42 A NEW TYPE OF EED CLOVER. 



texture, and g;labroiis throughout except at the apex, which is some- 

 times tipped with a few slender hairs. In the American form the 

 under side and margin of these bracts are covered with many fine 

 hairs. 



The stipules also show some constant dissimilarities. On plants 

 of equal age the stipules of the American strains are larger, hairy on 

 the back, margins, and tip, and in the cured hay are harsh and woody; 

 in the Orel clover they are smaller, of finer texture, much less prom- 

 inently veined, and hairless except at the tip, where there is usually 

 a tuft of hairs. According to a comparison of a large number of 

 measurements of the stipules and petioles of the basal leaves of both 

 forms, although the stipules of Xo. 16 are shorter, the petioles are 

 longer. In the former the stipules constitute about 8 per cent of 

 the total length; in the latter, about 15 per cent. The average length 

 of the stipules in both No. 16 and the American forms was found to 

 be 22 mm. and 24 mm., respectively, and of the petioles 270 mm. 

 and 160 mm., respectively. The same proportion was not found to 

 hold true in regard to the leaves of flower-bearing stems. In these, 

 both the stipules and petioles, comparing similar parts of plants of 

 about equal development, are shorter in the hairless form. The 

 average lengths of stipules and petioles in the latter are 20 mm. and 

 104 mm., while in the domestic form they are 22 mm. and 114 mm., 

 respectively. (See PL II, fig. 1.) 



The calyx of the smooth clover is sparingly covered with short, 

 appressed hairs, while in the hairy American form it is densely cov- 

 ered with more erect hairs, which are in general from Ih to 2^ times 

 longer. The calyx in both forms is five-toothed, one tooth being 

 considerably longer than the other four. In the American form the 

 long tooth appears to be always more than twice as long as the four 

 short ones, which are of about ecpial length, while in the variety 

 foliosum the long tooth seems never to be as much as twice as long 

 as the others. 



The few hairs that occur on the Orel clover, no matter upon what 

 portion of the plant they are found, are comparatively very short 

 and always appressed to the part bearing them, jwhile in the domestic 

 clover they are numerous, in young plants matted (see PI. II, fig. 2), 

 and extend at right angles from the organ on which they are borne. 



LATER OBSERVATIONS. 



Notes taken during May and June of 1906 on the plats in Nebraska 

 and North Dakota, now in their third year, tend to confirm the obser- 

 vations recorded for all stations during the growing season of 1905. 

 In only one case was the seed production of clover No. 16 satisfactory 

 under the method of taking two full crops. This was in southern 

 Indiana, where its yield was fully up to the average for other varieties. 



95 



