Fruit spine epidermis (surface) (x500)

Left: Echinocereus bakeri

Right: Echinocereus coccineus subsp. coccineus

Hello,
my name is Wolfgang Blum I'm an active founding member and Vice Chairman of the Echinocereus Study Group of the German Cactus Society and I' ve written the book “Echinocereus” with Michael Lange, Werner Rischer & Jürgen Rutow.
The book about this fine genus Echinocereus (Cactaceae) was published in 1998 in english and german.
496 pages, 215 color images, 13 distribution maps, 35 SEM images,
12 new descriptions and 30 combinations.

www.arbeitsgruppe-echinocereus.de
http://ag-echinocereus.de/images/Statusliste_2022_10_18.pdf

I' ve written the books:
http://www.arbeitsgruppe-echinocereus.de/index.php/second

Echinocereus reichenbachii-fitchii-complex (2004)
336 pages, 405 color images, 12 sw images, 6 distribution maps, 67 herbar sheets, 61 SEM images,
and 2 new descriptions (E. fitchii ssp. bergmannii, E. reichenbachii ssp. comanchensis)

Echinocereus Section Wilcoxia (2008 )
142 pages, 250 color images, 1 distribution map, 21 herbar sheets,
36 SEM images, Chapter about roots and wood cylinders and
one new description (E. poselgeri ssp. gerhardii)
https://www.ag-echinocereus.de/index.php/second?view=article&id=78:wilcoxia&catid=80:publikationen

Echinocereus parkeri group (2011)
144 pages, 255 color images, distribution map, 12 herbar sheets, 18 SEM images,
one status change (E. parkeri ssp. rayonesensis) and two neo types

Echinocereus viridiflorus complex (2012)
336 pages, 397 color images, 3 distribution maps, 25 herbar sheets, 48 SEM images,
one new description (E. blumii) and one status change (E. canus)
https://www.ag-echinocereus.de/index.php/sonderausgabe?view=article&id=76:sonderausgabe&catid=80:publikationen

Echinocereus adustus group (2014)
136 pages, 180 color images, distribution map, 11 herbar sheets, 24 SEM images
and one neo type

Echinocereus triglochidiatus group (2015)
264 pages, 463 color images, 3 distribution maps, 28 herbar sheets, 78 SEM images
and one neo type
https://www.ag-echinocereus.de/index.php/second?view=article&id=96:wilcoxia&catid=80:publikationen

Echinocereus coccineus group (2016)
560 pages, 774 color images, 2 distribution maps, 23 herbar sheets, 126 SEM images
https://www.ag-echinocereus.de/index.php/second?view=article&id=112:sonderausgabe-coccineus&catid=80:publikationen

Echinocereus acifer group (2018)
416 pages, 648 color images, 4 distribution maps, 9 herbar sheets, 147 SEM images
and one new description (E. arizonicus ssp. oldachiorum)
https://www.ag-echinocereus.de/index.php?view=article&id=122:sonderausgabe-acifer&catid=80:publikationen

Echinocereus enneacanthus-complex (2022)
416 pages, 341 color images, 15 distribution maps, 18 herbar sheets, 91 SEM images
one neo type
an one new description (E. zapalinamensis).
https://www.ag-echinocereus.de/index.php/second

We are currently working on a book on the Subseries Echinacanthi which includes the following taxa:
E. bristolii W.T. Marshall
E. bristolii subsp. floresii (Backeberg) Blum & Lange
E. grandis Britton & Rose
E. sciurus (K. Brandegee) Dams
E. scopulorum Britton & Rose

E. scopulorum subsp. pseudopectinatus (N.P.Taylor) Blum & Lange
E. websterianus Lindsay

Booklets:
Echinocereus pulchellus and subspecies 2006
Echinocereus fendleri and subspecies 2014
Echinocereus dasyacanthus and subspecies 2015
Echinocereus pectinatus and subspecies 2016

So far I have under the genus Echinocereus: https://www.ipni.org/?q=W.Blum

27 descriptions of ranks [Series (4), Subseries (1), Species (6), Subspecies (15) and Cultivar (1)],
44 combinations of ranks [Subgenus (1), Series (6), Subseries (1), Species (5), Subspecies (30) and Forma (1)]
released.

I am looking for help.
Seeking Echinocereus herbar sheets from the following herbaria:
CALIFORNIA: CAS
ARIZONA: ARIZ
UTAH: BRY; UT; UTC
NEW MEXICO: SJNM
TEXAS: BRIT
COLORADO: WSC; FLD
WYOMING: RM; RMS
OKLAHOMA: DUR
KANSAS: WASH; KSC; KANU

MEXICO: UAT; IBUG; HJBC; GUADA; QMEX