BUR-REED FAMILY 21 



bracts. Perianth reduced to a few (3-6) irregular chaffy scales. Stamens 

 usually 5, distinct. Ovary 1- (seldom 2-) celled; style 1; stigma 1, seldom 

 2. Fruit nut-like, 1- or 2-celled, 1- or 2-seeded. Ovules anatropous. Endo- 

 sperm copious. 



1. SPARGANIUM (Tourn.) L. BUR-REED. 



Characters of the family. 



Achenes broadly obovoid or cuneate-obpyramidal, sessile, long-beaked; stigmas usually 



2 ; leaves somewhat keeled. 1. S. eurycarpum. 



Achenes fusiform (in 5. minimum somewhat obovoid, but then short-beaked and short- 



stipitate) ; stigmas solitary. 



Stipe and beak of the fruit each 2 mm. long or more; fruiting heads 1.5 cm. in diam- 

 eter or more; anthers 3-4 times as long as broad. 



Leaves, at least the middle ones, strongly triangular-keeled ; fruiting heads about 

 3 cm. in diameter; achenes brown, gradually tapering into the beak, which is 

 fully as long as the body. 2. S. simplex. 



Leaves not keeled or only slightly so, narrow and slender; stem often floating; 



beak of the achenes decidedly shorter than the body. 



Leaves usually 5-10 mm. wide, as well as the bracts conspicuously scarious- 

 margined; heads 1.7-2 cm. in diameter; achenes gradually beaked. 



3. S. multipedunculatum. 

 Leaves 3-4 mm. wide, not conspicuously scarious-margmed ; heads about 1.5 



cm. in diameter; achenes abruptly beaked. 4. S. angustifolium. 



Stipe and beak of the fruit short, less than 1 mm. long; fruiting heads about 1 cm. 

 in diameter; stigmas oblong; anthers 1.5-2 times as long as broad. 



5. S. minimum. 



1. S. eurycarpum Engelm. A stout glabrous perennial marsh plant, 5-25 

 dm. high; leaves linear, 5-10 dm. long, 7-10 mm. wide; inflorescence more or 

 less compound, the branches usually with one or two pistillate heads and several 

 staminate heads; the former compact, in fruit 2-2.5 cm. in diameter; achenes 

 bluntly 4- or 5-angled, the top rounded, flat or even a little depressed, abruptly 

 contracted into the style. In swamps and along streams: Newf. Fla. Utah 

 Calif. B.C. Plain Submont. Je-Au. 



2. S. simplex Huds. A slender marsh plant, 3-7 dm. high; leaves linear, 

 5-9 dm. long, 8-15 mm. wide; inflorescence simple; pistillate heads 2-5, generally 

 sessile or the lower ones peduncled, usually supra-axillary; achenes fusiform, 

 often contracted in the middle, and gradually acuminate at the apex. In marshes 

 and shallow water: Que. Ont. 'Wash. B.C.; Eu. Submont. Je-Au. 



3. S. multipedunculatum (Morong) Rydb. A rather slender marsh 

 plant, 3-5 dm. high; leaves linear, 2-5 dm. long, slightly keeled; inflorescence 

 simple or a little branched ; staminate heads 3-5, often close together, but distant 

 from the pistillate ones; these 2-6, the upper ones sessile, the lower peduncled, 

 and most often axillary; achenes fusiform, gradually acuminate above. S. sim- 

 plex multipedunculatum Morong. S. subvaginatum Meinsh , in part. In shallow 

 water: Mack. w Ont. Mont. Colo. Calif. B.C. Plain Subm. Je-Au. 



4. S. angustifolium Michx. A slender, more or less floating water plant; 

 leaves narrowly linear, 3-6 dm. long, flat, not keeled, often dilated at the base, 

 floating; inflorescence mostly simple; staminate heads 2-5; pistillate ones 2-4, 

 sessile, or the lowest one peduncled and supra-axillary; achenes fusiform, abruptly 

 acuminate at the apex. S. simplex angustifolium Engelm. In deep water: 

 Newf Conn. Pa. Colo. Calif. B.C. Plain Subalp. Je-Au. 



5. S. minimum Fries. A slender and floating water plant; stem 1-3 dm. 

 long, or in shallow water shorter and erect; leaves 1-4 dm. long, 1-7 mm. wide, 

 thin and flat, usually floating; inflorescence simple; staminate heads 1 or 2, close 

 together; pistillate heads 1-3, sessile or the lowest peduncled and axillary; body 

 of the achenes obovoid, abruptly contracted into a short beak. Ponds and 

 streams: Lab. N.J. Mich. Utah Ore. Alaska; Eurasia. Mont. Subalp, 

 Je-Au. 



Family 7. ZANNICHELLIACEAE. PONDWEED FAMILY. 



Immersed water plants, with slender jointed, often branching stems, flat 

 leaves, and perfect or monoecious flowers, in axillary spikes or clusters. 



