MICHIGAN ACADEMY OF SCIENCE. 199 



Onopordum acanthium L. Scotch Thistle — Apparently well established 

 in sandy ground at Point Edward. 



Silybum marianum (L.) Gaert. Lady's Thistle. Milk Thistle. — Fre- 

 quent as a weed in gardens and waste places. 



Centaurea cyanus L. Bachelor's Button. — Inclined to escape from cultiva- 

 tion to roadsides. 



Centaurea nigra L. Spanish Buttons. — Along roads and in old fields. Fre- 

 quent. Newton Tripp. 



Centaurea maculosa Lam. Spotted Knap-weed. — Along roads and in old 

 fields. 



Cichorium intybus L. Common Chicory. — Common in clayey ground on 

 roadsides and in waste places. Occasional as a weed in fields. 



Krigia amplexicaulis Nutt. Cynthia. — Occasional in moist open woods 

 and on damp banks. 



Leontodon autumnalis L. Fall Dandelion. Occasional along roads and 

 in fields. 



Tragopogon porrifolius L. Salsify. — Frequent along railways and in waste 

 places. Apparently well established as an escape. 



Tragopogon pratensis L. Goat's Beard. — Occasional in towns, villages, 

 depot grounds, and along railways. 



Taraxacum officinale Weber. Common Dandelion. — Very common in 

 pasture fields, lawns, open woods, and waste places. 



Sonchus arvensis L. Field Sow Thistle. — Occasional along railways and 

 in depot grounds. Noticed as a bad weed in grain fields. 



Sonchus oleraceus L. Common Sow Thistle. — Frequent as a weed in 

 gardens, cultivated fields and waste places. 



Sonchus asper (L). Hill. Spiny-leaved Sow Thistle. — Frequent in gardens, 

 cultivated fields and waste places. 



Lactuca scariola L. Prickly lettuce. — Occasional along banks of ditches 

 and railroads. 



Lactuca scariola integrata Gren. and Godr. Prickly Lettuce. — Common 

 along railways, on roadsides, in gardens, cultivated fields, pastures and waste 

 places. 



Lactuca canadensis L. Wild Lettuce.^ — Commom in rich ground on 

 borders of fields, in damp open woods and thickets. 



Lactuca integrifolia Bigel. Arrow-leaved Lettuce. — Reported by Prof. 

 John Macoun as noticed in woods near Wyoming Apparently rare, 



Lactuca hirsuta Muhl. Hairy Wood Lettuce. — Frequent in dryish open 

 groimd and open woods. 



Lactuca spicata (Lam.) Hitchc. Tall Blue Lettuce. — Common in damp 

 open woods, thickets and damp places. 



Prenanthes racemosa Michx. Glaucous White Lettuce. — Frequent in 

 damp and marshy places. T. C. Wheatley. 



Prenanthes racemosa pinnatifida Gray. — Pimiatifid white lettuce. Usually 

 found with the preceding. 



Prenanthes alba L. Rattlesnake Root. — Common in rich open woods and 

 thickets. 



Prenanthes altrissima L. Tall White Lettuce. — Common in rich open 

 woods and thickets. 



