A L IS MA CEAE. 57 



Fertile pedicels stout, reflexed in fruit; filaments dilated. 



Filaments pubescent; leaf-blades ovate or ovate-elliptic. 14. S. platyphylla. 



Filaments glabrous ; leaf-blades linear-lanceolate or reduced to phyllodes. 



15. S. subulata. 



1. Sagittaria longirostra (Micheli) J. G. Smith. LONG-BEAKED ARROW- 

 HEAD. (I. F. f. 193.) Monoecious, glabrous, scapes erect, rather stout, 0.4-1 m. 

 tall. Leaves broad, sagittate, 10-30 cm. long, abruptly acute at the apex, the 

 basal lobes ovate or ovate-lanceolate, acute, one-third to one-half the length of the 

 blade; scape usually longer than the leaves, 6-angled below; bracts triangular- 

 lanceolate, acuminate, 1.5-3 cm - l n g? longer than the fertile pedicels; petals 16-28 

 mm. long; styles curved, twice as long as the ovaries; achene obovate, about 4 mm. 

 long, winged on both margins, the ventral margin entire or undulate, the dorsal 

 eroded, its sides with a short crest, its beak stout, erect, or somewhat recurved. In 

 swamps and along ponds, N. J. and Penn. to Ala. July-Sept. 



2. Sagittaria Engelmanniana J. G. Smith. ENGELMANN'S ARROW-HEAD. 

 (I. F. f. 194.) Monoecious, glabrous; scape erect or ascending, slender, 20-50 cm. 

 high. Leaves narrow, 4-20 cm. long, 2-8 mm. wide, acute or obtuse at the apex, 

 the basal lobes narrowly linear, acuminate, one-third to one-half the length of the 

 blade; scape striate, about as long as the leaves; bracts lanceolate, acute, shorter' 

 than the slender fertile pedicels, 8-12 mm. long; flowers 1.5-?. 5 cm. broad; style 

 about twice as long as the ovaries; achene obovate, 4 mm. long, winged on both 

 margins, and with 1-3 lateral wing-like crests on each face, the beak short, stout, 

 erect, about I mm. long. In shallow water, N. H. and Mass, to Del., near the 

 coast. Aug.-Sept. (S. variabilis var. (?) gracilis Engelm.) 



3. Sagittaria latifolia Willd. BROAD-LEAVED ARROW-HEAD. (I. F. f. 195.) 

 Monoecious or sometimes dioecious, glabrous or nearly so ; scape stout or slender, 

 o. 1-1.2 m. tall, simple or branched. Leaves exceedingly variable in form and size, 

 sometimes linear-lanceolate and acuminate at the apex, sometimes wider than long 

 and obtuse; basal lobes from to \ as long as the blade; bracts acute, acuminate 

 or obtuse, the upper ones sometimes united; flowers 2.5-4 cm. wide; achene 2-4 

 mm. long, broadly winged on both margins, its sides even or i -ribbed, the beak 

 about one-third its length, horizontal or nearly so. In shallow water, throughout 

 N. Am., except the extreme north, extending- to Mex. July-Sept (S. variabilis 

 Engelm.) 



Sagittaria latifolia pubescens Muhl. Whole plant pubescent, varying from merely 

 puberulent to densely hirsute. Ont. to N. J., Fla. and Ala. 



4. Sagittaria arifolia Nutt. ARUM-LEAVED ARROW-HEAD. (I. F. f. 196.) 

 Glabrous or nearly so, terrestrial or partially submerged; scape weak, ascending, 

 0.2-0.5 m. long. Leaves sagittate, broad, acute at the apex, about as long as the 

 scape, their margins slightly curved, their basal lobes acute or acuminate, one- 

 fourth to one-third the length of the blade; petioles usually curving outwardly; 

 bracts lanceolate, acute, usually equalling or longer than the fertile pedicels, often 

 reflexed; petals 6-10 mm. long; achene cuneate-obovate, about 2 mm. long, winged 

 on both margins, the sides smooth, the beak short, erect. Quebec to Minn, and 

 Br. Col., south to Me., Mich., Kans., N. Mex., and Cal. 



5. Sagittaria cuneata Sheldon. FLOATING ARROW-HEAD. (I. F. f. 197.) 

 Aquatic, submerged, rooting in sand; scape very slender, simple, terete, 0.3-0.6 

 m. long, bearing the flowers at the surface of the water. Leaves long-petioled, 

 the blade floating, sagittate, linear-lanceolate, acuminate, 5-10 cm. long, the basal 

 lobes acuminate, about one-fourth its length; phyllodes of two kinds, one petiole- 

 like and as long as the leaves, the other lanceolate, and clustered at the base of the 

 plant; bracts ovate-lanceolate, acute, 4-6 mm. long, much shorter than the slender 

 fertile pedicels; flowers 1.2-1.6 cm. broad; achene only I mm. long, obovate-cune- 

 ate, its beak very short, erect. In shallow water, Minn, to Wash, and Br. Col. 

 Aug.-Sept. 



6. Sagittaria longiloba Engelm. LONG-LOBED ARROW-HEAD. (I. F. f. 198.) 

 Monoecious; glabrous; scape slender, simple or rarely branched, 0.3-0.6 m. tall. 

 Leaves long-petioled, the apex acute, the basal lobes linear-lanceolate, acuminate, 

 about three-fourths the length of the blade; bracts lanceolate, acuminate, 6-8 mm. 

 long, much shorter than the very slender fertile pedicels which are longer than the 



