84 



utter worthlessness of such characters of distinction being employed in 

 the arrangement of the plants before us. 



The authors of the 'British Flora,' remark, under P. compressa, that 

 its flowers are " by no means always connected by a web ; in French 

 and North American specimens, and in those from this country, there 

 is often not the least trace of one, yet they are not otherwise distin- 

 guishable. In a (the normal form) there are usually only three veins 

 to the outer palea, all of them silky ; but an intermediate pair may be 

 occasionally detected, and this constitutes P. suhcomjpressa, Parnell. 

 In 5 (P. polynoda, Parnell) we have always observed five veins, of 

 which sometimes the two lateral ones and the midvein are silky, some- 

 times only the former ; sometimes all are naked." 



F. polynoda was first observed by Dr. ParneU, growing in small 

 patches on rather dry stony soil, in the vicinity of Edinburgh, where 

 it comes into flower about the last week in June, and ripens its seed 

 towards the close of July. Plants reared from seed retained the cha; 

 racters of the original, differing only from the wild state in the in- 

 creased size of the panicle. According to the account of its discoverer, 

 the learned author of the ' Grasses of Britain,' it does not appear to be 

 liked by cattle, " the leaves being always found entire, while the 

 surrounding foliage of other grasses was cropped close to the ground. 

 This is probably owing to the large quantity of silicious matter con- 

 tained in the sheaths and stems, which is considerably greater than 

 that found in other grasses, rendering the herbage hard and disagree- 

 able to the mouths of cattle. When dry, it might form a substitute for 

 fine sand-paper, and prove valuable to turners for polishing wood. 

 The minute granular surface can be very perceptibly, though disagree- 

 ably, felt by drawing the stem through the teeth." 



The circumstances above detailed may result from pecidiarity of 

 habitat, or may be really indicative of distinction as a species. At 

 present I incline to the former view, and to the belief that Foa 

 pratensts is not alone the type, but the origin of all the supposed 

 species of its section — in other words, of all the stoloniferous forms of 

 the genus as it is at present circumscribed. 



Genus 29. SCLEEOCHLOA. Hard Grass. 



Gen. Char. Inflorescence paniculate, generally more or less compact. 

 Spikelets many-flowered, rarely three- or four-flowered only. 

 Glumes two, unequal, acute, membranaceous. Palese two, mem- 

 branaceous; the lower one five-veined, cylindrical below, often 

 keeled at the tip, or terminating with a very minute mucro. 



A genus established by Palisot de Beau vols. The species, origin- 

 ally included in Foa, are grasses of little value, unless as colonists 

 vegetatmg almost exclusively on sandy sea-shores ; a few grow in 

 salt marshes occasionaUy overflowed at spring-tides, others inland 

 on walls or rocks, or in very dry, barren ground, unfavourable to the 

 development of more nutritious herbage. 



