Weed
blue lettuce
AcheneAchene:
A dry, hard, one-chambered, one-seeded indehiscent fruit, as in buckwheat (Fagopyrum) or sunflower (Helianthus). The fruit wall is not united with the seed coat.
EllipticElliptic:
Outline of an ellipse; greatest width midway sloping to an equally pointed apex and base.
with a short beak
Brown with a white apexApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
Moderately rough with serrated ribs
AcheneAchene:
A dry, hard, one-chambered, one-seeded indehiscent fruit, as in buckwheat (Fagopyrum) or sunflower (Helianthus). The fruit wall is not united with the seed coat. is compressed with flat margins and few longitudinal ribs on the flat surfaces.
The pappusPappus:
Modified calyx in Asteraceae, composed of hairs, bristles, awns, or scales. The pappus-like structure attached to milkweed seeds is termed a coma. 
collar sits on top of a short beak. However, the beak is often broken off.
State Noxious Weed: Alaska, Colorado, Hawaii, Idaho, Washington, Wyoming
Not included
Asteraceae
Lactuca tatarica (L.) C.A. Mey. var. pulchella (Pursh) Breitung
Lactuca oblongifolia Nutt.
Lactuca pulchella (Pursh) DC.
Lactuca tatarica (L.) C.A. Mey. var. heterophylla (Nutt.) B. Boivin
Lactuca tatarica (L.) C.A. Mey. ssp. pulchella (Pursh) Stebbins
Mulgedium pulchellum (Pursh) G. Don
Sonchus tataricus L. p.p.
