SAXIFEAGACEAE 501 



Terminal leaf -lobe elongate: petals, and filaments, thrice as long as 



the sepals or more. 3. H. villosa. 



Terminal leaf-lobe short and wide: petals, and filaments, twice as 

 long as the sepals or less. 

 Sepals thick, short-ciliate. 4. H. macrorhiza. 



Sepals thin, long-ciliate. 5. H. Arkansana. 



Petals shorter than the calyx or slightly longer, with short stout claws and 

 short blades. 

 Petals as long as the calyx or shorter. 



Hypanthium fully 1 mm. long, during anthesis, this together with 



the calyx becoming 4-5 mm. long. 6. H. Americana. 



Hypanthium barely 1 mm. long during anthesis, this together with 



the calyx becoming 3 mm. long. 7. H. calycosa. 



Petals longer than the calyx, or individually shorter. 



Petal-blades narrow, entire: flowering branches leafless. 8. H. lancipetala. 



Petal-blades broad, toothed: flowering branches leafy. 9. H. Curtisii. 



Flowers decidedly irregular: calyx oblique or 2-lipped. 



Flowering branches leafy: free portion of the hypanthium not gibbous. 

 Sepals of the upper flower-lip about as long as the free portion of the 



hypanthium, the lateral ones not spreading. 10. H. pubescens. 



Sepals of the upper flower-lip shorter than the free portion of the 



hypanthium, the lateral ones spreading. 11. H. aceroides. 



Flowering branches not leafy: free portion of the hypanthium gibbous below. 



Anthers long-exserted: flowers short. 12. H. hirsuiicauUs 



Anthers included or slightly exserted: flowers long. 



Longer stamens with exserted anthers: panicle narrow, strict. 13. H. hispida. 



Longer stamens with included anthers: panicle open, lax. 



Lower petals with spatulate blades, longer than the sepals. 14. H. scabra. 



Lower petals with orbicular or rhombic-orbicular blades, about 



as long as the sepals. 15. H. longijlora. 



1. Heuchera parviflora Bartl. Leaf-blades reniform, often broadly so, 5-14 

 cm. wide, more or less pubescent, often reddish beneath, the teeth broad, mucronate: 

 flowering branches 1.5-6 dm. tall, villous-hirsute: inflorescence-branches glandular- 

 hirsute: petals 2-2.5 mm. long, with linear or spatulate blades. 



On cliffs and in rocky places, Virginia to Illinois, Georgia and Alabama. Summer and 

 fall. 



2. Heuchera pub^rula Mackenzie & Bush. Similar to H. parviflora in habit 

 and closely related to it. Leaf -blades usually smaller and with shorter hairs: flower- 

 ing branches 0.5-3 dm. tall, puberulent: inflorescence-branches finely glandular- 

 pubescent: petals 3.5-4 mm. long, with linear-spatulate or spatulate blades. 



On bluffs, Kentucky, Tennessee and Missouri. Summer and fall. 



3. Heuchera villosa Michx. Leaf -blades 5-12 cm. wide, acutely 7-9-lobed; 



middle lobe relatively long and narrow; petioles villous or glabrate: flowering 



branches 2-4 dm. tall: calyx and hypanthium long-hairy: petals 2-2.5 mm. long: 



panicle at maturity, as well as during anthesis, rather lax and open. 



On cliffs and rocks, Virginia and Kentucky to Georgia and Tennessee. Summer and 

 fall. 



4. Heuchera macrorhiza Small. Leaf-blades 8-22 cm. wide, shallowly 5-9- 

 lobed; middle lobe very broadly triangular or depressed; petioles densely villous- 

 hirsute: flowering branches 2-8 dm. tall: calyx and hypanthium short-hairy: petals 

 2.5-3 mm. long: panicle at maturity, as well as during anthesis, rather compact. 

 [?H. crinita Eydb.] 



On bluffs, Virginia, Kentucky and Tennessee. Summer. 



5. Heuchera Arkansana Eydb. Leaf-blades 4-10 cm. wide, 7-9-lobed, the 

 lobes broad and coarsely toothed ; petioles glandular-pubescent : flowering branches 

 1-2 dm. tall, white-villous with glandular hairs: hypanthium sparingly pubescent: 

 sepals broadly ovate, long-ciliate: petals linear-spatulate, 2.5-3 mm. long: panicle 

 compact. 



On cliffs, northwestern Arkansas. Summer. 



6. Heuchera Americana L. Leaf -blades orbicular-ovate or suborbicular, 5-11 



cm. wide, the lobes broad and with broad teeth: sepals much longer than the free 



portion of the hypanthium: petals about 1.5 mm. long, spatulate, the blades oblong 



or elliptic, finely toothed. The campestrian plants are commonly copiously hirsute. 



In rocky woods, Ontario to Minnesota, Connecticut, Georgia and Louisiana. Spring 

 and summer. — A glabrous or nearly glabrous form with shining often colored leaf-blades 

 is H. glaitca Raf. 



7. Heuchera calycosa Small. Eesembling H. Americana, but more slender. 

 Leaf -blades ovate or orbicular-ovate, 5-10 cm. wide, shallowly lobed, ciliate and pubes- 



