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purple-petal bog orchid

Thurber's bog orchid

Habit Plants 24–80 cm. Plants 30–165 cm.
Leaves

few–several, abruptly diverging or sometimes ascending, scattered along stem;

blade oblong to ovate or lanceolate, 5.5–16(–28) × 1–4.5 cm.

few to several, spreading-ascending on base of stem, gradually reduced to bracts upwards;

blade lanceolate, 9–28 × 1.2–3.5 cm.

Spikes

very lax to dense, flowers sometimes irregularly grouped in fascicles.

dense to lax.

Flowers

resupinate, not showy, green to yellowish green, often suffused with blue or lip sometimes with red;

lateral sepals spreading to reflexed;

petals ovate- to lance-falcate, margins entire;

lip descending to somewhat reflexed or projecting, lanceolate to ovate, sometimes with prominent suborbiculate basal dilation, without basal thickening, 4–8 × 1.5–3 mm;

spur strongly clavate to scrotiform, 2–3 mm, apex obtuse;

rostellum lobes strongly diverging, very small, rounded, obscure;

pollinaria straight;

pollinia remaining enclosed in anther sacs;

viscidia orbiculate to oblong;

ovary rather slender to stout, mostly 5–9 mm.

resupinate, inconspicuous, green;

lateral sepals reflexed to spreading;

petals lanceolate-, ovate-oblong-, or ovate-falcate, margins entire;

lip descending to reflexed, linear-oblong, linear-elliptic, or rhombic-ovate, usually with inconspicuous to scarcely discernable (possibly sometimes absent) median basal thickening, 2.5–8.5 × less than 1–3.5 mm, margins entire;

spur filiform, tapering toward apex, very rarely filiform-conic from slightly stout base, 8–25 mm;

rostellum lobes mostly parallel, closely spaced, directed downward, very small, rounded, obscure;

pollinaria straight;

pollinia remaining enclosed in anther sacs;

viscidia evidently elliptic-oblong;

ovary rather slender to stout, mostly 4.5–11 mm.

2n

= 42 [63].

Platanthera purpurascens

Platanthera limosa

Phenology Flowering Jul–Aug. Flowering Jun–Aug.
Habitat Stream banks, shores, ditches, fens, seeping slopes, roadsides, commonly in thickets, open woods Open to lightly forested springy marshes, seeps, stream banks
Elevation 2500–3300 m (8200–10800 ft) 1800–2500 m (– 4000 m, Central America) (5900–8200 ft (– 13100 ft, Central America))
Distribution
from FNA
AZ; CA; CO; NM; WY
[WildflowerSearch map]
from FNA
AZ; NM; Mexico; Central America (to Guatemala)
[BONAP county map]
Discussion

Flowers of Platanthera purpurascens are strongly semen scented, and their musty scent is markedly different than the sweet and spicy scents of other fragrant species.

In some areas this species hybridizes with Platanthera dilatata var. albiflora, producing sweetly fragant plants with lanceolate green lips. At the southern edge of its range, however, it often occurs with similar plants in the absence of another putative parent. The identity of these plants is uncertain. Their rather generalized morphology might mask polyphyletic origins.

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

Platanthera limosa is traditionally distinguished from other slender-spurred plants and from P. sparsiflora by the presence on the lip of a median thickening that culminates in a small basal process. Although diagnostic when present, this feature is often obscure, especially in live material, and seems to be lacking in some plants. Platanthera limosa is most consistently separated from other green-flowered species by the combination of very small, narrow column and slender spur much longer than the lip. These features are in contrast to the very large, broad columns of P. sparsiflora and P. zothecina and much shorter spurs of the P. hyperborea complex. The lips of most plants are elliptic to elliptic-oblong, unlike any other species except the Aleutian P. tipuloides, and such plants are readily determined by lip shape and spur characters. Within populations plants may vary greatly in flower size, spur shape and length, and the ratio of spur to lip length. Individual plants may vary markedly in size of the flowers and density of the inflorescence in different years. That situation warrants additional study, as it may obscure the presence of other taxa.

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

Source FNA vol. 26, p. 560. FNA vol. 26, p. 563.
Parent taxa Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera Orchidaceae > subfam. Orchidoideae > tribe Orchideae > subtribe Orchidinae > Platanthera
Sibling taxa
P. aquilonis, P. blephariglottis, P. brevifolia, P. chapmanii, P. chorisiana, P. ciliaris, P. clavellata, P. convallariifolia, P. cristata, P. dilatata, P. flava, P. grandiflora, P. hookeri, P. huronensis, P. hyperborea, P. integra, P. integrilabia, P. lacera, P. leucophaea, P. limosa, P. macrophylla, P. nivea, P. obtusata, P. orbiculata, P. peramoena, P. praeclara, P. psycodes, P. sparsiflora, P. stricta, P. tipuloides, P. zothecina
P. aquilonis, P. blephariglottis, P. brevifolia, P. chapmanii, P. chorisiana, P. ciliaris, P. clavellata, P. convallariifolia, P. cristata, P. dilatata, P. flava, P. grandiflora, P. hookeri, P. huronensis, P. hyperborea, P. integra, P. integrilabia, P. lacera, P. leucophaea, P. macrophylla, P. nivea, P. obtusata, P. orbiculata, P. peramoena, P. praeclara, P. psycodes, P. purpurascens, P. sparsiflora, P. stricta, P. tipuloides, P. zothecina
Synonyms Limnorchis purpurascens, P. hyperborea var. purpurascens Habenaria limosa, Habenaria thurberi, Limnorchis arizonica
Name authority (Rydberg) Sheviak & W. F. Jennings: N. Amer. Native Orchid J. 3: 445. (1997) Lindley: Ann. Nat. Hist. 4: 381. (1840)
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