CERATOPHYLLACEAE. 137 



1. L. squarrosa Nutt. Much branched, prostrate or ascending, 

 5-15 cm. high; herbage glandular-pubescent; leaves and sepals 

 subulate setaceous, rigid and recurved, the leaves 4-6 mm. long, 

 the sepals somewhat shorter; capsule elongated, triquetrous, ex- 

 serted, many-seeded. 



Streets of Los Angeles and Pasadena, Davidson, Mc Clatchie. 



10. PENTACAENA Bartl. 



Tufted perennials with subulate pungent leaves and 

 silvery-hyaline stipules. Flowers sessile, clustered in 

 the axils. Sepals 5, unequal, hooded, the 3 outer larger 

 and with a stout divergent terminal spine. Petals 

 minute, scale-like. Stamens 3-5, inserted at the base 

 of the sepals. Style very short, 2-cleft. Utricle enclosed 

 in the rigid persistent calyx. 



1. P. ramosissima H. & A. Stems prostrate, forming dense 

 mats 15-30 cm. broad, woolly-pubescent; leaves crowded on the 

 stems, 6 mm. long; sepals woolly, except the divergent apex; utricle 

 apiculate. 



Common in sandy soil along the coast. 



Family 33. CERATOPHYLLACEAE. 



HoRNWORT Family. 



Submerged aquatics with slender widely branching 

 stems and verticillate leaves, the monoecious or dioecious 

 flowers solitary and sessile in the axils. Perianth many- 

 parted, the vsegments entire or toothed. Stamens numer- 

 ous, crowded on a flat or convex receptacle; anthers ses- 

 sile or nearly so, linear oblong, extrorse, appendaged. 

 Ovary superior, 1 -celled; ovule 1, pendulous; style fili- 

 form. Fruit an indehiscent nut or achene. Endosperm 

 none; cotyledons 4, verticillate. 



1. CERATOPHYLLUM L. Hornwort. 



Leaves crowded in verticils^ linear or filiform, spinu- 

 lose-serrulate, forked. Staminate and pistillate flowers, 

 generally at different nodes. Stamens 10-20; anthers 

 about equaling the perianth. Ovary and fruit slightly 

 exceeding the sepals, the fruit beaked with the long per- 

 sistent style. 



