DRAFT
March 2012
PLANTS
Spanish Needle Onion (Allium shevockii)
Spanish Needle Onion
(Allium shevockii)
Legal Status
State: None
California Rare Plant Rank: 1B.31
Federal: Bureau of Land Management Sensitive
Critical Habitat: N/A
Recovery Planning: N/A
Taxonomy
Spanish Needle onion (Allium shevockii) is a relatively recent addition
to the California flora—it was discovered by Shevock in 1985 and
described by McNeal in 1987. The genus Allium has been segregated
from the broadly circumscribed lily family (Liliaceae) into a more
narrowly defined family, the onion or garlic family (Alliaceae), in the
most recent treatment of the genus in California (Jepson Flora Project
2011). Others have placed Allium in the amaryllis family
(Amaryllidaceae) (Chase et al. 2009). Within Allium, Spanish Needle
onion is currently placed in subsection Sanborniana, although its
exact placement is uncertain (Nguyen et al. 2008). However, the
species is a very distinct member of its genus (McNeal 1987) and any
change in its placement within the genus—or in the higher-level
placement of Allium—would not affect its legal or conservation status.
This perennial bulbiferous herb stands approximately 10 to 20
centimeters (3.9 to 7.9 inches) tall (Jepson Flora Project 2011).
Descriptions of the species’ physical characteristics can be found in
McNeal’s (1987) original description and in the Jepson eFlora (Jepson
Flora Project 2011).
1
1B: Rare, threatened, or endangered in California and elsewhere; .3: not very threatened in California.
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Spanish Needle Onion (Allium shevockii)
Distribution
General
Spanish Needle onion is known from two areas in Kern County: the
type locality on Spanish Needle Peak in northern Kern County, and in
the Horse Canyon/Jawbone Canyon area in the Tehachapi Mountains
area on the southeast edge of the Tehachapi Range (Figure SP-P31)
(CDFG 2012a; CNPS 2011). The California Natural Diversity Database
(CNDDB) records 10 occurrences: one, the type locality, on Spanish
Needle Peak; and nine in the Horse/Jawbone Canyon area in the
Tehachapi Mountains (CDFG 2012a).
Distribution and Occurrences within the Plan Area
The nine Horse/Jawbone Canyon CNDDB occurrences are in the Plan
Area. The original discovery of Spanish Needle onion was on Spanish
Needle Peak just outside the Plan Area, and until relatively recently,
this was the only known location.
Historical
The original discovery of Spanish Needle onion was on Spanish
Needle Peak just outside the Plan Area in the Bureau of Land
Management’s (BLM’s) Caliente Recreation Area (Figure SP-P31) and
until relatively recently, this was the only known location.
Recent
Recent discoveries (from 1995 onward) of Spanish Needle onion
extended the range to the Tehachapi Mountain area. The Plan Area
encompasses this population, known from nine occurrences in the
Horse/Jawbone Canyon area (Figure SP-P31). Three occurrences are
in upper Horse Canyon; one is on a ridge just west of Horse Canyon;
two are in Jawbone Canyon; one is east of Miller Springs; and two are
near Pine Spring (CDFG 2012a).
Of the nine occurrences of Spanish Needle onion in the Plan Area, five
are on lands managed by BLM. About half of the population in Horse
Canyon is in the BLM Horse Canyon Area of Critical Environmental
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Species Accounts
March 2012
DRAFT
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PLANTS
Spanish Needle Onion (Allium shevockii)
Concern (ACEC), which was established and is managed for its
cultural resources, and not botanical resources.
Natural History
Habitat Requirements
Spanish Needle onion grows in rocky soil and at the edge of rock
outcrops and talus derived from volcanic and metamorphic rock
(Pitzer 2006; CDFG 2012a; Jepson Flora Project 2011). The rocky sites
inhabited by Spanish Needle onion are sparsely vegetated; the
occurrences are surrounded by sparse pinyon-juniper woodland with
pinyon pine (Pinus monophylla), California juniper (Juniperus
californica), chaparral yucca (Hesperoyucca whipplei), and narrowleaf
goldenbush (Ericameria linearifolia) (CDFG 2012a). An elevation
range of 2,000 to 2,500 meters (6,560 to 8,200 feet) is given in recent
literature (Jepson Flora Project 2011), whereas CNPS (2011) provides
a low elevation of 850 meters (2,790 feet). The Horse Canyon
occurrences are at 4,800 to 5,225 feet, and recent records in the
CNDDB give much lower elevations for the Jawbone Canyon
occurrences: 1,050 feet and 3,000 feet (CDFG 2012a). Therefore,
based on records in the CNDDB, its elevation range in the Plan Area
appears to be 1,050 to 5,400 feet (CDFG 2012a).
