Flowers: Zygomorphic, 3 sepals, 3 showy petals. One petal modified into a lip (LABELLUM). Flowers usually undergo a 180˚ twist during development and these are called RESUPINATE flowers. The inferior ovary is long and may be mistaken for a pedicel. The stamens and gynoecium are modified into a GYNANDRIUM sometimes called the column. Pollen is in coherent masses called POLLINIA. The 3 stigmas are modified into the ROSTELLUM.
Inflorescence: Various (spikes, racemes, panicles, etc.)
Fruits: Loculicidal capsules.
Seeds: Microscopic! May require establishing a symbiotic relationship with a fungal following germination to gain nutrition.
Habit: Perennial herbs. Terrestrial, epiphytic, epilithic (on rock), or mycotrophic. Many species (esp. epiphytic ones) have adventitious roots with a VELAMEN covering. Pseudobulbs present in some.
This family is second in size only to Asteraceae. It is the
source of a huge floricultural industry (plants and cut flowers).
Many hybrids (even between genera) are produced and marketed.
Examples:
Native Illinois Orchids
List of orchid genera of eastern U.S., list of orchid genera for midwest.
Aplectrum
- A. hyemale (putty-root orchid). Habit
of plant showing leaf that overwinters (photo from M. A. Homoya
"Orchids of Indiana" - a recommended book for Illinois orchids as
well!). Inflorescence. Closer view of flowers. Close-up of column. Fruits. Seeds.
Corallorhiza
- C. wisteriana (coral root orchid). Flowering shoot. Base of plant showing multi-branched rhizome that resembles coral, hence the common name. Another view of the coral "roots" that connect to the mycorrhizal fungi that feed the plant. Inflorescence.
Less than the coralroot, you know,
That is content with the daylight low,
And has no leaves at all of its own;
Whose spotted flowers hang meanly down
(Fobert Frost, `On Going Unnoticed' - Corallorhiza)
Cypripedium
- C. acaule (pink lady's slipper orchid). Flowering plant.
- C. candidum (white lady's slipper orchid). Habit of plants in flower. Flower dissected. Flower L.S.
- C. parviflorum (small yellow lady's slipper orchid). Flower.
Goodyera
- G. pubescens (rattlesnake orchid). Basal rosette of leaves with characteristic venation. Habit of plant nearly in flower.
Liparis
Platanthera
Spiranthes
Cultivated Orchids (mostly Old and New World tropical species)
Bletilla
Cattleya
- C. spp. (corsage orchids). Display of Cattleya orchids at Missouri Botanical Garden. Closer view of flower.
Encyclia
- E. cochleata (cockleshell orchid). The flowers of this species are non-resupinate.
Epidendrum
- E. ibaguense (formerly E. radicans; buttonhole orchid). Habit of plant along roadside in Oaxaca Mexico. Flowers. Flower face view looking at column. Column in L.S. Anther flap and pollinia along side.
Ludisia [formerly Haemaria]
Oncidium
Ophrys
Paphiopedilum
- P. sp. (Lady's slipper orchid). Flower.
Phalaenopsis
- P. spp. (moth orchids ). A pink flowered species and and white one.
Vanilla
Websites on Orchids
First see
The Orchid Mall that lists many sites with orchid photographs. My shorter list is below.
Internet Orchid Species Encyclopedia
CalypsoLip in Japan.
Orchids of Wisconsin.
Papua New Guinea Orchid News.
The Orchid Photo Page. Talk about eye candy!
The Pacific Orchid Society (of Hawaii) Homepage.
Wild Orchids of Alberta, Canada.
World Flowers (Japan).
Orchid Species Photographs (Eric Hunt)
Orchid Photography by Kokin
First Rays Orchids
Orchidstudium
- SIUC / College of Science / Elements of Plant Systematics
- URL: http://www.plantbiology.siu.edu/PLB304/Lecture25Aspar/Orchidaceae.html
- Last updated: 30-Mar-08 / dln
