Monopodial vs. Sympodial
What’s the difference between monopodial and sympodial orchids?
Monopodial orchids grow as a single upright “stem” with one leaf following another on opposite sides of the center. Monopodial orchids are repotted in the center of the pot as they will grow straight up. Common monopodial orchids are Phalaenopsis, Paphiopedilums, and Vanda (shown above).
- Orchids with this characteristic pattern of growth do not contain water reservoirs (no pseudobulbs) apart from their leaves and thick roots, thus should be watered just as the medium in which they are potted in dries out completely.
- At the base of monopodial orchids are small nodes that lie dormant, often for a very long time. Occasionally, however, monopodial orchids will multiply by starting a new shoots at the base of the plant and in this way develop into sizable specimen plants. The new plant is called a “basal Keiki.”
Sympodial growth is defined as an orchid that does not grow from a single vertical stem but from a stem that is more or less horizontal. They have the appearance of looking like flower bulbs but they are not. Their real function is to store water. These kind of orchids can go for prolong durations without water until the medium dries out because they store water in their pseudobulbs.
- Sympodial orchids grow new pseudobulbs from the base of the previous pseudobulb and over time develop multiple growth leads along a single horizontal stem. This horizontal stem is called the rhizome. From the rhizome roots will grow. Most orchid genera are sympodial such as the Cattleya, Cymbidium, Dendrobium and Oncidium.
- A pseudobulb refers to and individual “shoot” of a sympodial orchid which has a chunky base to hold water topped with leaves. Sometimes the pseudobulb is small and the leaves are long (as in Cymbidiums, shown at above, 1st pic above). Sometimes the pseudobulbs are long and thick (they look like leaf canes) and the leaves are small (as in Dendrobiums, shown above, 2nd pic above). Bloom spikes usually come from where the outermost leaf meets the pseudobulb. To assist in anchoring a sympodial orchid in the pot, a clip can be placed across the pot and between the pseudobulbs to secure.
Here is a helpful picture that further explains the difference
Photo copyright, American Orchid Society newsletter
Hope that Helps,
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