Boechera nevadensis

(Tidestrom) Windham & Al-Shehbaz

Spring Mountains Rockcress

G1Critically Imperiled Found in 1 roadless area NatureServe Explorer →
G1Critically ImperiledGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.873998
Element CodePDBRA40150
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCapparales
FamilyBrassicaceae
GenusBoechera
Other Common Names
Spring Mountains rockcress (EN)
Concept Reference
Windham, M. D. and I. A. Al-Shehbaz. 2006. New and noteworthy species of Boechera (Brassicaceae) I: Sexual diploids. Harvard Papers in Botany 11: 61-88.
Taxonomic Comments
Previously included in Kartesz's Arabis pendulina var. pendulina (as Arabis nevadensis). Accepted as a distinct species by FNA (vol. 7, 2010) which says, "Boechera nevadensis usually is treated as a synonym of Arabis pendulina (R.C. Collins 1993) or B. demissa (N.H. Holmgren 2005b), but is amply distinct from both (see M.D. Windham and I.A. Al-Shehbaz 2006 for detailed comparison)".
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2020-09-29
Change Date2010-04-05
Edition Date2020-09-29
Edition AuthorsTreher (2020)
Threat ImpactUnknown
Range Extent<100 square km (less than about 40 square miles)
Number of Occurrences1 - 5
Rank Reasons
Boechera nevadensis is a perennial herb endemic to the Charlestown Peak area of the Spring Mountain Range in Nevada. There may be a single occurrence made up of multiple sites. Some portion of this occurrence is on private lands. Threats are not documented but could include recreational activities, drought, and climate change. Trends are unknown.
Range Extent Comments
Boechera nevadensis only occurs in the western United States. It is endemic to the Spring Mountain Range of Clark and Nye Counties in Nevada (FNA 2010, Windham and Al-Shehbaz 2006).
Occurrences Comments
There are multiple sites in close proximity that constitute one occurrence. There may be new locations that represent separate occurrences (SEINet 2020).
Threat Impact Comments
Threats to this species are not well documented but could include climate change and recreational activities. A serious drought in 2020 and 2021 may impact this species negatively.
Ecology & Habitat

Diagnostic Characteristics

From Windham & Al Shehbaz 2006: easily distinguished from B. pendulina by being completely glabrous or having only a few simple trichomes on the petioles of basal leaves, prominently auriculate cauline leaves, glabrous sepals, nearly straight fruiting pedicels, divaricate, often secund fruits, and winged seeds. By contrast, B. pendulina has a mixture of simple and stalked, 2-rayed trichomes on basal leaves, mostly non-auriculate cauline leaves, sparsely hirsute sepals, recurved fruiting pedicels, pendent, non-secund fruits, and nearly wingless seeds. Boechera nevadensis differs from B. oxylobula by having auriculate cauline leaves, nearly straight fruiting pedicels, divaricate fruits (2.0)2.33.0 mm wide, 5272 ovules per ovary, and biseriate seeds. By contrast, B. oxylobula has non-auriculate cauline leaves, recurved fruiting pedicels, pendent fruits 1.22.0 mm wide, 2444 ovules per ovary, and uniseriate seeds. Boechera nevadensis is separated from the range of B. oxylobula by over 500 km, but it is sympatric with B. pendulina. As with so many other Boechera species, hybridization between B. nevadensis and B. pendulina has produced apomictic triploids that blur the boundaries between them. However, the diploid populations predominate and are easily recognized.

Habitat

Boechera nevadensis occurs on south facing limestone cliffs on ledges or talus (FNA 2010).
Terrestrial Habitats
Bare rock/talus/scree
Other Nations (1)
United StatesN1
ProvinceRankNative
NevadaS1Yes
Threat Assessments
ThreatScopeSeverityTiming
6 - Human intrusions & disturbanceRestricted - smallUnknownHigh (continuing)
6.1 - Recreational activitiesRestricted - smallUnknownHigh (continuing)
11 - Climate change & severe weatherPervasive (71-100%)UnknownHigh (continuing)
11.1 - Habitat shifting & alterationPervasive (71-100%)UnknownHigh - low
11.2 - DroughtsPervasive (71-100%)UnknownHigh (continuing)

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (1)
Nevada (1)
AreaForestAcres
Charleston - CarpenterHumboldt-Toiyabe National Forest17,828
References (3)
  1. Flora of North America Editorial Committee (FNA). 2010. Flora of North America north of Mexico. Vol. 7. Magnoliophyta: Salicaceae to Brassicaceae. Oxford University Press, New York. xxii + 797 pp.
  2. Southwest Environmental Information Network (SEINet). 2020. Collections Databases. Online. Available: http://swbiodiversity.org/seinet/collections/index.php (accessed 2020).
  3. Windham, M. D. and I. A. Al-Shehbaz. 2006. New and noteworthy species of <i>Boechera</i> (Brassicaceae) I: Sexual diploids. Harvard Papers in Botany 11: 61-88.