The UCR Herbarium Collection: Overview

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:

• The purpose of a herbarium is to provide an extensive collection of species for a variety of scientific studies. Our collection includes cultivated material from greenhouses, weeds growing in gardens, as well as collections from natural areas.

  Because specimens enter our collection in many ways, there are a variety of ways in which one taxon, genus or family might be collected much more extensively than another taxon. In addition, rare plants are sometimes over-represented in our database, since we seek to include examples of all taxa.

• In contrast, a flora of an area includes not only a list of species, but includes their abundance and an analysis of the flora as well. A herbarium is the starting and ending place for each flora, but much other work is required in between. Most botanists begin a flora of an area by reviewing herbaria collections to get an idea of how much of that area has been surveyed and documented, and to get a basic understanding of the flora from the collections. Much field work is then done to adequately survey an area, with more herbarium work to identify all newly-collected specimens. The field work provides an estimate of the abundance of each taxon in that area that is very difficult to obtain from herbarium specimens alone. Finally, all taxa are documented by making sure that good samples of every taxa, vouchers, are deposited in a herbarium.

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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

• Vascular Plants
• Lichens

Top Ten Taxa in each Southern California County In Our Database

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Voucher Statistics By Area

Voucher Statistics By Country

Country	# of Vouchers	% of Vouchers
U.S.	99,651	74.9%
Mexico	31,235	23.5%
Other countries	2,115	1.6%
Missing country	3	0.0%
Total	133,004	100.0%

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.

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Voucher Statistics By States in the U.S.

U.S. State	# of Vouchers	% of Vouchers
CA	76,113	76.4%
AZ	8,341	8.4%
NV	3,978	4.0%
NM	3,407	3.4%
TX	3,093	3.1%
CO	1,929	1.9%
UT	1,355	1.4%
other	1,435	1.4%
Total	99,651	100.0%

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 Vouchers		U.S. State	# of Vouchers	% of Vouchers		U.S. State	# of Vouchers	% of Vouchers
OR	216	0.2%		NH	11	0.0%		GA	3	0.0%
RI	210	0.2%		NY	10	0.0%		MO	3	0.0%
AK	186	0.2%		NE	9	0.0%		AL	2	0.0%
ID	125	0.1%		WV	9	0.0%		AZ	2	0.0%
WY	115	0.1%		KS	8	0.0%		IA	2	0.0%
WA	96	0.1%		TN	8	0.0%		IN	2	0.0%
MT	83	0.1%		DC	6	0.0%		KY	2	0.0%
OK	71	0.1%		NC	6	0.0%		BC	1	0.0%
LA	63	0.1%		NJ	6	0.0%		ME	1	0.0%
AR	52	0.1%		PA	6	0.0%		MS	1	0.0%
MA	28	0.0%		MD	5	0.0%		NB	1	0.0%
FL	26	0.0%		IL	4	0.0%		VT	1	0.0%
HI	17	0.0%		OH	4	0.0%
SD	16	0.0%		VA	4	0.0%
MI	15	0.0%		CT	3	0.0%		Total	1,435	1.4%

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

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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 Vouchers		Mexico State	# of Vouchers	% of Vouchers		Mexico State	# of Vouchers	% of Vouchers
SON	5,470	17.5%		MICH	640	2.0%		SLP	124	0.4%
JAL	5,084	16.3%		NL	443	1.4%		HGO	113	0.4%
BCN	4,114	13.2%		OAX	437	1.4%		TAMPS	104	0.3%
COL	2,389	7.6%		ZAC	357	1.1%		MEX	91	0.3%
BCS	1,873	6.0%		MOR	345	1.1%		TLAX	86	0.3%
CHIH	1,484	4.8%		AGS	325	1.0%		QR	13	0.0%
SIN	1,458	4.7%		NAY	308	1.0%		TAB	13	0.0%
DGO	1,395	4.5%		COAH	289	0.9%		GTO	6	0.0%
QRO	1,163	3.7%		DF	257	0.8%		not classified	202	0.6%
CHIS	753	2.4%		CAMP	196	0.6%
VER	708	2.3%		PUE	176	0.6%
YUC	646	2.1%		GRO	173	0.6%		Total	31,235	100.0%

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Voucher Statistics By Counties in California

County	# of Vouchers	% of Vouchers		County	# of Vouchers	% of Vouchers
San Bernardino	20,060	26.4%		Mono	1,867	2.5%
Riverside	18,221	23.9%		Imperial	1,432	1.9%
Los Angeles	7,690	10.1%		Orange	1,254	1.6%
San Diego	4,243	5.6%		Ventura	1,249	1.6%
Inyo	3,721	4.9%		Tulare	1,165	1.5%
Kern	2,846	3.7%		other	7,818	10.3%
San Luis Obispo	2,581	3.4%
Santa Barbara	1,966	2.6%		Total	76,113	100.0%

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 Vouchers		U.S. State	# of Vouchers	% of Vouchers		U.S. State	# of Vouchers	% of Vouchers
Monterey	675	0.9%		Modoc	203	0.3%		Butte	82	0.1%
Fresno	481	0.6%		Yolo	183	0.2%		Alameda	77	0.1%
Mendocino	382	0.5%		Sonoma	179	0.2%		Colusa	69	0.1%
Siskiyou	370	0.5%		Plumas	171	0.2%		Calaveras	68	0.1%
Trinity	324	0.4%		Napa	165	0.2%		Stanislaus	63	0.1%
Humboldt	323	0.4%		Solano	165	0.2%		Contra Costa	50	0.1%
Madera	290	0.4%		Shasta	154	0.2%		Merced	43	0.1%
Santa Clara	253	0.3%		San Benito	149	0.2%		Amador	41	0.1%
El Dorado	240	0.3%		Marin	141	0.2%		San Francisco	40	0.1%
Del Norte	225	0.3%		Lassen	140	0.2%		Glenn	39	0.1%
San Mateo	221	0.3%		Sacramento	130	0.2%		Yuba	38	0.0%
Tuolumne	213	0.3%		Sierra	128	0.2%		(county indeterminate)	37	0.0%
Nevada	210	0.3%		Placer	109	0.1%		Kings	26	0.0%
Lake	208	0.3%		Tehama	104	0.1%		Sutter	23	0.0%
Mariposa	207	0.3%		Santa Cruz	92	0.1%
Alpine	203	0.3%		San Joaquin	84	0.1%		Total	7,818	10.3%

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.

