66 



THE INDIANA WEED BOOK. 



angular dark spot near the center. Spikes solitary or in panicles, pink 

 or dark purple, 1-2 inches long, oblong, dense-flowered, erect on smooth 

 stems. Seeds heart-shaped or triangular, black, smooth, shining, 1/12 

 inch long. 



Common in gardens, barnyards, waste places and cultivated, 

 fields, especially those of moist clover-lands. June-Oct. The name 

 lady's thumb is given it on account of the dense oblong reddish 

 spikes. According to Dr. S. A. Forbes it harbors the corn-root 

 aphis, the louse appearing with the first leaves of the plant. Rem- 

 edies, same as for the preceding. 



21. POLYGONUM HYDROPIPER L. Common Smartweed. Water-pepper. (A. 

 I. 2.) 



Stem erect, slender, simple 

 or branched, often red or red- 

 dish, 8-24 inches high ; leaves 

 lanceolate, 1-4 inches long, 

 marked with pellucid punctures. 

 Spikes slender, weak, drooping, 

 1-3 inches long; flowers scat- 

 tered, greenish-white ; stamens 

 4 or 6. Seeds either lens-shaped 

 or 3-angled, oblong, opaque or 

 dull not shining, J inch long. 

 (Fi'g. 33.) 



Abundant in dooryards, 

 barnyards, upland as well as 

 lowland cultivated fields, 

 ditches and borders of ponds. 

 June-Oct. The leaves are 

 very acrid and the juice 

 when applied to the skin 

 sometimes causes blisters or 

 ulcers. Remedies : pulling or 

 mowing ; thorough cultiva- 

 tion. 



The mild water-pepper (P. hydropiperoides Michx.), a peren- 

 nial having the leaves narrower, not punctate, the stamens 8 and 

 the seed shining, is often found with the preceding, while the 

 swamp smartweed (P. emersum Michx.), also a perennial with 

 much broader leaves and only 1 or 2 spikes of flowers, is common 

 in moist lowlands. Altogether 12 species of true smartweeds are 

 known from the State, but the five mentioned are the more widely 

 distributed and the ones likely to be most troublesome. 



Fig. 33. Showing the flower and the fruit with cross- 

 sections of latter. (After Small.) 



