USING THE KEYS xi 



which it is separated from the bark. Tracing the shrub is 

 simple: no. 1 to 140; to 141; to 142; to 143; to 144; to 145, 

 where I stop at Tamarix. The species (p. 238) are not easily 

 distinguished, but the color of the twigs makes me believe 

 that this is the commonly cultivated Tamarix gallica. 



Several years ago a squirrel overlooked some sort of a 

 nut that he had buried next a fence. It has grown into a 

 small tree with sumach-like foliage, that must be either a 

 hickory or black walnut or butternut. I want to know which. 

 The twigs present several peculiarities: leaf-scars are alter- 

 nate, raised above the level of the stem, shaped much as in 

 the poison ivy, with 3 usually C-shaped or fragmented bundle- 

 traces; over each leaf-scar are two scaly buds, one superposed 

 above the other; and the twig, when split, shows a peculiar 

 pith, not solid, but consisting of thin brown plates separating 

 cavities or chambers. The key leads me from no. 1 to 140; 

 to 150; to 172; to 202; to 203; to 219; to 224; to 225; to 227; 

 to 255; to 256; to 259; to 260; where I decide that my tree is 

 a Juglans. The characters of this genus (p. 16) satisfy me 

 that this is right, and the short gray silky terminal bud and 

 the absence of moustache-like velvety lines above the leaf- 

 scars show that it was a black walnut that the squirrel planted 

 and forgot, here as along many other fences. 



A horticultural friend brings me a twig of one of the 

 golden bells which survived the last severe winter better than 

 the common Forsythia viridissima, and asks if it can be the 

 hybrid ( X F. intermedia) between that species and the hardier 

 F. suspensa. The, key (1 to 2; to 15; to 19; to 22; to 35; 

 to 40; to 86; to 87; to; 92; to 97; to 104; to 124; to 126) 

 convinces me that what he has is really a Forsythia. Turn- 

 ing to p. 308 I find that the twig has the solid tissue at its 

 nodes characteristic of F. suspensa (f. 3), but the thin plates 

 or their remains between the nodes characteristic of F. viri- 

 dissima (f. 1) ; for the hybrid X Forsythia intermedia (f. 2) 

 is intermediate between the parent species in this as in other 

 characters. 



