Genus 5. 



WATER PLANTAIN FAMILY. 



101 



7. Sagittaria longiloba Engelm. Long-lobed 

 Arrow-head. Fig. 237. 



Sagittaria longiloba Engelm. in Torr.Bot. Mex, Bound. 

 Surv. 212. 1859. 



Monoecious, glabrous, scape slender, simple or 

 rarely branched, i°-2° tall. Leaves long-petioled, 

 the apex acute, the basal lobes linear-lanceolate, acu- 

 minate, about three-fourths the length of the blade; 

 bracts lanceolate, acuminate, 3"-4" long, much shorter 

 than the very slender fertile pedicels which are 

 longer than the sterile ones ; stamens numerous, the 

 filaments longer than the anthers; achene about 1" 

 long, quadrate-obovate, somewhat broader above than 

 below, winged on both margins, its beak exceedingly 

 short. 



In shallow water, Nebraska to Colorado, south to 

 Texas and Mexico. 



8. Sagittaria ambigua J G. Smith. Kansas 

 Sagittaria. Fig. 238. 



Sagittaria ambigua J. G. Smith, Ann. Rep. Mo. Bot. 

 Gard. 6 : 48. pi. 17. 1894. 



Monoecious, glabrous, scape erect or ascending, 

 simple or sparingly branched, l°-2° high. Leaves 

 lanceolate, entire, long-petioled, acute or acuminate 

 at both ends, seemingly pinnately veined, really 5-7- 

 nerved, s'-8' long, equalling or shorter than the scape ; 

 bracts lanceolate, acuminate, 5"-8" long, much shorter 

 than the slender fruiting pedicels, connate at the 

 base, papillose ; stamens 20-25 ; filaments glabrous, 

 longer than the anthers; achene about 1" long, ob- 

 long, curved, narrowly winged on both margins, its 

 sides smooth and even, its beak short, oblique. 



In ponds, Kansas and Oklahoma. 



g. Sagittaria falcata Pursh. Scythe-fruited ^ 

 Sagittaria. Fig. 239. 



Sagittaria falcata Pursh, Fl. Am. Sept. 297. 1814. 



Sagittaria lancifolia falcata J. G. Smith, Mem. Torrey 

 Club 5: 25. 1894. 



Monoecious, glabrous to the inflorescence, scape 

 erect, longer than the leaves, sometimes branched. 

 Leaves erect or nearly so, almost linear to elliptic, 

 the blades mostly 4'-l6' long, often slightly acumi- 

 nate, much shorter than the petioles; whorls of the 

 inflorescence few or many; flowers c/'-is" broad; 

 bracts ovate, less than 5" long, obtuse or acutish, 

 granular-papillose ; filaments not dilated, pubescent ; 

 anthers shorter than the filaments; achene cuneate, 

 about 1" long, narrowly winged, the slender beak 

 usually ascending. 



In shallow water and swamps, Delaware to Florida, 

 Texas and Mexico. Sagittaria lancifolia L., admitted 

 as including this species in the first edition, is distinct 

 from it, and inhabits Florida and tropical America. 



