Why is it that so few orchids have mass popularity? With the profusion of diverse, alluring orchids — species and hybrids — one would think that a whole bunch of orchids would be "mainstream."

There are a few answers. For an orchid to be a staple at every nursery, it must meet several criteria — it must be unique and showy, easy to grow, and readily available to even the most casual orchid admirer at a reasonable price. Move over dendrobia, catalya and vanda — in Hawai'i, the Brassia, or spider orchid, is on the rise.

Native to Central and South America, Brassia grows extremely well in Hawai'i's warm climate. Named after William Brass, a 19th-century British botanical illustrator, the Brassia got its spider nickname from the appearance of its flowers. The narrow flower sepals and petals resemble the long legs of an arachnid. Typical colors range from chartreuse to yellow with a degree of brown spotting on the sepals and petals.

The insect disguise is part of Brassia's survival kit — in the plant's native habitat, parasitic wasps lay their eggs on unsuspecting spiders. By mimicking spiders, Brassia gets pollinated.

Easy to grow, Brassia does well in filtered sunlight in a greenhouse or outdoors under a canopy of trees. Avoid direct midday sunlight, which can burn it. At Foster Botanical Gardens, we have Brassia mounted on tree branches or tree ferns in the same conditions as our oncidium spacleatum (popcorn orchid).

Give them lots of water and fertilizer from spring through summer and during this time, they will reward you with multiple sprays of flowers. In winter, allow them to dry slightly between waterings. They are easily divided and you can make many plants, but if you resist the urge to divide them, they can grow into huge spectacular specimen plants.

Probably the most common Brassia you will find is the Brs. Rex. It's a favorite of Tina Kaneshiro, secretary to the mayor. She likes to call the plant "Sexy Rexy." Several other varieties, including Sakata, Lea and Christine are available in Hawai'i.

My favorite Brassias? Brs. gireoudiana Maikai Farms (which is one of the parents of Brs. Rex), Brs. Edvah Loo Nishida AM/AOS (which, a few years back, won a prize on Maui with its almost 18-inch-long flowers), and Brs. Memoria Fritz Boedeker (it has flowers that are more than eight inches wide).

Brassias are often hybridized with oncidiums, resulting in Brsdm. Lillian Oka, which has larger flowers with larger brown blotches. Different colors are achieved when hybridized with Miltonias. The result is Mltssa. Memoria Charles M. Fitch Izumi AM/AOS, which has a medium purple color with darker purple spots. This cultivar was named after the late George Izumi of Kane'ohe who was one of my early orchid-breeding mentors.

I believe Brassias will grow in popularity. Orchid experts will continue their efforts to develop new, exciting colors. All orchid growers should consider the Brassia a great starter orchid and a good addition to any collection.