i02 OF THE PERICHJETIUM 



Arista^/. 149, Beard or Awn, a bristle -shaped appen- 

 dage, usually spiral, and possessing the property of 

 an hygrometer. This, however, is not always pres- 

 ent, even in different individuals of the same species. 



" Unfortunately for the science, 

 On the awn there's no reliance." 



So says, or rather sings, with more truth than sub- 

 limity, the ingenious author of the Flora Loiidmensisj 

 fasc. 6, ?. 8. 



The spiral kind of awn is most frequently attached 

 to the Coroll of grasses, which is precisely of the same 

 husky nature as their calyx, and is, by some bota- 

 nists, considered as such. Specimens o? glumce muti- 

 cce^ beardless husks, are seen in Phalaris canariensis, 

 Engl. Bot. t. 1310, and glumes aristatcs^ awned ones, 

 in Lagurus ovatuSy t, 1334, and Stipa pennata^ t, 

 1356. 



6. Perichcetium, f. 150. A scaly Sheath, investing the 

 fertile flower, and consequently the base of the fruit- 

 stalk, in some Mosses. In the genus Hypnum it is 

 of great consequence, not only by its presence, con- 

 stituting a part of the generic character, but by its 

 differences in shape, proportion, and structure, serving 

 frequently to discriminate species. See Engl. Bot. t. 

 1037 — 9, 1182, 1445 — 8, &:c. ; see also the same 

 part in Neckera, t. 1443, 4. Linnaeus appears by his 

 manuscripts to have intended adding this to the different 

 kinds of calyx, though it is not one of the seven enu- 

 merated in his printed works. Nor is he, surely, cor- 

 rect in allowing it to the genus Jungermannia. The 



