| 5306093 |
purple starthistle |
Centaurea calcitrapa |
Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 3: 559. |
| 5306095 |
yellow starthistle |
Centaurea solstitialis |
Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 3: 560. |
| 5306094 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 3: 558. |
| 2153083 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
Roots |
| 1594655 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594755 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594752 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594749 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594747 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594746 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594744 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594742 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594741 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594740 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594739 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594734 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594725 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594726 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594721 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594719 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594718 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594714 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594715 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594713 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594710 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594709 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594708 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594650 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594669 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594665 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594663 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594664 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594662 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594659 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594660 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594658 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594657 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594656 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594652 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594654 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594653 |
yellow starthistle |
Centaurea solstitialis |
|
| 1594651 |
yellow starthistle |
Centaurea solstitialis |
|
| 5468280 |
spotted knapweed |
Centaurea stoebe |
single flower |
| 5458132 |
purple starthistle |
Centaurea calcitrapa |
Lateral view showing fruit attachment scar (at base) ± head-on. |
| 5458133 |
purple starthistle |
Centaurea calcitrapa |
Close-up. |
| 5456018 |
spotted knapweed |
Centaurea stoebe |
|
| 5456020 |
spotted knapweed |
Centaurea stoebe |
|
| 5456028 |
spotted knapweed |
Centaurea stoebe |
|
| 5456029 |
spotted knapweed |
Centaurea stoebe |
|
| 5456021 |
spotted knapweed |
Centaurea stoebe |
|
| 5455998 |
spotted knapweed |
Centaurea stoebe |
|
| 5454182 |
spotted knapweed |
Centaurea stoebe |
spotted knapweed (Centaurea stoebe); December |
| 0021039 |
meadow knapweed |
Centaurea moncktonii |
|
| 1350048 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
seedhead |
| 2153087 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1355037 |
yellow starthistle |
Centaurea solstitialis |
|
| 5435716 |
meadow knapweed |
Centaurea moncktonii |
hybrid with diffuse knapweed |
| 5435710 |
meadow knapweed |
Centaurea moncktonii |
|
| 5435711 |
meadow knapweed |
Centaurea moncktonii |
|
| 5435712 |
meadow knapweed |
Centaurea moncktonii |
|
| 5435713 |
meadow knapweed |
Centaurea moncktonii |
|
| 5435715 |
meadow knapweed |
Centaurea moncktonii |
white color morph |
| 5438446 |
spotted knapweed |
Centaurea stoebe |
|
| 5438448 |
spotted knapweed |
Centaurea stoebe |
|
| 5438449 |
spotted knapweed |
Centaurea stoebe |
|
| 5438443 |
spotted knapweed |
Centaurea stoebe |
|
| 5438436 |
spotted knapweed |
Centaurea stoebe |
|
| 5438438 |
spotted knapweed |
Centaurea stoebe |
|
| 2153090 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 5436663 |
brown knapweed |
Centaurea jacea |
|
| 1316001 |
yellow starthistle |
Centaurea solstitialis |
|
| 0022046 |
yellow starthistle |
Centaurea solstitialis |
|
| 0021032 |
diffuse knapweed |
Centaurea diffusa |
|
| 5436283 |
yellow starthistle |
Centaurea solstitialis |
flower head showing elongated spiny bracts |
| 5436284 |
yellow starthistle |
Centaurea solstitialis |
flower head |
| 5436285 |
yellow starthistle |
Centaurea solstitialis |
plant |
| 1459276 |
squarrose knapweed |
Centaurea virgata |
|
| 1459269 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1350049 |
diffuse knapweed |
Centaurea diffusa |
|
| 5435687 |
cornflower |
Centaurea cyanus |
infestation |
| 5435709 |
alpine knapweed |
Centaurea nigrescens |
hybrid of meadow knapweed and yellow starthistle |
| 5435720 |
spotted knapweed |
Centaurea stoebe |
|
| 5435722 |
spotted knapweed |
Centaurea stoebe |
|
| 5435694 |
diffuse knapweed |
Centaurea diffusa |
pink flowers with out spotted bracts. |
| 5435723 |
spotted knapweed |
Centaurea stoebe |
|
| 5435724 |
spotted knapweed |
Centaurea stoebe |
|
| 1459021 |
cornflower |
Centaurea cyanus |
|
| 2153085 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1350055 |
black knapweed |
Centaurea nigra |
seedhead |
| 1350069 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
suitable for a biocontrol program |
| 1350068 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1350050 |
squarrose knapweed |
Centaurea virgata |
|
| 1350053 |
meadow knapweed |
Centaurea moncktonii |
seedhead |
| 0022002 |
squarrose knapweed |
Centaurea virgata |
|
| 1350008 |
yellow starthistle |
Centaurea solstitialis |
Bolting stage |
| 1350047 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 0022045 |
yellow starthistle |
Centaurea solstitialis |
|
| 0022044 |
yellow starthistle |
Centaurea solstitialis |
|
| 0021040 |
meadow knapweed |
Centaurea moncktonii |
|
| 0022048 |
yellow starthistle |
Centaurea solstitialis |
|
| 1553213 |
meadow knapweed |
Centaurea moncktonii |
|
| 5422012 |
meadow knapweed |
Centaurea moncktonii |
In July |
| 1148149 |