Reproduction
Spanish Needle onion is a small perennial that grows each year from
an underground bulb, with the leaves withering after flowering. The
flowering period for Spanish Needle onion is given variously as May to
June (CNPS 2011) and June to July (Jepson Flora Project 2011). This
information probably comes from the original Spanish Needle Peak
population, and it is likely that the lower-elevation Tehachapi
populations flower earlier—photographs available online through the
CalPhotos database (CalPhotos 2011) of the plant in flower show
plants in the Jawbone Canyon flowering as early as late April.
Like several other onion species in California, Spanish Needle onion
appears to reproduce mostly vegetatively, by production of new bulbs
that form on short rhizomes that grow from the base of the parent
bulb (McNeal 1987), at least in the Spanish Needle Peak population
(Pitzer 2006). The flowers, however, are large and distinctive and are
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Species Accounts
March 2012
DRAFT
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PLANTS
Spanish Needle Onion (Allium shevockii)
probably attractive to insect pollinators, and plants in the Horse
Canyon area have been reported to produce seed (Hare pers. comm.
1997, cited in Pitzer 2006). There has been no research on pollinators,
seed production, establishment of bulbs, or other aspects of its
reproduction (Pitzer 2006).
Population Status and Trends
Global: G1, Critically Imperiled (NatureServe 2011; last reviewed
February 5, 2003)
State: S1.3, Critically Imperiled; no current threats known (CDFG 2012b)
Spanish Needle onion has a very small global range (Figure SP-P31),
with relatively small numbers of plants in each occurrence, and as a
result is vulnerable to extirpation from random events. The number of
plants recorded at most occurrences is small: Five occurrences
support fewer than 50 plants, and two contain 90 to 100 plants; at
least 300 plants were noted in an incomplete count of the occurrence
west of Horse Canyon (CDFG 2012a). Only one occurrence appears to
have a substantial number of plants; this location is just west of Peak
4859 southeast of the Piute Mountains (CDFG 2012a). Eight of the
nine occurrences in the Plan Area were considered to be in excellent
condition when visited; the ninth was considered good (CDFG 2012a).
There are no ongoing surveys that could provide information on
population trends.
Threats and Environmental Stressors
Because of the relatively remote and rugged character of its habitat,
threats to the species are considered minimal (Pitzer 2006; CDFG
2012a). Potential threats mentioned by surveyors are wind energy
development, grazing, off-highway vehicle use, and road/trail
construction (CDFG 2012a), but there is no evidence that these
threats are causing actual damage to any populations. An additional
potential threat comes from the showy flowers that could attract
collectors, but so far, there is no evidence that bulb collection is
occurring (Pitzer 2006).
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Spanish Needle Onion (Allium shevockii)
Conservation and Management Activities
Of the nine occurrences of Spanish Needle onion in the Plan Area, five
are on lands managed by BLM. About half of the population in Horse
Canyon is in a BLM ACEC, which was established and is managed for
its cultural resources, and not botanical resources. Spanish Needle
onion occurrences lie just outside the West Mojave Plan Area so it is
not covered under that plan.
Data Characterization
As a relatively recently discovered species, it is likely that new
occurrences remain to be found. In the past 8 years, the number of
known occurrences in the Plan Area has more than doubled, with two
new occurrences found in 2003, and three in 2010 (CDFG 2012a). The
new occurrences have been found in habitats similar to the previously
known locations, so it appears that the habitat requirements are
relatively well understood; however, some of the new occurrences are
at much lower elevations than was previously known (CDFG 2012a).
