Category Archives: Tropical ornamentals

All about tropical, ornamental plants, exotic and common…

Heliconia wilsonii in Flower

Heliconia wilsonii, an uncommon species that naturally grows in Costa Rica and Panama, has finally flowered in Singapore after about three years. Grown from seeds, this plant could have flowered earlier as it was transplanted from an outdoor location a year ago into a container where it has been growing for about a year.

Its inflorescence, from a far, looked like those produced by Heliconia psittacorum cultivars. The bracts are bright red in colour while the true flowers inside are bright yellow in colour – what a perfect contrast of tropical colours!

This is the first time it flowered and it is not certain whether it will be floriferous under local conditions. There is limited information about this plant and the only profile can be found in the book ‘Heliconia – An Identification Guide’ by Berry and Kress. Internet resources are very scarce and an online herbarium resource (Las Cruces Herbarium Collection) at the time of writing this entry featured specimens collected in localities with highland altitudes above 1000 m. This may suggest a shy flowering habit of this heliconia in lowland, tropical Singapore. Hence it may grow but flower less often here.

The plant is grown under partial shade conditions with well-draining soil. Currently, it measures about 1 m in height and grows as a tight clump with a distinctive cannoid growth habit. Not particularly fast-growing, it will surely make a less invasive and much welcomed mid-ground to foreground heliconia species for outdoor tropical landscapes, provided it flowers often enough locally.

Grow some Botanical Butterflies!

The genus Christia contains two species of plants from the bean family (Fabaceae) that never fail to intrigue and make conversation pieces whether they are grown in the garden or in a pot indoors. The species include Christa obcordata and Christia vespertilionis. The interesting feature about these two species lies in their leaves – they resemble and flutter in a slight breeze like butterflies! As such, they are excellent candidates for planting in a children’s garden!

These two Christia species grow as perennials in the tropics (in Singapore). They are rather upright shrubs with slightly arching branches and grow to a height of about 60 cm. Like other relatives in the same family, Christa obcordata and Christia vespertilionis have a compound leaf with three leaflets. The leaflet in the center is roughly triangular in shape and has a size that is larger than the remaining two leaflets. Plants have rather thin stems and leaves are attached to stems via flexible, wiry petioles, which explains why the leaflets move easily with the slightest agitation. Leaves of Christia hang downward during night time.

Christa obcordata is known via a range of common names such as the Butterfly Stripe Plant, Swallowtail and Iron Butterfly. From Internet sources, the version that is grown horticulturally is perhaps a cultivar and has a cultivar name called ‘Stripe’, which has reddish brown stripes on a green leaf. The leaves of this plant are often larger compared to those of Christia vespertilionis. I have not witness it flower yet under local conditions.

The other species, Christia vespertilionis, is commonly referred to as Mariposa or Red Butterfly Wing. As the latter common name suggests, Christia vespertilionis has red leaves that are striped red. The leaves of this species are generally smaller compared to those found on Christa obcordata ‘Stripe’. The central leaflet has a concave margin which makes it look like a little boomerang. It has been observed to flower and the plant self-seeds.

Both Christia  species are best grown under semi-shade outdoors. They are best kept out of direct sunlight outdoors as plants dry out quickly and the colour in the leaves becomes bleached. In an apartment, grow them in a location where they can be exposed to filtered sunlight for 4 to 6 hours daily. Both species prefer to be grown in soil that is well-draining and kept moist at all times. One can propagate them via stem-cuttings. Some pruning can be performed to keep plants looking great and encourage a bushier growth habit. Under conducive growing conditions, both species are relatively pest- and disease-free.

To date, the supply of these two species is quite sporadic in Singapore. They are not the ”bread and butter’ plants that appear all the time in local nurseries here. Christia vespertilionis appears to be more commonly available compared to Christa obcordata.

Musa ‘Siam Ruby’ and its Mutation

Musa ‘Siam Ruby’ is a spectacular and unique ornamental banana cultivar with beautiful ruby red leaves which are sometimes speckled with random small specks of chartreuse green. It is a plant that screams for one’s attention which makes it an excellent candidate as a focal plant in any tropical garden. Leaves of ‘Siam Ruby’ are held at a slightly higher angle than most other Musa plants. So far, the specimens I have seen in local nurseries are at most 1.5 m at most and I have never witnessed a plant in flower.

It was said to have been discovered growing in the wild in Papua New Guinea and is most probably a sport of Musa acuminata ‘Tapo’. When it was first offered for sale via online nurseries, this ornamental banana cultivar was referred to via two other cultivar names, namely, ‘Palawan Red’ and ‘Ace of Hearts’. It took some time before everyone settled for the cultivar name ‘Siam Ruby’.

