498 



WE3ED FLORA OF IOWA 



Pig.376A rig.376Al Fig. 376B Fig. 376C 



Fig. 376. Seeds of Picria and Tragopogon. A and Al. Bristly Ox-tongue 

 (Picris ecMoides). B. Oyster Plant (.Tragopogon porrifolius) ; a, achenes 

 enlarged, b, achenes natural size. 



C. Meadow Salsify (.Tragopogon pratensis). 



(A, drawings by L. R. Collins ; B, after Hillman, Bull. Mich. Agr. Exp. Sta. ; 



C, drawing by C. M. King.) 



Dark-seeded Dandelion {Taraxacum erythrospermum Andrz.). 



Achenes one-sixth to one-fifth in. long; lance-shaped, or spindle- 

 shaped, 5 longitudinal ridges, upper end with rough tubercles, per- 

 sistent long beak about two-fifths in. long, brownish, somewhat 

 pointed, prominently ribbed ; pappus of numerous capillary, fragile, 

 white bristles ; color reddish ; toothed at apex ; beak and pappus both 

 shorter; achenes more prominently tubercled than in T. officinale. 



m 



a * A 



Fig. 377A Fig. 377B 



Fig. 377. Dandelion seeds. A, Red Seeded Dandelion (.Taraxacum erythroa- 

 perrmim') ; a, seed enlarged, b and c, seed, natural size, c, with pappus. 

 Common Dandelion (Taraxa^cum officinale). A, an enlarged view of one 

 of the two similar faces of an achene, in which no attempt Is made to show 

 the minute surface-scales which are not evident under the ordinary lens. 

 B, a group of seeds, natural size, b, one bearing the beak and pappus. C. 

 a group showing common variation in the form of the achenes. 



(After Hillman: A, Bull. Mich. Agr. Exp. Sta.; B, Bull. Nev. Agr. Exp. Sta.) 



B. 



