Lowland Tropics - What's in Bloom?

In the steamy, lush jungles of the Lowland Tropics Gallery, a light rain falls on the canopy of majestic palms. An enormous kapok tree lies on the forest floor while brightly colored orchids and falling water cascade around it. Coffee berries, cacao pods, and tropical fruits hang heavily from branches, and the sweet fragrance of jasmine and Stanhopea orchids mingle in the air. The gallery is also home to the Conservatory's centenarians, including the towering Imperial Philodendron, a pygmy date palm from San Francisco’s 1915 Panama-Pacific International Exhibition, and 100-year old Cycads, which are primitive gymnosperms that pre-date the dinosaurs.

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Acalypha hispida

Common name: chenille plant ("chenille" means caterpillar in French)

Native to: New Guinea and the Malay Archipelago

Location in Conservatory: Lowland Gallery

 

The fuzzy, pendulous inflorescence of the chenille plant range in color from vibrant red through a creamy white. The chenille plant is dioecious, which means that staminate (male) and pistillate (female) flowers are on separate plants. The showy flowers we are accustomed to seeing on display are female. The individual flowers which make up the inflorescence are very tiny, have no petals, and are made up of feathery pistils. These pistils are tightly packed into cylindrical flower clusters along the raceme called catkins. Flowers with catkins, including the chenille, are predominantly pollinated by wind and and on occasion by insects.

Alternanthera ficoidea 'Party Time'

Location in Conservatory: Pond at the entrance to the Lowland Gallery

 

The colorful foliage of ‘Party Time’ is especially eye catching. Its green leaves have hot pink streaks and blotches. Some leaves are entirely pink and others entirely green. It grows well in low light and in water and it is used as an ornamental container plant.

 

Alternanthera is a genus of flowering plants in the amaranth family, Amaranthaceae. It is a widespread genus with most species occurring in the tropical Americas. Alternanthera plants are known to produce compounds that injure other plants, including crops, and one species, commonly known as alligator weed, is an invasive species that clogs waterways, slowing shipping and increasing flooding. But here at the Conservatory, 'Party Time' is a festive and well contained addition to the Lowland Gallery. 

Areca vestiaria

Location in Conservatory: Lowland Gallery next to lobby entrance
Native to: shaded low mountainous terrain in the rain forests of eastern Indonesia, Maluku, and Sulawesi

 

This palm varies from a red crown shaft with maroon leaves, to an orange version with green leaves, and everything in between. It has been observed that there is substantial color variation depending on elevation, with the more colorful plants coming from higher elevations. This photo shows the three stages of the palm's fruit - the yellow inflorescence emerging, the full-sized but unripe yellow fruit, and the ripe red fruit.

Calanthe Orchid

Native to: all tropical regions

 

Calanthe are unlike most orchids in they are terrestrial, meaning they grow in the ground rather than epiphytically on other plants. Also unusual is that the genus is divided into two groups – deciduous species and evergreen species. Many of the species found in the Conservatory are deciduous. The pleated leaves shed at the end of the growing cycle, leaving behind only the pseudobulbs. The new inflorescence emerges from the pseudobulb at the start of the next season.

 

In Greek, calanthe means "beautiful flower". The flower's delicate pink or white petals and sepals form a fan shape that tops the prominent lip.

Carica papaya

Location in Conservatory: alcove in the Lowland Gallery across from Potted Plants

Native to: tropical America 

 

The papaya is commonly referred to as a “tree,” but it is technically a giant herb because it never produces true woody tissue. The papaya typically has a single, unbranched, non-woody trunk. The trunk is topped by an umbrella-like canopy of palmately lobed leaves. The stems and leaves contain white milky latex. Papayas are dioecious (male and female flowers are on separate plants), but many cultivars are hermaphroditic. Their yellowish-white trumpet-shaped flowers are fragrant and bloom throughout the year. 

 

The papaya is used all over the world in traditional medicine for its digestive, wound-healing, and anthelmintic (drugs that expel parasitic worms) properties. These properties originate from the presence of the enzyme papain in the latex of the papaya plant and its fruit.

Cocos nucifera

Common Name: Coconut Palm

Native to: Pacific Islands

 

Cocos nucifera, most commonly known as the coconut palm, is a long lived palm that may grow up to a 100 years. The coconut palm is native to the tropical islands of the west Pacific and require hot, moist conditions to grow. Coconuts are buoyant and able to float in sea currents for long distances while remaining viable and able to germinate upon arrival. For that reason, coconut palms are often found along the coast and seaboard of tropical areas.

 

What is a coconut? A seed, nut, or fruit? The short answer is all three. Botanically, a coconut is a one-seeded drupe. A drupe is a fruit with a hard covering enclosing a seed (like a peach or mango). The coconut fruit has three layers: a thin, smooth outer epicarp layer that surrounds the thick, fibrous mesocarp layer, which encloses the woody endocarp layer. The endocarp houses the seed. Usually, the coconuts we see in stores have the two outer layers removed, with only the endocarp and seed remaining. Also, while the coconut is not a true nut, one loose definition of a nut is a one-seeded fruit, and by that definition we could consider the coconut a nut.

