ELATINACEAE 133 



fruiting calyx inflated. — Adventized in fields and along loads thronghout. 

 Eather common. June-September. 



Family 83. HYPERICACEAE Lindl. 

 Herbs witli opposite, entire, punctate or blaok-dotted leaves, and 

 oymose-panioulate regular and perfect flowers. Sepals and petals 5 each. 

 Stamens few-many, often in sets. Ovary 1-celled with 3-5 parietal 

 placentae or 3-5-oelled. Ovules numerous. Leaves usually sessile. 



1. HYPERICUM L. St. John's Wort. 



Characters of the family as given above. 



Flowers V-2' broad. 1. 3. Ascyron. 

 Flowers 3"-12" broad. 



Stems 4-angled. 2. M. sphaerocarpum. 

 Stems terete. 



Leaves clasping at base. 3. S. maculatum. 



Leaves tapering to base. 4. H. corynibosum. 



Flowers \"-'i" broad. 5. H. mutilum. 



1. H. Ascyron L. 3°-6° high : leaves ovate-oblong : pods 5-celled : 

 styles 5 : stamens numerous, 5-adelphous. — In woods near Independence, 

 Courtney and Atherton. Very local. July- August. 



2. H. sphaerocarpum Michx. 1°-2J° high :, leaves oblong-linear : 

 pods 1-celled : styles three : stamens numerous, not in groups. — On rocky 

 banks and in low grounds throughout. Eather common. July-August. 



3. H. maculatum Walt. l°-2° high : leaves oblong-elliptic, strongly 

 black-dotted, as are the petals and sepals : pods 3-celled : styles 3 : sta- 

 mens numerous. 3- or 5-adelphous.^ — Not uncommon on low prairies in 

 the southern part. July-September. 



4. H. corymbosum Mnhl. Like the last but leaves strongly tapering 

 at base and less blaok-dotted : sepals hardly dotted. — Frequent in woods, 

 especially in the northern part. July-September. 



5. H. mutilum L. 6''-34'' high : leaves ovate-oblong : pods 1-oelled : 

 styles 3 : stamens 5-12. Locally common in low grounds. Adams, 

 Courtney, Buckner. July-September. 



Family 84. ELATINACEAE Lindl. 

 Herbs with opposite stipulate leaves and axillary regular and perfect 

 flowers. Sepals, petals and stamens 3-5 each. Ovary 2-5-oelled and 

 styles 2-5. Ovules numerous. Seeds striate. 



Parts of the flowers in twos and fours. 1. Elatikb. 



Parts of the flower in fives. 2. Bebgia. 



1. ELATINE L. 



Small glabrous marsh herbs. 



1. B. Americana (Pursh) Arn. Wateewoet. e'^-lS" long : leaves 

 obovate, entire, l''''-3" long : parts of the flowers in twos : seeds more 



