Packera franciscana
Encyclopedia
Packera franciscana is a rare species of flowering plant in the aster family
known by the common name San Francisco Peaks groundsel, or San Francisco Peaks ragwort. It is endemic to Arizona
in the United States, where it is known only from the San Francisco Peaks
in Coconino County
. It is threatened by recreational activities in its habitat. It is a federally listed threatened species of the United States.
perennial herb growing just a few centimeters tall. The purple or purple-tinged stems have woolly or cobwebby fibers. The basal leaves have lyre
-shaped to somewhat oval blades measuring up to 2 centimeters long by 5 wide. They have ruffled edges and purple undersides. Leaves higher on the stems are smaller and sometimes divided into lobes.
The inflorescence
is a solitary flower head
or a few heads clustered together atop the woolly stem. The flower head is enclosed in hairy purple phyllaries
and contains 8 or 13 yellow ray florets up to a centimeter long. The fruit is an achene
tipped with a pappus
half a centimeter in length. Blooming occurs in August through October.
The plant reproduces sexually
via seed, but more often vegetatively
by resprouting from its rhizome. Most plants occur in wide patches made up of several cloned stems, but some are solitary, having sprouted from seed.
and Agassiz Peak
, and the saddle
between them. These are the two tallest mountain peaks
in Arizona. It grows in alpine tundra
habitat in the volcanic
talus
of the mountain slopes, an area with little vegetation located above the tree line. This is the only alpine zone in Arizona. The elevation
is between 3200 and 3800 meters, with most of the plants occurring between 3525 and 3605 meters.
The plant is apparently adapted to a fellfield
habitat made up of unstable talus, as evidenced by its long rhizome and adventitious roots which may not be anchored to any stable surface. As rocks tumble, the root may break, and pieces of the root can generate new plants through cloning
. Despite its being limited to a small area, the plant is common locally.
, hiking
, and skiing
. Expansion of the Arizona Snowbowl
was likely to disturb the habitat, but construction was put on hold after a legal challenge. Conservation efforts have included the installation of trails away from spots where the plants are growing and the closing of alpine habitat to recreation except by permit. This mountaintop-dwelling plant may suffer during climate change
, because it cannot move to higher or colder habitat as warming occurs.
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
known by the common name San Francisco Peaks groundsel, or San Francisco Peaks ragwort. It is endemic to Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
in the United States, where it is known only from the San Francisco Peaks
San Francisco Peaks
The San Francisco Peaks are a volcanic mountain range located in north central Arizona, just north of Flagstaff.The highest summit in the range, Humphreys Peak, is the highest point in the state of Arizona at in elevation. The San Francisco Peaks are the remains of an eroded stratovolcano...
in Coconino County
Coconino County, Arizona
-2010:Whereas according to the 2010 U.S. Census Bureau:*61.7% White*1.2% Black*27.3% Native American*1.4% Asian*0.1% Native Hawaiian or Pacific Islander*3.1% Two or more races*5.2% Other races*13.5% Hispanic or Latino -2000:...
. It is threatened by recreational activities in its habitat. It is a federally listed threatened species of the United States.
Description
Packera franciscana is a small rhizomatousRhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
perennial herb growing just a few centimeters tall. The purple or purple-tinged stems have woolly or cobwebby fibers. The basal leaves have lyre
Lyre
The lyre is a stringed musical instrument known for its use in Greek classical antiquity and later. The word comes from the Greek "λύρα" and the earliest reference to the word is the Mycenaean Greek ru-ra-ta-e, meaning "lyrists", written in Linear B syllabic script...
-shaped to somewhat oval blades measuring up to 2 centimeters long by 5 wide. They have ruffled edges and purple undersides. Leaves higher on the stems are smaller and sometimes divided into lobes.
The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a solitary flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
or a few heads clustered together atop the woolly stem. The flower head is enclosed in hairy purple phyllaries
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
and contains 8 or 13 yellow ray florets up to a centimeter long. The fruit is an achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
tipped with a pappus
Pappus (flower structure)
The pappus is the modified calyx, the part of an individual disk, ray or ligule floret surrounding the base of the corolla, in flower heads of the plant family Asteraceae. The pappus may be composed of bristles , awns, scales, or may be absent. In some species, the pappus is too small to see...
half a centimeter in length. Blooming occurs in August through October.
