HORTUS GRAMINEUS WOBURNENSIS. 281 



From which it appears, that the produce of this grass, on a 

 heath soil, is superior to that on a clayey loam, in the proportion 

 of 2 to 1. An instance was brought forward under the subject 

 of Agrostis canina, where the Agrostis stolonifera produced, the 

 first year of sowing, one-third less of grass on a clayey soil than 

 on a sandy soil ; but in succeeding years, the produce from the 

 clayey loam tripled that from the sandy soil. With the zig-zag 

 hair-grass the case is directly the reverse, for the produce of the 

 clayey soil diminishes yearly, till the grass at length disappears 

 altogether. I mention this merely to shew the danger of drawing 

 hasty conclusions from the experience of one or two seasons 

 only. 



The Aira flexuosa is much more productive on its natural soil 

 than the Festuca ovina ; but it requires a deeper soil, though not a 

 richer. The Festuca ovina is more common among heath (Erica 

 vulgaris), the Aira flexuosa among furze (Ulex Europ&us), though 

 both grasses frequently grow intermixed on the same soil. To 

 those who attempt the improvement of such soils in a secondary 

 manner only, this species of hair-grass appears to be the best of 

 those grasses natural to the soils in question, and may form a 

 principal part of a mixture of seeds for that purpose of improve- 

 ment. 



Flowers in the first week of July. Seed ripens in August. 



POA cenisia. Soft Meadow-grass. 



Specific character: Panicle diffuse, nodding; spikelets oblong 

 5-7-flowered ; florets connected at the base by a villus ; 

 sheath-scale short ; root fibrous. Flo. Ger. 422. 



Obs. This grass holds a place between the Poa laxa and Poa 

 alpina. It differs from the first, to which it is nearest allied, 

 in the culms being twice the height, and roundish towards 

 the top; sheath-scale short; panicle diffuse, but always 

 contracted before and after flowering; spikelets larger, ob- 

 long 5-7-flowered. From the Poa alpina it differs also as 

 above, but chiefly in the panicle, which is nodding, spikelets 

 oblong, and florets free. 



German, Cenisisches-Rispengras. 



Native of Germany. Root perennial. Flo. Ger. ; Host. 3, 

 p. 11, t. 16. 



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

 sandy loam is . 



