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bog wintergreen, common pink wintergreen, large wintergreen, liver-leaf wintergreen, pink pyrola, pink shinleaf, pink wintergreen, pyrole à feuilles d'asaret

American shinleaf, American wintergreen, pyrole d'amérique, round-leaf pyrola

Habit Plants rhizomatous, (0.8–)1.5–4.3(–6.4) dm. Plants rhizomatous, 0.1–0.3(–0.4) dm.
Leaves

petiole (6–)15–65(–109) mm, channeled adaxially, glabrous;

blade not maculate, dull and light green to purplish abaxially, shiny and dark green adaxially, ovate, elliptic, round, or reniform, (10–)24–71(–98) × (10–)13–49(–83) mm, coriaceous, base cordate or rounded to decurrent, margins entire or crenulate or denticulate, apex obtuse to acute.

petiole (8–)15–70 mm, channeled adaxially, glabrous;

blade not or, sometimes, maculate, dull to shiny and light green to green abaxially, shiny and dark green sometimes with white tissue bordering larger veins adaxially, ovate to obovate or round, 16–73(–80) × 16–70 mm, coriaceous, base rounded to decurrent, margins crenate, apex subacute to obtuse, rounded, or retuse.

Inflorescences

1 per stem, 4–29-flowered;

peduncular bracts 1–3(–5), ovate to oblong-ovate, 7–16 × 2.5–5 mm, chartaceous or membranous, margins entire;

inflorescence bracts ovate to oblong-ovate, usually as long as or longer than, sometimes shorter than subtended pedicels, 3–17 × 1–3.6 mm, chartaceous.

1 per stem, 4–22-flowered;

peduncular bracts 1–5, oblong-ovate, 5.5–13 × 2–4 mm, chartaceous or membranous, margins entire;

inflorescence bracts lanceolate-ovate, longer than subtended pedicels, 4–12 × 1.2–3 mm, chartaceous.

Pedicels

(3–)4–11 mm.

4–8 mm.

Flowers

calyx lobes appressed or spreading in fruit, green or pinkish with margins hyaline to white or pinkish, triangular to triangular-ovate, 1.4–5.5(–5.8) × 1.3–2.7 mm, margins entire or erose-denticulate, apices acute to acuminate;

petals white, white proximally and pinkish distally, or pink to purplish red throughout, obovate to round, 4.8–9.1 × 2.9–6 mm, margins entire;

stamens 4.5–7.5 mm;

filament base 0.6–1.1 mm wide;

anthers (1.7–)2–3.5(–3.9) mm, apiculations 0.1–0.5(–0.7) mm, thecae creamy white or tan to dark pink, tubules pink to dark pink, 0.1–0.4 mm, gradually narrowed from thecae, lateral walls touching for most of their lengths, pores 0.1–0.2 × 0.05–0.1 mm;

ovary smooth;

style exserted, 7–10 mm;

stigma 0.7–1.6 mm wide, lobes erect, (without subtending ring of hairs).

calyx lobes appressed or spreading in fruit, green or pinkish with margins hyaline to white or pinkish, ovate, ovate-oblong, or obovate, 2–4.3(–4.5) × 1.4–2 mm, margins entire or erose-denticulate, apices obtuse to acute;

petals white, often suffused with pink, obovate to round, 6–10.5 × 4.5–5 mm, margins entire;

stamens 4–7 mm;

filament base 0.6–0.9 mm wide;

anthers 2–4.1 mm, apiculations 0.1–0.3 mm, thecae creamy white or greenish white to pink or reddish, tubules yellowish brown to pink or reddish, 0.2–0.3 mm, gradually or abruptly narrowed from thecae, lateral walls touching for most of their lengths, pores 0.1–0.2 × 0.1–0.2 mm;

ovary smooth;

style exserted, 6–9 mm;

stigma 0.7–1.6 mm wide, lobes erect.

Capsules

depressed-globose, 4–5 × 6–8 mm.

depressed-globose, 3–3.5 × 4.2–5 mm.

2n

= 46.

= 46.

