THE PLANT WOKLD 63 



BRIEFER ARTICLES. 



Root Relations of Pogonia verticillata. 



The fact of Pogonia verticillata growing in extensive colonies in 

 Various localities around this city, Philadelphia, made me think that 

 the connected root system described by Mr. Saunders for P. ophioglos- 

 fioides could be also applied to this species as a means of accounting for 

 its gregariousness. One will scarcely recall ever having seen a solitary 

 individual of this whorled-leaf Pogonia, but rather the reverse, the 

 plants always growing in company or colonies of considerable extent. 

 They are not found in such groups as violets or may-apples and some 

 other plants delight to form, but are more or less distant from each 

 other, not to say reserved, the effect indicating a relation which, while 

 not existing above ground, seems necessary beneath it. To test this 

 latter idea, I made a late fall trip to my favorite grounds at Tullytown, 

 in Bucks county. Pa., near the Delaware river, and found a number of 

 plants not jei destroyed by frost. Selecting a mature form, I soon 

 found its roots to be large but not fleshy fibers, several inches beneath 

 the surface and at various depths, extending in horizontal directions 

 everywhere, apparently without end. 



Following up the course of one "runner" for from twelve to four- 

 teen inches, 1 had the satisfaction of finding another mature plant at- 

 tached; in fact, this was the parent of the "runner," as beneath the 

 connection were several other roots horizontally disposed, but unfortu- 

 nately broken off during removal from the soil with one exception that 

 I traced to another mature plant. That these plants were all mature, 

 is shown from the fact that some of them still bore fruit, and all had 

 from five to seven stem scars alternately at caudex or base, and the 

 next season's bud well developed. 



The thread of relationship was broken by reason of carelessness in 

 •operating among roots of surrounding trees, but I believe that all the 

 plants are joined in this manner, and that this is the means of mainte- 

 nance of the species rather than that of propagation by seed distribu- 

 tion. I can scarcely recall a small or immature form, nearl}^ all the 

 sterile plants being mature in size. 



The fibers were all similar in dimensions, there being no thicken- 

 ing anyAvhere, even at the point of contact with the stem, and there the 



