POLYPETALOUS EXOGENOUS PLANTS. 287 



P. SEDOIDES, L. Stem erect, l°-2° high ; leaves lanceo- 

 late; j5e^«/5 commonly none. Ditches and muddy places. 



57. SAXIFEAGE FAMILY. Order, Saxifragace^. 



Calyx of 4-5 more or less united sepals, free, or more or 

 less adherent to the ovary, persistent ; petals as many as 

 the sepals, rarely wanting ; stamens as many, or 2-4 times 

 as many, inserted with the petals on the calyx; ovaries 2 

 or sometimes 3-4, commonly united below, and separate at 

 the summit; seeds few-many; einhryo straigkt, in the axis 

 of fleshy albumen. 



SYNOPSIS. 



Sub-order I. Saxifrageee. Herbs. Petals imbri- 

 cated in the bud. Stipules adnate to the petiole, or none. 



* stamens twice as many as the sepals. 

 t Called, 



Flowers perfect. Stamens 10. Leaves entire or lobed Saxifbaga. 



+t Capsule 1-celkd. 



Stamens 10. Petals 5, ejitire Tiarella. 



10, 5, pimiatiiid Mitella. 



8-10. none Chrysoplentom. 



Sub-order II. Hydrangiese. Shrubs. Petals val- 

 vate or convolute in the bud. Leaves opposite. Stipules 

 none. 



Petals valvate. Stamens 8-10. Styles distinct Hydrangea. 



convolute. 20 or more. Styles 4. Capsule i-valved Philadelphus. 



SAXIFEAGA, L. Saxifrage. 



Calyx free, or cohering with the base of the ovary, deeply 

 5-cleft : petals 5, commonly deciduous ; stamens 10 ; styles 

 2; capsule 2-celled, 2-beaked, opening between the beaks; 

 seeds numerous, smooth ; lowest leaves clustered. 



