Guides Corner

THE LOWLAND TROPICS GALLERY
Entering the Conservatory's dome, visitors feel the humidity and heat of the Lowland Tropics. Here, in the lush jungles of the tropical rainforest, large plants with huge leaves compete for sunlight and resources. This gallery houses the Conservatory's prized century-old imperial philodendron as well as a host of food-producing tropical plants such as cacao, allspice, vanilla and coffee.

ARCHITECTURE/DESIGN/ARTWORK
The central planting bed contains a fallen kapok tree (a Ceiba pentandra), a botanical sculpture built by Cemrock. The tree sculpture cantilevers above a jungle pool gently fed by a stream flowing from a sculpted rock-face dripping wall beside the timber bamboo. The fallen tree sculpture is equipped with planting pockets and drainage to support the epiphytes perched on the trunk representing a decomposing tree trunk overgrown with epiphytes and primary succession invaders.

The Dome

• The upper dome of the Conservatory weighs about 29,000 pounds without glass and the dome is 56 feet in diameter and 55 feet tall. The finial atop the dome is 13 feet tall and weighs about 800 pounds. 90% of the colored glass pieces were salvaged before the 1998-2003 restoration and reused. The Conservatory's dome has burned twice, in the1883 and 1918 fires.

• The Lowland Tropics contains two display cases along the north wall that are filled with fieldwork related artifacts. The right or east case includes tools and artifacts describing the state of plant collecting in the tropics in the late 1870s. Beside this case is a Wardian case; plant explorers used these during the Victorian era to ship living plant specimens from the wild rainforests to their home countries. Wardian cases acted as miniature greenhouses and provided protection from salt spray during the rough sea voyage.
• The case on the west side of the door contains modern day tools in stark contrast to the tools of the Victorian plant collectors. Botanists today catalogue the flora of the tropics using modern technology such as helicopters and global positioning systems. This exhibit also contrasts the state of the tropical ecosystems themselves.
• In the 120 years since the Conservatory opened, human beings have perpetuated an incomprehensible conservation crisis in the tropics. This exhibit suggests ways that visitors can become botanists, horticulturists, conservationists and become involved with conservation organization.

• The Lowland Tropics are one of the most prolific of all plant communities in the world with the highest density of tree species compared to other forest biomes. They are found between sea level and 3,000 feet.
• The lowland tropical forest is comprised of layers: herbaceous layer comprised of leaf litter and ground covers, under-story comprised of smaller and younger plants, lianas and epiphytes, and canopy which reaches upwards of 150 feet with a few emergent trees pushing through the canopy nearing 200 feet. A quarter of all plant species in lowland rainforests are epiphytes.
• Light is a major factor in forest growth and density. In clearings and along river edges, dense vegetation has an opportunistic chance to "grow-up," but once in the interior of the forest, the amount of light reaching the floor is very limited and prevents much from growing close to the ground.
• In areas with very thin soils, which provide little physical support as well as few nutrients, some trees get added support through buttress trunk bases and stilt root structures. There are massive epiphyte communities in the canopies of these rainforests. (Though epiphytes grow in all elevations of the rainforest, we feature our epiphytes in the Highland Tropics and Aquatic Plants galleries.)
• Tropical rainforests cover only 2% of the Earth's surface, yet they are home to over half this planet's plant species. Tropical rainforests are found along the equator in a zone between the Tropic of Cancer in the northern and the Tropic of Capricorn in the southern hemisphere. They receive anywhere from 80 to 400 inches of rain annually (San Francisco receives approximately 21 inches per year), maintaining a warm, wet climate year-round, perfect growing conditions for many plants.
• The rainforests of the world are being cut down, bulldozed and burned at an incredibly rapid rate--100 acres a minute. That's an area roughly the size of San Francisco destroyed every five hours.
• The forests are being destroyed primarily by timber, cattle, oil and mining interests. Much of what is produced from the rainforests, such as coffee, beef, paper, furniture and gasoline are exported and sold in the United States. We can help save the rainforests by becoming conscientious consumers.

PLANTS
Here in the Lowland Tropics gallery, the Conservatory features a wide variety of economic plants that are used in products that we eat and use in the home every day. The Conservatory's Lowland Tropics economic plant collection includes: Balsa, banana, cacao, calabash, cinnamon, coffee, miracle fruit, papaya, palm plants, pineapple, starfruit, timber bamboo, cardamom, allspice, horseradish tree, strawberry guava, breadfruit and vanilla.

