These colorful and fast-growing trees are from the tropics, and warm temperate areas like the Himalayas and Argentina. There are over 114 species and varieties, widely distributed throughout the world. Waimea had one of the world’s best collections of these genus until a microscopic wasp found its way to Hawai`i in 2004. In Hawai‘i, the popular wiliwili tree, E. sandwicensis, had been decimated. Even old trees growing in the Valley from long before the botanical garden were established, are on their last legs. The Erythrina Gall Wasp lays its eggs on newly emerging leaf and flower buds which then swell to grotesque shapes. In December of 2008, another predator wasp was released as a bio-control. There is now a dynamic balance between these two alien wasps in Hawaii, but the Wiliwili trees survived.
These trees can grow up to 30 feet high and its bright red seeds are used in lei-making. The lightweight wood of the wiliwili was used by early Hawaiians for surfboards and fishnet floats, and is still used for outrigger canoes. In Central and South America, these trees are often used to shade crops like coffee.
Several species may prove to have important medicinal and economic uses. This collection is part of an international research effort to study the medicinal value as well as other uses of these plants.
Bamboos are actually giant members of the grass family, Poaceae. At least 1500 species can be found widely distributed in the topics and warm temperate areas of the world. Bamboos are the fastest-growing woody plants with some towering over 60 feet high. Many selections are highly prized for their variegations, and unusual stem shapes.
Next to palms man uses the bamboos more than any other plant family. They are unsurpassed for building construction and scaffolding. Artisans use the fine-grained wood to create farm tools, musical instruments, brushes, baskets and limitless handicrafts.
Bamboo is the sole food source for the endangered Giant Panda of China and in many oriental dishes the tender bamboo shoot is indispensable.
One surprising characteristic of most types of bamboo is that after many years, all the plants of one species will flower at the same time, even when widely separated. The massive amount of fruit produced use to cause an infestation of rats in historical China, which then led to famine.
Among the most popular flowers of tropical regions are the magnificent blooms of the hybrid Hibiscus.
The Hibiscus hybrid collection presents a dramatic floral display of several hundred cultivars from throughout the world. Many of these are antique or heirloom varieties, no longer in vogue.
(Visit the Hibiscus Evolution Garden to learn of the development of the Modern Hibiscus hybrid).
Hibiscus Evolution Garden
Hawai‘i's state flower is the Hibiscus. This garden shows us how the modern Hibiscus has been developed since the early 1800’s.
This is the only garden of its kind in the world and highlights many different Hibiscus, including several that are endangered.
There are 10 sections to this garden:
- The first section is a collection of true species.
- The second grouping shows old forms, including Hibiscus varieties found by early European visitors to Asia and the South Pacific Ocean.
- The next seven sections show the results of crossing members of the first two groups.
- The last section features the magnificent blossoms of the modern hybrid.
Among the Hibiscus plants and serving as groundcovers are members of the Commelinaceae family. A family of mainly tropical and subtropical plants with about 500 species in 38 genera. All the species are herbaceous and most have fleshy stems.
Some members have long been cultivated for decoration or as pot plants. Eg. Dichorisandra (“Blue Ginger”); Tradescantia(“Wandering Jew”) several species of honohono, Commelina, are valued as cattle fodder and are sometimes eaten raw or cooked, by humans.
Sap from these plants can cause an allergic reaction on the skin of sensitive persons.
This family is one of many in the major plant group monocotylononae; note that the flower parts are in multiples of 3, typical of plants in this group.
The genus hibiscus adds a great variety of color to the Hawaiian flora. Surprisingly, the bright red Hibiscus kokio flowers are descended from the same pioneer ancestor that evolved to become our two white-flowered species: H. waimeae from Kaua’i named for Kaua’i’s Waimea Canyon and H. arnottianus found on other islands. These two native whites, Koki`o ke`oke`o, are the only hibiscus in the world that give off a faint perfume at dawn and dusk.
For no good reason, the state flower used to be a Chinese red hibiscus. That was changed in the late 80’s when the bright yellow-flowered endemic Hibiscus brackenridgei, Ma`o hau hele, was given that honor. This endangered species survives in the wild in very few places. Fires in 2007 impacted the already limited range of the O’ahu subspecies Mokuleianus. Lana’i’s last few plants are not doing well, but several collections are growing well at Waimea. A subspecies found on Moloka’i in 1930 wasn’t seen again until a small population of 16 plants was found in a military reservation on O’ahu’s west coast in 2001.
