230 ERICACEAE. (HEATH FAMILY.) 



1. M. uniflora, Gray. Herb with 1-flowered scape 2 to 4 inches high, a 

 cluster of roundish and serrulate thin leaves at base, on a short stem or the 

 ascending summit of a filiform rootstock : corolla white or tinged with rose- 

 color, about inch in diameter. Deep moist woods, Colorado and Utah to 

 Oregon, Pennsylvania, and northward. 



8. PYR.OLA, Tourn. WINTERGREEN. SHIN-LEAF. 



Acaulescent evergreens ; with a cluster of round or roundish leaves, and 

 some scarions scales on the ascending summit of slender subterranean root- 

 stocks : scape more or less scaly-bracted, bearing a raceme of white, greenish, 

 or purplish nodding flowers, in summer. 



* Style straight, much narrower than the expanded depressed 5-rayed stigma : 

 anthers not narrowed below the openings. 



1. P. minor, L. Leaves orbicular, thiunish, obscurely serrulate or creuu- 

 late, an inch or less long : scape a span high, 7 to 15-flowered : petals white or 

 flesh-colored, orbicular, naked at the base, globose-connivent : stigma peltate, 

 large, obscurely 5-lobed : hypogynous disk none. Mountains from New Mexico 

 to Oregon and northward, thence eastward across the continent. 



2. P. secunda, L. Inclined to be caulescent from a branching base : 

 leaves thin, ovate, serrulate or crenate, 1 or 2 inches long : scape a span long, 

 bearing numerous flowers in a secund spike-like raceme : petals greenish white, 

 oblong, each with a pair of tubercles on the Itase, equally connivent : stigma pel- 

 tate, large, 5-lobed : hypogynous disk 10-lobed. Mountains of Colorado, Cali- 

 fornia, and far northward and eastward. 



* * Style strongly declined or decurved and toward the apex more or less curved 

 upward, longer than the concave somewhat campanulate-connivent or partly 

 spreading petals : stigma much narrower than the truncate and usually exca- 

 vated apex of the style, which forms a ring or collar : anthers more or less 

 contracted under the terminal orifices. 



3. P. chlorantha, Swartz. Leaves small (^ to 1 inch in diameter), 

 orbicular or nearly so, coriaceous, not shining, shorter than the petiole: scape 4 to 

 8 inches high, 3 to 10-flowered : calyx-lobes very short and obtuse or rounded, 

 appressed to the greenish-white corolla : anther-cells with distinctly beaked tips. 

 Mountains of Colorado, northward and eastward. 



4. P. elliptica, Nutt. Leaves oval or broadly oblong, 1| to 2 inches long, 

 membranaceous, acute or merely roundish at base, longer than their petioles, pli- 

 cately serrulate: scape a span or more high, loosely several to many-flowered : 

 calyx-lobes ovate and acute, short : corolla greenish ichite : anther-tips hardly at 

 all beaked. Mountains of New Mexico to British Columbia, the N. Atlantic 

 States, and Canada. 



5. P. rotundifolia, L. Leaves generally orbicular or broadly oval, 1^ to 

 2 inches long, obscurely crenulate or entire, coriaceous, shining above, mostly 

 shorter than the slender petioles: scape a span to a foot high, several to many- 

 flowered, scaly-bracteate : calyx-lobes lanceolate to ovate-lanceolate, usually or 

 $ the length of the white or flesh-colored petals. Dry woods, from California, 

 New Mexico, and Georgia, northward to the arctic regions. 



