320 WATER-PLANTAIN FAMILY. 



8. ALISMA. Flowers perfect, loosely panicled. Petals involute in the bud. 

 Stamens 6. Ovaries many, in a ring, very flat-sided, becoming coriaceous 

 flat akenes, 2 - 3-keeled on the back. 



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

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

 less akenes. 



6. SAGITTAKIA. Flowers monoecious, rarely dioecious or polygamous, in 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. 



III. FLOWERING-RUSH FAMILY. (BUTOJIEJE.) Dif- 

 fers from the preceding mainly in the few ovaries having numerous 

 ovules distributed all over ihe inside. 



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

 mens numerous 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. paliistre. Slender, 6' -18' high, with linear-club-shaped ovary and 

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



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

 rounded at base. Var. EL\TUM, in bogs of the interior, N., 20' -30' high, the 

 pieces of the fruit sharp-angled on the back. 



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

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



2. SCHEUCHZERIA. (Named for the early Swiss botanist, Scheuchzer.) 

 S. pallistris. Peat-bogs from Penn. N. : 1 high : fl. early summer. ^ 



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

 meaning.) Fl. all late summer. 



A. PlantagO. Shallow water : leaves long-petioled, varying from or oblong- 

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

 loose small flowers. % 



4. ECHIN6DORUS. (Named probably from Greek words for prickly 

 flask, the head of fruit being as it were prickly-pointed by the styles, but 

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

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

 creeping. 



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

 few-flowered umbels, 9 stamens, and almost pointless akenes. (T) 



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; akenes beaked with slender 

 styles. 



E. radicans, with broadly heart-shaped and larger leaves (3 r - 8' wide) 

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

 becoming l-4 long and bearing many whorls ; flowers $'-\' broad ; akenes 

 short-beaked. 



5. SAGITTABJA, ARROW-HEAD. (From the Latin for arrow, from 

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

 summer. 2/ 



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



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

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



