Ill] VEGETATIVE CHARACTERS 49 



Lolium perenne, L. (Perennial Rye-grass). Very valu- 

 able pasture-grass, especially on clay. Less successful as 

 hay. Deep rooted tufts. Glossy dark green. Ligule short 

 (Fig. 11). Sheath red or purplish below. Blade con- 

 duplicate and keeled, often rounded, collared or eared 

 at the base ; with rounded ridges and rough above, 

 shining below. When the ears are well developed their 

 points often cross one over the other in front of the sheath. 



L. italicum, Braun. (Italian Rye-grass), is an earlier and 

 better variety for hay and sewage farms. Shoot more 

 rounded in section, and has less marked veins on the more 

 rolled leaf. 



L. temideutum, L. (Common Darnel), is annual and a 

 weed of corn-fields. Foliage usually rougher. 



Lolium perenne presents some difficulties in relation to such 

 forms as L. italicum, species of Agrostis and Festuca, Alopecwrus 

 pratensis, Cynosurus and Agropyrum. 



Owing to the leaves not being always strictly conduplicate in 

 the first year, the flat shoots may not sharply mark it off from 

 L. italicum. Its somewhat looser, almost stoloniferous tufts, and 

 darker green foliage, less polished below and usually narrower and 

 harder, have then to be taken into account. 



The ridges of Lolium are often like those of Festuca pratensis ; 

 and the shining lower smface and rather firm leaves and red sheaths, 

 present other points of confusion. The smooth basal margins of 

 Lolium, absence of white translucent lines when held up, and the 

 difterent ligule and ears afford distinctions — the ligule of Festuca 

 being a mere line, and the ears pointed and projecting, whereas 

 they may be mere lateral ledges in Lolium. 



Cynosurus has the ligule and ears very like those of LoUvm, the 

 ears being mere ledges ; but the former has yellow sheaths, firmer 

 and thicker leaves with more evident ridges, and the old plants 

 usually have the characteristic crested spikes remaining. Cynosurus, 

 moreover, has the sheath split only a short way down. 



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