ELATINACEAE. 241 



Family 64. ELATINACEAE. WATERWORT FAMILY. 

 Low annual marsh herbs; leaves opposite, not punctate, with 

 membranous stipules; flowers minute, axillary, regular, sym- 

 metrical; sepals 2-5, free; petals 2-5, hypogynous; stamens as 

 many or twice as many as the petals; ovary 2-5-celled, with a 

 many-ovuled axile placenta; fruit a capsule. 



Plants glabrous; flower parts 2-4. 319. ELATINE, 241. 



Plants pubescent; flower parts 5. 320. BERGIA, 241. 



319. ELATINE. 



Dwarf glabrous plants growing in or near the water, often 

 rooting at the nodes; sepals 2-4, obtuse; petals 2-4, hypogynous; 

 stamens as many or twice as many as the petals; styles or sessile 

 stigmas 2-4; pod membranaceous, 2-4-celled, several-many- 

 seeded. 



Elatine americana (Pursh) Arn. Mostly branched from the base, spreading 

 to erect, 2-4 cm. high; leaves obovate, obtuse, 2-5 mm. long; flowers sessile, 

 the parts mostly in twos, rarely in threes; capsule globose; seeds subcylindric, 

 slightly curved, marked with 9 or 10 longitudinal lines and 20-30 cross lines. 



Moist banks of the Columbia River, according to HowelL 



320. BERGIA. 



Diffuse or ascending herbs, branching, often pubescent; leaves 

 entire or serrate; flowers axillary, solitary or clustered; parts of 

 the flowers in fives; sepals acute, each with a prominent midrib; 

 capsule crustaceous, ovoid, 5-valved; seeds numerous. 



Bergia texana (Hook.) Seubert. Annual, branched from the base, 4-20 

 cm. high; stems erect or ascending, glandular-pubescent; leaves lanceolate, 

 obovate or spatulate, serrate, 1-2 cm. long, petioled; flowers in small axillary 

 fascicles; sepals acuminate, 3 mm. long, equalling the white or pinkish petals; 

 stamens 5 or 10. 



Banks of the Columbia River, perhaps reaching our limits. 



Family 65. VIOLACEAE. VIOLET FAMILY. 

 Herbs with alternate or basal leaves, with stipules; flowers 

 perfect, axillary, nodding; sepals 5, hypogynous; corolla some- 

 what irregular, 1-spurred, of 5 petals; stamens 5, hypogynous; 

 anthers adnate, united over the pistil; ovary 1-celled, with 3 

 parietal several-ovuled placentae; capsule 3-valved; endosperm 

 copious. 



321. VIOLA. VIOLET. 



Mostly perennial herbs; leaves alternate, with foliaceous 

 stipules; peduncles 1-flowered, axillary; flowers usually of two 



17 



