100 
IOWA ACADEMY OF SCIENCE 
982. Cirsium iowense (Pam.) Fern. Iowa Thistle. Not common in 
fields. 
983. Cirsmm, hillii (Canby) Fern. Hill’s Thistle. Scarce in dry sandy 
fields near Hills Siding. 
984. Cirsium arvense (L.) Scop. Canada Thistle. Scarce along rail- 
ways and in fields. 
CICHORIUM (Tourn) L. 
985. Cichorium intybus L. Chicory or Wild Succory. Scarce in fields 
and along railways. 
KRIGIA S'Chreb. 
986. Krigia virginica (L.) Willd. Cynthia or Virginia Goats-Beard. 
Common in rich woodlands. 
TRAGOPOGON (Tourn) L. 
987. Tragopogon porrifolius L. Oyster Plant or Purple Goats-Beard. 
Sparingly escaped from cultivation. 
988. Tragopogon pratensis L. Meadow Salsify. Locally plenty near 
Iowa City. 
TARAXACUM (Haller) Lud. 
989. Taraxacum officinale Web. Dandelion. A common weed every- 
where. 
990. Taraxacum erythrospermum Andrz. Red Seeded Dandelion. Less 
common and in drier soils. 
SONCHUS (Tourn) L. 
991. Sonchus arvensis L. Corn Sow Thistle. An introduced weed not 
uncommon in waste places. 
992. Sonchus oleraceus L. Annual Sow Thistle. Also common as a 
weed of waste places. 
993. Sonchus asper (L.) Hill. Spiny Sow Thistle. Common along rail- 
ways, clay banks, etc. 
LACTUCA (Tourn) L. 
994. Lactuca scariola L. Prickly Wild Lettuce. 
995. Lactuca scariola Var. integrata Gren. & Godr. 
996. Lactuca canadensis L. Tall Wild Lettuce. This with the above 
are common as introduced weeds in fields and waste places. 
