Herbarium Summary Statistics
compiled and written by Thomas Chester

This page gives a snapshot of the 133,034 records in the database as of 26 October 2004. Each record corresponds to a voucher in the UCR Herbarium. A vascular plant voucher is a pressed, dried plant specimen collected in the field, pasted onto heavy paper, and labeled with its scientific name, and details on the location. Lichen vouchers are similar, but may be still attached to the rock substrate on which they grew. They are called vouchers because they vouch for the name assigned to it by the collector. In the following, they are also sometimes called specimens, or collections.

As of this date, we have completed the inventory of all our North American collections from north of Mexico, all the Latin American dicots, gymnosperms and ferns and about 75% of the Latin American monocots. We have also completed entry of all our material from cultivated sources, including our large holdings of wheat relatives and of Phaseolus. The accessioned lichen collection is over 90% entered, but recent large additions of material, not yet accessioned, have not been entered. The vascular plant specimens remaining to be inventoried probably represent less than 5% of the collection.

In this page, we first breakdown the number of vouchers by area, and then by taxa in selected areas.

Note that although there is much interesting and scientifically-useful information in the numbers given below, those numbers do not necessarily reflect the distribution of plants in natural areas! The statistics presented on this page should not necessarily be viewed as being representative of the true distribution of plants in a given area.

In particular, a herbarium collection is different from a flora of an area:


Voucher Statistics By Area

Country
States in the U.S.
States in Mexico
Counties in California

Voucher Statistics By Taxon By Area

Number of Taxa in Each Southern California County In Our Database

Top Ten Taxa in each Southern California County In Our Database


Voucher Statistics By Area

Voucher Statistics By Country

Country# of Vouchers% of Vouchers
U.S.99,65174.9%
Mexico31,23523.5%
Other countries2,1151.6%
Missing country30.0%
Total133,004100.0%

The table shows that almost exactly 3/4 of the collection is from the U.S., with nearly a quarter of the collection from Mexico.


Voucher Statistics By States in the U.S.

U.S. State# of Vouchers% of Vouchers
CA76,11376.4%
AZ8,3418.4%
NV3,9784.0%
NM3,4073.4%
TX3,0933.1%
CO1,9291.9%
UT1,3551.4%
other1,4351.4%
Total99,651100.0%

Interestingly, California makes up roughly the same percentage of the U.S. collection as the U.S. makes up of the entire collection, both being about 3/4. Almost 1/10 of our U.S. collection is from our neighboring state of Arizona, with all other states making up ~15% of the collection.

The other states combined in the above table are detailed in the following histogram:

U.S. State# of Vouchers% of VouchersU.S. State# of Vouchers% of VouchersU.S. State# of Vouchers% of Vouchers
OR2160.2%NH110.0%GA30.0%
RI2100.2%NY100.0%MO30.0%
AK1860.2%NE90.0%AL20.0%
ID1250.1%WV90.0%AZ20.0%
WY1150.1%KS80.0%IA20.0%
WA960.1%TN80.0%IN20.0%
MT830.1%DC60.0%KY20.0%
OK710.1%NC60.0%BC10.0%
LA630.1%NJ60.0%ME10.0%
AR520.1%PA60.0%MS10.0%
MA280.0%MD50.0%NB10.0%
FL260.0%IL40.0%VT10.0%
HI170.0%OH40.0%
SD160.0%VA40.0%
MI150.0%CT30.0%Total1,4351.4%

Only six states are not represented in our database so far: Delaware, Minnesota, North Dakota, Nebraska, South Carolina and Wisconsin.


Voucher Statistics By States in Mexico

Surprisingly, the distribution of vouchers among Mexican states is not highly concentrated, and the closest Mexican state, Baja California North, is not even the one with the most vouchers. Hence the following table simply lists every state.

Interestingly, the UCR Herbarium contains vouchers from every state in Mexico, even though it is missing six U.S. states.

Mexico State# of Vouchers% of VouchersMexico State# of Vouchers% of VouchersMexico State# of Vouchers% of Vouchers
SON5,47017.5%MICH6402.0%SLP1240.4%
JAL5,08416.3%NL4431.4%HGO1130.4%
BCN4,11413.2%OAX4371.4%TAMPS1040.3%
COL2,3897.6%ZAC3571.1%MEX910.3%
BCS1,8736.0%MOR3451.1%TLAX860.3%
CHIH1,4844.8%AGS3251.0%QR130.0%
SIN1,4584.7%NAY3081.0%TAB130.0%
DGO1,3954.5%COAH2890.9%GTO60.0%
QRO1,1633.7%DF2570.8%not classified2020.6%
CHIS7532.4%CAMP1960.6%
VER7082.3%PUE1760.6%
YUC6462.1%GRO1730.6%Total31,235100.0%


Voucher Statistics By Counties in California

County# of Vouchers% of VouchersCounty# of Vouchers% of Vouchers
San Bernardino20,06026.4%Mono1,8672.5%
Riverside18,22123.9%Imperial1,4321.9%
Los Angeles7,69010.1%Orange1,2541.6%
San Diego4,2435.6%Ventura1,2491.6%
Inyo3,7214.9%Tulare1,1651.5%
Kern2,8463.7%other7,81810.3%
San Luis Obispo2,5813.4%
Santa Barbara1,9662.6%Total76,113100.0%

