233 PRACTICAL BOTANY. 



Stamens not over 10, not jointed on a pedicel. Ovary not 



stalked. Herbs without milky juice 685 



G85, Stipules of the alternate leaves sheathing the stem 

 above the tumid joints. Stamens 8 (rarely G or 5). Styles 



3, or 2. Achenium 3-comered 086 



Stipules not sheathing, or altogether wanting. .688 



686. Pedicels usually (not always) fascicled 687 



Pedicels solitary, with imbricated, truncate bracts. 



Sepals erect-spreading, 3 of them at length closed, wither- 

 ing-persistent on the achenium. Leaves linear, caducous 

 from the top of the tubular, truncate sheath. 



Polygonella articulata, Meisn. 

 {Pohjf/onuni artlculatum., L.) 



687. Sepals all at length closed on the achenium. Em- 

 bryo semilunar! y curved around half of the albumen. 



Polygonum. 



Sepals all open. Stamens with nectariferous 



glands between. Embryo straight in the centre of the 



albumen ; cotyledons twisted-plaited. Leaves triangular, or 



halberd-form. Fagopyrmn esculentum, Moench. 



688. Perianth 4-cleft or sepalled 689 



Perianth 5-parted or sepalled 690 



689. Perianth 4-cleft, greenish-yellow, with purple lines. 

 Ovary half superior, 2-styled. Stamens 8, very short ; an- 

 thers orange-colored. Flowers in leafly cymes, the terminal 

 one 10-androus. Leaves orbicular, crenate, chiefly opposite. 

 Aquatic herb. Chrysosplenium Americaniun, Schw. 



Perianth 4-sepalled. Ovary entirely superior, 1- 

 styled. Stamens 6, 4 of them antherless. Silicic kidney- 

 form, or bitubercular, 2-seeded. Senebiera didyma, Pers. 



690. (678.) Styles or stigmas 2, or style 1, bifid 691 



Styles or stigmas 4 or 3 692 



691. Perianth bell-shaped, 5-parted. Stamens 5 (or 10, 

 only 5 of them fertile). Styles 2. Joints of the stem swol- 

 len. Stipules none. Seleranthus annuus, L. 



Perianth o-sepalled. Sometimes bristles in place 

 of the corolla. Stamens 5, 3, or 2. Style bifid, or sessile. 

 Stigmas 2. Flowers small, enveloped in dry bracts. Sti- 

 pules scarious, silvery. Paronychia & Anychia. 



