Its common names include the Stinking Passion Vine or Wild Water Lemon. Its species name ‘foetida’ has the meaning of “stinking” in Latin which refers to the strong odour that is emitted by damaged foliage. Note that the stems and leaves of this vine are toxic and suspected to have caused poisoning in livestock. Interestingly, the young shoot tips and leaves are also valuable, wild-gathered vegetables in several South East Asian countries where they are thoroughly cooked by boiling first and then consumed in a soup. Leaves have medicinal properties where they are used to treat neurasthenia, insomnia, early menstruation, edema, itching and coughs.

The plant itself, is a vine, like other Passiflora species. The stems of this plant are thin and wiry and covered with numerous sticky hairs. They are herbaceous when young and gradually turn woody with age. Its leaves are three- to five-lobed and hairy to touch too. The flowers of this plant are quite attractive but small in size, about 5 cm in diameter. Flowers are usually white in colour with a purplish center.

The fruits of this species are quite interesting as they are encased with leafy sepals that are finely dissected. Each fruit is about 2 to 3 cm in diameter and they turn from green to orange when ripe. There are varieties which produce fruits that turn red when ripe. The fruits do not split open when ripe. Note that the young fruit is cyanogenic and hence poisonous. They are only edible when ripe and children in rural villages in Singapore decades ago would be able to recall the fun of popping the yellow/orange ripe fruits into their mouths as they play along in the kampong. Each fruit has numerous black seeds embedded in the whitish, sweet pulp where seeds dispersed by birds.

Passiflora foetida is considered as a protocarnivorous plant. When the vine flowers, the leafy sepals that encase the flower are reported to produce sticky, dew-like secretions at the tip ends and these may help the plant to trap insects. There is insufficient evidence to show whether or not, the plant gains any form of nourishment from trapped prey.

This Passiflora species mainly occurs as a weed, sometimes invasive, in wet areas although it can tolerate drought when established. It is common in plantations, rough pastures, roadsides and wasteland. It is a ‘useful’ weed which is sometimes used as a soil cover in plantations to control lalang (Imperata cylindrica) and soil erosion.

It also plays an important ecological role. The young leaves and shoots of Passiflora foetida are consumed by caterpillars of the Leopard Lacewing (Cethosia cyane) and Tawny Coaster (Acraea terpsicore) found locally in Singapore.

However, this cactus is a leafy cactus that is not a desert-adapted plant like many other leafless cacti we are familiar with – it grows in the shady and moist forests of Central America. This probably explains why specimens grown in hot and sunny spots often become yellow and stunted. Desert cacti have lost all their leaves to avoid excessive loss of water via transpiration.

It may seem strange at first that it can be a cactus with leaves. In fact, this genus of plants is determined one of the two genera from which all other cacti evolved. If one look closely at the stem of the Pereskia, a tell-tale feature that it is a cactus is evident via its cluster of spines grow from specialized structures called areoles which is a feature that all true cactus species have.

Some English common names of Pereskia bleo include Leaf Cactus, Rose Cactus and Wax Rose. These common names somewhat describe some characteristics of this plant. Pereskia bleo is a true cactus and it is one with leaves unlike many others that are commonly grown as houseplants. The latter two common names very well describe its rather large and highly ornamental flowers with multiple thick orange petals that are arranged in almost the same manner as seen in roses. After flowering, plants produce interesting, funnel-looking fruits which ripen into a bright orange colour.

Pereskia bleo can grow into a small, woody but prickly tree of about 2 m in height. It can take relatively hard pruning which can be employed to help keep it small and manageable. Its prickly nature can be exploited for using it to make a living fence – individual plants can be planted at regular intervals to form a prickly screen to deter intruders. Plants are propagated most easily via stem-cuttings. It is best grown in well-draining soil rich in organic matter and kept moist at all times. As mentioned above, unlike other leafless cacti species, this plant is not exactly a succulent and hence not drought-tolerant.

The leaves of this plant are eaten raw by locals here with the belief that it can prevent or cure one of cancer. Leaves are relatively blant to taste. Solid scientific evidence to support this belief is still not available as limited scientific studies have been done to date and all are still confined to the petri-dish. Reference of these studies are given below:

• Tan ML, Sulaiman SF, Najimuddin N, Samian MR and Muhammad TS. 2005. Methanolic extract of Pereskia bleo (Kunth) DC. (Cactaceae) induces apoptosis in breast carcinoma, T47-D cell line. J  Ethnopharmacol, 96(1-2):287-94.
• Er HM, Cheng EH and Radhakrishnan AK. 2007. Anti-proliferative and mutagenic activities of aqueous and methanol extracts of leaves from Pereskia bleo (Kunth) DC (Cactaceae). J Ethnopharmacol, 113(3):448-56.
• Malek SN, Shin SK, Wahab NA and Yaacob H. 2009. Cytotoxic components of Pereskia bleo (Kunth) DC. (Cactaceae) leaves. Molecules, 14(5):1713-24.

