tfHE FLOKAL ENVELOPES PEBIANTH. 



117 



forked at the top, and often with two distinct principal ribs ; hence it 

 is regarded as composed of two confluent scales. This is called the palea 

 or the inner palea. These scales often bear a projecting bristle (awn, 



Fig. 215. 



Fig-. 216. 



Fig. 214. 



Fig. 214. Naked flower of the Ash (Fraxinus excelsior). 

 Fig. 215. Flower of the Elm ( Ulmus), with a regular 5-toothed perianth. 

 Fig. 216. Involucre or young cupule of the Chestnut (Castanea vesca), with two female 

 flowers, each having a regular perianth. 



arista) at the top or on the back (fig. 218, >*). Within the pale (fig. 219) 

 occur two or in some Grasses three-little hypogynous scales (lodiculce, #, rr), 

 corresponding to petals ; and to them succeed the stamens and pistil. 



Fig. 217. 



Fig. 218. 



Fig. 217. Spikelet of the Oat : a, a, glumes ; 5, 6, the flowering glumes or outer pales of the 

 two florets. 



Fig. 218. One floret detached and opened: 6, the outer pale (with an awn &*) ; 5', the inner pale. 



Fig. 219. The same, magnified, with the outer pale removed : b, the inner (double) pale ; x, at, 

 the lodiculce or hypogynous scales representing the petals, within which are the 

 three stamens and the ovary, with its double feathered stigma. 



The hypogynous scales are three in number in Stipa, restoring the sym- 

 metry. The upper glume is sometimes abortive, as in Lolium, while in 

 Nard-us both are absent. In Alopecurus only one pale is developed. The 

 spikelet often contains one or more imperfect flowers. 



The perianth of Cyperaceae, where it exists, presents a still simpler 



