A SECOND OHIO WEED MANUAL. 



331 



148 Shepherd's=purse (A) *Bursa Bursa-pastoris (L.) Britton. This 

 illustration, Fig. 27, will enable one who does not already know this plant to 

 recognize it; the triangular or purse-shaped pods are unlike any other. Shep- 

 L %* herd's-purse as a winter annual is a trouble- 



some pest in gardens, orchards and vine- 

 yards, and in enriched cultivated lands 

 generally. It is freely attacked by the white 

 mold, Cystopus candidus (P) Lev., but no- 

 where destroyed. It also harbors on its roots 

 the fungus of club-root, Plasmodiophora 

 Brassicce Wor. 



Seeds light brown, oblong in outline, 

 1-20 inch long and half as wide, shown 

 natural size, and x6, a, b, Fig 27. They 

 may be looked for in hay and seeds. To 

 destroy shepherd's-purse one needs to be 

 diligent. For those situations where it is 

 most annoying some winter growth to crowd 

 it out, together with cultivation, seems the 

 best available method. Both red and crimson 

 clover are w T orth trying for this purpose 

 where rye can not be used. 



149 False Flax (A) *Camelina sativa 

 (L.) Crantz. False flax is appearing with in- 

 creasing frequency; the seeds are introduced 

 in clover seed. With recent importations of 

 Fig. 27. Shepherd's-purse. crimson clover seed from Europe, this seed 



has also been entered duty free. The plant has narrow, arrow-shaped leaves 

 and a very short, inversely egg-shaped pod. 



Seeds brown, 1-10 inch long and about half as wide; pitted-roughened, 

 occurring in clover, alfalfa and flax seeds. Its habits are the same as shepherd's 

 purse and peppergrass. The methods of destroying it are likewise similar. 



150=151 Whitlow=grass (A) -Draba vctna L. and Draba Caroli?iiana Walt. 

 These two winter annuals are often found forming dense masses and disfiguring 

 lawns. They require the same treatment as shep- 

 herd's-purse. 



152 Rock=cress (B) Arabis Iczvigata (Muhl.) 

 Poir. Rock-cress is a smooth, upright plant 

 with parti}' clasping, narrow leaves. It is often 

 found near the borders of woods and in dry semi- 

 woodlands. It is readily destroyed by cultivation. 



153 Spreading Mustard (A) ^Erysimum re- 

 pandum L. This mustard has small, narrow, 

 toothed leaves and an innocent look until seed 

 ripening approaches, when the seed pods spread 

 out and are jagged and obtrusive. (See Fig. 28) 

 It is a winter annual growing in wheat and 

 likewise as a summer annual in oats; with the 

 latter, the seeds cling in the slit of the grain and 

 at times cause horses to reject the oats; a pestifer- 

 ous weed identified for the writer by Lyster H. 

 Dewey. First introduced in clover seed at Zanes- 

 field, Logan county and latterly reported abundant 

 in Sandusky county by E. W. Roush of Lindsey,0. 



Fig. 28- Spreading- Mustaro 



