10 NORTH AMERICAN FLORA ([VoLuME 17 
about 2 mm. long, curved; stigma short, oblique, oblong; anthers oblong, about one third 
as broad as long. 
TYPE LOCALITY: Ponds at the base of the White Mountains [New Hampshire]. 
DISTRIBUTION: Cold lakes and ponds, from Maine to Connecticut and Minnesota. 
ILLUSTRATION: Bull. Torrey Club 15: 1. 79, f. 6. ‘ 
14. Sparganium minimum Fries, Summa Veg. Scand. 2: 560. 1849. 
Sparganium natans Oeder, Fl. Dan. 25: 5. 1764. Not S. matansL, 1753. 
Sparganium natans gp I,. Fl. Suec. ed. 2. 323. 1755. 
Sparganium angustifolium A, Gray, Man. ed. 2. 430. 1856. NotS. angustifolium Michx. 1803. 
Perennial, with a creeping rootstock, more or less thickened at the end; stem in deep 
water floating, 1-3 dm. (rarely 1 m.) long, in shallow swamps sometimes erect, in mud 
decumbent or ascending, much shorter; leaf-blades dark-green, 1-2 dm., in deep water 
sometimes 4 dm. long, 1.5-7 mm. wide, obtuse, flat; upper sheaths somewhat dilated but 
rarely scarious; peduncles somewhat bent; pistillate heads about equally distant, 1-3, axil- 
lary, the lowermost sometimes short-stalked, in fruit about 1 cm. in diameter; achenes 
greenish-brown, dull, broadly ellipsoid or obovoid, usually constricted below the middle, 
acute at both ends, sessile or rarely short-stipitate, short-beaked, the beak 0.5-1.5 mm. 
long; stigmas oblong, oblique; sepals spatulate, scarcely clawed, erose at the apex; 
Staminate heads usually solitary, usually at some distance from the uppermost pistillate 
one; anthers short, about twice as long as broad. 
TYPE LOCALITY: Sweden. 
DISTRIBUTION: Labrador to New Jersey, Tennessee, Utah, Oregon, and Alaska; also in 
Europe and Asia. 
ILLUSTRATIONS: Fl. Dan. p/. 260 (as S. natans); Bot. Notiser 1852: p/.1, 7.2; Fl. Deuts. ed. 
5. pl. 134; Bull. Torrey Club 15: p/. 79, 7.9; Britt. & Brown, Ill. Fl. f. 147; Engler, Pilanzen- 
reich 410; 7.5.4. 
15. Sparganium Williamsii Rydberg, sp. nov. 
Perennial, with a horizontal rootstock; stem slender, ascending, about3 dm. high; leaf- 
blades light-green, 1-3 dm. long, 3-4 mm. wide, obtuse, cellular-reticulate, especially the 
lower part; sheaths, especially those of the bracts, dilated and decidedly scarious- 
margined ; peduncles strict; pistillate heads 3-4, the lower two usually on supra-axillary 
peduncles 1-3 cm. long, the upper sessile, in fruit 8-10mm. in diameter; sepals oblance- 
olate, gradually tapering downward, erose at the apex, about half as long as the achenes; 
achenes yellowish-green, dull, ellipsoid, acute at both ends, sessile, usually somewhat con- 
stricted below the middle; beak fully 0.5 mm. long; stigma short, ovate; staminate heads 
usually solitary, confluent with the upper pistillate one, or on a very short stalk; anthers 
short, about half longer than broad. 
Type collected at Klondike Bottom, Yukon Territory, in July, 1899, R.S. Wiliams (herb. N. Y. 
Bot. Gard.). 
16. Sparganium hyperboreum Laest.; Beurl. Oefv. Sv. Vet.- 
Akad, Forh. 9: 192. 1852. 
Sparganium natans submuticum Hartm. Handb. Skand. Fl. ed. 4. 312. 1843. 
Sparganium submuticum Hartm. Handb. Skand. Fl. ed. 12. 108. 1889. 
Sparganium angustifolium Meinsh. Ml, Biol. Acad. St. Petersb. 13: 396. 1893. Not P. angusti- 
Jolium Michx. 1803. 
Perennial, with a rootstock ; stem slender, in deep water elongated, floating, sometimes 
5 dm. long, in shallow water or mud decumbent or ascending, 1-2 dm. long; leaves light- 
green, flat or slightly round-keeled at the base, 1-4 mm. wide, in deep water sometimes 6 
dm. long; sheaths slightly dilated but not scarious-margined ; peduncle more or less flex- 
uose ; pistillate heads 2-4, the lower one or two usually stalked and supra-axillary, in fruit 
8-10 mm. in diameter; achenes dark-yellow, dull, ellipsoid, acute at both ends, neither 
stalked nor beaked; stigmas sessile, irregularly nipple-shaped ; sepals about half as long as 
the fruit, clawed; blades cuneate or cuneate-spatulate, truncate; staminate heads usually 
solitary, often close to the uppermost pistillate one; anthers short, about one and a half 
times as long as broad. 
TYPE LOCALITY: Manu, Torne Lapmark, Sweden. 
DISTRIBUTION : Greenland to Newfoundland, Hudson Bay, and Alaska; also in arctic and sub- 
arctic Europe and Asia. : 
ILLUSTRATIONS : Fl. Dan. f/. 2792; Bull. Torrey Club 15: £1. 79, f. 10; Engler, Pflanzenreich 
0: LIC. 