Pyrola asarifolia

Pyrola americana

Phenology Flowering Apr–Jun.
Habitat Moist to dry, deciduous or coniferous forests, bogs
Elevation 10-2100 m (0-6900 ft)
Distribution
from FNA
AK; CA; CO; IA; ID; IN; MA; ME; MI; MN; MT; ND; NH; NM; NV; NY; OR; PA; SD; UT; VT; WA; WI; WY; AB; BC; MB; NB; NS; NT; NU; ON; PE; QC; SK; YT; Asia
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; DE; IL; IN; KY; MA; MD; ME; MI; MN; NC; ND; NH; NJ; NY; OH; PA; RI; SD; TN; VA; VT; WI; WV; MB; NB; NF; NS; ON; PE; QC; SPM
[WildflowerSearch map]
[BONAP county map]
Discussion

Subspecies 3 (2 in the flora).

Regional variation in Pyrola asarifolia in North America was examined by E. Haber (1983) using morphological and flavonoid data. Despite finding some longitudinal geographic differentiation, he concluded that most earlier-recognized segregates of the P. asarifolia complex were best included within a single, polymorphic species, with the large-bracted, denticulate-leaved, Pacific Northwest and northern Rocky Mountains element (subsp. bracteata) distinguishable from the relatively short-bracted, crenate-leaved, transcontinental element (subsp. asarifolia). Included within his concept of the latter subspecies were Asian plants referred to P. incarnata (de Candolle) Freyn. A more comprehensive study of the Asian element (Haber and Hiroshi Takahashi 1988) led to the conclusion that this vicariad was sufficiently distinct to warrant recognition as P. asarifolia subsp. incarnata (de Candolle) Haber & Hir. Takahashi; it is distinguished from the North American subspecies by its narrower sepals. Takahashi (1993) found differences also in the seeds of the two subspecies.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

The relationship between Pyrola americana and other members of sect. Pyrola awaits resolution; various interpretations exist. Some authors follow M. L. Fernald (1920) in treating it as conspecific with the Eurasian P. rotundifolia. B. Křísa (1966, 1971) considered P. americana to be morphologically distinct from P. rotundifolia, treating it as P. asarifolia subsp. americana (Sweet) Křísa. E. Haber (1972) likewise treated P. americana as a subspecies of P. asarifolia, noting similarities in stamen morphology, flavonoid chemistry, and geography. Later, in a detailed study of P. asarifolia, Haber (1983) did not address directly the position of P. americana, which he did not include as either an infraspecific taxon or synonym of P. asarifolia. The taxon is maintained here as a distinct species pending further studies.

M. L. Fernald (1920) referred plants from Newfoundland and the Gulf of St. Lawrence area, which grow on barrens and in spruce forests, often on calcareous substrates, to Pyrola rotundifolia, considering them indistinguishable from European plants. E. Haber (1972) interpreted them as ecotypic variants of P. asarifolia subsp. asarifolia, noting the occurrence of similar populations outside that area.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Margins of leaf blades entire or crenulate; proximal inflorescence bracts usually as long as or longer than subtended pedicels, sometimes shorter than subtended pedicels; calyx lobe apices acute to acuminate; leaf blades round, ovate, elliptic, or reniform.
subsp. asarifolia
1. Margins of leaf blades denticulate or, rarely, entire; proximal inflorescence bracts longer than subtended pedicels; calyx lobe apices acuminate; leaf blades ovate or elliptic.
subsp. bracteata
Source FNA vol. 8, p. 380. FNA vol. 8, p. 380.
Parent taxa Ericaceae > subfam. Monotropoideae > Pyrola Ericaceae > subfam. Monotropoideae > Pyrola
Sibling taxa
P. americana, P. chlorantha, P. elliptica, P. grandiflora, P. minor, P. picta
P. asarifolia, P. chlorantha, P. elliptica, P. grandiflora, P. minor, P. picta
Subordinate taxa
P. asarifolia subsp. asarifolia, P. asarifolia subsp. bracteata
Synonyms P. rotundifolia var. americana
Name authority Michaux: Fl. Bor.-Amer. 1: 251. (1803) Sweet: Hort. Brit. ed. 2, 341. 1830 ,
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