Phragmipedium

Family

Orchidaceae

Botanical Name

Phragmipedium

Plant Common Name

Lady's Slipper Orchid, Orchid

General Description

Orchids in Phragmipedium display long-lasting flowers with a bulbous pouch-like floral lip, which is why they are commonly called “slipper orchids,” just like those in the related genus, Paphiopedilum. Phragmipedium are distributed throughout from the New World tropics, from southern Mexico southward into the mountainous regions of Brazil. At the beginning of the 20th century, about ten species were identified but by the end of that century further botanical explorations increased that tally to nearly 30 species. Today there are hundreds more hybrids.

Most Phragmipedium are terrestrial, meaning they grow in soil like most other plants, but a few are epiphytes (tree dwellers) and lithophytes (rock dwellers). The low-growing plants exhibit sympodial growth and lack pseudobulbs. Sympodial orchids creep laterally along growing surfaces with thick roots that appear at the base of the plants. These orchids develop a few leaves on sturdy shoots in a fan-like arrangement. The flower stalks emerge from the middle of the leaves and depending on species display single or multiple flowers at once. Usually the buds open in succession. As plants get bigger with age so do the flowers produced.

The flowers have six showy petal/tepals. One of the petals is upright, two spread noticeably outward (oval shaped or like curly dreadlocks), while two more join under the pouch or look like floppy tongues. The pouch is a unique structure because it captures pollinating insects (halictine bees or syrphid flies) and forces them past the male and female reproductive parts to capture and distribute pollen. The pollen is bound together into two large masses, called pollinia, which only orchids have. Insects move the pollinia from flower to flower as they crawl through an escape at the base of each pouch. The flowers come in a wide variety of shades and color combinations.

Phragmipedium culture is variable. Each species has its own needs for best growth and flowering. Many require indirect but bright light to sustain leaves with lighter green pigmentation. They prefer humid environments, regular water and are sensitive to cold and frost. Many prefer warm days and cool nights. Slipper orchids grow best when tightly potted in good potting soil amended with orchid bark for good drainage. They can be a bit challenging and slow growing, but once the right combination of light, water, humidity and growing medium is found they prosper. The compact plants make good houseplants. Most grow well in a window with moderate light (no full sun) on a tray of rocks (to increase drainage and humidity) and prefer regular water and fertilization.