One of our native hibiscus species is indigenous. H. furcellatus, `Akiohala, with big pink flowers, got to Hawai’i without man’s help, but wild plants of this species can also be found in Mexico and the Caribbean.
The jury is still out as to whether the hau tree, H. tiliaceus, is a native or a Polynesian introduction. Unusual forms of these trees are planted along the banks of the stream above the first bridge. Taxonomists will soon put the hau tree in to a new genus, Talipariti.
The Hawaiian Hibiscus collection is large. Four sections separated by roads and paths start at the Hale ‘Iwi burial site and extend down to the main road makai of the banyan tree.
In ancient Hawai‘i, plants played an important part in all aspect of life. Plants were not only a food source, but were used in medicines, building, clothing, weapons, and as food containers.
The kāhuna were skilled in utilizing the plants around them for medicines and religious ceremonies. The ti plant was used to reduce fevers, while the ginger root was mashed and mixed with salt water for a purification mixture. kō (sugar cane) juice helped make medicines more palatable.
Early Hawaiians used koa wood for building canoes and surfboards, and the wauke for pounding into tapa cloth. Leaves of the ahuhu were crushed and put in tide pools where it made fish an easy prey by immobilizing them.
This garden highlights many of the plants utilized by ancient Hawaiians and has individual markers telling the specific uses. A row of ti plants separates the edible from the non edible plant sections. The small medicinal garden is planted under and around 2 Milo trees.
As you enter this collection from the upper road you'll see an'ulu (breadfruit) tree, and beyond it are tall, flowering ko (sugar cane) plants surrounding three fenced kalo (taro) plantings. Hawaiian varieties of mai'a (banana) are planted near the kalo beds, and beyond them are two 'ohi'a 'ai (mountain apple) trees from the South Pacific which fruit twice a year. The ground covers under the sugar cane are varieties of 'uala (sweet potato). These can be recognized by their flowers which resemble miniature morning glories which are closely related.
Our named varieties of 'uala are being grown the traditional way a bit further up the Valley- the tubers grow in loamy soil in low rock cylinders. You can see these by the edge of the grass near the banyan tree.
After walking past the kalo beds you'll see a row of ti plants separating the edible from the non-edible plant sections. A medicinal garden is planted under and around two milo trees, hibiscus relatives with excellent wood brought by the Polynesians. Across the trail in the non-edible section are two calabash trees. These along with the Kona orange tree in the food section did not get to Hawaii until after western contact. The thin-shelled calabash fruit, about 6" in diameter, surprisingly grow right from the bar of the tree. Calabash's gourd-like fruits were used as bowls and made into musical instruments. In this same area is the only type of bamboo early Hawaiians used and the favorite loulu palm species used for thatching.
Native Fern Garden
Our native fern garden, established recently is located next to the Pikake Pavilion. One sixth of Hawai`i's native flora is in the pteridophytes. The well-known endemic tree fern, hapu`u (Cibotium chamissoi), is commonly found in mesic to wet forests of O`ahu. Other species of hapu`u dictate at higher elevations. We are encouraging Hawai`i residents to plant the endemic tree fern in lieu of the invasive Australian tree fern that is used commonly for landscaping. In the wild, the hapu`u is threathened by feral pigs that eat the new growth; some plants were cut down for their fibrous trunk used for decoration or to mount epiphytic plants on them, such as orchids.
Ferns are a crucial part of the Hawaiian culture. In lei making, fronds are used abundantly. It is mentioned commonly in song and chant as well.
The lei garden consists of plants that produce flowers, seeds, and leaves that include color, fragrance, lasting quality, and rarity for lei making.
Today, in Hawai`i, the lei is a symbol of friendship, love, and trust. It is offered as a gift of honor to friends and visitors. The connection to its origins goes back to Southern Asia, after many hundred of years of migrating form island to island eastward across the vast Pacific Ocean, bringing with them the arts and traditions of the lei which generations before them had developed on the continent of their origin. The materials of lei making were substituted, the reasons for and the rituals of the lei suffered changes also as people moved form place to place. A greater and richer variety of leis was made in Hawai`i at this time than in any other Polynesian group. Most plants in this garden bloom profusely in March and September.
