NOTES ON THE AQUATIC PHENOGAMS OF IOWA, i^i 



few inches to several feet deep. 6 in. to 2 ft. high; petioles 

 about equaling the scape in height, the leaf slightly resemb- 

 ling the petiole in form and structure, 3 to 5 in. long, linear 

 or linear lanceolate, thick, spongy, somewhat triangular in 

 cross section, and when flattened in the herbarium specimen, 

 appearing more nearly lanceolate in form. Submerged phyl- 

 lodia linear or linear lanceolate, acute or obtuse, 4 to 8 in. long, 

 rigid, with about live principal and many intermediate nerves, 

 coarsely reticulated, clustered at the base of the plant, and 

 appearing in tufts from the nodes of the stolons by means of 

 which the plant is propagated, and which extend for a con- 

 siderable distance along the muddy bottom. Scape slender, 

 bearing 4 to 6 whorls of flowers, rarely more than the lower 

 whorl fertile ; pedicels of sterile and fertile flovyers about equal, 

 ^ to I in. long, bracts connate, acute or slighth' obtuse; petals 

 white, delicate, wavy; filaments pubescent, thickened below^ 

 longer than the anthers. Fruit heads ^ to 3^ in. in diameter, 

 shrinking much in drving; achenia obovate with a conspicuous 

 horizontal style, and crested back and sides. 



The type specimens of this plant with flowers and mature 

 fruit were collected by the wn-iter in a small lake, since dried 

 up, one mile east of Armstrong, Emmet county, Iowa, in 

 August, 1881, and were sent to Dr. Geo. Engelmann for 

 determination. In his reply he stated that while it was closelv 

 allied to ^S". graniinea Michx., he could not decide definitely 

 in regard to it without thoroughly revising the genus. How- 

 ever, under date of March 5, 1882, he sent to Dr. Arthur the 

 provisional name S. cristata, which was published with a few 

 lines of description in Arthur's Coiitribntio)i to the Flora of 

 loiva as above noted. The late Dr. Mororfg, who studied the 

 plant critically, considered it a good species, and it is so re- 

 garded in J. G. Smith's recent monograph. Plants collected 

 at Ames and Carnsforth. and conjectured to be this species, 

 are best considered as forms of S. graminca Michx. 



Besides the localit}- above given, the plant has also been 

 found in several places in Minnesota. See Sheldon in Minn. 

 Bot. Stud.. Bull. 9, p. II. 



Ill— 4. B 



