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Romanzoffia thompsonii

Marttala

Thompson's Mistmaiden

G3Vulnerable Found in 6 roadless areas NatureServe Explorer →
G3VulnerableGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.147854
Element CodePDHYD0E050
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderSolanales
FamilyHydrophyllaceae
GenusRomanzoffia
Concept Reference
Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-03-20
Change Date1991-02-08
Edition Date1999-05-28
Edition AuthorsVrilakas, Sue. (1999), rev. Soteropoulos (2025)
Threat ImpactUnknown
Range Extent5000-20,000 square km (about 2000-8000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Romanzoffia thompsonii is an annual herb in seasonally wet, open, sunny cliffs and gravelly slopes that is endemic to the central and southern Cascade and Siskiyou Mountains in to western Oregon in the northwestern United States. There are an estimated 50 occurrences which face threats from habitat loss and habitat changes, such as erosion, succession of habitat to forest, hydrological alterations, logging, invasive species, trampling, and grazing. Monitoring of populations should be conducted to improve our understanding of reproduction, plant abundance, threats, and trends, as well as continuing conservation measures to protect the taxon.
Range Extent Comments
Romanzoffia thompsonii is endemic to the central and southern Cascade and Siskiyou Mountains in to western Oregon in the northwestern United States, predominantly in the foothills to mid-elevations (Marttala 1996, OSU 2025). Range extent was estimated to be approximately 15,000 square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025 (RARECAT 2024, GBIF 2025, iNaturalist 2025, NatureServe 2025, SEINet 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are 50 occurrences rangewide (RARECAT 2024, GBIF 2025, iNaturalist 2025, NatureServe 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, this species is threatened by habitat loss from development and road widening as well as habitat changes, such as erosion, succession of habitat to forest, hydrological alterations, logging, invasive species (including dogtail grass), and other threats in some places, including trampling and grazing, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species (Marttala 1996, NatureServe 2025).
Ecology & Habitat

Habitat

Romanzoffia thompsonii grows in "seasonally wet, open, sunny cliffs and gravelly slopes" at elevations from 700 to 6100 feet, usually facing south to southwest (Marttala 1996, OSU 2025). These habitats are saturated or innundated during the early growing season followed by a summer drought (Marttala 1996).
Terrestrial Habitats
Bare rock/talus/screeCliff
Other Nations (1)
United StatesN3
ProvinceRankNative
OregonS3Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined———

—

Plant Characteristics
DurationANNUAL
Economic Value (Genus)No
Roadless Areas (6)
Oregon (6)
AreaForestAcres
Bulldog RockUmpqua National Forest6,056
Bulldog RockWillamette National Forest559
Echo MountainWillamette National Forest8,098
French Pete (a)Willamette National Forest1,668
Hardesty MountainUmpqua National Forest2,597
Medicine Creek AppendageUmpqua National Forest745
References (8)
  1. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  2. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  3. Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
  4. Marttala, V.M. 1996. Romanzoffia thompsonii (Hydrophyllaceae), a new species from Oregon. Madrono 43(3):404-414.
  5. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  6. NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2024. Version: 1.1.1 (released Oct 01, 2024).
  7. Oregon State University (OSU). 2025. Oregon Flora website. Oregon State University Herbarium at Oregon State University. Online. Available: https://oregonflora.org/ (accessed 2025).
  8. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).