THE GENERAL CHARACTERS OF SEEDS 



431 



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A ••(. B 



Fig. 266. Pennsylvania Smartweed (Polygonum pennsylvanicum). A, a side 

 view of a seed (achene). B, one surrounded by the calyx; the opposite side 

 has two segments between those on the edges. C, a cross section of a 

 seed. D, seeds, natural size. 



(After HlUman, Bull. Nev. Agr. Exp. Sta.) 



Bushy Knotweed {Polygonum ramosissimum Mx.). 



Achenes sharply 3-angled, sides less deeply concave than in 

 P. aviculare, one-eighth in. in length; color blackish, dull; calyx 

 greeni&h, light straw-colored in dried specimens. 



Figure 267A 



Figure 267B 



Figure 267C 



Fig. 267. A. Pennsylvania Smartweed (.Polygonum pennsylvanicum.). B. Tan- 

 weed (Polygonum, muhlenbergii) . C. Bushy Knotweed (Polygonum ramos- 

 issimuTii ) . 



(A and B, drawings by Charlotte M. King; C, drawings by L. R. Collins.) 



CHENOPODIACEAE, GOOSEPOOT FAMILY. 



Cycloloma {Cycloloma atripUd folium (Spreng.) Coult.). 



Fruit enclosed by the calyx, lower surface prominently rayed, 

 upper surface depressed, wing-margined, one-tenth to one-eighth in. 

 in diameter; seed nearly spherical, somewhat flattened, one-twelfth 

 in. in diameter, blackish ; scar whitish ; embryo slender,, forming a 

 ring about the endosperm. 



Fig. 268. Cycloloma (Cyclolom,a atriplicifolium) . a, b, seed in envelope; 

 d, enlarged views ; e, seeds, natural size ; f, cross section. 

 (After Hillman, Bull. Mich. Agr. Exp. Sta.) 