The plant reproduces sexually
Sexual reproduction
Sexual reproduction is the creation of a new organism by combining the genetic material of two organisms. There are two main processes during sexual reproduction; they are: meiosis, involving the halving of the number of chromosomes; and fertilization, involving the fusion of two gametes and the...
via seed, but more often vegetatively
Vegetative reproduction
Vegetative reproduction is a form of asexual reproduction in plants. It is a process by which new individuals arise without production of seeds or spores...
by resprouting from its rhizome. Most plants occur in wide patches made up of several cloned stems, but some are solitary, having sprouted from seed.
Distribution
Packera franciscana grows on two of Arizona's San Francisco Peaks, Humphreys PeakHumphreys Peak
Humphreys Peak is the highest natural point in the U.S. state of Arizona, with an elevation of and is located within the Kachina Peaks Wilderness in the Coconino National Forest, about north of Flagstaff, Arizona. Humphreys Peak is the highest of a group of extinct volcanic peaks known as the...
and Agassiz Peak
Agassiz Peak
Agassiz Peak is the second highest mountain in U.S. state of Arizona at . It is located in the San Francisco Peaks within the Coconino National Forest near Flagstaff, Arizona. The peak was named for Louis Agassiz, the celebrated naturalist....
, and the saddle
Mountain pass
A mountain pass is a route through a mountain range or over a ridge. If following the lowest possible route, a pass is locally the highest point on that route...
between them. These are the two tallest mountain peaks
Summit (topography)
In topography, a summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. Mathematically, a summit is a local maximum in elevation...
in Arizona. It grows in alpine tundra
Alpine tundra
Alpine tundra is a natural region that does not contain trees because it is at high altitude. Alpine tundra is distinguished from arctic tundra, because alpine soils are generally better drained than arctic soils...
habitat in the volcanic
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
talus
Scree
Scree, also called talus, is a term given to an accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles...
of the mountain slopes, an area with little vegetation located above the tree line. This is the only alpine zone in Arizona. The elevation
Elevation
The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....
is between 3200 and 3800 meters, with most of the plants occurring between 3525 and 3605 meters.
The plant is apparently adapted to a fellfield
Fellfield
A fellfield or fell field comprises the environment of a slope, usually alpine or tundra, where the dynamics of frost and of wind give rise to characteristic plant forms in scree interstices.-Soil dynamics:...
habitat made up of unstable talus, as evidenced by its long rhizome and adventitious roots which may not be anchored to any stable surface. As rocks tumble, the root may break, and pieces of the root can generate new plants through cloning
Cloning
Cloning in biology is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments , cells , or...
. Despite its being limited to a small area, the plant is common locally.
Habitat threats
Threats to this species include recreational activities such as mountaineeringMountaineering
Mountaineering or mountain climbing is the sport, hobby or profession of hiking, skiing, and climbing mountains. While mountaineering began as attempts to reach the highest point of unclimbed mountains it has branched into specialisations that address different aspects of the mountain and consists...
, hiking
Hiking
Hiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking...
, and skiing
Skiing
Skiing is a recreational activity using skis as equipment for traveling over snow. Skis are used in conjunction with boots that connect to the ski with use of a binding....
. Expansion of the Arizona Snowbowl
Arizona Snowbowl
Arizona Snowbowl is an alpine ski resort located on the San Francisco Peaks, 7 miles north of Flagstaff, Arizona. The Snowbowl is a long-standing center of controversy regarding its effect on Native American sacred sites and religious practices...
was likely to disturb the habitat, but construction was put on hold after a legal challenge. Conservation efforts have included the installation of trails away from spots where the plants are growing and the closing of alpine habitat to recreation except by permit. This mountaintop-dwelling plant may suffer during climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
, because it cannot move to higher or colder habitat as warming occurs.