FNA: Cypripedium montanum vs. Cypripedium

Phenology

Flowering Feb–Sep.

Habitat

Mesic to dry (rarely wet) coniferous, deciduous, and broadleaf evergreen forests, openings, and thickets, around shrubs on open slopes

Elevation

0–2400 m (0–7900 ft)

Distribution

AK; CA; ID; MT; OR; WA; WY; AB; BC

[WildflowerSearch map]

[BONAP county map]

Primarily temperate Eurasia and North America; ranging from arctic to subtropics in East Asia and Cordilleran North America and Central America

[BONAP county map]

Discussion

Plants of Cypripedium montanum grown in exposed, relatively sunny situations have the ascending leaves inserted along the basal portion of the stem and the flowers displayed well above the leaves. In shadier, especially sheltered sites, the spreading leaves may be more evenly scattered along the stem. In this species the apical margin of the orifice of the lip is usually acute, in common with C. candidum, and in contrast to the usually obtuse margin in C. parviflorum; this difference can aid determination of discolored herbarium specimens. Hybrids of C. montanum and C. parviflorum have been designated C. ×columbianum Sheviak. See 11. C. parviflorum for a general discussion of hybridization and variation within and between related species.

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

Species ca. 45 (12 in the flora).

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

Key

1. Lip orifice a longitudinal fissure, length of lip; leaves 2, radical, stem a leafless scape.	C. acaule
1. Lip orifice basal, 4–37 mm; leaves 2–several, cauline.	→ 2
2. Lip appearing angular, adaxial surface swollen near middle, apex abruptly deflected downward; lateral sepals distinct.	C. arietinum
2. Lip not angular, slender slipper-shaped to globose sac, apex not deflected; lateral sepals connate or nearly distinct.	→ 3
3. Leaves 2, subopposite to alternate, near midpoint of stem (very rarely, leaves 3, closely alternate near midpoint of stem); lip prominently marked reddish or brownish between veins.	→ 4
3. Leaves 3 or more (very rarely 2), alternate on basal to middle portion of stem or along length; lip yellow, ivory, or white, without extensive markings between veins.	→ 6
4. Flowers (1–)2–4 in short nodding spike, dull yellow to reddish brown or dark purple, lip mostly 8–14(–25) mm.	C. fasciculatum
4. Flowers solitary, erect, white to yellowish or greenish, mottled with pink or brownish; lip 15–30 mm.	→ 5
5. Petals slightly shorter than to equaling globose to obovate lip, constricted near apex, lanceolate-subpandurate in general outline; markings pink to magenta.	C. guttatum
5. Petals much shorter than oblance-fusiform to oblance-ovate lip, constricted near middle, acuminate-subpandurate to pandurate in general outline; markings brownish or tan.	C. yatabeanum
6. Petals flat, oblong to ovate, unmarked, white or green, yellow-green, or brownish.	→ 7
6. Petals spirally twisted or undulate (rarely flat), linear-lanceolate, or rarely linear-oblong, spotted and striped (sometimes minutely so) or suffused with darker reddish brown or madder on yellowish or greenish ground color (rarely without markings).	→ 9
7. Flowers large; lip 25–53 mm.	Cypripedium reginae
7. Flowers small; lip 11–20 mm.	→ 8
8. Plants usually less than 35 cm; flowers 1(–2); lateral sepals nearly distinct to connate almost to apex.	C. passerinum
8. Plants usually much more than 35 cm; flowers 3–18(–22); lateral sepals connate almost to apex.	C. californicum
9. Lip orifice 27–37 mm; flowers very large; lip (41–)53–65 mm, ivory to pale yellow.	C. kentuckiense
9. Lip orifice usually less than 23 mm (rarely to 27 mm, then lip deep yellow); flowers smaller; lip mostly 15–45 mm (rarely to 54 mm, then lip deep yellow), white or yellow.	→ 10
10. Lip white, rarely suffused with magenta; staminode lanceoloid or oblong-lanceoloid to ellipsoid.	→ 11
10. Lip white or yellow; staminode cordiform-ovoid, deltoid to lance-ovoid, or ovoid-oblong (rarely staminode narrower or ellipsoid, then lip yellow).	→ 12
11. Sepals and petals green or yellowish, usually spotted and striped with reddish brown or madder; dorsal sepal 15–35 mm; leaves lanceolate or elliptic to oblanceolate, ascending from insertions toward base or middle of stem.	C. candidum
11. Sepals and petals suffused with reddish brown or madder; dorsal sepal 33–60 mm; leaves suborbiculate to ovate or elliptic-lanceolate, ascending to spreading, inserted toward base or scattered along stem.	C. montanum
12. Lip white, 19–33 mm; sepals and petals suffused with reddish brown or madder, often intensely so (very rarely clear green), long and slender; dorsal sepal 33–60 mm, ratio of length to width 2.5–6.5; cordilleran.	C. montanum
12. Lip yellow (very rarely white), 15–54 mm; sepals and petals suffused with reddish brown or madder or more commonly spotted and striped (often minutely so), rarely unmarked, short and broad to long and slender; dorsal sepal 19–80 mm, ratio of length to width 1.3–3.7; widespread.	C. parviflorum