 

Coconut palms are one of the most widely grown and iconic palms in the world. The coconut palm has a wide variety of uses and, in some cases, coconuts are considered survival food. Coconut water is a good source of iron, calcium, phosphorous, proteins, and vitamins. Coconut meat has a large diversity of food uses, including coconut oil. The coir can be used as a fiber to make rope, floor mats, mattress filling, and fish nets. The leaves are traditionally used to make baskets and roof thatching, while the trunk is used to make furniture, houses, and even musical instruments. Additionally, an alcoholic drink known as palm wine or Toddy is made from the sap of the coconut palm. 

Coffea arabica

Location in Conservatory: Throughout the Lowland Gallery

Native to: Highlands of Ethiopia

 

Coffea arabica and Coffea canephora are the two major commercially grown species of coffee. Arabica is said to produce better tasting coffee because the lower caffeine content makes it less bitter.

 

Scientists have determined a number of ways coffee plants use caffeine to their benefit. When leaves die and decompose on the ground they contaminate the soil with caffeine which makes it difficult for other plants to grow. Coffee plants also use caffeine to deter insects from eating their leaves and beans. At the high doses of caffeine contained in these plant parts, a bite can be fatal to insects. But the nectar contained in coffee flowers is laced with a small dose of caffeine. When insects feed on caffeine-spiked nectar, they are more likely to remember the flower and revisit it again, which aids in pollen dispersal. 

Dioon spinulosum

Common name: giant Dioon

Location in Conservatory: center planting area near the doors to the Lowland Gallery

Native to: cliffs and rocky hillsides in the tropical rainforests of Mexico

 

Cycads are usually linked to palms or ferns, when in fact they are not related to either. They are actually a unique, ancient family unrelated to any other group of living plants. Cycads flourished in the Mesozoic Era some 250 million years ago. This specimen is over 100 years old. Dioon spinulosum is one of the tallest cycad species in the world, growing to 40 feet high. 

 

A cycad is either male or female and the cones of each sex are usually quite different in size and shape.  The two cones on this female plant are emerging from the center of the leaf tufts at the top of the plant and will soon be as large as in the photo. They will grow upwards and then grow down. When the cones ripen and open they will reveal hundreds of orange, unfertilized ovules.

 

For the cone’s ovules to be fertilized, the Conservatory would need pollen from a male plant of the same species, which we do not have at the Conservatory. So, this giant Dioon will repeat it’s cycle of producing unfertilized cones, year after year, without producing offspring. Fortunately, cycads can also produce stem offshoots or suckers (often called pups). These can be separated from the parent and rooted to create new plants.

Hibiscus

Location in Conservatory: Aquatic and Potted Plants Galleries

 

The Hibiscus captures the magic of the tropics by combining the lush, deep greens of the foliage and the bright colors of the flowers. The plant serves many purposes in different cultures. 

The red Hibiscus flower is traditionally worn by Tahitian women. A single flower, tucked behind the ear, is used to indicate the wearer's availability for marriage. Dried hibiscus is edible, and is a delicacy in Mexico. The tea made from hibiscus flowers is known by many names in many countries around the world and is served both hot and cold. The beverage is well known for its color, tanginess, and flavor. Certain species are also beginning to be used more widely as a natural source of food coloring, replacing synthetic dyes.

Many of the 300 species have a classic structure with five overlapping petals arranged in a trumpet-like whorl. A long reproductive column protrudes from the center of the petals. The column is covered with stamens, the “male” part of the flower that produces pollen. At the tip of the column are five spots, or stigmas, which are the “female” part and act as the receivers of the pollen.

Hibiscus schizopetalus

Common name: Japanese lantern

Location in Conservatory: Lowland Gallery

Native to: tropical eastern Africa

 

The red or pink flowers of this Hibiscus are distinctive in their frilly, finely divided petals that curve up and create a globe shape. A long reproductive column protrudes from the center of the petals. The column is covered with stamens, the “male” part of the flower that produces pollen. At the tip of the column are stigmas, which are the “female” part and act as the receivers of the pollen.

Jasminum rex

Common name: royal jasmine

Location in Conservatory: Lowland Gallery, climbing the white post across from the Gala display

Native to: Thailand

 

Jasminum is a genus of shrubs and vines in the olive family (Oleaceae). It contains around 200 species native to tropical and warm temperate regions of Europe, Asia, and Africa. Jasmines can be either deciduous (leaves falling in autumn) or evergreen (green all year round), and can be erect, spreading, or climbing shrubs and vines. This winter-flowering jasmine has some of the largest flowers in the family.

