GARDENING : INCONSPICUOUS PLANTS CAN BRING CONSPICUOUS PLEASURE.

Byline: Joshua Siskin

Some of the plants that bring the most pleasure are those that, virtually unnoticed throughout the year, suddenly come into view on account of their spectacular, if brief floral display.

Each spring, for several weeks anyway, the lavender trumpet vine puts on a memorable show. The remainder of the year, you might not even know it's there. The leaves of the lavender trumpet vine (Clytosoma callistegioides) are thoroughly unremarkable - oval shaped and dull yellow green in color. During winter, moreover, the trumpet vine goes dormant and many of these leaves fall off. The leaves that do remain have a washed-out look and are burnt along the margins, giving the vine a dilapidated, moribund appearance. If you are unfamiliar with this plant, you will seriously wonder, by winter's end, if it is about to die. You will want to fertilize it at the very least to get it growing again.

But nothing needs to be done. Like most established trees, shrubs, and vines, no fertilization or other special treatment is required for this plant to maintain its health and to bloom at its appointed time.

My favorite lavender trumpet vine is the one that blooms behind the Arco station at the corner of Van Nuys Boulevard and Moorpark Street in Sherman Oaks. Daily, it absorbs the exhaust of hundreds of cars and trucks, yet it flowers with insouciant abundance each May.

At this same gas station, incidentally, growing against the wall of the cashier's kiosk, is a variety of hibiscus known as ``Itsy Bitsy Red.'' Compared to most hibiscuses, the flowers of ``Itsy Bitsy'' are rather small, yet they are borne with such profusion - studded amongst sparkling, deep green, finely scalloped leaves - that they make the standard hibiscus varieties on the other side of the gas station look sad, if not pathetic.

I have been ogling Itsy Bitsy for more than a decade. It has survived flood, drought and earthquake. It has been severely butchered back on several occasions, and even survived a six-month period of enforced neglect when the station was shut down and cordoned off with caution tape while underground storage tanks were replaced. Through it all, Itsy Bitsy has continued to bestow its panoply of flowers.

One of the most fascinating spring bloomers is the golden trumpet tree, Tabebuia chrysotricha. By winter's end, the Tabebuia is reduced to a leafless, lifeless-looking collection of twigs, branches and bark. Then, in April or May, its brilliant phosphorescent yellow flowers suddenly appear before a single leaf is on the tree. My favorite Tabebuia grows on the corner of Ventura Boulevard and Willis Avenue, about halfway between Van Nuys and Sepulveda boulevards. The genus name Tabebuia (tab-i-BU-ya) is taken from words used by Indians of Brazil in whose midst this tree naturally grows. The species name chrysotricha is a combination of the Greek words for gold (chrysos) and hair (trichion), referring to the tawny fuzz that covers the shoots and branches of this tree.

Another twiggy plant - easily mistaken for dead during the winter - is the pomegranate. During winter it has the driest, most forlorn appearance. This condition is miraculously relieved by the pushing forth of shiny bronze foliage in the spring, to be followed by unique orange red flowers.

Perhaps leafless plants give us such a fright because, in this part of the world, they are so rare. Virtually all of the trees and shrubs in the hills and canyons around Los Angeles are evergreen. Most of our garden plants are also evergreen. All plants undergo dormancy, including evergreens, but only those that lose their leaves all at once visibly let us know when they are resting.

Dorothy Wood of Woodland Hills draws our attention to a plant in the squash family that has become a serious weed where she lives, which is south of Ventura Boulevard and west of Shoup Avenue. Unlike most of our troublesome weeds, this one is a California native. It is commonly known as bigroot or manroot because of its roots' unusual size and shape. Dorothy Wood recalls a specimen with a root that weighed more than 300 pounds. The root also has tentacles that resemble human limbs. Anyone who hikes in Southern California has encountered this massive tendriled plant with the vining growth habit, five-lobed leaves and spiny, melonlike fruits. Dorothy Wood is adamant about people destroying this weed before it spreads. Be kind to your neighbors and uproot it at once, lest it strangle their plants.