Foothills. Mancos Shale. Spring, summer.
Discovered June 8, 2008 and
Published June 3, 2011.

Photographs on this page show a new species of Asteraceae, Packera mancosana, that Betty and I found at Lone Mesa State Park in the summer of 2008.  With the valued assistance of Loraine Yeatts and Guy Nesom we published this new species in the online journal "Phytoneuron" June 3, 2011. Click to read the description.

The new species has been found only at the southern end of Lone Mesa State Park in Dolores County, Colorado, and on adjacent lands. There are at least 400 plants.

The plant grows on barren-seeming Mancos Shale, but this Mancos Shale is anything but barren.  It supports numerous plants in a very open and airy arrangement.  A number of the plants growing on this Shale are unusual for this elevation (~7,600 feet).  Some of these plants are normally found up to 4,000 feet higher; some are found 2,000 feet lower.

One other plant, Gutierrezia elegans, which I discovered on this same Mancos Shale, is also rare and known from nowhere else. The Gutierrezia elegans pages show the Mancos Shale habitat. 

Physaria pulvinata, discovered by Reveal and O'Kane about 18 miles north of this area, is found only in its type location and in (and very close to) Lone Mesa State Park on this same Mancos Shale, often immediately next to both Packera mancosana and Gutierrezia elegans. 

Click for photographs of the terrain that Packera mancosana grows in.

Click to see how Packera is distinguished from Senecio.

Foothills. Mancos shale. Spring, summer.
Lone Mesa State Park, May 15, 2009 and May 1, 2017.

As the photographs at left show, the plant has a tightly packed growth form and very short stature. Most other species growing on this Mancos Shale form dense, low mounds and often provide habitat for one another so it is common to find several species growing intertwined.

John Packer was a Canadian botanist. (More biographical information about Packer.)

The specific epithet “mancosana” refers to the Mancos Shale soils on which the species is found. The name “Mancos Shale” is derived from the type location of this shale near the town of Mancos in southwest Colorado where this shale formation is abundant. The word “manco” is Spanish for “one –handed or one-armed” and for some now unknown reason the word was associated with this area by the Escalante-Dominguez expedition of 1776.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Packera mancosana