Medinilla

Location in Conservatory: Highland, Aquatic, Potted Plants Galleries

Native to: Africa, Madagascar, Asia, Pacific Islands

 

Medinilla are a species of evergreen shrubs with white, pink, or orange flowers. The flowers are arranged on a "panicle", which is a branched cluster of flowers. When pollinated, the plant bares showy berries. The leaves on many species of Medinilla are arranged in a whorl or are alternating. This allows the maximum amount of sunlight to hit each leaf instead of blocking sun from hitting the leaf below it on the stem.

Musa

Common name: banana plant

Native to: Bananas are cultivated in 135 tropical and subtropical countries and are native to Southeast Asia and Australia

 

In horticulture, parthenocarpy (which literally means “virgin fruit”) is the natural or artificially induced production of fruit without fertilization of ovules. The fruit is therefore seedless. Seedlessness is seen as a desirable trait in edible fruit with hard seeds such as watermelon, clementines, grapes, and grapefruit. Bananas are another example of parthenocarpy, which explains how the Conservatory’s plantains and banana plants can bear fruit without a pollinator being present. The common banana is triploid, meaning it has three sets of chromosomes. Triploids cannot produce a functional seed, but they still develop good fruit through parthenocarpy. After the stalk has flowered and borne fruit, it dies. So how does a banana plant reproduce? There are side shoots or suckers at the base of the main stalk, which can be removed and replanted.

 

Banana flowers are protected by bracts. The bracts fold away one-by-one and reveal hundreds of flowers. Female flowers appear first and develop into hands of fruit. The male flowers emerge last and do not become fruit. In Southeast Asia the male flowers are boiled and eaten as a vegetable.

Oncidium Orchid

Common name: dancing lady Orchid

Location in Conservatory: Lowland Gallery

Native to: the American tropics, from breezy coastlines to cloud forests

 

Some species of Oncidium have long bouncing stems full of abundant flowers that flutter in the breeze and look like male bees. Pollination occurs when actual angry male bees attack the flowers thinking they are a competitor.

 

The Greek word "onkos" means pad or mass and refers to the fleshy, warty callus on the lip of many species. Some calluses are known to provide oil droplets, which are consumed mainly by bees. The common name, dancing lady Orchid, refers to the elaborate lip that looks like a dress with a full skirt. The petals and sepals look like the arms and head of a tiny lady.

Phoenix roebelenii

Common name: pygmy date palm

Native to: southeastern Asia

Location in Conservatory: In the Taube and Friend Families Palm Court in the Lowland Gallery

 

The Conservatory's pygmy date palm is a prized relic from the Panama-Pacific International Exposition. The Expo was held 100 years ago in 1915. This elegant arching palm was donated to the Conservatory after the closing of the exposition. Each pinnate leaf, or frond, has 100 narrow, shiny leaflets. When in bloom, it drops hundreds of tiny white flowers that blanket the ground of the gallery.

 

In 1889 James O'Brien, one of the most famous horticulturalist a of the 1800s, named the palm "roebelenii" in honor of the German orchid collector Carl Roebelen who was the first to completely document the plant in Laos. The pygmy date palm quickly became popularly used in landscapes and collections for its attractive leaves and trunk. By 1915, this palm would have been a common hot house plant.

Psidium cattleyanum

Common Name: strawberry guava

Location in Conservatory: Lowland Gallery flanking the doors into the Potted Plants Gallery

Native to: Brazil

 

Psidium cattleyanum is a small tropical evergreen tree that in the same family as the common guava, Psidium guajava. The fleshy fruit of the strawberry guava turn purple or red as the fruit matures; some varieties of Psidium cattleyanum have yellow fruit. The fruit is edible and juicy with a strawberry-like flavor. The upper surface of the leaves are dark green and glossy, while the lower surface is whitish-green in color and punctuated with small oil cavities that give it aromatic qualities. 

 

Strawberry guava is native to the coastal areas of eastern Brazil, where it is known as "araçá". However, the tree quickly adapts to a variety of climates, and is considered an invasive weed in many tropical areas, particularly Hawaii and the Caribbean islands. The strawberry guava was brought to Hawaii in 1825 for its fruit and ornamental attributes; however, it now threatens Hawaii’s native forests. The strawberry guava grows in monotypic stands that displace native tree species. Psidium cattleyanum quickly spreads both by shoots and seeds, with the help of non-native birds and pigs that consume the fruit and spread the seeds to new areas. Restoration efforts are underway in Hawaii to control the growth of P. cattleyanum and restore native forest species. 

Verschaffeltia splendida

Common name: Seychelles stilt palm

Location in Conservatory: Lowland Gallery

 

Verschaffeltia splendida is found only on three islands in Seychelles where it is threatened by habitat loss. It grows in the canopy or under story in moist rainforest on steep hillsides and ledges. The stilt root system is thought to have evolved to stabilize the palm on sleep slopes and in strong winds. The spikes on the trunk of the younger palm protect it from hungry animals.