SAXIFRAGACEjE. (saxifrage family.) 95 



8. PABNASSIA, Tourn. Grass of Parnassus. 



Perennial smooth herbs, with the leaves entire and chiefly radical, and the 

 large solitary flowers terminating the long naked stems. Petals white, with 

 greenish or yellowish veins. 



* Petals sessile, entire. 



1- P. parviflora, DC. Leaves ovate or oblong, tapering at the base : petals 

 little longer than the calyx : sterile filaments about 5 in each set. — Along 

 streams in the mountains and eastward to Lake Michigan. 



2. P. palustris, L. Leaves heart-shaped : flower nearly an inch broad : 

 petals rather longer than the calyx, few-veined : sterile filaments 9 to 15 in each 

 set. — Montana and Wyoming, eastward to Lake Superior, and throughout 

 British America. 



* * Petals contracted into a short claw, fringed. 



3. P. fimbriata, Banks. Leaves from reniform to cordate-ovate : the 

 margin of the petals fringed below the middle or towards the base : sterile 

 filaments 5 to 9 in each set and united below into a fleshy carinate scale, or 

 sometimes a dilated scale destitute of bristle-like filaments. — From Colorado 

 to California and northward to British America. 



9. PHILADELPHUS, L. Syringa. Mock Orange. 



Calyx-limb 4 to 5-parted. Petals rounded or obovate, large. Styles 3 to 5, 

 united below or nearly to the top. Seeds with a, loose membranaceous coat 

 prolonged at both ends. — In ours the leaves are entire, and the showy white 

 flowers 1 to 3, terminal. 



1. P. microphyllus, Gray. Branches slender, erect: leaves small, 6 

 to 9 lines long, ovate-lanceolate or oblong, shining above, pale and minutely 

 pilose beneath, narrowed at base into a very short petiole : calyx 4-cleft, gla- 

 brous without, tomentulose within : styles united to the apex. — PI. Fendl. 54, 

 S. Colorado and southward. 



10. JAMESIA, Torr. & Gray. 



Calyx-lobes sometimes bifid. Petals 5, obovate. Alternate stamens shorter; 

 filaments linear, flattened acuminate. Capsule included. Seeds striate-reticu- 

 late. — Low, diffusely branching, 2 to 3 feet high: leaves ovate, mucronately 

 serrate, canescent beneath, as well as the petioles, calyx, and branchlets, with 

 a soft hairy pubescence : flowers cymose, in terminal panicles. 



1. J. Americana, Torr. & Gray. Cymes often longer than the leaves, 

 5 to 10-flowered : petals white, glabrous or softly hairy within : calyx-lobes 

 shorter than the petals, enlarged and foliaceous in fruit. — Fl. i. 593. Utah, 

 Colorado, and New Mexico. 



11. FENBLEBA, Eng. & Gray. 



Calyx-tube 8-ribbed. Petals ovate-deltoid, unguiculate, emarginate. Sta- 

 mens 8 : filaments 2-forked at the apex, the lobes divaricate and extended 

 beyond the cuspidate anther. Capsule crustaceous. Seeds reticulate, winged 

 below. — Erect shrub. 