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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	# Taxa	Max # Vouchers For Any One Taxon	Mean # Vouchers Per Taxa	Median # Vouchers Per Taxa
San Bernardino	20,060	7	20,053	3,295	67	6.1	3
Riverside	18,221	10	18,211	3,893	145	4.7	2
Los Angeles	7,690	4	7,686	2,792	77	2.8	1
San Diego	4,243	4	4,239	1,713	24	2.5	1.5
Imperial	1,432	0	1,432	463	14	3.1	2
Orange	1,254	2	1,252	751	9	1.7	1
Ventura	1,249	0	1,249	798	12	1.6	1

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 could 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.

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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
Riverside	3,694	172	99	3,423
San Bernardino	3,247	110	70	3,067
Los Angeles	2,741	92	42	2,607
San Diego	1,639	40	20	1,579
Ventura	774	16	2	756
Orange	711	24	10	677
Imperial	456	10	1	445

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
7	26
6	185
5	328
4	521
3	775
2	1,205
1	3,493

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:

Family	Latin Name		Family	Latin Name		Family	Latin Name
AMA	Amaranthus albus		CNV	Cressa truxillensis		NYC	Mirabilis laevis
API	Tauschia arguta		CRY	Spergularia marina		POA	Cynodon dactylon
BOR	Heliotropium curassavicum		CYP	Scirpus californicus		POA	Leptochloa uninervia
BRA	Brassica rapa		EUP	Croton californicus		POA	Melica imperfecta
BRA	Lepidium lasiocarpum		EUP	Euphorbia polycarpa		POA	Muhlenbergia microsperma
CHN	Atriplex lentiformis		FAB	Lotus strigosus		POA	Phalaris minor
CHN	Atriplex semibaccata		HYD	Eucrypta chrysanthemifolia		POA	Polypogon monspeliensis
CHN	Chenopodium berlandieri		LAM	Salvia apiana		SCR	Castilleja foliolosa
CHN	Chenopodium murale		MLV	Malva parviflora

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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
Riverside	199	8	191
San Diego	74	6	68
Los Angeles	51	3	48
San Bernardino	48	4	44
Orange	40	6	34
Ventura	24	3	21
Imperial	7	1	6

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
4	3
3	20
2	57
1	260

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.

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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.

Imperial			Los Angeles			Orange
Taxon Name	# Vouchers		Taxon Name	# Vouchers		Taxon Name	# Vouchers
Camissonia claviformis	14		Aegilops triuncialis	77		Pulicaria paludosa	9
Aristida adscensionis	14		Triticum turgidum	54		Leproloma membranaceum	9
Cryptantha angustifolia	13		Triticum aestivum	51		Salvia mellifera	8
Cryptantha maritima	13		Cryptantha muricata	33		Lolium perenne	8
Euphorbia polycarpa	13		Aegilops cylindrica	30		Solanum douglasii	8
Astragalus crotalariae	13		Aegilops speltoides var. ligustica	28		Cupressus forbesii	7
Dalea mollissima	13		Aegilops speltoides var. speltoides	25		Scirpus maritimus	7
Eriogonum deserticola	13		Lotus strigosus	24		Ambrosia chamissonis	6
Eriogonum thomasii	13		Triticum boeoticum	24		Artemisia californica	6
Plantago ovata	13		Aegilops umbellulata	23		Centaurea melitensis	6

Riverside			San Bernardino			San Diego			Ventura
Taxon Name	# Vou- chers		Taxon Name	# Vou- chers		Taxon Name	# Vou- chers		Taxon Name	# Vou- chers
Triticum boeoticum	145		Cryptantha pterocarya	67		Quercus engelmannii	24		Arctostaphylos parryana	12
Phaseolus acutifolius	128		Eschscholzia minutiflora	62		Viguiera laciniata	22		Punctelia punctilla	9
Cryptantha intermedia	86		Eriogonum davidsonii	61		Hemizonia fasciculata	20		Solanum xanti	7
Triticum dicoccoides	74		Phacelia distans	55		Apiastrum angustifolium	17		Sanicula crassicaulis	5
Triticum urartu	65		Eriogonum pusillum	54		Cryptantha muricata	17		Gnaphalium californicum	5
Gilia angelensis	58		Cryptantha muricata	53		Xylococcus bicolor	17		Lasthenia californica	5
Hemizonia pungens ssp. laevis	51		Chaenactis stevioides	52		Eriophyllum confertiflorum	15		Trifolium willdenovii	5
Camissonia bistorta	49		Juniperus californica	50		Mimulus brevipes	15		Phacelia cicutaria var. hispida	5
Hemizonia paniculata	48		Juniperus osteosperma	50		Cryptantha intermedia	14		Malacothamnus fasciculatus var. laxiflorus	5
Euphorbia polycarpa	48		Cryptantha barbigera	49		Antirrhinum nuttallianum	13		Festuca 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