HORTUS GRAMINEUS WOBURNENSIS. 355 



Obs. — The creeping roots terminate in jointed culms; fibrous 

 roots numerous. Culms very high, from three to six feet. 

 Leaves straight, broad, smooth on every part except the 

 edges and keel; sheaths a little compressed, striated, smooth; 

 scales short, obtuse. Panicle very large, upright ; branches 

 pressed towards the main stalk before and after flowering. 

 German, Wasser-Rispengras. 

 Native of Britain. Root perennial. 



Experiments. — At the time of flowering, the produce from a 

 strong tenacious clay is — 



Produce per Acre, 

 dr. qr. lbs. 



Grass, 186 oz. The produce per acre - - 126596 



80 dr. of grass weigh, when dry - 48 ^ 75957 12 

 The produce of the space, ditto - 1785 2-/^ S 

 The weight lost by the produce of one acre in drying 50638 

 64 dr. of grass afford of nutritive matter 2 2^ 4945 

 The produce of the space, ditto - 116 1 3 



At the time the seed is ripe, the produce is — 

 Grass, 180 oz. The produce per acre - 122512 



80 dr. of grass weigh, v^rhen dry - 40 ^ 612^6 



The produce of the space, ditto - 1440 3 



The weight lost by the produce of one acre in drying 61256 

 64 dr. of grass afford of nutritive matter 70 gr. "^ 44(1(1 

 The produce of the space, ditto - 3150 3 



The weight of nutritive matter which is lost by 



leaving the crop till the seed be ripe, is - 478 9 



At the time of flowering, therefore, the produce contains more 

 nutritive matter than at the time the seed is ripe, in the proportion 

 of 19 to 17. 



This grass is common on the banks of rivers, and frequent on 

 the margin of standing pools. On the banks and little islands of 

 the Thames, where it is generally mown twice in the year for hay, 

 it affords abundant crops of valuable winter fodder. Mr. Curtis 

 informs us, that in flat countries, which do not admit of being 

 sufficiently drained, it is almost the only grass for hay and pas- 

 turage. In the fens of Cambridgeshire, Lincolnshire, 8cc. immense 

 tracts that used to be overflowed and produce useless aquatic 

 plants, and still retain much moisture, though drained by mills, 

 are covered with this grass : which not only affords rich pasturage 



