HORTUS GRAMINEUS WOBURNENSIS. 267 



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

 siliceous sandy soil is 



Produce per Acre, 

 dr. qr. ' Ibs. 



Grass, 14 oz. The produce per acre 9528 12 



80 dr. of grass weigh, when dry 24 7 9050 IA r\ 



The produce of the space, ditto 67 OJ 3 



The weight lost by the produce of one acre in drying is 6670 2 

 64 dr. of grass afford of nutritive matter 127 093 * 4 

 The produce of the space, ditto 513 



This grass is found on walls and dry barren places. As soon as 

 the seeds are ripe they fall out of the husks, and vegetate quickly 

 after without any covering of earth ; the plants are of the finest 

 green colour, which they retain during the winter. This circum- 

 stance seems to have led some to suppose it a biennial or two-year- 

 lived plant. The seeds being numerous, the young plants form a 

 turf of the most beautiful dark green colour; in this respect sur- 

 passing every other grass. As soon as the weather is sufficiently 

 warm in the spring for the growth of grasses in general, this 

 property declines, and before the period of coming into flower, it is 

 invariably attacked with the rust disease : which renders its produce 

 of little value, were it even afforded in sufficient quantity to induce 

 its propagation. 



The above details shew the whole produce of one year, which 

 is very inconsiderable. The chief effort of annual plants is to 

 perfect their seed ; when cut before the time of flowering, and at 

 any time before the seed be perfected, the roots push up fresh 

 shoots, which flower and perfect seed in a much less space of time 

 than the primary culms that are previously taken away. If the 

 first shoots are suffered to remain, the secondary or dwarf shoots 

 seldom appear : unless when a continuance of dry weather is suc- 

 ceeded by much rain during the time of inflorescence, which gives 

 a new impulse to the vegetative powers. Hence, in attempts to 

 eradicate these unprofitable annual grasses from pastures, by 

 mowing them before they perfect their seed (to which only they 

 owe their continuance of existence), it is absolutely necessary that 

 the mowing should be often repeated during the season, otherwise 

 the intention will be completely frustrated. 



It flowers in the first week of July, and the seed is ripe about the 

 last of the same month. Birds appear to be very fond of the 

 seed. 



