Reappearance of the Vanishing Wild Buckwheat: A Status Review of Eriogonum evanidum (Polygonaceae)

2012·5.1 MB·English

by  Naomi S Fraga

Madrono, Vol. 59, No. 3, pp. 150-155, 2012
REAPPEARANCE OF THE VANISHING WILD BUCKWHEAT: A STATUS
REVIEW OF ERIOGONUM EVANIDUM (POLYGONACEAE)
Naomi Fraga, Elizabeth Kempton, LeRoy Gross and Duncan Bell
S.
Rancho Santa Ana Botanic Garden, 1500 North College Avenue, Claremont, CA 91711
[email protected]
Abstract
Eriogoulun evaniduni Reveal is an annual herb in the buckwheat family that is endemic to southern
USA
California, and northern Baja California, Mexico. It was described by James Reveal in 2004 and
was determined to be extinct due to the lack of recent observations and accessioned specimen
collections. During field surveys conducted in 2007 and 2008 this species was rediscovered across its
known range in southern California. Three of 10 historic occurrences that were presumed extirpated
were located. One new occurrence was documented in the vicinity ofHolcomb Valley, San Bernardino
Mountains, CA. Location and habitat information are provided and the current conservation status
of this species is discussed.
Key Words: California, conservation, Eriogonum, endemic, extinct, Polygonaceae, rare, rediscovery.
Eriogomnn evaniduni Reveal (vanishing wild most of the documentation for E. evaniduni took
buckwheat) is an annual herb in the buckwheat place between 1920 and 1940, primarily from the
family (Polygonaceae) that was recently described vicinity of Big Bear Valley in the San Bernardino
(Reveal 2004; Fig. 1). This species was given the Mountains of southern Cahfornia (Reveal 2004;
common name 'vanishing wild buckwheat' be- Table an area that has experienced substantial
1 );
cause it was presumed extinct due to the lack of development over the last century. Eriogonum
recent observations and herbarium specimen evaniduni was "presumed extinct" in the Flora of
records (Reveal 2005; CNPS 2011). Focused North America (Reveal 2005) and considered
surveys were conducted by botanists at Rancho "possibly extirpated" in the second edition of the
Santa Ana Botanic Garden (RSABG) in late Jepson Manual (Baldwin et al. 2012), although
summer and fall of 2007 and 2008 to locate E. Reveal has reported seeing specimens of the E.
evanidwn across its known range in southern evaniduni that were collected in the late 1990's
California, USA. Eriogonum evaniduni was found (Costea and Reveal 2011). Two specimens that
to be extant across its historic range within the were not cited in the original description, and
United States, although the status of this species therefore not likely viewed prior to its descrip-
in Baja California, Mexico is unknown. Although tion, are housed at RSA and were collected in
several occurrences were located, it is likely that 1976 {Davidson 4471) and 1994 {Hirshberg s.n.).
some occurrences have been extirpated (Fig. 2).
Details of the 2007 and 2008 field surveys are Field Survey Methods
discussed here, including additional information
on distribution, habitat, and conservation status. Surveys for E. evaniduni were conducted by
RSABG
botanists at using a focused, or intuitive-
TAXONOMIC AND COLLECTION HISTORY controlled, field survey method (USDA FS 2005),
which targets habitats with the highest potential
Eriogonum evaniduni was discovered during for locating target species at the appropriate time
herbarium studies by Reveal (2004). The new for proper identification. Herbarium specimen
species was described from specimens that were records (RSA, UCR), databases (CalFlora, Con-
previously identified as Eriogonum foliosuni S. sortium of Cahfornia Herbaria, and California
Watson. In his description. Reveal (2004) stated Natural Diversity Database), and literature
that ''this distinctive species has been hidden reports were used to identify historic populations
quietly under Eriogonum foliosuni S. Watson of E. evaniduni and these were targeted for field
RSABG
awaiting rediscovery of an extant population so surveys. Surveys by botanists at were
that it might be more precisely characterized than conducted during August 2007, and August and
possible from dried material." Reveal designated September of 2008. U.S. Department of Agricul-
a holotype that was collected in 1902 {Ahranis ture (USDA) Forest Service Element Occurrence
2894) and paratypes collected from as early as forms were used to document all populations
1893 {Alderson 399) to 1967 {Ziegler s.n.). Based of E. evaniduni that were encountered (e.g., exact
on accessioned herbarium specimen records location, population status, existing or potential
examined by Reveal (2004), it appeared that threats or disturbances, habitat, associated
2012] FRAGA ET AL.: STATUS REVIEW OF ERIOGONUM EVANIDUM 151
Occurrences previously documented in the vicin-
ity of Big Bear Lake and Baldwin Lake in the San
Bernardino Mountains were not found in 2007 or
2008. It is possible that these occurrences have
been extirpated due to development in the region
(Table
1).
