2002 SCST Proficiency test:  Wheat purity
pure seed:  Triticum aestivum
contaminants: 
Secale cereale (crop) – 6 seeds
Avena fatua (weed) – 1 seed
Convolvulus arvensis (weed) – 2 seeds
Aegilops cylindrica (weed) – 3 seeds
(Photos courtesy USDA/ARS  NCGRP)

Pure seed:  Triticum aestivum
Other Crop :  Secale cereale
triticum
secale

Weeds:


Avena fatua
Aegilops cylindrica
Convolvulus arvensis
Avena
Aegilops
Carvensis1


Convolvulus arvensis and similar species
3way



Convolvulus arvensis - field bindweed
carvensis1
carvensis2
carvensis3
carvensis4

Convolvulus equitans - texas bindweed or hoary bindweed
cequit1
cequit2
cequit3
cequit4

Calystegia sepium - hedge bindweed (Convolvulus sepium - synonym)
csepium1
csepium2
csepium3

Ipomoea purpurea
ipurpurea1   ipurpurea2

Ipomoea sp.
ipomoeasp

Polygonum convolvulus - wild buckwheat
pconv1pconv2  












Additional reference:
Gunn, Charles R.  1969. Seeds of the United States Noxious and common Weeds in the Convolvulaceae,
excluding the genus Cuscuta.  Proc. Assoc. of Official Seed Analysts.  59: 101-115.