Mr. Woods on the British Species of Rosa. 163 



aciilei of the petioles. Setae are found on the same parts as the 

 aculei, and are besides frequent on the peduncle and fruit, and 

 sometimes on the leafits of the calyx : they differ, in being longer 

 or shorter in proportion to the size of the gland by which they arc 

 terminated. 



The Glands of Roses are almost always on little footstalks, 

 which however being weak, and seldom of length greater than 

 the diameter of the gland, may in general be distinctly separated 

 from the setae above mentioned. 



Glands rarely occur on the stems ; but they are found on the 

 stipulae, which are frequently fringed with them; on the petioles 

 and nerves; in some Roses on the under, and in some also on the 

 upper side of the leaf, and sometimes on the edges, tipping the 

 serratures, or giving the appearance of secondary ones; on the 

 fruitstalk, receptacle, and calyx. Tlie latter part is not unfre- 

 qiiently furnished with setae at the base, which, gradually dimi- 

 nishing in length and strength, pass insensibly into glands to- 

 wards the termination of the phyllus. To these glands the odour 

 of the leaves of Roses seems to be invariably owing. They are 

 generally most abundant on tl«) early and imperfectly-formed 

 leaflets, and sometimes fall off or dry up towards autumn. 



Some Roses are furnished with only one sort of these arms, others 

 have two, others again all three. In some, one sort is confined to 

 one or two parts of the plant, as the setae of R. villosa ; in others 

 it occurs generally, as the setae of It. rubella. Some species, as 

 Rosa Eglanteria, proceed by almost insensible gradations in one 

 part or other of the plant from hooked to straight prickles, to 

 setae, and to glands ; others again, though furnished with all these, 

 display them perfectly distinct. In some the aculei, though 

 always distinct from setae, vary very much in size and character; 



V 2 ill 