Tropical Fruit, Nut, and Spice
While we expect tropical fruit to grow on trees, there are a large number, which come from shrubs and even herbs.
In this garden, there are well-known fruits like mango, guava, and papaya, along with custard apple and rukam, which are equally tasty but not as well known. There is the jackfruit, which grows quite large and can weigh up to 40 pounds. And, a delicious fruit called durian, which has an obnoxious smell.
There are also a few subtropical nut and spice trees that grow here, such as the macadamia nut and the Brazilian chestnut trees. Please come to the garden to smell the spice trees and guess what they are before reading the labels mounted on the trees.
Malvaceae Family -Hibiscus species collection
The ornamental hibiscus hybrids are the best known, but there is great diversity and beauty in these wild hibiscus species and their relatives, which include cotton and okra. Of all the different hibiscus species in the world, only the two white flowered endemics (Koki`o ke`oke`o) found in Hawai`i have a fragrance. There are about 300 species from tropical and sub-tropical areas.
This plant family has over 1,100 species, but the Crinum, or spider lilies, are especially favored in this garden. Efforts are underway to preserve many of the unusual and rare plants, and already this collection is one of the largest in the world.
Ferns and Begonias
Ferns are a very primitive group of flowerless, spore-bearing plants divided into about 20 families and 300 genera. The nearly 10,000 species we know of are survivors among the millions that evolved and went extinct long before flowering plants appeared on earth. Coal deposits are the carbonized remains of the vast fern forests of the Devonian era.
Most ferns have fronds, which uncurl as they grow. Spots on the undersides of these leaves called sori produce millions of single-celled spores, which are carried like dust by the wind. Ferns depend on water to complete their life cycle, so most are found in moist areas.
Take a look at our Native Fern collection in the Pikake Pavilion.
This family of perennial herbs and shrubs is found in every tropical region of the world. Begoniascan usually be recognized by their asymmetrical leaves and succulent jointed stems.
Their tiny seeds account for their wide dispersal, even to places as remote as Hawai`i. The endemic genus Hillebrandia is endemic to the islands.
Begonias have been extensively hybridized for their ornamental leaves and clusters of white, pink, red or yellow flowers.
Gingers and Heliconia
There are over 1000 species of Gingers in the Zingiberaceaefamily. They are widely scattered throughout the tropical regions of the world, with the heaviest concentration in the Indo-Malaysia area. Some species are grown for their ornamental foliage and flowers, while others are used to make dyes, perfumes, medicines, spices, and condiments. Flowers are borne either on the leafy vegetative stems or on a separate leafless flowering stalk.
Most of the over 150 species of Heliconia, in the family Heliconiaceae, are native to central and South America. A few are found on various islands in the South Pacific. Different species range in height from 2 to 20 feet and are easily distinguished by their long leaf stems. The colorful, boat-shaped bracts are on either erect or pendant stems and usually conceal the small true flowers within. The leaves are used for roof construction and wrappings for food, while the long lasting ornamental bracts are prized for cut flower arrangements.
This family which includes the pineapple ginger is closely related to the gingers, except the plant parts do not have a fragrance. Other plants in this family are sometimes called “crepe ginger” or “spiral flag gingers”.
The genus Bauhinia is popular for its brightly colored five-petaled flowers that resemble orchids. There are about 250 species distributed throughout the tropics. They can usually be recognized by their deeply lobed leaves which look like paired leaflets. Bauhinias, in the legume or fabaceae family, all bear flattened, double-seamed pods.
Bauhinia variegata is cultivated in India for its bark used for tanning and dyeing and its wood, called mountain ebony. The seeds of B. petersian are eaten in Africa and used as a substitute for coffee.
Bauhinias are frequently used in landscaping because they are compact and prolific flowerers. B.x blakeana, commonly called the Honk Kong Orchid Tree, is widely lused as a street tree because it never sets seed nor even drops pods.
Many Bauhinias are climbers. You can the the large leaves and coiling tendrils of B. vahlii, covering the monkeypod tree overhead.
The genus of "twin-leaved" plants was named by Linnaeus for John and Caspar Bauhin, twin Swiss botanists fo the 16th century.