6 



Millspaugh even found a few specimens upon our side of the 

 divide, but none have been found since. We live in hopes that 

 The clan may yet get up courage enough to span the few miles 

 that still separate us. 



A characteristic species of the Delaware valley unaccount- 

 ably absent from our region is the red or river birch (Bctula 

 nigra). It is scarcely possible that it could have been over- 

 looked with us, for the tree, especially in winter and spring, is 

 so easily distinguished from its companions on the river banks 

 that it can be identified with certainty from long distances. It is 

 common again in the Susquehanna valley in Pennsylvania, but 

 apparently does not cross the line into New York. Why it does 

 not is a mystery. 



A companion of the wild indigo, the partridge pea ( Cassia 

 chamaecrista) is another species that we would gladly welcome to 

 a place in the Upper Susquehanna Flora. Like all other species 

 that become too common, this is in many sections considered a 

 weed to be classed with the poke, Jimson weed, rag-weed and 

 toad-flax, but in my own opinion the sections in which the road- 

 sides are bordered with the pretty pinnate leaves and bright yel- 

 low flowers of this species are to be congratulated. I never tire 

 of the sight of its golden flowers, and could connive at spreading 

 such a " weed " with good grace. 



Two related species, the wild senna ( C. Marilandica) and 

 the wild, sensitive plant ( C. nictitans) find a home with us, but 

 the partridge pea holds itself aloof. That it will grow and thrive 

 here is proved by the fine specimens that at present are growing 

 in my garden from seed gathered on Staten Island late in the 

 autumn of last year. Although Cassia nictitans is called the 

 sensitive plant, the leaves of the partridge pea also respond 

 promptly to stimuli. They close at a touch, though so slowly 

 that the eye does not perceive the motion. The sensitiveness to 

 the contact of foreign bodies seems to vary with the day. After 

 being whipped about by the wind for some time it is much less 

 sensitive. 



