwort blooms from April to June. These flowers have both ray (8 to 13) and disk (60 to 70) florets. Packera quercetorum Oak Creek Ragwort has green or whitish green leaves. Leaves are both basal (rosette type) and cauline (on stem). Note here that the stems and leaves have a blue or purple ting. The upper leaves are lightly tinged. Packera quercetorum – Southwest Desert Flora   Packera quercetorum, Oak Creek Ragwort, Southwest Desert Flora Oak Creek Ragwort flowers likely are visited by many species of insects which may feed on the flowers. Packera quercetorum – Southwest Desert Flora   Oak Creek Ragwort is also called Oak Creek Greek Groundsel. Note plants are erect (or ascending) with two or four clustered stems. Packera quercetorum – Southwest Desert Flora

Scientific Name: Packera quercetorum
Common Name: Oak Creek Ragwort

Also called: Oak Creek Groundsel

Family: Asteraceae, Sunflower Family

Synonyms: (Senecio macropus, Senecio quercetorum)

Status: Native

Duration: Perennial

Size: 2 to 3.5 feet (60-100 cm) tall

Growth Form: Forb/herb; plants erect to ascending 2 to 4 stems clustered.

Leaves: Green or whitish green; both basal and lower cauline leaves petiolate, lower leaves purple or blue tinged and upper leaves lightly tinged, glabrous or tomentose at base and in leaf axils (distinctive to P. quercetorum); leaves variable ovate or lyrate.

Flower Color: Bright yellow showy flowers; flower heads 15 to 40 or more, heads glabrous; ray florets 8 to 13, disk florets 60 to 70; fruit a cypsela.

Flowering Season: March to May, blooms earlier and lasts longer in California; April to June.

Elevation: 2,500-7,500 feet (762-2,286 m)

Habitat Preferences: Rocky soils, open areas; Upper desert, chaparral vegetation, scrub-oak andpinyon-pine.

Recorded Range: Oak Creek Ragwort is rare in the United States where it is found only in small populations in central and southern Arizona and west-central New Mexico. In Arizona, Oak Creek Ragwort is found in the north, northwest, central and southern part of the state and in central western New Mexico.

North America & US County Distribution Map for Packera quercetorum.

U.S. Weed Information: No data available.
Invasive/Noxious Weed Information: No data available.
Wetland Indicator: No data available.
Threatened/Endangered Information: No data available.

Genus Information: In North America there are 58 species for Packera. Worldwide, The Plant List includes 66 accepted species names and a further 159 scientific names of infraspecific rank for the genus. The genus Packera was published by Áskell Löve and Doris Benta Maria Löve in 1975. Packera is a genus that was previously included in the genus Senecio.

In the Southwestern United States: Arizona and Utah each have 11 species of genus, California has 16 species, Nevada has 8 species, New Mexico has 23 species, Texas has 11 species. All data approximate and subject to revision.

Comments: Oak Creek Ragwort is a tall robust showy upper desert spring bloomer that is primarily an Arizona species named after its type location in Oak Creek Canyon, Arizona. This species is never found in the field in large numbers, but always a delight to find isolated specimens.

In Southwest Desert Flora also see: New Mexico Groundsel, Packera neomexicana.

Importance to Wildlife, Birds and Livestock

Special Value to Native Bees, Butterflies and Insects
Insects may feed from the florets of Oak Creek Ragword.

The genus Packera is named in honor of John George Packer (1929-2019) who specialized on the flora of Alberta and on Arctic and alpine flora. The genus Packera was published by Áskell Löve and Doris Benta Maria Löve in 1975.

The species epithet "quercetorum" (quercetor'um) means of oak woods.

Date Profile Completed: 07/11/2012, updated 02/21/2020
Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles, as Senecio quercetorum.
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search - (accessed 02/18/2020) - for Packera
The Plant List (2013). Version 1.1. Published on the Internet; (accessed 02/18/2020).
Theodore M. Barkley✝, Luc Brouillet, John L. Strother, FNA | Family List |FNA Vol. 20 | Asteraceae | Packera; 44. Packera quercetorum 47: 101. 1992; Flora of North America North of Mexico. 16+ vols. New York and Oxford.
FNA 2006, Kearney and Peebles 1969, Editor: Steve Buckley, 2010, Field Guide from SEINet (accessed 02/18/2020).
'Packera', Wikipedia, The Free Encyclopedia, 13 February 2020, 03:26 UTC, [accessed 18 February 2020]
SEINet for synonyms, scientific names and recorded geographic locations,
Etymology:Michael L. Charters California Plant Names: Latin and Greek Meanings and Derivations; A Dictionary of Botanical and Biographical Etymology - (accessed 02/03/2020 and 02/19/2020)