i68 REPORT OF NEW JERSEY STATE MUSEUM. 



occur mainly along the Delaware River or Bay. The variability 

 in the leaves of these plants, both in size, shape and proportions, 

 makes their identification often very puzzling, and those with 

 lanceolate or submerged leaves (phyllodia) can only be cer- 

 tainly determined by their fruits, the relative size and shape of 

 the achenes being the best character. The Water Plantain occurs 

 in swamps except in the Pine Barrens. 



Key to the Species. 



a. Flowers small (s mm. broad), in a large erect panicle. Alisima, p. i68 

 aa. Flowers large (12-35 i^™. in diameter), in whorls of three on an erect 

 scape. 



b. Leaves arrow-shaped, basal lobes prominent. 



c. Beak of achene erect, bracts longer than fruit pedicels. 



Sagittaria longirostra, p. 171 

 cc. Beak of achene horizontal, bracts shorter than fruit pedicel. 



S. latifolia, p. 169 

 bb. Leaves elliptic, sometimes with very short curved basal lobes (often 

 on one side only), achene beak erect, fruit sessile. S. rigida, p. 171 

 bbb. Leaves ovate lanceolate or linear on slender petioles, often only 

 submerged phyllopodia. Achene very small (i mm.), nearly beak- 

 less ; fruit long-pedicelled.* S. graminea, p. 172 

 bbbb. Leaves lanceolate or linear, strap-shaped or with a narrow blade, 

 not more than 75-100 mm. in height. Whorls of flowers I to 3. 



5". subulata, p. 172 

 aaa. Flowers not over 16 mm. in diameter, pedicelled in a terminal umbel. 

 b. Umbel 3 flowered, leaves taller than scape, petioles widened at base. 



S. subulata, p. 172 



bb. Umbel 2-8 flowered, leaves shorter than scape, petioles not widened 



at base. H elianthium parvulum, p. 169 



ALISMA L. 

 Alisma subcordatum Raf. Water Plantain. 



Alisma subcordatum Refinesque, Md. Reposit. IL 5. 362. 1808 [United 



States]. 

 Alisma plantago Britton 255. 

 Alisma pawiUora Pursh, Fl. Am. Sept. L 253 [Salt Marshes coast of N. J. 



and Penna.]. 



Common in swamps except int he Pine Barrens, where it is 

 absent. 



* Occasional forms of S. longirostra and latifolia with lanceolate leaves 

 can be recognized by their large beaked achenes. 



