CLOVER 



CLOVER 



233 



acidity. Lack of the nitrogen-gathering bacteria 

 may sometimes, be a cause. Inoculation of soils 

 with artificial cultures has been tried, but not with 

 uniform or very important results, although the 

 nitragin culture has given promising returns in 

 Europe. Inoculation with soil from an inoculated 

 field has given good results in this country, and its 

 value seems to be fully demonstrated. 



Group I. The forage clovers. 



(1) Red clover, medium red 

 clover (Trifolium pratense, 

 Linn.) Fig. 333, is one of the 

 most important of hay plants. 

 It is variable in size, 

 habit and other charac- 

 teristics, suggesting 

 that it offers a promis- 

 ing field for the plant- 

 breeder. It is usually perennial, 

 although tending to run out 

 after the third year, and some- 

 times even after the second 

 year. It is a spreading, hairy 

 plant, bearing purplish (or 

 sometimes rarely white) heads 

 on the summits of branching, ■ 

 leafy stems, the upper leaf be- 

 ing nearly or quite sessile and 

 borne close under the head; 

 leaflets oval or oblong-ovate, 

 sometimes notched at the end, 

 very short - stalked, marked 

 with a prominent whitish spot. 



The perennial, mammoth, or 

 pea - vine red clover (var. 

 perenne) has less tendency to die 

 out after the second year, is of 

 taller and stouter growth than 

 the common red, the flower-head somewhat stalked, 

 the plant bearing mostly larger and darker heads 

 and maturing later. This is the most valuable 

 of the cultivated red clovers. It is the plant com- 

 monly known as Trifolium medium, and is des- 

 ignated by Thomas Shaw as T. magnum. By some 

 it has been considered to be the result of crossing 

 between T. pratense and the true T. medium. The 

 botanical or descriptive characters that are usually 

 employed to separate the mammoth clover (var. 

 •perenne) from the common or medium red {T. pra- 

 tense) are of small diagnostic value. The chief dis- 

 tinction seems to lie in the perennial character, 

 the larger size and the later maturity. 



The zigzag or cow clover (the true Trifolium 

 medium, Linn.) seems not to be in cultivation in 

 this country. Stems- usually flexuose or zigzag; 

 leaflets and stipules narrow, usually elliptical, not 

 spotted, the edges entire or slightly toothed toward 

 the base ; heads standing one or two inches above 

 the upper leaf, globular to oblong. There are no 

 important and constant botanical differences be- 

 tween T. medium and the forms of T. pratense. The 

 chief distinguishing marks of T. medium are the 

 always more or less peduncled heads (only infre- 

 quently peduncled in T. pratense), more oblong 



Fig. 333. Red clover. 



heads with brighter-colored flowers, the narrower 

 stipules and leaflets. The perennial form of T. pra- 

 tense, or mammoth clover, is apparently a different 

 plant ; the name perenne has been applied to it in 

 popular writings, but the name has no technical 

 botanical standing. 



The Orel clover (T. pratense \ar. foliosum. Brand) 

 is a hairless form introduced from Russia. It 

 "is distinguished by the dustlessness of its hay, 

 due to almost complete absence of hairiness from 

 all parts of the plant, by its heavy yields for the 

 first crop, by its leafiness and the persistence of 

 the basal leaves, by the succulence of the stems, 

 which improves greatly the quality of the hay and 

 reduces the waste due to woody uneatable por- 

 tions, by greater palatability than hay from domes- 

 tic seed, and by the fact that it comes to proper 

 maturity for harvesting from ten days to two 

 weeks later than the ordinary American red clover " 

 [Charles J. Brand, Bulletin No. 95, Bureau of Plant 

 Industry, United States Department of Agriculture, 

 1906]. The plants are more upright than those of 

 the common red clover and branch more freely ; 

 the spots are sometimes absent from the leaves ; 

 the fiower-heads are smaller and less 

 compact and tend to be more elongated. 

 It seems to be perennial. This new clover 

 has been tested in a number of places in 

 the United States and 

 Canada with promising 

 results. It is recom- 

 mended as a supplement 

 to common red clover. It 

 is thought that it may 

 profitably supplant com- 

 mon red clover "where 

 the best methods of man- 

 agement indicate that 

 only one crop, either of 

 hay or seed and a light 

 aftermath, or some good 

 pasturage can be advan- 

 tageously expected from 

 clover - fields " because 

 of its "extraordinarily 

 heavy first crop and the 

 free seeding capacity." 



The succeeding arti- 

 cles on Clover, by Smith 

 and Wing, together with 

 the discussion under 

 Meadows and under 

 Green-manures in Vol. I, 

 will sufficiently explain 

 the uses and culture of 

 the red clovers. 

 Alsike or Swedish clover (T. hybridum, Linn.) 

 (Fig. 335) is a tall-growing, slender-stemmed per- 

 ennial clover with small whitish or rose-colored 

 heads ; the leaves are long-stalked, the leafiets 

 obovate and serrulate. The alsike is readily dis- 

 tinguished from the white clover by its forking 

 stalks (the flower-stems not rising directly from 

 the ground) and the pinkish heads (which are 

 usually white toward the top). One of the best 



Fig. 334. Manunotli oi per- 

 ennial clorer (.Trifolium 

 pratense, var. perenne). 



