ALISMACEAE. 



Vol. I. 



i. Alisma subcordatum Raf. Amer- 

 ican Water-plantain. Fig. 221. 



Alisma subcordatum Raf. Med. Repos. N. Y. 5 : 



362. 1808. 

 Alisma Plantago Bigel. Fl. Bost. 87. 1814. 

 Alisma Plantago parvifiorum Torr. Fl. N. U. S. 



382. 1824. 

 Alisma Plantago americanum R. & S. Syst. 7 : 



1598. 1830. 



Plants erect; leaves oblong, elliptic, oval or 

 ovate, or sometimes narrower, li'-6' long, 

 usually abruptly pointed at the apex, cuneate 

 to truncate, or cordate at the base, the petioles 

 often longer than the blades; scapes i°-3° tall, 

 solitary or several together, the branches and 

 pedicels in whorls of 3-10, variable in length, 

 usually slender, sometimes filiform; bracts 

 lanceolate or linear, often acuminate ; sepals 

 broadly ovate to suborbicular, obtuse; petals 

 white or pinkish, i"-i" long; achene-heads 

 il"-2i" broad, the achenes obliquely obovate, 

 i"-i" long, the beak small, ascending. 



In shallow water and mud, Massachusetts to 

 Minnesota,- Florida and Texas. Differs from 

 the Old World A. Plantago-aquatica L., with which it has been united. Great Thrumwort, Mad- 

 dog-weed, Deil's-spoons. June-Sept. 



2. Alisma brevipes Greene. Western Water- 

 plantain. Fig. 222. 



Alisma brevipes Greene, Pittonia 4: 158. 1900. 



Alisma superbum Lunell, Bull. Leeds Herb, 2 : 5. 1908. 



Plants similar to A. subcordatum in habit, but com- 

 monly larger; leaves oblong or oblong-lanceolate to 

 ovate, a'-7i' long, acute, sometimes abruptly pointed at 

 the apex, rounded, truncate or subcordate at the base 

 or sometimes gradually narrowed to the petiole which 

 commonly exceeds the blade in length; scapes 3° tall or 

 less, the branches and pedicels very numerous, except in 

 small plants ; bracts lanceolate or linear-lanceolate ; 

 sepals suborbicular or orbicular-ovate, mostly over i4" 

 long; petals white, 2V-3" long; achene-heads 2i"-3i" 

 broad, the achenes obovate, ii"-ii" long. 



In swamps and streams, Nova Scotia to Ontario, British 

 Columbia, North Dakota and California. July-Sept. 



3. Alisma Geyeri Torr. Geyer's 

 Water-plantain. Fig. 223. 



Alisma arcuatum Lunell, Bot. Gaz. 43: 210. 

 1907. Not Michalet. 1854. 



Alisma Geyeri Torr. in Nicollet, Rep. Hydro- 

 graph. Miss. Riv. 162. 1843. 



Plants diffuse; leaves- oblong, elliptic, 

 oblong-lanceolate or ovate-lanceolate, or 

 rarely linear, a'-3i' long, acute or slightly 

 acuminate at the apex, narrowed at the 

 base, the petioles usually longer than the 

 blades ; scapes mostly J°-ii° long, more or 

 'ess diffusely spreading, the branches and 

 pedicels relatively stout ; bracts lanceolate ; 

 sepals orbicular-ovate, about ii" long; 

 petals pink, i"-2" long; achene-heads 2i"- 

 2!" broad, the achenes suborbicular, about 

 1 in diameter, the beak erect or nearly so. 



In mud and shallow water, New York to 

 North Dakota, Oregon and Nevada. July-Sept. 



