430 Amaranthaceae Acnida 



5. Amaranthus blitoides Wats. Prostrate Amaranth. Map 882. 

 An infrequent to frequent weed throughout the state. It prefers a moist 

 soil and is most frequently found on the muddy slopes of banks and gravelly 

 liars of streams, in cultivated fields and waste places, and along roadsides 

 and railroads. 



Minn, to Mo. and Tex. and westw. ; established in e. U. S., s. Canada, 

 and adventive in s. Eu. 



6. Amaranthus graecizans L. Tumbleweed. Map 883. An infrequent 

 weed throughout the state. It prefers a dry, sandy soil, hence is much 

 more frequent in the northern part of the state. It is most commonly 

 found in sandy waste places, gravel pits, and cultivated fields and along 

 roadsides and railroads. 



S. Canada, southw. through the U. S. to n. Mex. ; adventive in Eu., Asia, 

 Africa, and S. A. 



2300. ACNIDA L. Water Hemp 



Utricle circumscissile, verrucose all over; bracts longer than the utricle; staminate 

 flowers mostly 3.5-4 mm long, their sepals rigid, long-acuminate, the outer con- 

 spicuously longer than the inner, their bracts 2-3 mm long; plants erect, 5-16 dm 



high, mostly of a moist or dry, sandy habitat 1. A. tamariscina. 



Utricle irregularly dehiscent or indehiscent, smooth or verrucose mostly below the 

 middle; bracts shorter than the utricle; staminate flowers 2-2.5 mm long, their 

 sepals thin, acute, of nearly equal length, their bracts about 1-1.5 mm long; plants 

 erect, decumbent, or prostrate; mostly of a muddy habitat, such as muddy banks, 

 bars in streams, and dried-up ponds and sloughs. 

 Plants erect, mostly 4-12 dm high; leaves of an ovate or lanceolate type, hence 



broadest below the middle; seed about 0.8 mm wide 2. A. altissinut. 



Plants prostrate or decumbent; leaves obovate, spatulate or lanceolate; seed mostly 

 1-1.2 mm wide 3.-4. subnuda. 



1. Acnida tamariscina (Nutt.) Wood. Map 884. I found this species 

 in 1919 and 1921 to be common in sandy soil about a half mile east of 

 Lyle, Gibson County, along the roadside and in adjacent cornfields. I found 

 it also as a common plant, 4-6 feet high, in a roadside ditch 4 miles south 

 of Johnsonville, Warren County. This location is in the prairie area of the 

 state. I have also a specimen collected by Umbach in ballast near Miller, 

 Lake County. From what I can learn of the habitat of this species I think 

 it is a native of the western part of the state. Blatchley says he found it to 

 be common along the Wabash River in Vigo County on gravel and sandy 

 banks which is the preferred and native habitat of the species. 



Ind. to S. Dak., southw. to Tex. 



2. Acnida altissima Riddell. (Acnida tnberculata Moq.) (See North 

 Amer. Flora 21 : 122. 1917.) Map 885. Infrequent to common in all parts 

 of the state on the muddy banks and bars of streams, on the borders of 

 ponds and sloughs, in ditches and dried-up ponds and sloughs, and in 

 moist, alluvial cornfields along streams. This is strictly a low ground 

 species and is very common on the muddy slope of the bank of the Ohio 

 River. 



Ont. to Colo., southw. to Ky. and Mo. 



