CONCERNING THE PAPPUS. 



93 



302 303 



Fig 802. A seed of the Cotton-plant, with its tuft of coma, or cotton. 



Fig. 803. A seed of the Cotton-tree {Populus)^ with its silky coma. 



Fig. 304. A winged seed of the Catalpa. 



Fig. 805. Achenium of Eclipta; it has no pappus. 



Fig. 806. Achenium of Horseweed ; scarcely any pappus. 



Fig. 807. Achenium of Sunflower; has two awns for pappus. 



Fig. 308. Achenium of Ageratum ; has five sepals for pappus. 



Fig. 309. Achenium of Blue Milkweed; has abundant pappus. 



Fig. 310. Achenium of Wild Lettuce ; with pappus raised on a beak 



188. The learner must distinguish between the coma of a 

 seed and the pappus of a fruit. Tlie down of Thistle or Dan- 

 delion hpa^us^ for the little fruit on which it grows is not 

 merely a seed, but a pericarp (achenium), also containing one 

 Beed. In a word, the seed may be fledged with a coma, but 

 %\\Q fruit is fledged with a pappus, both intended as wins^s 



.0 bear away the seed to distant places. 

 Dotany, § 485.) 



(See Class Book of 



188. What is the distinction between coma and pappus? 



