THE VENATION OF THE SPECIES OF SALIX. 59 



ish until near the border, where ascension is rapid to join 

 the next above, making an acute loop — a more or less 

 straight marginal line resulting from this mode of junction. 



Secondaries mostly very irregular. Tertiaries strong, 

 forming large meshes mostly polygonal, embracing in 

 young leaves peculiar gnarled terminals which, by obliter- 

 ation, gradually fade, or, occasionally, leave a central 

 stellate point. — Plate 2, fig. 21. 



Veining as a whole uneven as to caliber, broken, brilliant. 

 The impression on the eye is quite peculiar, — say Oriental 

 or Chinese, — where it is said to be native. 



22. S. longifolia, Muhl. — Primaries strong, distant, 

 straight-ascending to a straight, firm marginal line extend- 

 ing from base to tip. Intervening costals several, often 

 looping more or less completely inwards from the marginal 

 line. Secondaries close, parallel, partially obscured, un- 

 even, forming therefore very indefinite meshes. Tertiaries 

 wanting. The meshes are all longish, blunt at ends, hori- 

 zontal or ascending, — the long diameters all extending in 

 the one direction. 



There is no proper reticulated venation corresponding to 

 anything as seen in other willows. In young leaves, very 

 faint terminals, filling up the background, may be seen. 

 Obliteration early, of all but the principals. Green lines 



along midrib 



Teeth seldom sup- 



plied by any visible veins, — a unique exception to all the 

 rest; in young plants, however, with pinnatifid leaves, the 

 usual rule prevails. As a whole, the veining of this leaf is 

 extremely exceptional. — Plate 3, fig. 22. 



Illustration from specimen from vicinity. 



23. S. herbacea, L. — Primaries straight, even, high- 

 ascending, partially palmate, dividing 

 to the margin. Secondaries scarcely distinguishable from 

 the tertiaries, both irregular, forming medium-sized sharply 

 angular meshes. — Plate 1, fig. 23. 



Illustration from Herbarium specimen collected on Mt. 



14 



and sub-dividing on 



