128 VEINS AND RIBS OF LEAVES. 



Concavum, hollow, depressed in the middle, owing 

 to a tightness in the border, as Cyamus Nelumbo y 

 Exot. Bot. t. 32. 



Venosum^f. 88, veiny, when the vessels by which 

 the leaf is nourished are branched, subdivided, 

 and more or less prominent, forming a network 

 over either or both its-surfaces, as Crat&gus, or 

 rather Pyrustorminalls, Engl. Bot. t. 29 8, and 

 Verbascum Lychnitis, t. 58. 



Nervosum, f. 89, or Costatum, ribbed, when they 

 extend in simple lines from the base to the point, 

 as in Cypripedium Calceolus, t. 1, the Conval- 

 larice, t. 279 and 280, Stratiotes aUsmoides y 

 Exot. Bot. t. 15, and Roxburghia viridiflora, 

 t. 57. The greater clusters of vessels are gene- 

 rally called nervi or costtf, nerves or ribs, and 

 the smaller m^,veins,whether they are branched 

 and reticulated, or simple and parallel. 



Avenium> veinless, and Enerve, ribless, are opposed 

 to the former. 



Trinerve, f. 90, three-ribbed, is applied to a leaf 

 that has three ribs all distinct from the very base, 

 as well as unconnected with the margin, in the 

 manner of those many-ribbed leaves just cited ; 

 see Blakca trincrvis *, Curt. Mag. t. 45 1 . 



Basi t rinerve, f. 9 1 , three-ribbed at the base, is 

 when the base is cut away close to the lateral ribs, 



* Authors incorrectly use the termination trinervius, tir'merola. Sec. 

 for the more classical trinervis, trinerve, enervis, cncrve. 



