4-15 Orchidaceae, orchid family
Keywords:
Magnoliophyte, orchid family, monocots, Cypripedium, lady's-slipper, Arethusa, Corallorhiza, coral-root, Platanthera, Pogonia, Calopogon, Epipactis, Malaxis, Listera, Liparis, Goodyera, Spiranthes, dragon's mouth, grass-pink, moccasin flower, greenAbstract
The orchid family is one of the world‘s largest families of vascular
plants. Numbering more than 30,000 species worldwide, the majority are
tropical epiphytes. In Nova Scotia, all 40 species are terrestrial
perennial herbs.
Typically these plants have the leaves alternate, rarely opposite or
whorled. Flowers are three-merous, any parts therein may be modified
or irregular. The developing flower usually has its uppermost petal
resupinate, emerging in the lowermost petal‘s position, as the
labellum or lip. The labellum may be ornamented or modified further
into a pouch. Generally it serves as an attractant and nectar guide.
Pollinator specificity is high in this family. Anthers are cuplike,
containing the pollinia. The stigmas and styles are united to form the
column, unique to this family. Stigmas are trilobed, but may have only
two fertile lobes. The third may be modified to form the rostellum, a
beaklike surface for pollinia attachment. Ovary is three-parted and
inferior in position. Fruit is a dry capsule, which shatters releasing
dustlike seeds, no more than 0.5mm long. Cotyledons are absent.
Terrestrial seedlings are mycorrhizal, and thence saprophytic.
Many orchids are cultivated and hybrids are common at both
intergeneric and intrageneric levels. Vanilla, a tropical vine
provides vanilla extract, a common flavouring agent.
Photographs provided by David Mazerolle, Sean Blaney, Eugene Quigley,
Martin Thomas, Ross Hall, Mark F Elderkin, Alain Belliveau, Charles
Linney, Jamie Ellison.