Variegated Hawaiian banana, Musa x paradisiaca 'Ae Ae,' Musaceae

• Southeast Asia
• Bananas are grown for their fruit, fiber and foliage. They are grown extensively in all tropical countries.
• These monocots may be pollinated by bats, sunbirds, or may be self-pollinating. They can also be parthenocarpic, meaning that they produce fruit without fertilization. This explains why they don't have any seeds.
• The banana isn't really a tree, it's a giant herbaceous plant with an above ground pseudostem (similar to a trunk) made up of tightly wrapped leaf sheaths. Each of these pseudostems arises from an underground corm. What can look like hundreds of banana trees may actually be one plant with a huge underground stem sprouting many pseudostem 'trunks.'
• Each spike produces 200-300 individual bananas depending on the cultivar it is.
• The banana is included in Asian Buddhist texts dating from 2,600 years ago; the first known banana plantation was in China (200 AD). By 650 AD Arabic merchants had distributed the banana all over Africa. Europeans brought the banana to the Americas approximately 500 years ago.

• Central and South America
• The flowers and fruits of this plant are cauliflorous, meaning that they are produced from the woody trunks and limbs. The flowers are pollinated by biting midges.
• The Sterculiaceae contains our native flannelbush (Fremontodendron californicum).
• The seeds of this tree's fruit are the source of cocoa and cocoa butter, the primary ingredients in chocolate.
• The Mayans began making a cocoa drink approximately 1,500 years ago, in the Yucatán. The Mayans cultivated the earliest known cacao plantations.
• The Aztec emperor, Montezuma, drank thick chocolate that was dyed red, which was served in golden goblets that were thrown away after only one use. He liked it so much that he was said to drink 50 goblets every day.
• The cacao beans were used as currency in both of these empires. For example, ten cacao beans would have bought one rabbit.
• The average person in the United States eats 11 pounds of chocolate a year.

• Tropical Americas
• This plant is a major source of red body paint for the Indian tribes of the tropical Americas.
• It is now planted throughout much of the tropics for the bright yellow dye derived from the arils of the seeds. The dye is nearly tasteless and is used in foods, such as margarine, cheese, butter and chocolate.

• Tropical Africa
• Coffee flowers smell similar to gardenia, which is also a member of the Rubiaceae.
• This plant is the source of coffee seeds, more commonly called beans. It is cultivated in Latin America, Africa, India and Indonesia.
• Coffee plants are pruned to 2 to 4 feet in height, encouraging a dense, bushy habit for easier hand harvesting. If left to their natural habit, these plants would grow to 20 feet.
• Coffee is native to Africa, but it was in Arabia that coffee became a domesticated crop. In Ethiopia the Galla tribe used coffee, but not as a drink. They would wrap the beans in animal fat as their only source of nutrition while on raiding parties. The Turks were the first to process coffee into a drink, often adding spices to the brew.
• Coffee plantations are a major source of oxygen in many parts in the world, it is estimated that each hectare (100 acres) of coffee produces 86 pounds of oxygen a day.
• As coffee is among the three most traded commodities in the world, it makes sense that the coffee plant is also one of the most common plants in the world.

• South and Central America
• The pineapple was first farmed in the high plateaus of central South America, where it was widely planted for its fiber and fruit. Pineapple was called "Anana," which means "excellent fruit". Highly regarded for its intense sweetness, it was a staple of South and Central American Indian feasts.
• The pineapple is poisonous until it ripens, severely irritating to the mouth and throat. This adaptation prevents the fruit from being consumed before the seeds are ready.
• In Europe during the 1600s, the pineapple was so valuable and prized that King Charles II of England posed for an official portrait receiving a pineapple as a gift. Wealthy Europeans rented pineapples by the hour to be displayed as centerpieces in their party buffet arrangements. The pleasure of actually consuming the pineapple, after it had been rented to dozens of parties, was the ultimate symbol of affluence.
• Today Hawaiian plantations produce almost a third of the world's crop.

