24 TYPHACEAE. 



densely crowded in a terminal spike, often subtended by spatha- 

 ceous bracts; ovary one, 1- or 2-celled, with as many persistent 

 styles; fruit nutlike. 



33. TYPHA. 



Flowers in a dense cylindrical spike; staminate and pistillate 

 portions of the spike contiguous; stamens with very short con- 

 nate filaments, mixed with numerous long hairs; ovary long- 

 stalked, 1-celled, surrounded by numerous bristles and rudi- 

 mentary ovaries; fruit minute, usually splitting on one side. 



Typha latifolia L. Cat-tail. Stout, 1-3 m. tall; leaves flat, sheathing at 

 base, 1-2 cm. wide; pistillate and staminate portions of the spike close to- 

 gether, each 8-30 cm. long, the pistillate dark brown; stigmas rhombic- 

 spatulate; pollen grains in fours. 



Margins of lakes and ponds, abundant. 



Family 11. SPARGANIACEAE. Bur-reed Family. 



Marsh or pond herbs with creeping rootstocks and erect or 

 floating stems ; leaves linear, alternate, 2-ranked, sessile, sheath- 

 ing at the base ; flowers monoecious, densely crowded into globose 

 heads which are in a raceme on the upper parts of the stem and 

 branches, the staminate above; spathes linear; perianth of a few 

 chaffy scales; stamens usually 5; fruit mostly 1-celled, nut-like. 



34. SPARGANIUM. Bur Reed. 



Characters of the family. 



Heads all axillary; inflorescence branched. 5. androcladum. 



Heads, or at least some of them, supra-axillary. 



Leaves, or at least the larger ones, keeled; plants usually 



terrestrial. 5. simplex. 



Leaves not keeled; floating aquatics. 



Beak of fruit short-conical; stigma oblong. S. minimum. 



Beak of fruit slender; stigma linear. S. angustifolium. 



Sparganium androcladum (Engelm.) Morong. Stems stout, 40-100 cm. 

 high; leaves 5-12 mm. wide, dark green; inflorescence branched, the branches 

 strictly axillary, each bearing 3-7 staminate heads and usually 1 or 2 pistillate 

 heads; fruiting heads 2-2.5 cm. in diameter; fruit dull, the fusiform body 

 5-6 mm. long, the beak about 3 mm. long. 



Margins of ponds and lakes, common. 



Sparganium simplex Huds. Stems rather stout, 30-60 cm. high; leaves 

 thin, 6-15 mm. broad, scarious-margined below; inflorescence simple; fruiting 

 heads 12-25 mm. in diameter, some of them supra-axillary; fruit fusiform, 

 somewhat shiny, the body 3-4 mm. long, tipped with a beak about as long; 

 stalk 1-2 mm. long; stigmas linear. 



More common than S. androcladum and occurring in similar places. 