 

This banana cultivar seems to produce suckers quite prolifically. New suckers that emerge have leaves that are often less red in colour and feature a prominent yellow mid-rib and veins. The leaves of the young plant are more comparatively narrower and have a sharp leaf tip. Unlike other bananas, suckers of ‘Siam Ruby’ are best taken from the parent clump and allow to establish first in a pot of fertile, well-draining soil before transplant to a spot in the garden.

‘Siam Ruby’ is not an easy ornamental banana plant to grow. Note that drainage is exceptionally important to this particular banana cultivar, otherwise plants can rot at the base. It thrives under full sun so that leaves take on an intense ruby red colour. Also, avoid letting the leaves become injured as broken parts can become infected easily. Hence it is recommended to space other plants apart from ‘Siam Ruby’. Clumps tend to become quite crowded rather quickly and hence thinning of suckers need to be performed periodically. Like all other bananas, ‘Siam Ruby’ prefers to be grown in fertile soil that is rich in organic matter. Mulch plants with well-rotted compost to keep roots moist and cool. Feed with organic fertiliser that is also rich in potassium.

Musa ‘Siam Ruby’ has been observed to mutate to an all chartreuse green version. With more chlorophyll content in its leaves, the mutation appears to be more vigorous – it grows at a faster rate and attains a height that is taller than the original ruby red version.

The Prickly Lasia spinosa

Lasia spinosa is an obscure member of the yam family, Araceae. The common names of this plant that I have come across include simply lasia, unicorn plant (probably due to the appearance of its inflorescences) and geli-geli (in Malay). It is a perennial tropical plant that is native to India, Southern China and Southeast Asia.

It is a large herbaceous plant that can grow up to 2 m tall. Like many plants in the yam family, the leaves of Lasia spinosa rise from the base and are arranged like a rosette. Each leaf is divided into several lobes and numerous small spines arm the leaf stalk and along the veins found at the back of leaves. Plants grow and spread via underground stems which are rich in starch.

Visually, Lasia spinosa is largely a plain green plant and is saved by its attractive, curious-looking inflorescence. Typical of an aroid, the real flowers are borne on a spike-shaped spadix. Unlike most other aroid species, the spathe of Lasia spinosa is not sail-like. The tip of the spathe is long and extended, twists along its length and held erect above the plant. Fruits of this plant are each aggregated on a club-like structure.

This aroid is an aquatic plant that thrives in a location with semi-shade to full sun. Naturally, it grows along the banks of rivers and in swamps and is tolerant of waterlogged conditions. It is edible and grown as a vegetable. Raw parts of the plant are documented to contain toxic constituents such as hydrocyanic acid and calcium oxalate and must be processed such as by cooking prior consumption. As a vegetable, the young tender leaves of Lasia spinosa are peeled to remove the spines. In Thailand, the young leaves are severed with ‘nam phrik plaa raa’ (spicy fermented fish sauce), stir-fried or added to hot and sour soup.

Like many other plants, Lasia spinosa has medicinal properties. Both the rhizomes and leaves possess expectorant properties. The latter also help ease stomachaches. The roots are boiled and the water used to bath newborn babies. The leaves are also used for the treatment of coughs, stomachache and various aches and pains.

The genus Lasia has been believed to be a monotypic genus until 1997 when a wild population of anew species, Lasia concinna, was discovered in a paddy field in West Kalimantan in Indonesia. Like Lasia spinosa, the farmer there had been growing them for its edible young leaves. This Lasia species had been known of previously only from a single specimen at the Bogor Botanic Gardens. At the time specimen was believed to have been a hybrid between Lasia spinosa and Cyrtosperma merkusii. The subsequent discovery by Hambali and Sizemore led to the realization that it was in fact a new species.

Afgekia sericea – A Beautiful Legume

The Silver Afgekia is a highly ornamental flowering plant belonging to the bean family, Fabaceae. It is a fast-growing vine with soft, furry, pinnate leaves. The new growth of the Silver Afgekia takes on an attractive, silvery appearance. Its flowers, produced in a spike held on a long, flexible stalk, are exceptionally showy. Each pea flower-like blossom is pink in colour, covered with fine hairs and spots a yellow-orange spot in the center. Lasting for only one day, flowers open successively from the base of the flower stalk towards the tip.

Botanically known as of Afgekia sericea, this vine is a species that is thought to be endemic to Thailand. There are two other species of Afgekia and all three have their own limited distribution in Thailand. The genus Afgekia was named in honour of Dr Arthur Francis George Kerr (his initials were spelled out as ‘AFGEK’) who was a distinguished British plant taxonomist for the Flora of Thailand Project.