There are three occurrences in southern Cali-
fornia that are doubtful and not supported by
herbarium specimens (Table These include
1).
reports from Valencia in Los Angeles County,
Warner Springs in Riverside County, and Viejas
Mountain in San Diego County (CNPS 2011;
CNDDB
201 The only source for the reported
1 ).
occurrence at Valencia in Los Angeles County is
a report prepared by Dudeck and Associates
CDFG
(unpublished) to the and Newhall Land
and Farming Company (CalFlora 2011; CDFG
2011). The population at Warner Springs was
referenced by Reveal 1989) in his treatment of E.
(
folioswn. The source for the occurrences at Viejas
Mountain is from Craig Reiser's 1994 account in
(CNDDB
Rare Plants of San Diego County
2011). None of these occurrences has been
verified in the field, and none are documented
by herbarium specimens. In addition, all three are
reported at lower elevations than vouchered
occurrences and therefore they may lack suitable
habitat (Table Future surveys should be
1).
conducted to verify if E. evanidiun occurs at
these locations.
Fig. Eriogouuni evanidiun in flower with a fisher
1 . Habitat
space pen (9.6 cm X 0.8 cm) for scale.
In previous floristic treatments, habitat for E.
species). Herbarium specimens were collected and evanidiun was described as sandy to gravelly flats
deposited at the RSA herbarium and photo- and slopes, in sagebrush communities, oak
graphs of plants were contributed to the CalPho- woodland and montane conifer woodlands at
USDA
tos database (calphotos.berkeley.edu). 1150 2300 meters in elevation (Reveal 2005;
Forest Service Element Occurrence forms, along CNPS 2011; Costea and Reveal 2011; Fig. 3).
with U.S. Geologic Survey (USGS) maps of The described habitat requirements were sub-
surveyed populations, were submitted to the stantiated while conducting surveys, except that
California Department of Fish and Game plants were not found in oak woodland. Oak
(CDFG), and USDA Forest Service. Plant woodland vegetation was presumably included in
identifications were made using taxonomic keys the habitat description because of the previous
and descriptions in The Jepson uuimial: higher reference of this species at Warner Springs in
plants of CaUfomia (Hickman 1993), A flora of Riverside County. Occupied habitat for E.
southern California (Munz 1974), and Flora of evanidiun included sandy soils derived from
North America (Reveal 2005). Identifications decomposed granite, in primarily full sun with
were verified through comparison with annotated little to no leaf litter, on a flat aspect in sagebrush
RSA
specimens in the herbarium. scrub dominated by Artemisia tridentata Nutt.
The sagebrush community was often surrounded
Distribution by coniferous forest dominated by Finns jeffreyi
Balf. or F. ponderosa P. Lawson & C. Lawson.
In the United States, E. evaniclum is restricted Eriogonum evanidiun was also observed to occur
to southern California and has been documented in dry meadows dominated by Artemisia triden-
in the San Bernardino Mountains in San tata in Holcomb Valley, San Bernardino Moun-
Bernardino County, San Jacinto Mountains in tains, CA.
