Hawai'i may not have the East Coast's famous autumnal turning of the leaves, but our summer brings a riotous show of color. Take the sometimes dull drive down South King Street beyond the downtown center, now a tour of vividly flowering trees.

"This flower-blooming season really started with the gold trees in the spring. That heralded the onset of flowering tree season," said Bob Loy of The Outdoor Circle. "Almost everywhere on this Island there is some example of a flowering tree in full bloom."

In 1965, Honolulu adopted the proposal of then-Mayor Neal S. Blaisdell and made the "Wilhelmina Tenney" rainbow shower tree and its dusty pink blossoms the city's official tree. Shower trees are some of Honolulu's most visible harbingers of summer.

Other dramatic blossoms around town include the flame-like flowers of the royal poinciana and the ever-popular plumeria.

The gold tree, another spectacular display, hits the pinnacle of its blooming season in early spring; yet some can still be seen flowering now, said Joshlyn Sand, horticulturalist with Honolulu Botanical Gardens.

"Gold trees, plumeria, royal poinciana — they respond to wet and dry cycles in the weather. So you'll have sporadic blooming, depending on rainfall," Sand said.

Here's a guide to the city's flowering trees and where to find them.

RAINBOW SHOWER

"It has a beautiful dusty pink color that's wonderful this time of year," horticulturist Joshlyn Sand said of the official tree of the City and County of Honolulu, a hybrid of the golden shower tree and the pink and white shower tree, pictured above and top.

The original tree was planted in the yard of Wilhelmina Tenney on Lunalilo Street in 1920. Once it matured and bloomed, it was sought after for its magnificent pinkish-yellow appearance and because it did not produce messy seed pods. Offspring of the original were planted all over the city.

Appearance: The blossoms are a fusion of yellow and pink. Two other color variations have been named — "Queen's Hospital White" and "Lunalilo Yellow."

Flowering period: Now. Usually from March through November, reaching its peak in July and August.

Best spots to see it: Along South King Street, diamondhead end of Kapi'olani Park and Foster Botanical Garden.

GOLD

"It's huge, and when it's flowering, it's hard to miss," Sand said. "You can see them miles and miles away. You can be driving and just see them up in the hills."

In Hawai'i, gold trees herald spring with their clusters of yellow, horn-shaped flowers. Before flowering, the tree's leaves fall and are replaced with the blossoms.

Appearance: As its popular name implies, when in bloom, the tree is a canopy of yellow.

Flowering period: Normally early spring, but some gold trees may still be flowering because they prefer dry weather. "It's one of the few benefits of lack of rain — the beautiful flowering on some of these trees," Sand said.

Best spot to see it: Tantalus.

QUEEN'S CREPE MYRTLE

"It's really one of the most beloved flowering trees. It's absolutely fantastic," Sand said. "It goes dormant in the winter time, so you don't have the leaves, but the seed pods will persist. So it's interesting year-round. It has the beautiful crepelike flowers when it's flowering and when it goes dormant, it's still attractive."

The original tree is at Foster Garden and is the largest of its kind in the country.

Appearance: The lavender-colored flowers have a crepelike texture, hence the name.

Flowering period: Now. Late spring and summer, just when the new leaves emerge. The tree is leafless in the winter.

Best spots to see it: Maunawili, and in Kane'ohe near Alii Shores.

ROYAL POINCIANA

"It's so obvious when it's flowering, because it's outrageously flamboyant," Sand said. "It's sometimes called the flame tree because it literally looks on fire when it's going on."

The Madagascar native is popular throughout tropical and subtropical areas. Once used as a street tree, it was replaced because of its aggressive roots and messy pods.

Appearance: The clusters of flowers can range from a deep red to orange. There is also a rare yellow variety called the golden royal poinciana.

Flowering period: Now. As early as January to as late as October, reaching its peak in May and June.

Best spots to see it: Waikiki, Lunalilo Home Road in Hawai'i Kai, Makiki District on Wilder Avenue. The golden royal poinciana can be seen in front of the Academy Art Center at Linekona on Victoria Street and in the Queen Kapi'olani Garden on Paki Avenue.

MONKEYPOD

"Sometimes they're not something you would notice, but they're actually quite pretty right now," Sand said.

Brought to Hawai'i in 1847, the monkeypod is a big source of shade throughout the Islands. Its wood is used for bowls and platters, and its seeds are used in lei. The tree is also known as the "rain tree" because its leaves curl up at night or on cloudy days to allow rain to penetrate the soil below.

Appearance: While not dramatic, the pink powder-puff blossoms are impressive on some of the larger specimens.

Flowering period: Summer.

Best spots to see it: Possibly the most impressive monkeypods can be found at Moanalua Gardens, which are known in Japan as "Hitachi trees" because of their use in long-running television commercials by the Japanese company. There is also a whole row of monkeypods along Paki Avenue. Both the Moanalua trees and Paki Avenue trees are protected under the state's Exceptional Trees Act.

PLUMERIA

"This is one of those that we here take for granted, but there are people worldwide who are absolutely crazy about them," Sand said. Once a popular graveyard planting and now a dependable lei flower, the fragrant, colorful plumeria is sought after by Mainland plant enthusiasts, she said. An eBay search will reveal many people willing to spend hundreds on cuttings of rare, unusual color varieties of plumeria.

Appearance: The white "Singapore" plumeria is often used in landscaping, but the plant comes in a variety of colors.

Flowering period: Now. Usually peaks from April through September

Best spots to see it: Koko Crater Botanical Garden has a plumeria grove with more than 80 varieties. "From white to pinks to yellows to deep reds, it's a great place to compare and contrast different varieties," Sand said. Blaisdell Arena has many of the evergreen white "Singapore" version, and plumerias are also featured throughout Waikiki.

OCTOPUS

Also known as the umbrella tree, the octopus tree was introduced to Hawai'i in the 1900s. By the 1970s, it had invaded forests in Manoa and is now considered one of the worst invaders of wet forest areas. To see how widespread they are, look alongside the undeveloped stretches adjoining H-3.

AFRICAN TULIP

Producing a beautiful deep scarlet or orange flower, the African tulip tree was introduced in the 1880s. More than 30,000 were planted as reforestation trees on many of the islands. The tree produces messy seed pods and has an aggressive root system. Many have since been replaced, but some can still be found in older neighborhoods on the windward side.

COLVILLE'S GLORY

With flower stalks that can reach 18 inches, this Madagascan tree can be found at Ho'omaluhia Botanical Garden, Koko Crater Botanical Garden and Lyon Arboretum in Manoa Valley. You'll have to wait until the end of summer to see this one at its best.

BROWNEA

Flowering now at most botanical gardens, this tropical American native has dramatic scarlet-red flowers sometimes called "rouge puffs." The flowers develop along the tree trunk and on the stems and tips of stems. When new leaves emerge, they're pink and later turn green. See it at Foster, Wahiawa and Ho'omaluhia botanical gardens, Lyon Arboretum and the Waimea Valley Audubon Center.

Reach Loren Moreno at lmoreno@honoluluadvertiser.com.