The Silver Afgekia  is a perennial climber on trees, usually at or near the margins of dry dipterocarp forest from low to medium altitudes. In its native habitat, it is reported to flower mainly in the rainy season. In Singapore, this vine flowers all year round. This plant has become a rare species in its native habitat due to fragmentation of its natural habitats by increasing needs of land for agricultural purposes, housing and road construction.

Propagation of this plant is reported to be via seeds. However, in Singapore, I have never observed any seed pods being produced by the plants I have come across. The same has been reported to occur in Bangkok, Thailand. Its rarity was speculated to be due to the disturbance and fragmentation of its natural habitat which led to the reduction in the population of its effective pollinators. Research by Thai scientists revealed that fruit set in this legume species depended largely on bee pollinators and the percentage of fruit set was extremely low since less than 0.2% was observed from two natural sites.

In the garden, the Silver Afgekia is best grown in a sunny and well draining location. It looks good enough to be trained on a vertical trellis where one can appreciate its flower spikes face-on. Note that the plant winds itself around a support like many other leguminous vines and growth tends to become woody with age. Mulch around the bases of plants with well-rotted compost to help conserve moisture and suppress weed growth. Established plants appear do well with occasional irrigation and are not bothered by pests and diseases. Not much is known about this leguminous vine’s ability to fix nitrogen.

References

1. Floral Visitors and Fruit Set in Afgekia sericea Craib (Fabaceae)

2. Morphometric Relationships among Three Populations of Afgekia sericea Craib (Fabaceae) in Thailand

The Interesting Calabash Tree…

The Calabash Tree is not a common tree in Singapore. The place that I can recall seeing this tree is in the National Orchid Gardens in the Singapore Botanic Gardens. I vaguely remember seeing some planted amongst some bromeliads near the vicinity of Yuen-Peng McNeice Bromeliad Collection.

Although the appearance of its large fruits are gourd-like, it is not a member of the melon or gourd family, Cucurbitaceae. Instead, it is classified in the Bignoniaceae family, where the once common African Tulip Tree and currently a very popular ornamental shrub, Yellow Bells, belong to. Its exact origins is not known and today can be found growing throughout the Caribbean, Mexico, Central America, and northern South America. It has been introduced throughout the tropics.

Scientifically known as Crescentia cujete, the Calabash Tree grows as an evergreen tree can attain a height of 10 m. It features a broad but irregular crown comprised long, spreading and arching branches which is capable of providing dappled shade on sunny days. Leaves are simple and elliptical in shape clustered at the nodes. As a result of this growth habit, this tree often becomes a surrogate for orchid-growers to perch their plants on its branches. Crescentia cujete is grown in lawns and parks, and used for hedges.

This tree produces greenish-yellow flowers marked with purple veins on the trunk or main branches. Flowers are reported to open in the evening and emit a slight odour. They close and wither away by afternoon time. The oval, gourd-like fruit has a hard and woody rind and can grow up to 25 cm in diameter. Each fruit takes up to seven months to ripen. Ripened fruits are brown in colour and the seeds inside are surrounded by light-colorud pulp. The shell of the dried fruits is used to make a wide range of household utensils or filled with sand to make musical instruments. The larger fruits are used as bowls or made into helmets that are worn by bird hunters.

The fruits are not eaten as a dessert fruit but have medicinal properties. From Plant Resources of South East Asia (PROSEA), the fresh fruit pulp is documented to be macerated in water and is considered depurative, cooling and a febrifuge and good for headache and burns in West Africa and the Caribbean. In Vietnamese folk medicine, the dried fruit is used as an expectorant, antitussive, laxative and stomachic. In West Africa, the ash of the roasted fruit is considered mildly purgative and diuretic. In Central America, various parts of the fruit are a common ingredient in syrups for cough and colds.

Other parts of the tree are also used medicinally. In Sumatra, a decoction of the bark is used to clean wounds, and the pounded leaves are applied as a poultice for headache.  In Thailand and Central America, crushed leaves are applied on wounds to stop bleeding and promote healing. A decoction of the leaves or bark is astringent and taken for diarrhoea and dysentery.

Wood from this tree has a range of uses which include manufacture of cattle yokes, tool handles, wooden wheels, ribs in boat building and thin strips are used to make baskets and hampers.

Crescentia cujete is easily confused with another related species, Crescentia alata. The latter has a more upright form, with much fewer criss-crossing branches, and possesses smaller fruits and trifoliate leaves.

