BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Cypripedium passerinum | Spotted Lady's Slipper 



GENERAL BOTANICAL CHARACTERISTICS : 
Spotted lady's slipper is a perennial orchid which grows 4 to 14 inches
(10-35 cm) tall.  The leaves are 2.5 to 8 inches (6-20 cm) long.  The
flowers are usually single.  The sepals are green, the petals white.
The lower petal is pouchlike and has deep reddish-purple spots inside.
The capsule is erect and ovoid [4,12].  Spotted lady's slipper has
shallow rhizomes.  Plants will grow in groups of 1 to 137.  The
horizontal rhizomes produce a new aerial leaf shoot each year [5].


RAUNKIAER LIFE FORM : 
   Geophyte


REGENERATION PROCESSES : 
Vegetative recruitment is more prevalent for spotted lady's slipper than
seedling establishment.  Some flowers may be lost to insect damage;
flowers not damaged have high capsule set.  The plant is
self-compatible, but seed set for these is unknown.  Normally, there are
thousands of tiny seeds per capsule; seeds are wind dispersed.  It can
take 15 years from seedling establishment to flowering.  The flower exit
hole is only 2.5 to 3.0 mm wide, which restricts the pollinator size.
In a study set up to determine insect pollinators of spotted lady's
slipper, none were observed, suggesting that the plants could have been
self-pollinating [5].


SITE CHARACTERISTICS : 
Spotted lady's slipper grows in moist to wet spruce forests at low
elevations.  It often occurs on calcareous substrates.  It also grows on
sand dune complexes and near streambanks or lakeshores.  It grows more
rapidly in the open than in the shade [5,7,11].  Spotted lady's slipper
has been reported at 4,200 to 5,300 feet (1,280-1,615 m) in Montana
[12].

Common associates include white spruce (Picea glauca), Engelmann spruce
(P. engelmannii), western redcedar (Thuja occidentalis), red-osier
dogwood (Cornus sericea), willows (Salix spp.), horsetail (Equisetum
spp.), longtube twinflower (linnaea borealis), sedges (Carex spp.),
one-sided pyrola (Pyrola secunda), and moss carpet (Pleurozium
schreberi) [5,11].


SUCCESSIONAL STATUS : 
Obligate Initial Community Species

Seedlings of spotted lady's slipper were found only on early
successional sites.  As succession progressed, the environment became
less suitable for seedlings and more suitable for mature plants [5].


SEASONAL DEVELOPMENT : 
Flowering of spotted lady's slipper is highly variable but usually
begins in mid-June.  In Ontario, immature capsules were present in early
July but were not mature by July 19.  Some capsules did not dehisce for
a full year.  Flowers were open to pollination about 1 week after
budding.  They wilted 2 to 8 (usually 4 or 5) days later.  The time of
capsule opening and seed dispersal varied widely [5].

Related categories for Species: Cypripedium passerinum | Spotted Lady's Slipper