OR APPENDAGES OP PLAN'TS. 



in Atractiflis cancclldta.,/. 1\[). Linnfeus 

 observes that no bracteas arc to be found 

 in the class Tctradjinamia. 



The ochrea of Rotlboll, JVllldenorv's 

 Principles of llotanij, ,50, which enfolds 

 ihe^ flower-stalks in Ci/perus, see Frngl. 

 Bot. t. 1309, seems to me a species oF 

 brae tea. 



;5. Spina,/. 120. A Thorn. This proceeds from 

 the wood itself, and is either terminal like 

 Ilippophae rhamnoidcs, Engl. Bot. t. 425, 

 IViannius catharticiis, t. l629; or late- 

 ral as Crataegus (or Mcspilus) Crus-galli, 

 tomentosa, parvifolia, &c. 



Linnicus observes that this sometimes 

 disappears by cultare, as in the Pear-tree, 

 Byrus ^citiva, which when wild has strong 

 thorns ; hence he denominates such culti- 

 vated plants tamed, or deprived of their 

 natural ferocity. Professor Wilidenow^, 

 Frinciples of Bot. t. 270,,considers thorns as 

 abortive buds, and thence very ingeniously 

 and satisfactorily accounts for their disap- 

 peai'ance whenever the tree receives more 

 nourishment. 



