158 ■ PODOSTEMACEAE 



Endosperm present, usually copious and fleshy : stipules mostly wanting. 

 Herbs. 

 Carpels as many as the sepals : stamens as many as the sepals or twice 

 as many. 

 Plants succulent : carpels distinct or united at the base, opening 



lengthwise. Fam. 2. Crassulaceae. 



Plants not succulent ; carpels united to the middle, circumscissile. 



Fam. 3. Penthoraceae. 

 Carpels fewer than the sepals. 

 Staminodia present : carpels 3-4, wholly united into a i-celled gynoe- 



cium. Fam. 4. Parnassiaceae. 



Staminodia wanting : carpels ipostly 2, distinct or partially united. 



Fam. 5. Saxifragaceab. 

 Shrubs or trees. 

 Leaves opposite. Fam. 6. Hydrangiaceae. 



I,eaves alternate. 

 Fruit a 2-celled capsule. 

 Capsule thin-walled, almost free from the hypanthium. 



Fam. 7. ITEACEAE. 



Capsule woody or thick-walled, manifestly adnate to the hypanthium, 



Fam. 8. Hamamelidaceae. 

 Fruit a i-celled berry. Fatn. 9. Grossulariaceae. 



Endosperm wanting or scant (copious in Opulaster, Rosaceae) : stipules 

 mostly present. 

 Flowers monoecious, in dense capitate clusters. 



Fam. 10. Platanaceae. 

 Flowers perfect, or if monoecious or dioecious not in capitate clusters. 

 Flowers regular. 

 Carpels several or numerous, or if solitary becoming an achene. 

 Carpels distinct, rarely adnate to the hypanthium : fruit achenes or 



follicles. Fam. 11. Rosaceae. 



Carpels united, enclosed by the hypanthium and adnate to it : fruit 

 a pome. Fam. 12. Pomaceae. 



Carpel solitary, not becoming an achene. 

 Ovary with 2 ovules : leaf-blades simple : fruit a drupe. 



Fam. 13. Drttpaceae. 

 Ovary with several ovules : leaf-blades 2-3-pinnate ; fruit a legume. 



Fam. 14. Caesalpiniaceae. 

 Flowers irregular (nearly or quite regular in Glediisia and Gymnocla- 

 dus oi the Caesalpiniaceae). 

 Upper petal enclosed by the lateral ones in the bud. 



Fam. 14. Caesalpiniaceae. 

 Upper petal enclosing the lateral ones in the bud. 



Fam. 15. Papilionaceae. • 



Famii^y I. PODOSTEMACEAE Lindl. River-weed Family. 



1. PODOSTEMON Michx. 



1. Podostemon Ceratophyllum Michx. RivER-weED. (Man. p. 472; 

 I. F. / /808.) In shallow streams, Mass. to Ont., Minn., Ga. and Ala. 

 — Pennsylvania : Pike ; Monroe ; Northampton ; Chester ; Lan- 

 caster, Tucquan Island ; DEIvAWARE. 



