152 CLASSIFICATION OF [CH. 



"Yorkshire Fog," of little vise or importance, except that it is 

 frequently found as an impurity of other hairy grasses — e.g. Alope- 

 curus. 



It cannot easily be confounded with any other grass : Antho- 

 xanthum and Alopecurus, Arrhenatherum, &c. present superficial 

 resemblances only. 



These glumed hairy " seeds '' are uncommon and form an easily 

 recognised type. 



Fig. 65. Holcus lanatus. a, "seed" — i.e. complete spikelet — and ditto 

 deToid of glumes, nat. size; 6, spikelet, and c the same devoid of 

 glumes, X 7. The "seed" is here composed of the keeled glumes 

 enclosing two pairs of pales and their flowers (c) : the upper of 

 these is barren and has a hooked sub-terminal awn to its outer palea. 

 The lower awnless one is fertile. Nobbe. 



Holcus lanatus, L. (Fig. 65). 



The "seed" consists of the complete spikelet, separated 

 below the compressed and acute, keeled glumes; these 

 have hairs on the keel, and completely enclose the two 

 flowers and their palese. Palea ribless, white to gi'ej'^, 

 shining, obtuse, that of the upper (male) flower with a 

 sub-terminal short hook-like awn. Total length about 

 4 — 5 mm. Caryopsis oblong-ovate, grooved. In its 

 palea about 2 — 3 mm. long and with a few hairs at the 

 base. 



