Dendrobium is a massive genus containing more than (conservatively) 900 species. These range from cool-growing miniatures to huge specimen plants growing in hot conditions year round. The most commonly found types of Dendrobium are the phalaenopsis type (commonly known as den-phals, and named for the species most used in their breeding, which used to be known as Dendrobium phalaenopsis, but which is now known as Dendrobium bigibbum), and the nobile type (named for the species most used in their breeding, which is known as Dendrobium nobile).
Many neotropical orchids are pollinated by male orchid bees, which visit the flowers to gather volatile chemicals they require to synthesize pheromonal attractants. Males of such species as Euglossa imperialis or Eulaema meriana have been observed to leave their territories periodically to forage for aromatic compounds, such as cineole, to synthesize pheromone for attracting and mating with females. Each type of orchid places the pollinia on a different body part of a different species of bee, so as to enforce proper cross-pollination.
Like most monocots, orchids generally have simple leaves with parallel veins, although some Vanilloideae have reticulate venation. Leaves may be ovate, lanceolate, or orbiculate, and very variable in size on the individual plant. Their characteristics are often diagnostic. They are normally alternate on the stem, often folded lengthwise along the centre ("plicate"), and have no stipules. Orchid leaves often have siliceous bodies called stegmata in the vascular bundle sheaths (not present in the Orchidoideae) and are fibrous.
Hi. I have a moth orchid that was in bloom when I got it, five years ago. After the blooms dropped off, the flower stock dried out and I cut it off (thought I was supposed to) and it hasn't bloomed since. I thought it would grow a new stock and bloom again the next year. But it hasn't. I'm not experienced with orchids, so am guessing I did the wrong thing by cutting off the stock. Can you give me some direction on this? Is this plant likely to every bloom again? Thank you for any help you can provide.
Disa is a genus of beautiful plants with rather triangular flowers, often red. They require VERY different care than other types of orchids, so it's easy to kill them if you don't know what you're doing. In particular, they like it wet and should never dry out. The best-known Disa is Disa uniflora, which in South Africa is known as the Pride of Table Mountain.
Epiphytic orchids, those that grow upon a support, have modified aerial roots that can sometimes be a few meters long. In the older parts of the roots, a modified spongy epidermis, called a velamen, has the function of absorbing humidity. It is made of dead cells and can have a silvery-grey, white or brown appearance. In some orchids, the velamen includes spongy and fibrous bodies near the passage cells, called tilosomes.
Cymbidium carry tall stems with many flowers that have a more typical orchid shape. They are easily identified by their grassy leaves, and they readily form large clumps. Most common are the cool-flowering types, which need to experience a cooler winter (nights in the 40s for some time in the fall) in order to initiate flowering. Once the flowers open, they can last for up to two months or more, especially in a cool environment. These are very showy and rewarding plants, and a plant in a six-inch pot can carry three stems with 15 or more flowers each, depending on the type.