As one might expect, the distribution of vouchers within California is much less concentrated than the concentration of the U.S. among countries and California among U.S. states. Nonetheless, almost exactly half of the vouchers are from the two counties closest to UCR: San Bernardino and Riverside. The next nearest county to UCR, Los Angeles, has the next largest number of vouchers. After that county, the effect of county proximity is not large; other effects, such as obtaining specimens of non-local taxa, or exploring interesting locations in the Sierra Nevada or deserts, are often as important in determining the number of vouchers from a given county.

The UCR database contains vouchers from every county in California.

The other counties combined in the above table are detailed in the following histogram:

U.S. State# of Vouchers% of VouchersU.S. State# of Vouchers% of VouchersU.S. State# of Vouchers% of Vouchers
Monterey6750.9%Modoc2030.3%Butte820.1%
Fresno4810.6%Yolo1830.2%Alameda770.1%
Mendocino3820.5%Sonoma1790.2%Colusa690.1%
Siskiyou3700.5%Plumas1710.2%Calaveras680.1%
Trinity3240.4%Napa1650.2%Stanislaus630.1%
Humboldt3230.4%Solano1650.2%Contra Costa500.1%
Madera2900.4%Shasta1540.2%Merced430.1%
Santa Clara2530.3%San Benito1490.2%Amador410.1%
El Dorado2400.3%Marin1410.2%San Francisco400.1%
Del Norte2250.3%Lassen1400.2%Glenn390.1%
San Mateo2210.3%Sacramento1300.2%Yuba380.0%
Tuolumne2130.3%Sierra1280.2%(county indeterminate)370.0%
Nevada2100.3%Placer1090.1%Kings260.0%
Lake2080.3%Tehama1040.1%Sutter230.0%
Mariposa2070.3%Santa Cruz920.1%
Alpine2030.3%San Joaquin840.1%Total7,81810.3%

In the above table, a small number of vouchers where the county was indeterminate between two neighboring counties have been associated with the first-mentioned county on the voucher. This was done to avoid cluttering the table even further.


Number of Taxa in Each Southern California County In Our Database

See the caveat above about how these numbers might differ from the true number of taxa in each county.

The table is in decreasing order of the number of vouchers in each county.

County# Vouchers# Vouchers
With Blank
Genus
# Vouchers
With Genus
Names
# TaxaMax #
Vouchers
For Any
One Taxon
Mean #
Vouchers
Per Taxa
Median #
Vouchers
Per Taxa
San Bernardino20,060720,0533,295676.13
Riverside18,2211018,2113,8931454.72
Los Angeles7,69047,6862,792772.81
San Diego4,24344,2391,713242.51.5
Imperial1,43201,432463143.12
Orange1,25421,25275191.71
Ventura1,24901,249798121.61

Remember that the taxa here include lichens as well as vascular plants. These taxa are broken into those two subsets in the next two sections.

Because not all specimens are identified fully, the taxa count includes such taxa as Gnaphalium sp., Gnaphalium canescens, and Gnaphalium canescens ssp. beneolens. A proper count of the number of distinct taxa would count only the separate subspecies of Gnaphalium canescens, and not the species itself or the genus alone. Remember, this summary table is not giving a count of the number of species in Southern California; it is summarizing how many categories of species names are in our database.


Number of Vascular Plant Taxa in Each Southern California County In Our Database

This table is sorted in decreasing number of unique vascular taxa among the vouchers from each county. The meaning of the columns is given below the table.

County#
Vascular
Taxa
#
Vascular
"sp."
#
Vascular
Hybrid
Taxa
#
Vascular
Actual
Taxa
Riverside3,694172993,423
San Bernardino3,247110703,067
Los Angeles2,74192422,607
San Diego1,63940201,579
Ventura774162756
Orange7112410677
Imperial456101445

The second column above is the number of unique names among all the vouchers in a county. Some of the vouchers are identified only to genus; the count of all the unique genera that are not further identified to the species level is given in the third column. Some of the vouchers are determined to be hybrids of two separate taxa; the count of all the unique hybrids is given in the fourth column. The last column gives the number of unique taxa that are not hybrids that have been determined to at least the species level.

The total count of all separate vascular taxa from these counties is 6,533 taxa. Again, that includes not fully-identified taxa.

As always, most taxa are found in only a single county, with very few taxa found in all counties:

# of Counties# Taxa
726
6185
5328
4521
3775
21,205
13,493

Thus only 26 taxa have vouchers in our database from every one of these seven counties. Over half (53%) of the taxa found in any one of these seven counties has vouchers from only a single one of those counties.

