Platanthera dilatata

(Pursh) Lindley ex L. C. Beck

Bot. North. Middle States, 347. 1833.

Endemic
Basionym: Orchis dilatata Pursh Fl. Amer. Sept. 2: 588. 1814
Synonyms: Habenaria dilatata (Pursh) Hooker Limnorchis dilatata (Pursh) Rydberg
Treatment appears in FNA Volume 26. Treatment on page 556. Mentioned on page 553, 557, 558, 559, 560, 561.

Plants 11–130 cm or more. Leaves few–several, ascending to recurved-spreading, scattered along stem, gradually reduced to bracts distally; blade linear, linearlanceolate, oblong, or oblanceolate, 3.5–32 × 0.3–7 cm. Spikes very lax to very dense. Flowers resupinate, rather showy, conspicuous, white; lateral sepals spreading to reflexed; petals ovate to linear-lance-falcate, margins entire; lip descending or apex adhering to dorsal sepal and petal apices, linearlanceolate to lanceolate, without basal thickening, 4–11 × 2–5 mm, base slightly rounded-dilated to orbiculate, rarely rhombic, margins entire; rostellum lobes parallel to slightly divergent, directed downward, very small, obscure, rounded; pollinaria straight; pollinia remaining enclosed in anther sacs; ovary rather slender to stout, 5–15 mm. 2n = 42.

Discussion

Varieties 3 (3 in the flora).

Selected References

None.

Key

1 Spur shorter than lip, clavate to slightly capitate. Platanthera dilatata var. albiflora
1 Spur nearly equaling to exceeding lip, slender to slightly clavate. > 2
2 Spur about equal to lip (mostly within 2 mm). Platanthera dilatata var. dilatata
2 Spur markedly exceeding lip (commonly 11/2 or more times length of lip). Platanthera dilatata var. leucostachys
... more about "Platanthera dilatata"
self-pollination +
lanceolate +
Charles J. Sheviak +
(Pursh) Lindley ex L. C. Beck +
0.4 cm4 mm <br />0.004 m <br /> (?) +  and 1.1 cm11 mm <br />0.011 m <br /> (?) +
rhombic +, slightly rounded-dilated +  and orbiculate +
2mm +  and 5mm +
Orchis dilatata +
indehiscent +
not +  and articulate +
conduplicate +  and plicate +
3.5 cm35 mm <br />0.035 m <br /> (32 cm320 mm <br />0.32 m <br />) +
oblanceolate +  and oblong +
0.3 cm3 mm <br />0.003 m <br /> (7 cm70 mm <br />0.07 m <br />) +
North America +
3-merous +, sessile +  and pedicellate +
conspicuous +  and showy +
ellipsoid;cylindric +
lateral +  and terminal +
spreading +  and reflexed +
petiolate +, sessile +  and simple +
ascending;recurved-spreading +
Few (?) +  and Several (?) +
reduced +
descending +
3-partite +  and lobed +
larger +
0.4 cm4 mm <br />0.004 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
rhombic +, slightly rounded-dilated +  and orbiculate +
2mm +  and 5mm +
differing in form and color +
slender +  and stout +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1-many-flowered +  and cymose +
pendent +  and erect +
ovate;linear-lance-falcate +
Bot. North. Middle States, +
aerial +  and subterranean +
lancefusiform +
slender +
downward +  and directed +
minute +
free +, distinct +, adnate +  and connate +
foliaceous +
not +  and alike +
leafless +  and leafy +
pendent +  and erect +
proliferous +
thickened +  and stout +
concave +  and convex +
Habenaria dilatata +  and Limnorchis dilatata +
Platanthera dilatata +
Platanthera +
species +
aquatic +, lithophytic +, terrestrial +  and epiphytic +
saprophytic +, photosynthetic +  and mycotrophic +
erect to somewhat +