A Pandan that Climbs

Most Singaporeans are familiar with the Fragrant Pandan (Pandanus amaryllifolius) which produces fragrant leaves that find numerous uses in our local cuisine. That plant adopts a clumping growth habit and lives happily both in dry land or in water. In the Pandanaceae family, which the Fragrant Pandan belongs to, contains numerous other plants. One of which is Freycinetia cumingiana, which is also commonly called the Climbing Pandan. 

Freycinetia cumingiana is an evergreen climber that feature stems that can grow up to 2 m long. Slender roots grow along the stem which help the plant to attach to a tree, shrub or rock on which it is growing. The slender leaves of Freycinetia cumingiana are dark green and leathery and can grow up to 25 cm long. Each is pleated into an ‘M’ shape and has spines along the margins, similar to those seen in the Fragrant Pandan. For me, a clump of Freycinetia cumingiana looks like a bamboo plant when viewed from a distance.

Besides its interesting growth habit, plant collectors grow this plant also for its ornamental bright red-orange floral bracts. (bracts are modified leaves that on this plant resemble flower petals). Freycinetia cumingiana is native to Tropical Asia, Malesia and Philippines. This species is cultivated on Maui for sale as cut flowers throughout the United States. The Kalanguya tribesmen in the Philippines pound the roots of  this plant for fibers to sew a hunter’s coat.

Going back to the Fragrant Pandan, we know that it has never been recorded to produce flowers. Note that Freycinetia cumingiana is dioecious which means that the male and female flowers are produced on separate plants, although on occasion, the same plant will produce both flower sexes. Male and female flowers are densely produced on white cylindrical spikes housed in the middle of the bracts, while female flowers consist of several ovaries.  Clusters of three or four flower spikes containing either male or female flowers are borne at the terminal ends of branches.

Freycinetia cumingiana is easily propagated from stem-cuttings. For higher rate of success, choose stem tips with roots already developed. These stem sections will root easier.  Freycinetia cumingiana is forest plants so they are best grown under shade in an outdoor garden. Grow this plant in well-draining, slightly acid soil that is kept most at all times.

 The genus Freycinetia was named for Admiral Louis de Freycinet, a 19th century French navigator and explorer, who was the commander of the circumglobal expedition on which Charles Gaudichaud-Beaupré was the botanist. Charles Gaudichaud-Beaupré was the botanist who first collected and described the genus Freycinetia.
 

Pretty but poisonous Solanum pseudocapsicum!

Solanum pseudocapsicum (most commonly known as Jerusalem Cherry) has been a Lunar New Year festive plant  in Singapore. It is a good example of a non-traditional plant that has been turned into a festive plant for the Spring Festival. This plant could have acquired an auspicious meaning via its attractive fruits that come in a range of colours shown over the period of fruit maturation and ripening where they first appear green like jade, then gold and finally, red like a ruby. All parts of this plant is poisonous. Of particular note are its fruits which look like cherry tomatoes (they contain solanocapsine and other alkaloids), so keep fruiting plants and fallen fruit out of reach by young children and pets.

Solanum pseudocapsicum is documented to be a widespread and extremely variable species and this plant can grow as a small erect shrub. In Singapore, we get plants in the nursery that are in the range of 30 to 50 cm tall when they are sold as container plants for display. If left to grow, it is documented that a plant can grow up to 1 m tall, if grown in the ground. Some cultivars can also adopt a prostrating growth habit. Cultivated plants have rather smooth leaves  and produce have large flowers and fruit.

Some years back, only the variety with all green leaves is available for sale in Singapore and this year, we get to see a new cultivar with variegated leaves. Solanum pseudocapsicum is native to the drier areas of Central and South America, from Mexico to southern Brazil, Argentina, and Uruguay, from sea level to 2600 m. Widely cultivated throughout the world, often escaped in tropical and subtropical areas.

With these growing conditions in mind, if one is  to grow Solanum pseudocapsicum in Singapore, we have to ensure plants are grown in moisture-retentive and well-draining soil. Water well and let the soil become moderately dry between waterings. If you noticed leaves falling, it may be a sign that the plant is given too much water and the plant is experiencing wet feet. Fruit drop could be due to insufficient light. It is a sun-lover and hence it is best positioned in a sunny location.

To encourage bushiness, prune the plant regularly or by pinching the growing points. Do also remember to feed your Solanum pseudocapsicum with liquid fertilizer during the active growing stage. Like chillis and tomatoes, you can help to promote fruit set by tapping its flowers to distribute pollen but also make sure the plant is receiving sufficient sunshine and not grown in too windy a place which can be too dry. Similarly, note that Solanum pseudocapsicum is prone to attacks by whiteflies, mealy bugs, aphids and spider mites attack and frequent checks are required to ensure good health of your plant.

