320 WATER-PLANTAIN FAMILY. 



X AI ISMA Flowers perfect, loosely panicled. Petals involute in the bud. 

 Stamen's 6. Ovaries many, in a ring, very flat-sided, becoming coriaceous 

 flat akenes, 2 - 3-keeled on the bacli. - , , „ ^ , . , . 



4 KCHINODOKUS. Flowers perfect, in proliferous umbels. • Petals imbricated 

 ' in the bud. Stamens 9 or more. Ovaries lieaped in a head, becoming wing- 

 less akenes. , ,. . 



6 SAGITTARIA. Flowers monoecious, rarely diCECious or polygamous, m suc- 

 cessive whorls, the sterile at the summit of the scape; the lowest fertile. 

 Stamens usually numerous. Ovaries very many, heaped on the globular 

 receptacle, in fruit becoming flat and winged akenes. 



Iir. FLOWERING-KUSH FAMILY. (Bcto.he^.) Dif- 

 fers from the preceding mainly in the few ovaries having numerous 

 ovules distributed all over the inside. 



6. LIMNOCHARIS. Flowers perfect, long-peduncled. Petals large, yellow. Sta- 

 mens nupqeroiis with slender filaments, a few of the outermost without an- 

 thers, the rest with linear anthers. Ovaries 6 or more, somewhat united at 

 base. Leaves roundish and heart-shaped, long-petioled. 



1. TRIGLOCHIN, ARROW-GRASS. (Name in Greek means three- 

 pointed.) Insignificant rush-like plants, in marshes, mostly where the wa- 

 ter is brackish : fl. summer. ^ 



T. pallistrCi Slender, 6'-18' high, with linear-club-shaped ovary and 

 fruit, the 3 pieces when; ripe separating from the sharp-pointed base upwards. 



T. marltimum. 'Stouter, 12' -20' high, with fruit of about 6 pieces 

 rounded at base. — Var. elXtum, in bogs of the interior, N., 20' -30' high, the 

 pieces of the fruit sharp-angled on the back. 



T. tritodrum, a small slender species along the coast S., has only 3 

 sepals, no petals, 3 stamens, and a 3-lobed fruit. 



2. SCHEUCHZEIIIA. (Named for the early Swiss botanist, Sckeuckxr.) 

 S. pall^stris. Peat-bogs from Penn. N. . 1° high : fl. early summer. ^ 



3. ALJSMA, "WATER-PLANTAIN. (The old Greek name, of uncertain 

 meaning. ) Fl. all late summer. 



A. Plant&gO. Shallow water : leaves long-petioled, vaiying from or oblong- 

 heart-shaped to lanceolate, 3 - 5-ribbed ; panicle 1° - 2° long of very many and 

 loose small flowers, y, 



4. ECHI!N"<3D0RUS. (Named probably from Greek words for prickly 

 flusk, the head of fruit being as it wore prickly-pointed by the styles, but 

 hardly so in our species. The following occur in muddj or wet places, chiefly 

 W. & S. : fl. summer ; the flowering shoots or scapes mostly proliferous and 

 creeping. 



' E. pdrvulus : a tiny plant, l'-3' high, with lanceolate or spatulate leaves, 

 few-flowered umbels, 9 stamens, and almost pointless akenes. ® 



E. rostratUS, with broadly heart-shaped leaves (l'-3' long, not including 

 the petiole) shorter than the erect scape, which bears a panicle of proliferous 

 umbels ; flower almost ^' wide ; 12 stamens ; akeuos beaked with slender 

 styles, (j) 



E. radlcans, with broadly heart-shaped and larg-er leaves (3' - 8' wide) 

 which are very open or almost truncate at base ; the creeping scapes or stems 

 becoming l°-4° long and bearing ma'ny whorls'; flowers |'-3' broad; akenes 

 short-beaked. 



5. SAGITTARIA, ARROW-HEAD. (From the Latin for nrrow, from 

 the s.igittate leaves which prevail in the genus. In shallow water : fl. all 

 summer. ^ 



* Filaments long and slender, i. e. as long as the linear-oblong anthers. 

 S. laucifblia. Common from Virginia S. : with the stout leaves l°-3° 

 and scapes 2° - 5° high, the coriaceous blade of the former lance-oblong and 



