4§0 -" WEED FLORA OB" lOWA : 



Common Mallow {Malva roiundifoUa L.). 



Commonly called cheesed. Carpels arranged about a center, flat, 

 bealjless, indehiscent ; each carpel a single seed, kidney- shaped, one-' 

 si?;teenth, to on6-twelfth in. /in diameter, flattened, with a prominent 



Fig. 322. Common Mallow (.Malva rotundifoUa) . A, two seeds in side view. 

 B, a seed retained by a carpel of the seed-vessel. C, a seed in cross section 

 taken midway between the Scar and the opposite edge. D, seeds, showing 

 !■ the natural size. 

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



notch at base; seeds brownish or gray, minutely granular; sear 

 small, frequently containing spongy tissue; embryo curved; small 

 am<5lint of en^ospenp. Reported in alfalfa and red clover seed. 



/ Bladder Ketmia {Hibiscus trionum L.). •"—- 



Qa,psule 5-valved, globose-ovoid, hairy; seeds kidney-sihaped,' one- 

 fifteenth in. in length, blackened, roughened by short tubercular 

 processes, minutely granular; basal end of seed of much smaller 

 diameter; scar brownish; funicle extending to the notch. 



ONAGRACEAE, EVENING PRIMROSE FAMILY. 



-aoo r,:r.'t ?:i:- , : - " ■-, r'^r-. 



*" '.:■"■:: ;- Evening Primrose {Oenothera iiennisli.). 



1 T q : i T r" 



Seeds prismatic, 4 or 5-sided, sometimes curved, variable, one- 

 sixteenth in. in length, slightly wing-margined, rugose, brown, scar 

 indistinct at- due end, embryo straight. 



■■ UMBELLIFpRAE, PARSLEY FAMILY. 



Water Hemlock {Cicuta maculata L.). 



Fruit ovate to oval, curved or nearly straight, one-eighth in. in 

 length, smooth, with longitudinal brown and straw-colored lines; 

 apex widened with 2 styles; ribs corky; oil-tubes solitary, in the 

 intervals. 