Riverside County, and the Laguna Mountains in The following is a list of species associated
San Diego County (Fig. 2). Eriogonimi evanidiun within E. evanidum compiled from several loca-
has also been reported from northern Baja tions throughout its range (* denotes not native
California, Mexico (Costea and Reveal 2011). species): Artemisia tridentata. Astragalus doiiglasii
1
MADRONO
152 [Vol. 59
WW
118'0'0"W 117°0'0"W 116
I
. : ^ . 1 •Hesperia ~ •
^- lo^ AN;©tLES NEVADA
1
CALIFORNIA
LasVegas
'Glendali ^ -al^?^ ERNARD NO
I
LosAngeles / ' "COUNTY ARIZONA
•
LosAngeles
34°0'0"N- •34°0'0"N
Banning San DIei
BAJA
ir^^^^'^Spnngs CALIFORNIA
Hemet
ORANGE \
COUNTY ^ RIVERSIDE ;4
'
/ COUNTY
Saltan
Legend
Eriogonum evanidum
# SAN DIE©0 >
Historical Occurrences -
COUNTY.
Vj
33°0'0"N- ^1 2007-2008 Survey Occurrences IMPERIAL •33°0'0"N
COUNTY
N }
r
0 10 20 40 Kilometers El Cajon
1 I I I I I I I I I ,4, San Diego
V.
117 0'0"W 116°0'0"W
Fig. 2. Distribution of Eriogouuw evanidum based on vouchered occurrences. Historic occurrences are
represented by a black circle and occurrences located in 2007 and 2008 are represented by a white triangle. See
Table 1 for detailed information (source herbaria, collection date, locality, etc.) for each occurrence.
(Torr. & A. Gray) A. Gray var. parishii (A. Gray) has flowers that are 1.5 2 mm, the lobes are
M. E. Jones, *Bromiis tectorwn L., CcistiUeja oblong-obovate, and stems are glabrous. Eriogo-
cinevea A. Gray, Chenopodiwu leptophylluni num gracile has flowers that are 1.5-3 mm, the
(Moq.) Nutt. ex S. Watson, Chrysothanmus lobes are lanceolate to oblong, and stems are
viscidiflorus (Hook.) Nutt., Cryptcmtha micrantha generally tomentose, or sometimes glabrous
(Torr.) I. M. Johnst., Gutierrezia sarothrae (Baldwin et al. 2012).
&
(Pursh) Britton Rushy, Ericameria pinifolia Although not co-occurring within the United
(A. Gray) H. M. Hall, Eriogonum bciileyi S. States, there are two additional species {E.
Watson, E. dcividsonii Greene, E. wrightii Torr. ex foliosum and E. hastatum Wiggins; both endemic
Benth. var. subscaposum S. Watson, Ehastriuu to Mexico) that may be confused with E.
sapphirimiJii (Eastw.) H. Mason, Lessingia glcm- evanidum in Baja California, Mexico. Eriogonum
didifera A. Gray, Nicotiana attemiata Steud., evanidum can be distinguished from both of these
Pensteiuon ceutranthifolius (Benth.) Benth., Piuus species on the basis of several morphological
—
jeffreyi, P. pouderosa, ^Sisymbrium altisimum L., characters both E. foliosum and E. hastatum
Stephcmomeria exigua Nutt., and Trichostema have sprawling habits, foliaceous inflorescence
micrcmdium A. Gray. bracts, and elliptic basal leaves while E. evanidum
has an erect habit, scalelike inflorescence bracts,
Identification and broadly ovate to orbicular or reniform basal
leaves.
Eriogonum evanidum co-occurs with other
annual taxa in the genus Eriogonum that it may Conservation Status
be confused with including: E. baileyi, E.
