Vol. 36 



No I 



BULLETIN 



OF THE 



TORREY BOTANICAL CLUB 



JANUARY, 1909 



The ferns and flowering plants of Nantucket,— IV 



Eugene P. Bicknell 



ARACEAE 



Arisaema pusillum (Peck) Nash. 



Locally rather common in low or wet shaded thickets, mainly 



in the northeast quarter : Quaise; Polpis ; Pocomo ; Squam. In 

 fresh flower June 7, some fruit turning red Aug. 13, 1906 ; mature 

 fruit Sept 17, 1907. 



The Nantucket plant is more especially the state or form known 

 as A, Stewardsonii Britton. This, in its representative develop- 

 ment, shows a considerable divergence from typical A. pusilhun 

 but, in localities on Long Island where it grows in abundance, the 

 evidence appears unmistakable that the two plants are extreme 

 variations of a single species. The corrugate^ spathe, although 

 a noteworthy character, is an unstable one and may or may not 

 be shown by plants growing together in the same colony. I have 

 not, however, seen it as strongly emphasized in plants from any- 

 where on the coastal plain as in the type specimens from the 

 mountain region of east Pennsylvania. 



• On Long Island, A. pusillum is essentially a plant of the coastal 

 plain, where it replaces A. triphyllum of the hilly country. The two 

 species are not at all constantly different in size, and A. pusillum 

 when stoutly grown fully gains the proportions cJf good-sized 

 examples of A, triphyllum. Nor is the color of the spathe always 

 distinctive, that of A. pusillum^ normally of an uninterrupted black- 

 purple, being sometimes greenish and purple-striped or, exception- 



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[The Bulletin for December, 1908 (35 : 561-608) was issued 2 Ja 1909 (the 

 date ^'December 31, 190S," in the number itself is erroneous).] 



1 



