200 ALISMACE^. Alisma. 



sometimes \vithout blade; flowers long-pedicellate, mostly verticillate, in a loose 

 raceme or panicle, with lanceolate scarious bracts slightly connate at base. 



An order of 4 genera and perhaps 50 species, sparingly distributed through the temperate and 

 tropical regions of the globe. 



* Flowers perfect : stamens usually 6 : cai-pels verticillate. 



1. Alisma. Carpels numerous, distinct, obovate-oblong, flattened. 



2. Damasouium. Carpels 6 to 12, united at base, acuminate and radiately divergent. 



* * Stamens rarely few : carpels capitate. 



3. Echinodorus. Flowers perfect. Carpels several to many, turgid and ribbed, often beaked. 



4. Sagittaria. Flowei's moncecious or dioecious. Carpels numerous, flattened and niembranously 



winged. 



1. ALISMA, Linn. Water-Plantain. 

 Flowers perfect. Petals small. Stamens 6, rarely more, with short filaments. 

 Ovaries distinct, numerous, on a disk-like receptacle, 1-ovuled ; style very short, 

 ventral. Akenes in a crowded whorl, obovate-oblong, flattened, obtuse, somewhat 

 channelled on the back. — Perennial herbs, in shallow water or mud, Avith small 

 flowers in a verticillately branched panicle. 



About a dozen species, distributed through the northern temperate zone and tropical America ; 

 represented in the United States only by the following. 



1. A, Plantago, Linn. Stout; scape a foot or two high, diffusely paniculate 

 above : leaves ovate to oblong or lanceolate, often somewhat cordate at base, acute, 

 usually 7-nerved, 2 to 8 inches long, when groAving in water sometimes narrowly 

 lanceolate or linear : petals scarcely exceeding the sepals, a line long or less, white 

 or pinkish : carpels forming a circular or somewhat triangular whorl 2 or 3 lines in 

 diameter. — Eeichenb. Icon. Fl. Germ. vii. t. 57, 



About San Francisco and throughout Northern California to British Columbia, and eastward 

 across the continent ; also throughout Europe and northern Asia, and in Australia. The most 

 common species, and very variable as respects foliage, the forms being determined chiefly by the 

 place of gi'owth and not deserving to rank as varieties. 



2. DAMASONIUM, Juss. 



Flowers perfect. Stamens 6, with slender filaments. Ovaries 6 to 12, united by 

 the short ventral side, flattened, ovate and attenuate upward, 1 - 2-ovuled ; stigma 

 terminal. Akenes long-acuminate, radiately and horizontally divergent, — Perennial 

 herbs, with the habit of Alisma, but scapes simple. 



Two or three other species occur in the Mediterranean region, and one in Australia. 



1. D. Californicum, Torrey, Scapes usually more than one, from a somewhat 

 enlarged base, G to 18 inches high : leaves with usually much elongated slender 

 petioles, the blade ovate to narrowly lanceolate, 1 to 3 inches long, acutish or obtuse, 



3 - .5-nerved : flowers in 3 or 4 whorls, on pedicels an inch or two long : petals 3 or 



4 lines long, rounded, incised at the summit, exceeding the oblong obtuse sepals : 

 carpels usually 8 or 9, abruptly narrowed to a long rigid beak, much compressed, 4 

 or 5 lines long, 1 -seeded. — Pacif, P. Pep. iv. 142, t. 21 ; Benth, PI. Hartw, 341, 

 Alisma Californica, Bolander, Cat. 29. 



Valleys in the Sierra Nevada ; lone Valley, Amador County, in \\'a.ter (Bigclow) ; Sierra Valley 

 {Lemmon) ; also found by Hartimj. 



3. ECHINODORUS, Richard. 

 Flowers perfect. Petals small. Stamens 6 to many, with short slender filaments. 

 Ovaries usually numerous, crowded in a globose head, distinct, more or less attenuate 



