HORTUS GRAMINEUS WOBURNENSIS. 365 



The clavus often attacks the seed of this species, though not 

 so generally as to prevent it from perfecting a sufficiency, if the 

 value of the grass required its propagation on the farm. The dis- 

 ease termed clavus makes its appearance by the body of the seed 

 swelling to three times its usual size, and the want of the corcle. 

 Dr. Willdenow describes two distinct species of it : first, the simple 

 clavus, which is mealy, and of a dark colour, without any smell 

 or taste ; second, the malignant clavus, which is violet blue or 

 blackish, and internally too has a bluish colour, a foetid smell, and 

 a sharp pungent taste. The first is the disease which attacks the 

 grass now spoken of. Bread made from grain affected with the 

 last variety of the disease, or malignant clavus, is of a bluish 

 colour, and when eaten produces cramps and giddiness. 



Flowers about the first and second weeks of July, and ripens 

 the seed in three weeks afterwards. 



ELYMUS Pkiladelphicus. Philadelphian Lyme-grass. 



Specific character : Spike pendulous, open ; spikelets villose, 

 6-flowered, the lower ones ternate. (Linn.) ; Hort. Kew. i. 176. 



Obs. Culm from two to five feet high, smooth, round, of a 

 light green or glaucous colour. Leaves broad, mucronate, 

 slightly rough, glaucous, spikelets in pairs ; awns of the 

 calyx or involucre shorter than those of the florets. Hort. 

 Gram. Fol. 261. 



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



clayey loam and retentive subsoil is 



Produce per Acre, 

 dr. qr. Ibs. 



Grass, 45 oz. The produce per acre - 30628 2 



80 dr. of grass weigh, when dry - 40 7 iroi^ i r> 

 The produce of the space, ditto - 360 3 



The weight lost by the produce of one acre in drying 15314 1 



64 dr. of grass afford of nutritive matter 417 9033 14 6 

 The produce of the space, ditto 47 3| $ 



In the Hortus Kewensis we are informed, this grass was first in- 

 troduced into England by the Right Hon. Sir J. Banks, Bart., K.B., 

 in 1790, from North America. It is a very productive grass, and 

 with respect to foliage, is rather early in the spring : it contains a 

 considerable quantity of nutritive matter. From the large size it 

 attains, the produce is rank and proportionally coarse, and is unfit 

 for pasture. It appears that for soiling, or hay to be used in the 



