Phacelia submutica
J.T. Howell
DeBeque Phacelia
G2ImperiledGlobal Rank
Very high - highThreat Impact
U.S. Fish & Wildlife Service, https://www.usa.gov/government-works
Identity
Unique IDELEMENT_GLOBAL.2.159456
Element CodePDHYD0C492
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderSolanales
FamilyHydrophyllaceae
GenusPhacelia
Synonyms
Phacelia scopulina var. submutica(J.T. Howell) Halse
Other Common Names
Debeque phacelia (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic Comments
Evidence provided in Anderson and McGlaughlin (2020) supports treatment of this taxon as it was originally described by Howell (1944): Phacelia submutica, a species, distinct from Phacelia scopulina. It was treated as Phacelia scopulina var. submutica by Kartesz (1994 and 1999); USFWS tracks as Phacelia submutica (2010).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2022-08-26
Change Date1993-02-18
Edition Date2022-08-26
Edition AuthorsJ. M. Bert, (rev.) J. Handwerk (2003), rev. L. Morse (2006), rev. K. Neuhaus, J. Handwerk, and S. Panjabi (2006), rev. J. Handwerk (2009, 2012, 2022)
Threat ImpactVery high - high
Range Extent250-1000 square km (about 100-400 square miles)
Number of Occurrences6 - 80
Rank Reasons
Phacelia submutica is endemic to Colorado, USA, and is known only from Garfield and Mesa counties. Within this limited distribution it is threatened by inappropriate livestock grazing, off highway vehicle use, competition from invasive plant species, road development and maintenance for energy production and utility/communication lines, and the effects of prolonged drought and climate change.
Range Extent Comments
Phacelia submutica is endemic to Colorado, USA, and is known only from Garfield and Mesa counties. The estimated range extent in Colorado of 500 square kilometers was calculated in GeoCAT using occurrence data provided by the Colorado Natural Heritage Program (2022). Previous reports from Arizona were erroneous.
Occurrences Comments
As of 2022 there are 26 known occurrences documented in the Colorado Natural Heritage Program database. Seven of the occurrences have not been observed in over 20 years.
Threat Impact Comments
Phacelia submutica is threatened by inappropriate livestock grazing, off highway vehicle use, competition from invasive plant species, and road development and maintenance for energy production and utility/communication lines. All of the aforementioned stressors are especially concerning on private lands where Endangered Species Act protections are limited and disturbance may be high (USFWS 2021). Phacelia submutica is inherently vulnerable to habitat loss by virtue of it being restricted to barren and semi-barren habitat on specific members of the Wasatch geological formation that has a limited distribution within the Piceance Basin. Activities that lead to significant soil disturbance, or progressive soil erosion, would likely eliminate or sharply reduce the seed bank, which appears to be the mechanism by which populations survive (Ladyman 2003). Therefore, all actions that cause significant disturbances, including mechanized vehicle traffic and livestock grazing, are threats. Livestock use has been reported in or near 42% of the occurrences (CNHP 2022). Cattle trailing can leave small trenches which can alter hydrological flow patterns directing water away from occupied habits. Trailing can also trample above ground plants causing direct mortality, reduced fitness, and decreased reproductive success (USFWS 2021). Invasive plant species, such as Bromus tectorum (cheatgrass) and Halogeton glomeratus (halogeton) have been observed within over 60% of the occurrences where competition for resources can reduce available suitable habitat for P. submutica (CNHP 2022). However, there is some uncertainty on the severity of impact to P. submutica resulting from competition with invasive plant species (USFWS 2021). Off highway vehicle (OHV) use becomes an issue when users travel off designated recreational or energy roads located near prime or potential habitat areas (USFWS 2021). While oil and gas development does not present a direct stressor to P. submutica, roads to oil and gas wells can create opportunities for recreationists to better access remote areas with P. submutica plants (USFWS 2021). Prolonged drought and habitat alteration due to climate change within the species range are also threats to this species long term survival (Handwerk et al. 2015).
Ecology & Habitat
Description
A small tap rooted, summer annual. The stems are 2 to 8 cm long often branched at the base with a deep red color, and generally lay flat on the ground in a disc-shaped clump. The reddish-colored leaves are 5 to 15 mm long egg-shaped, or almost rectangular, with rounded corners, with the bases abruptly tapering to a wedge-shaped point; the leaf margins are smooth or toothed. The stems and leaves are covered by variable numbers of straight stiff hairs. The very small tube-shaped flowers are crowded and light-yellow or cream colored often with a purple tinge. Unlike many Phacelia species the stamens do not protrude beyond the petals. The elongated-egg shaped, blackish brown seeds tend to be iridescent, and are 1.5 to 2 mm long with 6 to 12 fine ridges or corrugations (Harrington 1954).
Diagnostic Characteristics
This species can be recognized by its compact arrangement of stems forming a flat disc, by its reddish foliage, and small densely arranged flowers (O'Kane 1987). Its hirsute leaves help distinguish seedlings from other annuals early in the season. In mid to late summer P. submutica shrivels up and may be washed or blown away. No evidence of this annual plant remains from one year to the next, hence identification may only be done when the plant is actively growing (usually April to June) (Scheck 1994).
