100 



ALISMACEAE 



2. Echinodorus cordifolius (L.) Griseb. 

 Upright Bur-head. Fig. 210. 



Alisma cordifoUa L. Sp. PI. 343. 1753. 



Echinodorus rostratus Engelm. in A. Gray, Man. ed. 2, 



538. 1856. 

 Echinodorus cordifolius Griseb. Abh. Kon. Gesell. Wiss. 



Gott. 7: 257. 1857. 



Leaves various, broadly ovate to lanceolate, 

 4-20 cm. long, obtuse or acute at the apex, com- 

 monly truncate or cordate at the base, 3-13- 

 veined ; petioles usually longer than the blades, 

 angled ; scapes solitary or clustered, 1-5 dm. tall 

 or more, simple or branched from the lower 

 whorls of the inflorescence ; pedicels 7-15 mm. 

 long, not very variable in length ; bracts lanceo- 

 late or linear-lanceolate ; sepals ovate, 4-5 mm. 

 long, rather acute ; petals white, twice as long as 

 the sepals or less, usually broader ; fruiting heads 

 bur-like, globose to ovoid, 4-10 mm. in diameter ; 

 achenes, 2.5-3 mm. long, the body cuneate, flat- 

 tish, very prominently ribbed, the beak slender, 

 fully one-half as long as the body. 



Borders of ponds and ditches. Austral Zones; Illinois 

 and Missouri to tropical America. On the Pacific Coast 

 it is found from the lower San Joaquin Valley, and Santa 

 Clara County, California, to Lower California. Type 

 Inralitv: Virginia. 



4. LOPHOTOCARPUS T. Durand, Ind. Gen. Phan. X. 1888. 



Annual aquatic or bog plants with basal long-petioled sagittate or cordate leaves, simple 

 erect scapes bearing flowers in several verticils of 2-3 at the summit, the lower perfect, the 

 upper staminate. Petals white. Sepals distinct, enclosing or enveloping the fruit. Recep- 

 tacle strongly convex. Stamens 9-15, hypogynous, inserted at the base of the receptacle. 

 Pistils numerous with solitary ovules and an elongated persistent style. Achenes winged or 

 crested; embryo horseshoe-shaped. [Greek, referring to the crested achenes.] 



An American genus of about 7 species, distributed from the cool temperate to the tropical regions. Type 

 species, Sagittaria calycina Engelm. 



1. Lophotocarpus californicus J. G. 



Smith. 

 California Lophotocarpus. Fig. 211. 



Lo[<hotocarpus californicus T. G. Smith, Rep. Mo. Bot. 

 Card. 11: 146. 1899. 



Plants einersed or subtuerged. Leaves 

 usually erect, mostly 1.5-5 dm. tall, the petioles 

 slender, hastate or sagittate, 2-6 cm., includ- 

 ing the divergent basal lobes, these as long as 

 the terminal lobe or shorter ; scapes about as 

 long as the leaves, with 3-5 rather approxi- 

 mate whorls ; sepals broadly ovate or suborbic- 

 ular, becoming 6-9 mm. long ; fruiting pedi- 

 cels short and thick, 1-2 cm. long, as long as 

 the internodes or nearly so ; fruiting heads 

 10-12 mm. in diameter; achenes cuneate or 

 obovate-cuneate, nearly 2-5 mm. long, the 

 beak minute, the dorsal wing broad and thick. 



Quiet, shallow water. Upper and Lower Sonoran 

 Zones; Lake County, Oregon, to Sacramento Valley 

 and southern California. Type locality: Coyote Creek, 

 Los Angeles County, California. 



5. SAGITTARIA L. Sp. PI. 993. 1753. 



Perennial aquatic or marsh herbs with tuber-bearing or nodose rootstocks. Leaves with 

 nerves connected by numerous veinlets. Scapes erect, decumbent or floating. Flowers 

 monoecious or dioecious, borne near the summit of the scapes in whorls of threes, pediceled. 

 the staminate usually uppermost, whorls 3-bracted. Perianth-segments 6, the outer three 

 herbaceous, persistent and reflexed or spreading in the pistillate flowers. Stamens numerous. 

 inserted on the convex receptacle ; anthers 2-celled, dehiscent by lateral slits. Pistillate flowers 

 with numerous distinct 1-ovuled ovaries and small persistent stigmas. Achenes densely 

 aggregated in globose heads, compressed; seeds curved; embryo horseshoe-shaped. [Latin, 

 in reference to the shape of the leaves.] 



