recently discovered in Scotland hy Mr. George Don. .335 



is perhaps the only mode with respect to grasses. This is by an 

 absolute transmutation, more or less complete, of the glumes of 

 the corolla into leaves. That such is the case, is evident, not 

 only from the change being mostly incomplete, part of the glume 

 retaining its natural state, but also from the awn terminatin<i- the 

 newly-formed leaf. Indeed it often seems as if the lower part 

 only of the awn itself had become leaf, the glume which bears 

 it remaining unchanged. The gay petals of a tulip often become 

 in part or entirely leaves. Why may not this happen to a gr.iss ? 

 It seems that the organs of impregnation are starved and obli- 

 terated in such viviparous florets of this Aira, and not as some 

 have supposed concerning other alpine viviparous grasses, that 

 those parts arc themselves transformed mio -a gemma, or leaf-bud ; 

 still less is the leafy appearance caused by the seeds vegetatin"- 

 in their husks, as Lightfoot thought of Poa alpina, and periiapt 

 Festuca vivipara. it is possible indeed that the stamens, and 

 even pistil, of all such grasses may be capable of change into 

 leaves, as well as the corolla, though I have not found \t so in 

 this Aira. 



2. AvENA alpina*, 



paniculd erectd subsimplici, calycibus subquinquefloris, recep- 

 taculis apice barbatis, foliis serrulatis nudis ; vaginis scabris. 



Discovered in 1807, on rocks upon the summits of the highest 

 mountains of Clova, Angusshirc, It is perennial, flowering in June. 



This is a very fine species ofAvcna, and, as far as I can discover, 

 perfectly new. I was inclined to refer it to ptibesce7is, with which 

 it most agrees in general aspect, but is larger in every part, and 



*Avena plankulmis. Engl. Bot. t. 2141, and as I presume of Schrader's Ft. Germ. 

 t/. 1. 381. t. 6./. 2 ; but Mr. G. Don thinks otherwise, and denies the flatness of the 

 stem in his plant. 



2x2 Mr. 