• Tropical America
• The orchid family is considered the second largest family of flowering plants (after the daisy family).
• The flowers are bee-pollinated in the Americas. However, most cultivated vanilla is grown in Madagascar, where the pollinating bees are absent. Because of this, the vanilla flowers are hand-pollinated. This process is made more labor intensive by the fact that the flowers only live for 24 hours, and so plants must be inspected every day for new blooms.
• This orchid produces pod-like fruits, inaccurately called beans, that are the source of vanilla extract used as a flavoring and in perfumes.
• One of the only vining orchids, vanilla plants climb on the trunks of trees or poles by means of aerial roots; they can grow to almost 90 feet.
• The Aztecs originally used vanilla as a flavoring for chocolate, and the Spanish carried it back to Europe where it was used for this same purpose.
• Vanilla extract is obtained from the unopened seed capsules; inside the pulpy pods are thousands of minute seeds. The tiny brown or black specks in vanilla ice cream can tell you that real vanilla beans were used.

• Burma, India and Sri Lanka
• The Lauraceae also contains our native California bay (Umbellularia californica) and avocados (Persea spp.).
• This tree's inner bark is peeled, dried and ground into cinnamon, dried in small sections to make cinnamon sticks.
• In this country it is used to flavor desserts and condiments. Cinnamon is very popular in Mexican, Middle Eastern and North African cooking and often used in coffee and tea.
• The cinnamon typically used is soft cinnamon Cinnamomum cassia from Mexico. Several varieties, each with different flavor intensity are commercially available.
• The original name came from the Malay word, "kayumanis," meaning sweet wood.
• The spice was once more valuable than gold.
• The Egyptians used cinnamon along with myrrh and cassia in embalming, perhaps because cinnamic acid has antibacterial effects.
• The Hebrews, among others, used cinnamon in religious ceremonies.
• The Roman Empire imported huge amounts of cinnamon, for use in perfumes and to flavor wines, but it was not favored as a cooking spice. In the Middle Ages cinnamon was imported from Egypt, having been taken there by Arabian traders. It became a favorite flavor in many banquet foods and was regarded as an appetite stimulator, a digestive, an aphrodisiac, and a treatment for coughs and sore throats.

• West Indies and Central America
• Allspice comes from this tree whose leaves and fruit smell like a combination of cloves, black pepper, nutmeg and cinnamon. Other members of this plant family are eucalyptus and metrosideros.
• It is used in North and South American, Caribbean and European cuisine; the spice plays a central role in Jamaican "jerked" meat recipes.
• As a medicinal plant it is a digestive and carminative. The oil increases the flow of blood to make the skin feel warmer. The tannins in allspice provide a mild anesthetic that, with its warming effect, make it a popular home remedy for arthritis and sore muscles, used either as a poultice or in hot baths.
• In the Napoleonic war of 1812, Russian soldiers put allspice in their boots to keep their feet warm and the resultant improvement in odors is carried into today's cosmetic industries, where the oil is usually associated with men's toiletries (especially products with the word "spice" on the label).

• Southeast Asia
• While most people refer to this as ginger root, the edible part of this plant is really a rhizome. Rhizomes are stems that grow horizontally, usually underground. The rhizome of the ginger plant is used around the world as a cooking spice and in herbal medicine.
• Ginger has been used in Asia for thousands of years for relief from arthritis, rheumatism, sprains, muscular aches and pains, catarrh, congestion, coughs, sinusitis, sore throats, diarrhea, colic, cramps, indigestion, loss of appetite, motion sickness, fever, flu, chills and infectious disease.
• Studies have found ginger treats motion sickness and seasickness more effectively than dimenhydrinate (Dramamine). Other medical research reports indicate that ginger reduces the effects of morning sickness in pregnant women.

• Tropical West Africa
• This unusual African shrub produces sweet, red berries that temporarily block the sour receptors on your tongue, making sour fruits & drinks taste sweet. The effect remains for some 30 minutes or more.
• Miracle fruit has been used as an appetite stimulant for people undergoing chemotherapy.

• Malaysia
• The common houseplant, ficus, and the trees that produce edible figs are also members of the Moraceae.
• The small flowers of the breadfruit are pollinated by flies.
• South Pacific islanders relied on breadfruit for clothing, tools and transportation as well as a nutritious food. The wood was used as timber for houses, canoes, drums, surfboards, furniture, statues (ki'i), firewood and poi boards (papa kui'ai). It is resistant to termites and marine worms. The bark was made into cloth.
• In old Hawaii 'Ulu was a staple food. When a child was born the parents would plant a breadfruit tree and a coconut palm and that would be enough food for that person for life.
• It is a traditional medicine for hypertension, skin diseases and infections, digestive problems, diabetes, headaches and ear infections.

