370 CLASS XXI. ORDER Vlll. 



row shaped, with an acute point and lobes. Scape somewhat 

 triangular, bearing whorls of three flowers each, on simple foot- 

 stalks. Petals three, roundish, very thin and deciduous, and dif- 

 ficult to preserve. Stamens in the upper flowers; pistils in the 

 lower. Fruit in globular heads. — Perennial. 



SaGITTARIA AUCtTIFOLIA. 



Leaves lanceolate-subulate, sheathing at base, con- 

 vex on the back ; scape few flowered ; bractes dilatedj 

 acuminate. 



Root fibrous, its branches white and reticulated, by numerous 

 transverse partitions. There is generally a tuber among these. 

 Leaves very small, linear-lanceolate, fleshy, concave. Petioles 

 six times as long, smooth, round, sheathing at the base. Scape 

 erect, round, simple, bearing its flowers in whorls of about three 

 together. Flowers monoecious pelioled, with membranous brac- 

 tes. Calyx leaves concave, obtuse. Petals roundish, white. 

 Anthers short, roundish. Germs numerous, ending in small de- 

 pressed heads of acute seeds. — Edges of Fresh pond. — August. — 

 Perennial. 



384. MYRIOPHYLLUM. 

 Myriopiiyllum spicatum. L. Spiked Water Blillfoil. 

 Leaves all pinnate, capillary ; spike terminal, 

 whorl ed, naked. Wllld. 



This plant grows in deep ponds and rivers, where it is fre- 

 quently drawn up by the lines of anglers. Stems long, smooth, 

 floating. Leaves in whorls of four or five together, finely divided 

 or pectinate, always under water. The flowering spikes, which 

 are the only part that emerges, are solitary, bearing their flow- 

 ers in small sessile whorls, Bractes three to each flower, ovate, 

 acute, the middle one much largest. Calyx leaves short, acute. 

 Petals oblong, obtuse, brownish gre^i, caducous. — July, August. 

 — Perennial. 



* Myriophyllum tenellum. Slender Water Millfoil. 



M. ererAiim., aphyllu n ; hracteis itilegris, obtiisis ; 

 petalls Unearibus conduplicatis et revoluti^. 



