LECT. VI.] THE STEM. BRANCHING. 265 



understand the descriptions of plants in the works 

 of systematic writers. 



With regard to surface, stems are either bare 

 or covered. They are said to be, 



1. BARE (nudi), when the epidermis is per- 

 fectly free from appendages of every description, 

 leaves, scales, spines, prickles, or any kind of 

 pubescence. The superficies of naked stems varies 

 considerably : it is termed, 



a. Shining (lucidus, nitidus) when it glistens, 

 as if varnished ; as in shining Crane's-bill, Ge- 

 ranium lucidum. 



b. Smooth (glaber), when it is free from all 

 kinds of roughness or hairiness * ; as in Peri- 

 winkle, Vinca major; Petty Spurge, Euphor- 

 bia Peplus, &c. 



c. Even (Icevis), when, throughout, it is per- 

 fectly free from inequalities ; as in the Somni- 

 ferous Poppy, Papaver somniferum. 



d. Punctured (punctatusj, when it is covered 

 with small yet visible perforations, either simple, 

 or surrounded, at the orifice, with a raised 

 border. In both instances, these punctures are 

 probably the excretory ducts of subcuticular 

 glands opening on the epidermis. Rue, Ruta 

 graveolens (Plate 4, fig. 4) ; and perforated 



* " Glaber, superficie laevi est." Phil. Bot. 82. 18. 



