TYPHACE^. (cat-tail FASIILY.) 481 



2. SPARGANIUM, Tourn. Pur-keed. 



Flowers collected in separate dense and spherical leafy-bracted heads, which 

 are scattered along the summit of the stem; the upper ones sterile, consistinj; 

 merely of stamens, with minute scales irregularly interposed ; the lower or fer- 

 tile larger, consisting of numerous sessile pistils, each surrounded by 3 -6 scales 

 much like a calyx. Fruit wedge-shaped or club-shaped. — Kootstocks creeping 

 and stolonifcrous : roots fibrous. Stems simple or branching, sheathed l)elow 

 by the base of the linear leaves. Flowering through the summer. ( Xame from 

 aniipyavov, aJiUet, from the ribbon-like leaves.) By Dr. G. Engelmann. 



♦ Enct, with branched inflorescence of numerous heads: pistil as lonrjas the surround- 



ing truncate scales, attenuated into a short style bearing one or ojlen two elongated 

 stigmas : nuts sessile, wedge-shaped, angular: leases for the greater part flat and 

 merely keeled, the base triangular with concave sides. 



1. S. euryc&.rpum, Engelm. Fruit many-angled (3j"-4"long) when 

 fully ripe, with a broad and depressed or retuse summit (2^"-3|" wide) ab- 

 ruptly tipped in the centre ; fruit heads 1' wide. (S. ramosum, in part, of most 

 American botanists.) — Borders of ponds, lakes, and rivers, from New Kngland 

 and Pennsylvania northward and westward. — Stems stout, 2° - 4° high ; heads 

 2 to 6 or more : the largest species known. 



(S. ram6sum, Hudson, of Europe, has not yet been found on this continent: 

 It is distinguished by smaller heads, and smaller, few-angled, usually 1 -seeded 

 fruit, with a conical and long-pointed summit.) 



* * Erect or rarely floating, with simple (or rarely branched) inflorescence of numer- 



ous heads ; the conspicuous style longer than the spatulate denticulate scales : stig- 

 mas always single, linear or oolong : nuts attenuated at both ends, and with a 

 stalked base, nearly terete : stems rather slender : leaves {unless floating) triangu- 

 lar with flat sides in the lower half. 



2. S. simplex, Hudson, genuinum. Erect (9'- 15' high), slender; in- 

 florescence simple, the lower heads supra-axillary, sessile or commonly pedun- 

 cled (""-8" wide); stigma linear, equal to the style; fruit more or less con- 

 tracted in the middle. — New England and northward. (Eu.) 



Var. Nuttallii. Like the last or type, but heads axillary ; stigma linear- 

 oblong, shorter than the style; fruitless contracted. (S. Americanum, A^u?/.) 

 — From Pennsylvania and New England northward and northwestward. — In- 

 florescence rarely branched ; heads 8" - 9" wide. 



Var. androcladum. Stouter (l^°-3° high) ; inflorescence branched be- 

 low; branches bearing numerous sterile (rarely also 1 or even 2 fertile) heads; 

 stigma linear, as long as the style; fruit larger, not contracted, long-tapering 

 upwards and dcwnwards. (S. ramosum, in part, of American authors.) — From 

 New England southward and especially westward. — Heads 10"- 12" wide. 



Var. fltiitans. Leaves floating ; inflorescence branched ; branches bearing 

 fertile heads below ; stigma oval, shorter than the style ; fruit somewhat con- 

 tracted and with a short stipe. (S. fluitans, Fries.) — Ponds at the base of the 

 White Mountains, Oakes. — Heads 6" -7" wide. (En.) 



Var. augustifdlium. Leaves floating, longer and narrower than in the 

 GM 21 



