146 



THE INDIANA WEED BOOK. 



mon sow-thistle (S. oleraceus L.), in which the lower leaves are 

 often divided, the margins toothed bnt not prickly, the ears at base 



pointed and the seeds with both cross and 

 lengthwise ribs. Both species are eaten 

 by sheep and infested pastures can be 

 cleared of them in that way. The young 

 leaves of the unprickly one are often used 

 as greens or eaten as salad. In corn-fields 

 which lie fallow for a year and in the un- 

 seeded shock rows of corn stubble wheat- 

 fields they are often abundant. Remedies : 

 cutting or pulling before the seeds ripen ; 

 burning mature plants. 



In England the common sow-thistle is 

 Fig. 106. (After Miiispaugh.) known as "hare's lettuce" or "hare's 

 palace" from the shelter it is supposed to afford that animal as, 

 "if the hare come under it he is sure that no beast can touch hym." 

 Another superstitution is: "When hares are overcome with heat 

 they eat of an herb called hare's lettuce, and there is no disease in 

 this beast the cure whereof she does not seek for in this herb." 



The perennial sow-thistle (S. arvensis L.) has not yet been re- 

 corded from Indiana, but is one of the worst weeds of Ontario and 

 some of the eastern States, and occurs in northern Ohio. It has the 

 bracts of the involucre glandular-hairy, the heads of flowers larger 

 and brighter yellow and spreads by deep running rootstocks as 

 well as by seeds. Remedies : deep cutting or digging ; crowding 

 out with clover; sheep-grazing. 



V 

 111. Lactuca scariola L. Prickly Lettuce. Milk Thistle. (A. I. 1.) 



Stem stiff, leafy, glabrous, usually much branched. 2-G feet high ; 

 leaves oblong or lanceolate, toothed or deeply cut-lobed. sessile or clasp- 

 ing, their margins and midribs strongly prickly, the lowest sometimes 10 

 inches long and 3 inches wide, upper much smaller. Heads J inch broad, 

 very numerous in a broad open panicle; flowers G-12, yellow; involucre 

 eylindrie. its outer bracts $ the length of inner. Achenes flattened, brown, 

 oblong, widening upward then suddenly contracting into a narrow neck. 

 ribbed lengthwise, ,', inch long; pappus of line soft while hairs. 



Abundant in waste places along railways, streets, alleys and 

 roadsides; also in old fields and gardens. June-Sept. From the 

 sow-thistles this and other forms of wild lettuce are separated 

 by having the upper end of the achenes or seeds tapering or beaked, 

 whereas in the sow-thistles they are truncate or squared off. The 

 prickly lettuce, like the majority of our vile weeds, came to us 