Habitat
Occurs on steep slopes and ridge-tops on xeric sites in chocolate-brown or gray clay adobe badlands of Western Colorado which often have high shrink-swell potential (large cracks in the soil). The species is adapted to grow only in very early pioneer habitats with sparse vegetation cover (Scheck 1994). The species occurs on Atwell Gulch and Shire Members of Wasatch Formation (O'Kane 1987). Associated species are Grindelia fastigiata, Sarcobatus vermiculatus, Atriplex confertifolia, Eriogonum gordonii, Monolepis nuttalliana, Oenothera caespitosa, Astragalus flavus, Helianthus sp., Lepidium sp., Chenopodium sp., Rumex sp., Cymopterus planosus, Sitanion hystrix, Ceratocephala testiculata, Lactuca serriola, Euphorbia fendleri, Asceplias cryptoceras, Mentzelia sp., Thelypodiopsis sp., Oryzopsis hymenoides, Bromus tectorum, Sphaeralcea coccinea, Gutierrezia sarothrae (O'Kane 1987). Other rare species occuring in the area are Sclerocactus glaucus and Astragalus debequaeus. The habitat of this species consists of open areas within ecosystems, which have primarily been mapped as Colorado Plateau Pinyon - Juniper Woodland (G900), Intermountain Basins Big Sagebrush Desert Shrubland (G303), and Intermountain Shadscale - Saltbush Scrub (G300) at the group level of the US National Vegetation Classification (NatureServe 2025).
Terrestrial Habitats
DesertBarrens
Other Nations (1)
United StatesN2
| Province | Rank | Native |
|---|---|---|
| Colorado | S2 | Yes |
Threat Assessments
| Threat | Scope | Severity | Timing |
|---|---|---|---|
| 2 - Agriculture & aquaculture | Large (31-70%) | Moderate - slight | High (continuing) |
| 2.3 - Livestock farming & ranching | Large (31-70%) | Moderate - slight | High (continuing) |
| 3 - Energy production & mining | Restricted (11-30%) | Slight or 1-10% pop. decline | High - moderate |
| 3.1 - Oil & gas drilling | Restricted (11-30%) | Slight or 1-10% pop. decline | High - moderate |
| 6 - Human intrusions & disturbance | Restricted (11-30%) | Moderate - slight | High (continuing) |
| 6.1 - Recreational activities | Restricted (11-30%) | Moderate - slight | High (continuing) |
| 8 - Invasive & other problematic species, genes & diseases | Large - restricted | Moderate - slight | High (continuing) |
| 8.1 - Invasive non-native/alien species/diseases | Large - restricted | Moderate - slight | High (continuing) |
| 11 - Climate change & severe weather | Pervasive (71-100%) | Serious - moderate | High (continuing) |
| 11.1 - Habitat shifting & alteration | Pervasive (71-100%) | Serious - moderate | High (continuing) |
Plant Characteristics
DurationANNUAL
Economic Value (Genus)No
Roadless Areas (1)
South Dakota (1)
| Area | Forest | Acres |
|---|---|---|
| Indian Creek | Buffalo Gap National Grassland | 24,666 |
References (15)
- Anderson, B. and M. McGlaughlin. 2020. Genetic studies of <i>Phacelia submutica</i> (DeBeque Phacelia). Final Report. University of Northern Colorado. Supported by Bureau of Land Management, Colorado.
- Burt, Julie. 1995. Status report for <i>Phacelia submutica</i>. Unpublished report prepared for the U.S. Fish and Wildlife by the Colorado Natural Heritage Program, Fort Collins, CO.
- Colorado Natural Heritage Program. 2003. Biological Conservation Datasystem. Colorado State University, Ft. Collins, CO.
- Colorado Natural Heritage Program (CNHP). 2022. Biodiversity Tracking and Conservation System (Biotics 5). Colorado Natural Heritage Program, Colorado State University, Fort Collins.
- Handwerk, J., L. Grunau, and S. Spackman-Panjabi. 2015. Colorado Wildlife Action Plan: 2015 Rare Plant Addendum. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado, USA.
- Howell, J. T. 1944. A revision of Phacelia section Miltitzia. Proceedings of the California Academy of Science 25(15):357-376.
- Ireland, T. 2002. Candidate and listing priority assignment form: Phacelia submutica. U.S. Fish and Wildlife Service, Grand Junction, Colorado.
- Johnson, B. 2001. Boilogical Assessment and Biological Evaluation for<i> Phacelia submutica</i>. Unpublished report prepaired for the White River National Forest, Glenwood Springs, Colorado. USDA Forest Service, Gunnison, CO.
- Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
- Ladyman, J.A.R. (2003, December 19). <i>Phacelia scopulina</i> (A. Nels) J.T. Howell var. <i>submutica </i>(J.T. Howell) Halse (Debeque phacelia): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region. Available: http://www.fs.fed.us/r2/projects/scp/assessments/phaceliascopulinavarsubmutica.pdf [March 2006].
- NatureServe. 2025. Ecosystems of the Conterminous US and Adjacent Areas, Version 1.0. NatureServe, Arlington, Virginia. Online. Available: https://natureserve.maps.arcgis.com/home/item.html?id=66c13612635d4ee9bd4d6500cf462e7f (Accessed 2025).
- Rondeau, R., K. Decker, J. Handwerk, J. Siemers, L. Grunau, and C. Pague. 2011. The state of Colorado's biodiversity 2011. Prepared for The Nature Conservancy. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado.
- U.S. Fish and Wildlife Service (USFWS). 2004. Species assessment and listing priority assignment form. <i>Phacelia submutica.</i> 9 pp.
- U.S. Fish and Wildlife Service (USFWS). 2010. Endangered and Threatened Wildlife and Plants; Listing <i>Ipomopsis polyantha </i>(Pagosa Skyrocket) as Endangered Throughout Its Range, and Listing <i>Penstemon debilis</i> (Parachute Beardtougue) and <i>Phacelia submutica </i>(DeBeque Phacelia) as Threatened Throughout Their Range. Proposed Rule. Federal Register 75(120):35721-35746.
- U.S. Fish and Wildlife Service (USFWS). 2021. DRAFT Species status assessment report for DeBeque phacelia (Phacelia submutica). Lakewood, Colorado.