Monographs Details: Pyrola
Luteyn, James L., et al. 1995. Ericaceae, Part II. The Superior-Ovaried Genera (Monotropoideae, Pyroloideae, Rhododendroideae, and Vaccinioideae P.P.). Fl. Neotrop. Monogr. 66: 560. (Published by NYBG Press
Synonyms:Braxilia, Amelia, Thelaia, Erxlebenia Opiz ex Rydb., Pyrola rotundifolia Torr., Pyrola grandiflora Radius, Amelia minor Alef., Thelaia rotundifolia Alef.
Description:Genus Description - Herbs or subshrubs, erect, to 3.5 dm tall (4.4 dm in fruit), stems usually single, glabrous. Leaves alternate or subopposite, clustered at the base in a rosette that represents several years’ growth, blades slightly inrolled or revolute, coriaceous, margin entire or crenate (rarely serrulate, the veins ending in minute teeth). Inflorescences symmetric racemes; scape bracts 1-4; pedicels bracteate. Flowers mostly nodding; calyx persistent in fruit; corolla crateriform or broadly campanulate, slightly zygomorphic, petals concave, white, or with a creamy, greenish, or pinkish tinge, without appendages or tubercles; stamens ± included, clustered on the adaxial side of the flower, the filaments flattened or ribbon-like, gradually tapering to their bases, glabrous, purple or purplish-red (?); the anthers oblong, wrinkled, smooth (mucronate at base), tubes short, slightly expanded near filament attachment, the pores oval or elliptic; ovary without a nectariferous disc; style declinate, exserted, the apex turned upward; stigma slightly expanded, subtended by an inconspicuous collar or ring below the 5 papillate stigmatic crests or lobes. Capsule depressed-globose, dark brown, pendant, borne on a recurved pedicel, dehiscence incomplete, the margins of the valves cobwebby; seeds light golden-brown, testa pitted (n = 23, 46).
Discussion:Approximately 20-30 species, some weakly defined, occurring in boreal, temperate, and arctic regions of the Northern Hemisphere, but disjunct in the tropics at high elevations in tropical Asia (northern Sumatra, ca. 5°N) and in tropical America (Mexico and Guatemala, south to ca. 15°N).