The 26 taxa in our database that have vouchers from each of these seven counties are:

FamilyLatin NameFamilyLatin NameFamilyLatin Name
AMAAmaranthus albusCNVCressa truxillensisNYCMirabilis laevis
APITauschia argutaCRYSpergularia marinaPOACynodon dactylon
BORHeliotropium curassavicumCYPScirpus californicusPOALeptochloa uninervia
BRABrassica rapaEUPCroton californicusPOAMelica imperfecta
BRALepidium lasiocarpumEUPEuphorbia polycarpaPOAMuhlenbergia microsperma
CHNAtriplex lentiformisFABLotus strigosusPOAPhalaris minor
CHNAtriplex semibaccataHYDEucrypta chrysanthemifoliaPOAPolypogon monspeliensis
CHNChenopodium berlandieriLAMSalvia apianaSCRCastilleja foliolosa
CHNChenopodium muraleMLVMalva parviflora


Number of Lichen Taxa in Each Southern California County In Our Database

See the caveat above about how these numbers might differ from the true number of taxa in each county.

County#
Lichen
Taxa
#
Lichen
"sp."
#
Lichen
Actual
Taxa
Riverside1998191
San Diego74668
Los Angeles51348
San Bernardino48444
Orange40634
Ventura24321
Imperial716

The second column above is the number of unique names among all the vouchers in a county. Some of the vouchers are identified only to genus; the count of all the unique genera that are not further identified to the species level is given in the third column. The last column gives the number of unique taxa that have been determined to at least the species level.

The total count of all separate lichen taxa from these counties is 340 taxa. Again, that includes not fully-identified taxa.

As always, most taxa are found in only a single county. In fact, no lichen taxa is found in more than 4 counties:

# of Counties# Taxa
43
320
257
1260

Thus only 3 taxa have vouchers in our database from four of these seven counties. Over three-fourths (76%) of the taxa found in any one of these seven counties has vouchers from only a single one of those counties.


Top Ten Taxa in each Southern California County In Our Database

This table gives the species that have the most vouchers in each county. See the caveat above about how these numbers might differ from the true number of taxa in each county.

The counties are in alphabetical order from left to right.

Latin Names in bold appear in the Top Ten List in multiple counties. All other Latin Names appear in only a single county's Top Ten List.

All taxa in these tables are vascular plants except Punctelia punctilla and Leproloma membranaceum, which are both lichens.

ImperialLos AngelesOrange
Taxon Name# VouchersTaxon Name# VouchersTaxon Name# Vouchers
Camissonia claviformis 14Aegilops triuncialis 77Pulicaria paludosa 9
Aristida adscensionis 14Triticum turgidum 54Leproloma membranaceum 9
Cryptantha angustifolia 13Triticum aestivum 51Salvia mellifera 8
Cryptantha maritima 13Cryptantha muricata33Lolium perenne 8
Euphorbia polycarpa13Aegilops cylindrica 30Solanum douglasii 8
Astragalus crotalariae 13Aegilops speltoides var. ligustica28Cupressus forbesii 7
Dalea mollissima 13Aegilops speltoides var. speltoides25Scirpus maritimus 7
Eriogonum deserticola 13Lotus strigosus 24Ambrosia chamissonis 6
Eriogonum thomasii 13Triticum boeoticum24Artemisia californica 6
Plantago ovata 13Aegilops umbellulata 23Centaurea melitensis 6

RiversideSan BernardinoSan DiegoVentura
Taxon Name#
Vou-
chers
Taxon Name#
Vou-
chers
Taxon Name#
Vou-
chers
Taxon Name#
Vou-
chers
Triticum boeoticum145Cryptantha pterocarya 67Quercus engelmannii 24Arctostaphylos parryana 12
Phaseolus acutifolius 128Eschscholzia minutiflora 62Viguiera laciniata 22Punctelia punctilla 9
Cryptantha intermedia86Eriogonum davidsonii 61Hemizonia fasciculata20Solanum xanti 7
Triticum dicoccoides 74Phacelia distans 55Apiastrum angustifolium 17Sanicula crassicaulis 5
Triticum urartu 65Eriogonum pusillum 54Cryptantha muricata17Gnaphalium californicum 5
Gilia angelensis 58Cryptantha muricata53Xylococcus bicolor 17Lasthenia californica 5
Hemizonia pungens ssp. laevis51Chaenactis stevioides 52Eriophyllum confertiflorum 15Trifolium willdenovii 5
Camissonia bistorta 49Juniperus californica 50Mimulus brevipes 15Phacelia cicutaria var. hispida5
Hemizonia paniculata 48Juniperus osteosperma 50Cryptantha intermedia14Malacothamnus fasciculatus var. laxiflorus5
Euphorbia polycarpa48Cryptantha barbigera 49Antirrhinum nuttallianum 13Festuca microstachys 5

These tables make it dramatically clear that these lists by county contain greenhouse-grown species. The tables for Riverside and Los Angeles Counties are heavily dominated by Triticum and Aegilops grass species grown for research, at both UCR and UCLA.

The appearance of Cryptantha species in all Top Ten Lists except for Orange and Imperial counties is not surprising, since many people have trouble identifying popcorn flowers, and many samples have been brought to UCR for identification.


Last update: 29 November 2004