2 THE PLANT WORLD. 



appearances just as. thrifty in their way as their big cousins in the 

 forests that surround the plains on every side. The reason for the ab- 

 sence of normal tree growth on the plains is a problem that the experts 

 are by no means agreed about. Continuously recurring lires datino- 

 from the time when the only human foot that trod the region was the 

 Indian's, sterility of soil, exposure to bleak winds — the land being 

 rather elevated for that low country — have all lieen assigned as causes, 

 but the mystery still remains a mystery. 



Rut these sunny sands supported other plants than scrubby trees. 



SCRUB OAKS SHOAVINC; RELATIVE HEIGHT TO WAN. 



Here the laurel {Ivalmia latifoUa) luxuriated, and the bearberry [Arc- 

 tostcqyhylo.^ uva-ursi), the latter's long, procumbent vines beaded with 

 green fruit; here were trailing arbutus and catgut {Tej?/trosm Virglu- 

 iana)^ mats of pyxie {Pyxidanthera harhulata) and beds of shiny sand 

 myrtle {Leiojpliylluin buxifoUum) mingled with gray hudsonia. The 

 most interesting product of the plains, however, was a low bushy shrub, 

 which one might mistake for hudsonia at first glance, but which is 

 really of quite a difl'erent family — that is, the broom crowberry 

 {^Co7'ema Conradi'i^. This plant which, outside of New Jersey, is 

 known but from a few isolated stations, grew in profusion on the Lower 

 Plains, and to some extent also in the pine barren woods six or eight 

 miles further west, where also we subsequently came upon it. The 

 flowers appear in March and April, the tufted sterile ones, borne on 

 separate plants from the fertile, being rather pretty in sombre brown 