dcividsonii, and E. gracile Benth. Eriogonum Eriogonum evanidum is not listed by the State
evanidum can be distinguished from these species of California or Federal government as threat-
by its relatively small flowers (0.8-1.2 mm), outer ened, or endangered, but is considered by the
perianth lobes that are more or less hastate in California Native Plant Society as "seriously
fruit, and stems that are tomentose. In contrast E. endangered in California" (California Rare Plant
baileyi has flowers that are 1.5-3 mm, the outer Rank IB.l; CNPS 2011). Eriogonum evanidum is
perianth lobes oblong to oblong-obovate, gener- also on the Sensitive species list for the Cleveland
ally constricted near middle, and stems are and San Bernardino National Forests. Presum-
glabrous or tomentose. Eriogonum davidsonii ably several populations have been extirpated in
'' ' '
2012] FRAGA ET AL.: STATUS REVIEW OF ERIOGONUM EVANIDUM 153
u
^ o ^
G
X)
=3 (U
H S o
G oooo' ^ CQ
-S > c PQQ B Q
a B Q
o a a
c
U
'u
> >
o^ -> ^2U > QHi 0 a c >
o o o o
< z w Z
> CI
Oh
> 0^3 00 nj 13
G §
(U OX) Dh G
o
_o C 003 2 >03 03 >2 -^>G IO0D3 Sa-H h0-3l
t— > CD B u
03 03
O bxj 1j S0-3i u P<Qu G
PQ Xu) > _-oIo—' GO o t gd:j 03 J4 >
O >.S
C/3 G 03
X) ^1
o o o C3 CO G 0033 c aa(U GO ((^—U G
W 03 <u O < >OO '-c033 D G o X I0D3
^ c f> 'a CQ
< CQ CQ G
on C/3 CO CO
m
(ON
O oo oo oo rrii o
^ o in
> in
.A inI oo1
5 (N (N oin
(N
(N (N
o 0 0 Q Q 0 0 Q Q <
u CQ CQ PQ
in CO C/2 00 00 oo
ON
ooo 0o0 oOn Orni ON O ooo (ONN oo
ON ON
a w Op
< G G <G <G a aI
o o < o <
IT) I z oI I CO —
*— inI inI 1^
D
o in OmN
in (N
m (mN
imn 5 in ON
in OmN
c o
<ou < 03 0 in < < O
m U 00 CO
ion ^*(<C^V!O-<mmm>sO<0i1^^n^ oo O O 0^ ^^Oh O:i^nN (SN rDijn O oP^: imn' Dh' OITN) ooiinn
ri ^ CO <ON ON ,^ OiN OiOn < <^ 00 rsi O
H<: 0 o Q q:^ > t>0 CO o WD- 00 CO o; c^ u UQ
Oh c^
MADRONO
154 [Vol. 59
Fig. 3. Typical habitat for Eriogoinun evauidiini. Photo from Pine Valley, San Diego County, CA.
the vicinity of Big Bear Lake and possibly specimens (Valencia, Warner Springs, and Al-
Baldwin Lake due to development in the region. pine, Table therefore the existence of these
1 ),
In addition, one population in Pine Valley has occurrences is suspect until verified. In 2008 a
been extirpated due to development; Hirshberg survey was conducted at Warner Springs and no
revisited a population she previously documented suitable habitat found.
in 1994 and states that ''there is now a house
there, and the population has apparently been
Discussion
extirpated" (CCH 2011). The primary threats to
this species include development, dispersed rec- There are several factors that may have
reation (vehicle use off designated roads, hiking, influenced the lack of recent documentation for
equestrian use, etc.), and non-native plant estab- this species and previous conclusion that this
lishment (CNPS 201 1). species was extinct. First, E. evanichim has a highly
limited distribution, only occurring in localized
Survey Results microsites within its distribution, and is generally
not locally common. Second, this species com-
There are ten documented locations of E. monly occurs in the general vicinity of similar
evanidimi (Fig. 2); four of these are known to be looking species (e.g., E. haileyi, E. davidsonii).
extant (Table 1). Several occurrences in the Third, E. evauidimi has exceedingly small flowers
vicinity of Big Bear Lake and Baldwin Lake and therefore diagnostic characteristics can be
were not located and are possibly extirpated difficult to detect in the field. Lastly, E. evcmidum
(Table 1). One historic occurrence in the San flowers from August to September, a time ofyear
Jacinto Mountains in Garner Valley (Hemet when few botanists make collections. Other
Valley), one historic occurrence in the Laguna summer to fall-blooming plants, such as Deinan-
Mountains in Pine Valley, and one occurrence in drci luoluiveiisis (D. D. Keck) B. G. Baldwin have
the San Bernardino Mountains along Van Dusen been mistakenly considered extinct (Sanders et al.
Canyon Road were located. An occurrence in the 1998). This brings to bear the importance of
vicinity Holcomb Valley in the San Bernardino collecting plant specimens late in the growing
Mountains was newly documented as a result season in the summer and fall months.
of this study (Table There are several report- There are undoubtedly additional occurrences
1 ).
ed locations for which there are no voucher of E. cvanidwn that have not been documented
,
2012] FRAGA ET AL.: STATUS REVIEW OF ERIOGONUM EVANIDUM 155
and we recommend additional surveys are Sacramento, CA. Website: http://www.cnps.org/
conducted to further assess the status of this cnps/rareplants/inventory/ [accessed November 11,
species. The status of CNPS list IB.l is ap- 2011].
