234 PENNYP ACKER— ON THE BEACH PLUM 



Until 1904 all the work was taxonomic and consisted of descriptions 

 more or less complete. At this time, Macfarlane (18, p 216), pointed 

 out marked variations in the fruits of the species under the following 

 heads: — 



(1) color 



(2) weight 



(3) size and shape 



(4) consistence 



(5) taste 



(6) time of maturation 



(7) comparison of the stones 



all of which the writer has confirmed by independent observation and 

 research eleven years later. 



Bigelow (3, p. 193) had, however, previously (1824) called attention 

 to three varieties, namely: — 

 Variety a. Fruit an inch in diameter, purple, with a glaucous bloom. 



b. Fruit similar, but smaller. 



c. Fruit crimson shining. 



He further states, "This is our Common Beach Plum, much prized 

 for its agreeable fruit, and deserving attempts at cultivation. I do 

 not find it described by any author, unless possibly by Michaux under 

 the name of P. sphaerocarpa, a name previously appropriated by Swartz 

 to a West Indian species. From P. maritima of Pursh it appears widely 

 different in its inflorescence, acumination, and fruit." 



Torrey and Gray (30, p. 408) fourteen years later (1838) described 

 two varieties. 



Var. 1. Leaves softly pubescent or pubescent beneath; fruit large, 

 pleasant. Corresponds to P. sphaerocarpa, Michaux; and P. liUoralis, 

 Bigelow. 



Var. 2. Leaves when old mostly glabrous on both sides; fruit smaller, 

 red or purplish. Corresponds to P. pygmaea, Willdenow and P. acu- 

 minata, Michaux. They state that these two forms may be traced 

 into each other with great certainty; and Bigelow seems to have in- 

 cluded both under his P. liUoralis. 



Stone (27) gives the best description of the distribution of the species 

 in the state of New Jersey. On page 250 the writer gives a detailed 

 technical description of P. maritima. 