Orchidantha – the Ultimate Houseplant

I was given a division of Orchidantha siamensis by a fellow collector a while ago who knew I was interested in plants that are classified in the order Zingiberales. There is only one genus, that is, Orchidantha, in the Lowiaceae family. This genus consists of about five to eight species of plants that grow in the wet understorey of the lowland forest and are native to Southeast Asia and some Pacific Islands.

The genus name is given due to the orchid-like appearance of the flowers produced by these plants. Flowers are usually produced via a subterranean inflorescence and are often hidden away. One of the petals in each flower is enlarged to give a large lip-like structure similar to what is seen in a true orchid. Flowers of one species, Orchidantha inouei of Borneo emits the smell of dung in order to attract small dung beetles as their pollinators! The plant I have freely flowers and thankfully, the smell of its flowers can only be detected when one really goes upclose to them!

I particularly like the Orchidantha as it is perhaps the most shade-tolerant group of plants I have come across so far. Many foliage plants introduced in many houseplant and indoor plant books cannot match it in terms of the ability to grow and thrive in deep shade often encountered in the indoor living environment. It seems to be also able to tolerate dry air rather well too. From this, I reasoned that they also make good candidates for planting in very dim areas in an outdoor garden.

Best grown and appreciated as foliage houseplants that confer a lush tropical feel, Orchidantha species are herbaceous perennial plants with a clumping growth habit. New growth rise from a rhizomatous underground stem. Leaves are lanceoate in shape andhas several pairs of longitudinal veins parallel to the distinct midrib.

I noticed Orchidantha is best grown in a very shaded area as even rays from filtered sunshine can bleach the leaves, giving them a sickly yellow colour. Intense sunshine will burn them. They prefer to be grown in soil that is rich in organic matter, open and kept moist at all times. Avoid growing them in a windy area as constant air movement can dry plants out. Propagation is easy via division of large clumps.

Orchidantha, apparently, have medicinal and folk uses. The scorched leaves of Orchidantha fimbriatum (syn. O. longiflora) are pasted on the back and chest to relieve chest and back pains. Leaves are sometimes used to wrap food in cooking.

At present, Orchidantha is still difficult to find in local nurseries but I believe its usefulness as a foliage plant for growing in very shady areas, once discovered, will greatly call for a demand for plants to be made available to the nursery trade.

The fragrant Tillandsia duratii

Tillandsia duratii is one of my favourite airplant species. This species is named after an Italian named Durat who was the first person to grow this airplant species in Europe.

This plant has a growth form that is quite unlike many other Tillandsia species. It is a caudescent epiphyte that develops a distinctive stem and has long silvery leaves that bend downwards to the base of the plant. One will notice that the older leaves, as they dry up, form ringlets that coil around a branch or any support that they come in contact with. This is how Tillandsia duratii supports itself in its native growing habitat. From afar, this particular Tillandsia species looks as if it was a bird resting on a tree branch!

Tillandsia duratii is a xeric species that is native to drier parts of Bolivia, eastern Paraguay and northern Argentina and grows at elevations of 200 to 3500 m. It is a species that thrives in Singapore’s climate and particularly suitable for growing in Singapore’s  highrise apartment balconies where the environment can be rather windy and dry.

I grow several Tillandsia duratii plants on my balcony where they receive bright reflected light for at least half a day for half a year and direct sunshine in another half, as the sun shifts its path every half a year here in Singapore. Regardless of the intensity of sunshine, this species seems to thrive. At 14 storeys up in the apartment block, their growing environment is relatively windy and dries the plant out promptly. I water this plant by spraying water on it every other day. To date, it hasn’t succumb to rot like some other species do. 

I would say that this is one hardly and fuss-free Tillandsia species to grow in Singapore. Just a word of warning is to not grow Tillandsia duratii in an area with high traffic or very strong winds. As this plant grows on a long stem, one can accidentally break the plant into two quite easily if he/she is not observant. I reckon a gust of very strong wind can do similar damage if a plant is not well secured to its support.

This Tillandsia species is reported to be able to grow up to 40 cm in diameter and a meter in height when conditions are conducive. Do you know that it also produces flowers that are fragrant?

Tillandsia duratii is one of the few species of airplants that produces flowers that emit a pleasant fragrance. Each flower has three petals that are lilac in colour. Flowers are produced on a long inflorescence that takes months to develop. An inflorescence in a well grown, healthy plant can reach as long as 1 m in length!