12.] CHAPTER II. SPECIAL MORPHOLOGY OF THE MEMBERS. 



47 



be seini-amplexicaul ; in the latter, amplexicaul (e.g. Grasses, 

 Onion, Fool's Parsley). 



The leaf -base sometimes produces a pair of opposite lateral 

 branches which are termed stipules ; when they are present the 

 leaf is said to be stipulate, and when they are absent, as is more 

 commonly the case, the leaf is said to be exstipulate. The stipules 

 are commonly winged appendages, similar in colour and texture to 

 the lamina, and they are then said to be leafy (Figi 28 B, (7), as in 

 the Willow, the Violet, and the Rubiaceas where they are branched, 

 and they are especially large in plants, like the Pea, where the 

 lamina is relatively small ; in other plants, on the contrary, they 





a 



FJG. 28.^. Part of a sessile leaf of Grass (Poa trivialis) with the ligule i ; a the haulm ; 

 v the sheathing leaf-base ; I lamina of the leaf. B Leaf of a Willow (Salix Caprea) ; a 

 stem ; s s stipules ; p petiole; / lamina ;' It axillary bu<i (nat. size). C Leaf of a Pea (Ptsitni 

 arvense) ; a stem ; s s stipules ; r mesopodium oi petiole ; //leafets ; rfrf the upper leaf- 

 lets metamorphosed into tendrils ; r' end of the epipodium likewise transformed into a 

 tendril. 



are small brownish scales, which fall oft soon after the leaf is un- 

 folded, as in the Beech, the Elm, and the Lime. Sometimes the 

 stipules appear as teeth on the upper margin of the sheathing leaf- 

 base, as in the Rose. Occasionally the two stipules are connate, 

 that is, they are more or less united ; when they cohere by their 

 outer margins they form a single opposite stipule, opposite, that 

 is, to the leaf to which they belong, as in Astragalus ; when they 

 cohere by their inner margins they form an axillary stipule, that is, 

 a stipule in the axil of the leaf to which they belong, as in Meli- 



