Water-Plantain Family 17 



eter; achenes obovate or falcate, 6-8-ribbed; beak apical oblique, 

 1.5 mm. long. (E. rostratus Engelrn.) 



Occasional along streams and banks of ponds. May-July. 



2. LOPHOTOCARPUS Durand. 



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. Re- 

 ceptacle strongly convex. Stamens 9-15, hypogynous 

 inserted at the base of the receptacle. Pistillate numer- 

 ous with solitary ovules and an elongated persistent 

 style. Achenes winged or crested ; embryo horseshoe- 

 shaped. 



1. It. calycinus (Engelm.) J. G. Smith. Scapes weak, at length 

 decumbent; leaves floating or ascending, entire, hastate or sagit- 

 tate, the basal lobes spreading ovate, acute or acuminate, 2-16 

 cm. long; verticils of flowers 1-5; bracts membranous, orbicular 

 or ovate, or those of the staminate flowers lanceolate ; pedicels 

 recurved in fruit ; petals 6-8 mm. long ; filaments flattened, papil- 

 lose; achenes obovate, 2 mm. long, narrowly winged on the mar- 

 gins, tipped with a short horizontal triangular beak. (Sagittaria 

 calycina Engelm.) 



Ballona Creek. 



3. SAGITTABIA L. ARROW-HEAD. 



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 3's, pedicelled, the staminate 

 usually uppermost, whorls 3-bracted. Perianth seg- 

 ments 6, the outer 3 herbaceous persistent and reflexed 

 or spreading in the pistillate flowers. Stamens numer- 

 ous inserted on the convex receptacle ; anthers 2-celled, 



