DESCRIPTIVE MANUAL 283 



flowers white in small, umbel-like, drooping, lateral clusters; calyx 

 spreading, the lobes obtuse, much shorter than the white corolla; 

 berries glabrous, globose, black; occasionally large. 



Distribution. — Found in northern United States; abundant 

 everywhere in Iowa in shady grounds and fields. A cosmopolitan 

 weed. 



Horse Nettle (Solanum carolinense L.). 



Description. — A deep-rooting perennial, propagating freely by 

 its underground root-stocks, the running roots often being 3 ft. 

 long; stem 1-2 ft. high, somewhat straggling, half shrubby at the 

 base; stem hairy or merely roughish with minute hairs which are 

 star-shaped, also armed with numerous stout, subulate, yellowish 

 prickles ; leaves oblong or sometimes ovate, 'obtusely sinuate-toothed 

 or lobed, or deeply cut, 2-4 in. long; flowers borne in one-sided 

 racemes ; calyx consists of slender lobes, corolla light blue or white, 

 an inch or less in diameter; flowers followed by yellow globose ber- 

 ries a /2-%' in. in diameter; small yellowish seeds, a little less than 

 V 12 in. long, minutely roughened. Flowers and yellow berries 

 resemble those of the potato. The spiny character of the leaves and 

 the further resemblance of the flower to the potato should render 

 it easy of. detection. 



Distribution. — Horse nettle is indigenous to the southern states, 

 but now occurs from Connecticut to northern Iowa. This weed 

 is most abundant in southern' Iowa and has been reported from 

 Floyd, Story, Boone and Linn counties ; in the north half of the 

 state, however, it is a recent introduction. 



Extermination. — There are two methods of propagation; one by 

 seeds, the other by perennial roots. It is so exceedingly tenacious 

 a weed, that it is almost impossible to remove it when fully estab- 

 lished. The following very suggestive methods have been given. 



Smothering. This is an effective method of removing the plant. 

 For this purpose probably rape or sorghum is the most suitable 

 crop. If the soil is not already rich, a liberal dressing of barnyard 

 manure should be applied during the winter or spring. The soil 

 should be harrowed or cultivated frequently until the time of seed- 

 ing, which may be any time during the months of May or June. 

 This cultivation will prevent the weed growth, and will also assist 



