Arabis mcdonaldiana
species of plant
Arabis mcdonaldiana is a species of flowering plant in the mustard family known by the common name McDonald's rockcress. It is native to northern California and Oregon, where it grows on newly exposed, barren serpentine soils in openings in temperate coniferous forest habitat. It is a rare and endangered plant known from several sites in California and approximately two occurrences in Oregon, where it is threatened mainly by mining, particularly of nickel, which is one of several metals plentiful in the serpentine. On September 29, 1978, this was the second plant to be federally listed as an endangered species.
Description
This is a perennial herb growing one or more slender stems from a small, branching caudex, reaching 10 to 30 centimeters tall. There is a basal patch of leaves with edges lined in small, widely spaced teeth which are sometimes tipped with spines. The leaves may lack teeth and have wavy margins. There may also be a few smaller leaves along the stem. The top of the stem forms an inflorescence of a few flowers, each with four bright rose-purple petals. The fruit is a flat, straight silique about 3 centimeters long which contains several oblong little seeds.
This brief starts where responsible research should: with the source description of “Arabis mcdonaldiana” as species of plant. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the science & nature register because the source frames it as species of plant. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Dec 27, 2025. The linked authority identifier is Q19849628. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1978.
Scientific names, classifications and consensus can change while older terminology persists in catalogues and historical literature. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Arabis mcdonaldiana”, its source revision and the description used here.
- Expand the search: follow Arabis mcdonaldiana primary sources, Arabis mcdonaldiana archive and Arabis research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Arabis mcdonaldiana”?
- Which observation, specimen, dataset or publication supports the account?
- Is the terminology current, historical or disputed?
Search terms from this dossier
This entry incorporates text from “Arabis mcdonaldiana” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.