• Tropical America
• The Bignoniaceae also contains Paulownia, Jacaranda and Chilopsis.
• Flowers and fruits are cauliflorous (they grow directly from this tree's trunks and limbs). The huge fruit takes up to seven months to ripen. The flowers have nectaries that attract ants, and the ants protect the trees from herbivores.
• This plant is pollinated by bats.
• The Taíno of the Caribbean cut eye holes into the "gourds" and fitted them over their heads. The hunters then waded out into lakes or the ocean. What looked like a floating gourd did not frighten birds as they were being closed in on. The disguised hunters would easily grab the fooled birds by their legs.
• Calabashes are used to make storage containers, cups, bowls, maracas, and many other tools, musical instruments and utensils.

• Sumatra
• These plants are monoecious; the flowers are unisexual, but both male and female flowers are present on one plant.
• This is beautiful clustering palm, with brilliant red petioles (leaf stems) and leaf bases is among the most dramatic and colorful palms.
• Sealing-wax palms received their English name when red pigment was extracted from the plant and used to color wax for sealing letters. The color of the crownshaft varies depending on how well fed the plants are.

• India, Burma and Thailand
• Giant timber bamboo has traditionally been used in Southeast Asia for buildings, boat masts, furniture, buckets, water pitchers, vases and crafts.
• Bamboo is the leader among the renewable timber sources, as it can grow twelve to twenty feet a week and it is easily harvested selectively without damaging younger canes. Culms can be harvested from a single plant for decades. Despite its height and woodiness, this plant is an herb in the same family as lawn grasses.
• Young shoots and canes are no less than 85% water, so to harvest for timber it's a three year wait for the water content to diminish and the tensile strength to increase.
• Bamboo absorbs water faster than most plants and in some parts of the world is used to clean sewage.
• In India bamboo plantations provide 60% of the country's massive paper requirements and much of its commercial timber needs.
• Every year over 2 million tons of edible bamboo shoots, rich in vitamins and low in carbohydrates, fats and proteins are consumed around the world, mostly in Asia.

• Madagascar
• Traditionally, thirsty travelers sought out stores of water in many parts of this plant including the leaf folds, flower bracts and inside each of the hollow leaf bases each of which can hold up to one quart of water.
• Although not a true palm, the traveler's palm is a striking and unique plant with its giant fan of leaves. Its cream colored flowers are reminiscent of birds-of-paradise, to which they are related.
• The flowers of this monocot are bird pollinated.

• Endemic to Hawaii
• Hibsicus arnottianus, subspecies immaculatus is endangered in Hawaii.
• Cotton (Gossypium spp.) and Abutilon spp.are also members of the Malvaceae.
• This hibiscus' petals were used by the Hawaiians as a source of dye.
• The flowers are edible and can also be made into a tea.
• The flowers have an exquisite fragrance, with delicate white petals, surrounding a fused column of red stamens.

• Tropical and subtropical parts of the world
• Cycads are primitive gymnosperms that first appear in the geological record about 170 to 200 million years ago. They were present before the rise of dinosaurs and small populations survive today in limited areas of the world.
• Cycads resemble palms or tree ferns in overall appearance, due to the large divided leaves. Cycads, however, differ greatly in almost all botanical aspects. They are cone bearing and dioecious, meaning that male and female reproductive structures are on separate plants.
• These "living fossils" are so sought after that poaching is a problem in Africa, Central America, Mexico and parts of Asia, including China and Thailand.
• Cycads are dioecious, with separate male and female plants. They are usually pollinated by beetles or the wind.

• Southeastern Brazil
• This is one of the largest leafed species of philodendron, the leaves near the top of the dome reach up to six feet and the lower, shaded leaves four feet. This particular plant is the largest in cultivation and is also uncommon in cultivation.
• Many philodendron houseplants are cousins to this species and share Brazil as a homeland. The family Araceae contains many other kinds of houseplants including colocasia, alocasia, dieffenbachia, caladium and monstera.
• The more than 100-year-old philodendron was the only plant that remained in the ground during the dome's 2003 restoration. It was equipped with a custom-made greenhouse while open-air construction occurred around it.

• Laos
• This species is dioecious; plants contain unisexual flowers, with male and female flowers on separate plants.
• The pygmy date palm is used extensively in landscapes and interiorscapes due to its tolerance of low light and variable humidity levels.
• The fruit is large (about 7 cm) with a thick layer of fruit pulp that is very sweet and rich in sugar.
• The Conservatory's palm came from the 1915 Panama-Pacific International Exposition.