knapweeds |
Centaurea spp. |
|
| 5427120 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 5427118 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 5427119 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 0886049 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 0021041 |
meadow knapweed |
Centaurea moncktonii |
|
| 1459656 |
yellow starthistle |
Centaurea solstitialis |
|
| 1624060 |
yellow starthistle |
Centaurea solstitialis |
Introduced from southern Europe and the Mediterranean region in the mid-1800s, is a serious rangeland weed throughout the western United States. |
| 1586283 |
knapweed |
Centaurea nervosa |
|
| 1350003 |
yellow starthistle |
Centaurea solstitialis |
|
| 5422903 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 5413050 |
Malta starthistle |
Centaurea melitensis |
Habit |
| 5418816 |
Malta starthistle |
Centaurea melitensis |
Habit |
| 1561172 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
photo taken 21 July 1994 |
| 5405762 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 5405722 |
diffuse knapweed |
Centaurea diffusa |
|
| 5405723 |
diffuse knapweed |
Centaurea diffusa |
|
| 5405724 |
diffuse knapweed |
Centaurea diffusa |
|
| 5407616 |
American star-thistle |
Centaurea americana |
|
| 5400995 |
yellow starthistle |
Centaurea solstitialis |
|
| 5400994 |
yellow starthistle |
Centaurea solstitialis |
|
| 5400997 |
yellow starthistle |
Centaurea solstitialis |
|
| 5400993 |
yellow starthistle |
Centaurea solstitialis |
|
| 5394997 |
cornflower |
Centaurea cyanus |
|
| 5394980 |
cornflower |
Centaurea cyanus |
|
| 5392042 |
yellow starthistle |
Centaurea solstitialis |
Q-tip stage |
| 5392039 |
yellow starthistle |
Centaurea solstitialis |
A large plant |
| 5392028 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
Big plant |
| 5391596 |
yellow starthistle |
Centaurea solstitialis |
|
| 5391594 |
yellow starthistle |
Centaurea solstitialis |
|
| 5391595 |
yellow starthistle |
Centaurea solstitialis |
|
| 1350056 |
brown knapweed |
Centaurea jacea |
in flower |
| 1350052 |
meadow knapweed |
Centaurea moncktonii |
in flower |
| 0024100 |
squarrose knapweed |
Centaurea virgata |
in flower |
| 1350054 |
black knapweed |
Centaurea nigra |
in flower |
| 5383102 |
diffuse knapweed |
Centaurea diffusa |
inflorescence stressed by biocontrol agents |
| 5383100 |
diffuse knapweed |
Centaurea diffusa |
typical features of a plant dying from attack by biocontrol agents. |
| 5383099 |
diffuse knapweed |
Centaurea diffusa |
|
| 5374351 |
alpine knapweed |
Centaurea nigrescens |
in flower |
| 5374352 |
alpine knapweed |
Centaurea nigrescens |
|
| 5374361 |
sulphur knapweed |
Centaurea sulphurea |
immature |
| 5374362 |
sulphur knapweed |
Centaurea sulphurea |
stem and leaves |
| 5374348 |
North African knapweed |
Centaurea diluta |
|
| 5374345 |
cornflower |
Centaurea cyanus |
|
| 5374346 |
cornflower |
Centaurea cyanus |
|
| 5374344 |
cornflower |
Centaurea cyanus |
in flower |
| 5374342 |
squarrose knapweed |
Centaurea virgata |
stem and leaves |
| 5374343 |
squarrose knapweed |
Centaurea virgata |
|
| 5374337 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
stem and leaves |
| 5374331 |
diffuse knapweed |
Centaurea diffusa |
stem leaves |
| 5379604 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
in flower in June |
| 1196233 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
in flower |
| 5358642 |
diffuse knapweed |
Centaurea diffusa |
Diffuse knapweed plant (Centaurea diffusa) in bloom, against a fence. |
| 5358641 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
Seedling spotted knapweed plant, Centaurea stoebe ssp. micranthos (Centaurea maculosa). |
| 5358639 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
Spotted knapweed plant, Centaurea stoebe ssp. micranthos (Centaurea maculosa), just beginning to bolt. |
| 5358637 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
Spotted knapweed plant, Centaurea stoebe ssp. micranthos (Centaurea maculosa), in bloom. |
| 1557020 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1557010 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
in flower |
| 1557009 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
After most seeds have been dispersed. |
| 1557006 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1557004 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1557002 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
in flower |
| 1557001 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1561074 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
photo taken on 21 July 1993 |
| 1553214 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
seed head |
| 1553211 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1553210 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 5352007 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 5352008 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 5351100 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1539018 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 1539019 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
|
| 2153086 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
Unopened flower showing spots on bracts |
| 1355036 |
yellow starthistle |
Centaurea solstitialis |
Morning dew on a yellow starthistle leaf. Evening inoculations with rust spores (from Puccinia jaceae var. solstitialis) are made to catch the overnight dew needed for spore germination and infection. |
| 1355034 |
yellow starthistle |
Centaurea solstitialis |
California Department of Food and Agriculture lab assistant Viola Popescu uses a cyclone spore collector developed at the Fort Detrick lab to harvest inoculum from plants at the CDFA greenhouse in Sacramento. |
| 1355035 |
yellow starthistle |
Centaurea solstitialis |
Small, rust-colored spots on starthistle leaves. The presence of these spots indicates that the first field releases of rust spores on starthistle are a success. |
| 1350073 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
releasing bioagents |
| 1350011 |
yellow starthistle |
Centaurea solstitialis |
Spines are equal to or greater than 45° angle from stem |
| 0021038 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
Field 20 miles east of Missoula |
| 0021036 |
spotted knapweed |
Centaurea stoebe ssp. micranthos |
Field 20 miles east of Missoula |
| 0022049 |
yellow starthistle |
Centaurea solstitialis |
|
