Orchids are best recognized by their bilaterally symmetrical flowers. Some of the most popular greenhouse genera are Cattleya , Cymbidium , Paphiopedilum , Phalaenopsis, Dendrobium, Odontoglossum , and Oncidium . Potted bulb plants are produced by forcing bulbs to flower, usually during the period between Christmas and Easter. Examples in this group include tulip, narcissus, crocus, hyacinth, iris, and amaryllis. Succulents Succulents are thick fleshy plants capable of storing large quantities of water in their leaves and stems.
Many succulent plants are spineless.
Succulents with spines differ from cacti in that the spines grow directly from the plant tissue rather than from structures called areoles. Elodea densa Gaylussacia spp. Hydrilla verticillata Juniperus spp. Nicotiana tabacum Picea spp. This list is subject to change and may not be inclusive.