84: REPORT OF THE COMMISSIONER OF AGRICULTURE. 



flowered, eacli flower being on a short, slender pedicel, or stem, which 

 bends backward at maturity. Each flower lias a long-toothed calvx 

 about half as long as the corolla, which is white, tinged with purple. 

 This species is found in rich, open Avood-lands and in jDrairies in Ohio, 

 Illinois, Kentucky, and westward. It is smaller in size and less vig- 

 orous in growth than the common red clover. (Plate IV.) 



Trifolium CaroUnanum (Southern clover). 

 A small perennial clover, having much resemblance to the common 

 white jlover. It usually grovv'S from G to 10 inches high, somewhat 

 pubescent, the stems slender, procumbent, and branching. The leaves 

 are trifoliate, on petioles of variable length. The leaflets are about 

 half an inch long, obovate, wedge-shaped at base, and somewhat 

 notched at the summit. The stipules are nearly as long as the leaf- 

 lets, ovate or lanceolate, and slightly toothed above. Each stalk has 

 usually two long-stalked heads, proceeding from the upper joints. 

 The roimdish heads are from one-half to three-fourths of an inch in 

 diameter, without an involucre, and with numerous crowded, small 

 flowers on slender pedicels, which become reflexed in age. The long 

 lanceolate teeth of the calyx are slightly shorter than the small, 

 purj)lish, pointed corolla. The pods are usually four-seeded. This 

 species occurs in all the Southern States and in Te:jtas. It is too small 

 to be valuable for fodder, but is worthy of trial as a constituent of 

 pastures in the South. (Plate Y. ) 



WEEDS OF AGRICULTURE. 



The majority of our most troublesome weeds are plants introduced 

 from other countries. As a locality becomes cleared wp and brought 

 into cultivation the character of the spontaneous vegetation always 

 undergoes marked changes. Many of the native plants disappear, 

 others become more abundant, and new plants introduced from for- 

 eign countries, or other parts of the same country, frequently become 

 the prevailing vegetation. 



Owing to the conditions of modern commerce and the natural pro- 

 vision for their distribution it is practically impossible to long ex- 

 clude outside weeds from any considerable district. _ The weedlaws 

 of various States have done much to call the attention of agricult- 

 urists to the most troublesome weeds, and have in many cases re- 

 tarded their introduction and distribution, but it is not to be ex- 

 pected that through any agency our worst weeds will become so sub- 

 dued as to require no further attention. An account like this can 

 only furnish the means of recognizing some of the more pernicious 

 ones, and give some account of their origin and methods_ of propaga- 

 tion, with suggestions for keeping them in check or eradicating them 

 for a time. 



If the plants troublesome in cultivated crops were only such as 

 were always and everyvv^here recognized as weeds, the question would 

 be much simpler. Unfortunately many of our worst weeds were 

 first introduced as useful plants. A large number have escaped from 

 flower gardens, as Indian mallow, toad-flax, and daisy. j\Iany plants 

 are useful in one locality, but known only as weeds in another. 

 Cock's-foot (Pam'cum crus-galU) is a coarse grass, very troublesome 

 in gardens in many Northern States, but in the South it is a valu- 

 able fodder plant. Besides these, there are plants of common culti- 

 vation which act as weeds, and are difficult to eradicate when it is 



