Over the weekend, the Regina Orchid Society held its annual show and sale. I know this, even though I was out of town, because when I got home we had orchids in our living room.
The Regina Orchid Society, which has about 40 members and has been around for 15 years, and countless societies like it, bear witness to the appeal of orchids. I find them appealing not only aesthetically, but also scientifically: hence this column.
The Orchidaceae are a family of flowering plants that grow everywhere in the world except for Antarctica (there are even species that grow above the Arctic Circle and others that live mostly underground in Australia). They’re the second-most geographically distributed family of flowering plants after the grasses. The number of orchid species is estimated at between 15,000 and 25,000.
All flowers are borne on stalks called pedicels, but in orchids, the pedicel rotates 180 degrees during the growth process, so that the mature orchid flower is upside down. Orchids have three sepals (outer floral whorls) and three petals (inner floral whorls). All the sepals and the two lateral petals are usually very similar to each other in color and shape; the remaining petal, however, is distinct—usually larger, and a different color or shape. To me it always looks like orchids are sticking their tongues out, but this unique petal is actually called the labellum, or lip.
(The name orchid comes from the Greek word orchis, which means testicle; a reflection of the fact that some orchids take shapes similar to human genitalia.)
Flowers are beautiful to us, but their extravagant colours and shapes of orchids are really intended to attract pollinators. (The labellum also acts as a convenient landing platform.)
Bees pollinate about half of the orchid species; others are pollinated by moths, butterflies, flies, birds, etc. Many orchid species are adapted for pollination by a single, specific type of insect. Some attract insects with the smell of food (rotting meat, in the case of one infamous example). Others fool male flies by looking like a female fly. One actually shoots stick pollen balls at bees; another seems to intoxicate them, so they’ll fall into a pool of water collected inside the flower and pick up pollen on the way out. This dependence on a specific pollinator is one reason so many orchid species are endangered; if the species that pollinates them dies off, the orchids die, too.
The pistil and stamens (female and male reproductive organs) of orchids are fused together into a column which lies opposite the labellum. (This is unique to orchids.) Orchids have only one stamen, and usually have only a single anther (pollen-producing structure). Orchid pollen is different from that of most flowering plants: instead of being granular, it lumps together into a number of masses.
Orchids usually have three pollen-receptive areas, called stigmatic lobes. Below the other flower parts is the ovary. Every orchid seedpod contains as many as two million tiny seeds—tiny because, unlike most other flowering plants, orchid seeds contain no food storage tissue. This makes it very hard to grow orchids from seed. In nature, orchid seedlings are nurtured by a symbiotic fungus; in 1917 it was discovered that seedlings could also be nurtured by growing them in a sugar-based solid media (essentially Jell-O), which is how most commercially produced orchids are now propagated.
Some people think orchids are parasites, but that’s a myth. About half of all orchids are epiphytic, which means they grow on other plants for support, but they don’t take any nutrients from them, so they’re not parasites. Other orchids are saprophytic, which means they live on the ground and get their nutrition from decaying vegetation.
The biggest orchid, Grammatophyllum speciosum, grows to more than 7 1/2 metres tall, with leaves up to three-quarters of a metre long. The flower stalk alone may be 2 1/2 metres long, and often bears more than 100 flowers, each around 13 centimetres across. (The biggest flowers, though, actually belong to a different species, Cattleya gigas, which forms flowers between 20 and 28 centimetres across, sometimes in clusters bearing as many as half a dozen flowers at once.)
Domestically, orchids fascinate people not only because they are beautiful, but because that beauty is endlessly manipulatable; countless new varieties of orchids are created almost daily, through mutation, cloning and hybridization. They can last, basically, forever; there are many orchids alive and blooming today that are decades old.
Experts also like to say that “orchids thrive on neglect.” Considering my track record with house plants, I hope they’re right.