Continuing surveys will help to refine the boundaries of the species
distribution, but it appears to be genuinely rare and restricted to a
small range.
Management and Monitoring Considerations
There is no ongoing management for Spanish Needle onion other than
the general protections conferred on BLM lands, which apply to the
species because of its status as a BLM sensitive plant.
Although small, Spanish Needle onion is a distinctive and showy plant
when in flower, so it is relatively easy to detect during floristic
surveys. Unlike many small desert annuals, there is no indication that
population sizes fluctuate greatly from year to year, although
quantitative information is scant.
Like many other small, rare onions, Spanish Needle onion grows well
in cultivation (Edwards, pers. comm. 1997, cited in Pitzer 2006), and
propagation would be possible should ex-situ conservation measures
ever become necessary.
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Spanish Needle Onion (Allium shevockii)
Predicted Species Distribution in Plan Area
There are 141,036 acres of modeled suitable habitat for Spanish
Needle onion in the Plan Area. Modeled suitable habitat occurs in the
Tehachapi-Piute Mountains and eastern slopes of the Sierra Nevada
from 1,000 to 8,600 feet in elevation. Modeled suitable habitat
includes woodland, forest, and riparian vegetation communities.
Appendix C includes specific model parameters and a figure showing
the modeled suitable habitat in the Plan Area.
Literature Cited
CalPhotos. 2011. “Allium shevockii.” A database of photos of plants,
animals, habitats, and other natural history subjects [web
application]. Berkeley, California: University of California.
Accessed November 2011. http://calphotos.berkeley.edu.
CDFG (California Department of Fish and Game). 2012a. “Allium
shevockii.” Element Occurrence Query. California Natural
Diversity Database (CNDDB). RareFind, Version 4.0
(Commercial Subscription). Sacramento, California: CDFG,
Biogeographic Data Branch. Accessed February 2012.
http://www.dfg.ca.gov/biogeodata/cnddb/mapsanddata.asp.
CDFG. 2012b. Special Vascular Plants, Bryophytes, and Lichens List.
California Natural Diversity Database (CNDDB). January 2012.
Accessed March 2012. http://www.dfg.ca.gov/biogeodata/
cnddb/plants_and_animals.asp.
Chase, M.W., J.L. Reveal, and M.F. Fay. 2009. “A Subfamilial
Classification for the Expanded Asparagalean Families
Amaryllidaceae, Asparagaceae and Xanthorrhoeaceae.”
Botanical Journal of the Linnean Society 161:132–136.
CNPS (California Native Plant Society). 2011. “Allium shevockii.”
Inventory of Rare and Endangered Plants. Online ed. Version 801a. Sacramento, California: CNPS. Accessed December 2011.
http://www.cnps.org/inventory.
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Spanish Needle Onion (Allium shevockii)
Jepson Flora Project. 2011. “Allium shevockii.” D.W. McNeal. Jepson
eFlora [v. 1.0] Berkeley, California: University of California.
Accessed December http://ucjeps.berkeley.edu/IJM.html.
McNeal, D.W. 1987. “Allium shevockii, (Alliaceae), a New Species from
the Crest of the Southern Sierra Nevada, California.” Madroño
34(2):150–154.
NatureServe. 2011. “Allium shevockii.” NatureServe Explorer: An Online
Encyclopedia of Life. Version 7.1. Arlington, Virginia:
NatureServe. Last updated July 2011. Accessed December
2011. http://www.natureserve.org/explorer.
Nguyen, N.H., H.E. Driscoll, and C.D. Specht. 2008. “A Molecular
Phylogeny of the Wild Onions (Allium; Alliaceae) with a Focus
on the Western North American Center of Diversity.” Molecular
Phylogenetics and Evolution 47:1157–1172.
Pitzer, B. 2006. “Spanish Needle Onion.” West Mojave Plan Species
Accounts. U.S. Department of the Interior, Bureau of Land
Management. January 2006. Accessed November 2011.
http://www.blm.gov/pgdata/etc/medialib//blm/ca/pdf/
pdfs/cdd_pdfs.Par.000a43e9.File.pdf/spanneed1.PDF.
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Species Accounts
March 2012