BiCKNELL : Ferns and flowering plants of Nantucket 449 



Aug. 



Still another noteworthy form collected at York Harbor, Me., 

 1 6, 1893, is characterized by erect habit, slender, somewhat 



fastigiate branches and narrowly linear and acute, appressed or as- 

 cending leaves of firm texture and more or less revolute. 



The main points of difference distinguishing typical P. neglectmn 

 from P. aviailare are more elliptic, prominently venose leaves of 

 firmer texture, usuallysomewhatscurfybeneath, firmer, more promi- 

 nent ochreae becoming stiffly laciniate and finally blackish, upper 

 leaves greatly reduced in size, with a subspicate inflorescence 

 towards the ends o{ the more sharply angled branches, and usually 

 brighter red flowers. Other but less constant differences are more . 

 striate and roughened stem of shorter internodes, at least above, 

 more flexuous branchlets, leaves revolute on margins or with 

 revolute tendency instead of with involute tendency as in P, avic- 

 tdare^ the ochreae brownish -tinged from the first with firmer atten- 

 uate divisions, achene more reddish in color and more exserted. 



4 ■ 



r 



* Polygonum prolificum (Small) Robinson. 



Along salt marshes and brackish creeks, in saline mud, less 

 often in sandy soil. Frequent along the harbor from near the 

 town to Quaise ; more common at the western end ol the island 

 towards Eel Point; not seen on the south or east side. 



A very distinct species, abundant along our coast from Maine 

 to New Jersey and flowering from the middle of July until killed 

 by frost. In its various forms it exhibits an unusually wide range 

 of variation. Although commonly erect, as required by des- 

 criptions, it may be straggling and ascending, prostrate or even 

 flatly depressed in ^^ns^ mats 1-2 dm. in diameter. Such a form 

 used to grow along the Harlem River in New York and would 

 not be easily recognized as the same species as the normal erect 

 form. It is numerously short-branched with very short inter- 

 nodes, the small leaves and the flowers numerous and crowded. 

 Specimens are deposited in the herbarium of the New York Botan- 

 ical Garden. A wide-spreading and ascending slender form has 

 elongated internodes and flexuous branches sometimes 5 dm. 

 long, the leaves much reduced in size towards their extremities. 

 The stoutest form of the plant is erect and densely bushy- 

 branched with solid woody stem sometimes 0.5 cm. in diameter 