California Natural Diversity Database
propriate given the current information. All
extant occurrences are known from National (CNDDB). 2011, RareFind 4.0. California Depart-
ment of Fish and Game, Sacramento, CA. Website:
Forest lands, and are therefore currently
https://nrmsecure.dfg.ca.gov/cnddb/view/query.
sppreoctieecstemdayfraolmso dbeeveplroepsemnetnti;n uhnodweovceurm,enttheids Calfalsopxra[:accIenssfeodrNmoavteimobneron11,C2a0l1i1f].ornia Plants
locations on private property. While E. evani- FOR Education, Research and Conservation
dum is extant throughout its current range with- [webapplication]. 201 1, The Calflora Database [a
in the U.S., this species has been impacted by non-profit organization], Berkeley, CA. Website:
anthropogenic disturbances (e.g., dispersed rec- http://www.calflora.org/ [accessed: November 1 1
OHV
reation, use, development). Specifically 2011].
plants in Pine Valley in San Diego County have Consortium of California Herbaria (CCH). 201 1,
been impacted by development. This was noted Consortium of California Herbaria Search Page.
by Hirshberg (CCH 2011) who was unable to Consortium of California Herbaria, Berkeley, CA.
Website: http://ucjeps.berkeley.edu/consortium/
locate an occurrence she previously document- [accessed November 11, 201 1].
ed because it has been extirpated by develop- COSTEA, M. AND J. L. REVEAL. 2011. Eriogonum. In
ment (CCH 2011). The conservation status of E. The Jepson eFlora. Website: http://ucjeps.berkeley.
evanidiim was brought to hght because it was edu/IJM.html [accessed November 11, 2011].
presumed extinct in recent floristic treatments; if Hickman, J. C. (ed.). 1993. The Jepson manual: higher
not for these recent publications, this species plants ofCalifornia. University ofCalifornia Press,
could have remained undetected and hidden in Berkeley, CA.
herbaria. MuNZ, P. A. 1974. A flora of southern California.
University of California Press, Berkeley and Los
Acknowledgments Angeles, CA.
USDA Reveal, J. L. 1989. The eriogonoid flora of California
This project was supported by the Forest (Polygonaceae: Eriogonoideae). Phytologia 66:295-
Service (San Bernardino and Cleveland National
414.
Forests). We wish to thank Scott Eliason, Melody 2004. New entities in Eriogonum (Polygona-
Lardner, and Lisa Young for logistical support. ceae. : Eriogonoideae). Phytologia 86:121-159.
Literature Cited . 2005. Eriogonum. Pp. 221^30 in Flora of
North America Editorial Committee (eds.). Flora
Baldwin, B. G., D. H. Goldman, D. J. Keil, R. of North America North of Mexico, Vol. 5:
Patterson, T. J. Rosatti, and D. H. Wilken, Magnoliophyta: Caryophyllidae, part 2. Oxford
(eds.) 2012. The Jepson manual: vascular plants of University Press, New York, NY.
California, 2nd ed. University of California Press, Sanders, A. C, D. Banks, and S. Boyd. 1998.
Berkeley, CA. Rediscovery ofHemizonia molmvensis Keck (Aster-
California Department of Fish and Game aceae) and addition oftwo new localities. Madrofio
(CDFG). 2011, Biological resources technical 44:197-200.
report for the Entrada Site, Los Angeles, County, United States Department of Agriculture,
California. Website: http://nrm.dfg.ca.gov/FileHandler. Forest Service (USDA FS). 2005, Threatened,
ashx?DocumentVersionID=21408 [accessed December endangered and sensitive plants survey: field guide.
1, 2011]. Washington, DC. Website: http://fs.fed.us/r6/
California Native Plant Society (CNPS). 2011, sfpnw/issssp/documents/inventories/inv-sp-tesp-
Inventory of rare and endangered plants (online survey-field-guide-2005-03.doc [accessed December
edition, v7-10c). California Native Plant Society, 1, 2011].