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

There are a number of ornamental arrowhead species which are grown by aquatic gardeners. There is one that caught my attention but this species is not commonly available in Singapore. It’s supply is sporadic at best. Botanically known as Sagittaria montevidensis, this plant has common names that range from Spongy Arrowhead, Hooded Arrowhead, Long-lobed Arrowhead, Mississippi Arrowhead, Giant Arrowhead and Aztec Arrowhead.

Note that this plant has been reported to be a weed. Sagittaria montevidensis began invading rice fields in southern Brazil in the 1980s. It was discovered at that time, that a herbicide-resistant biotype had developed within the populations found in agricultural areas.

Sometimes stated as a native of the United States or Brazil, Sagittaria montevidensis is one arrowhead species with large showy flowers. Its flowers are borne in whorls or pairs at nodes. Like other Sagittaria species, the flowers each has three petals, each of which is white with a yellow base, and three green sepals. What’s quite different is that there is a large dark red spot at the bottom of each petal.

In my research about this plant, I found out that Sagittaria are monoecious plants. The pistillate (female) flowers are borne low on the inflorescence while staminate (male) flowers produced higher up. The fruit is said to look like a flattened winged achene with a single seed. Female flowers are said to produce numerous seeds which have a high germination rate.

It grows as a marginal aquatic plant, thriving in boggy areas with shallow water. The large, sagitatte leaves of Sagittaria montevidensis are borne on upright spongy petioles (they bruise easily, so handle them with care!) which may reach a length of more than 0.75 m, depending on the growing conditions. Unfortunately, its attractive inflorescences are typically borne lower than the leaves and take on a decumbent growth habit (lying on the sides).

Sagittaria montevidensis is best planted in muck inside a large water-tight container with about 15 cm of water depth. Place this plant in direct sun or semi-shade outdoors. I would prefer the latter situation as the tropical sun can be far too intense.

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.

I remember seeing this attractive plant being offered for sale in Singapore a while ago, but it has since disappeared once again. Native to South America, Porphyrocoma pohliana grows as a shrub that can attain a height of about 30 cm. It features very ornamental leaves that are deep green which are adonred with silver veins. The plant also produces extremely showy terminal spikes which are covered with long-lasting deep pinkish-red  bracts. The true flowers of Porphyrocoma pohliana are purple in colour and they contrast quite starkly with the overlapping bracts.

One may wonder why this plant is has the ‘fireworks’ word in its common name. In one of my searches on the Internet, the fireworks part was said to have been derived from two sources. One is the appearance of its deep red flower bracts that develop purple flowers, creating an explosion of color. Second, as flowers fade, it can shoot its small black seeds across the surroundings where it grows. Porphyrocoma pohliana is said to be able to self-seed readily and may become a weed in your garden!

Interestingly, it is one of the shrubby Acanthaceae members which can be grown from seeds which are offered for sale by mail order nurseries. Like other Acanthaceae members, it can also be grown from stem-cuttings. It should be grown in a fertile, well draining soil mix that is rich in organic matter. Like many shrubs, it is necessary to prune Porphyrocoma pohliana regularly to ensure that it retains a compact growth habit.

Many Internet resources say that Porphyrocoma pohliana is an indoor plant because it is a shade-loving plant. However, the apartment gardener is to be advised that this plant is not suitable for growing long term inside your apartment. Conditions there are far too dark for the plant to grow. The best area in an apartment for growing Porphyrocoma pohliana is either on the balcony or corridor where it can receive filtered sunshine or bright indirect light for at least 6 hours daily. Outdoors, this plant can be grown in the shade, but not in full or direct sunlight. Strong sunshine can bleach the leaves. To date, I have not seen anyone in Singapore being able to grow this plant successfully. Plants that were put on sale (probably imported) look great but once brought home or left on the shelves in the nursery but they decline gradually.

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.

The desert rose (Adenium obesum) , tropical pitcher plant (Nepenthes species and cultivars), scarlet star (Guzmania lingulata cultivar) and miniature dendrobium orchid (Dendrobium hybrid) are plants that has been marketed for several years as festive plants for the Lunar New Year. The only new and ‘unconventional’ plant in the list is the nerve or snakeskin plant that is botanically classified in the genus Fittonia. Numerous new cultivars with appealing leaf colours, shapes and sizes are now available and some of those with intensely red leaves are highly suitable for the Lunar New Year due to their auspicious colour. There are a handful of cultivars with yellowish green leaves and red veins.

Read the above scanned newspaper article for more info!

But do you know that the water hyacinth is one beautiful water plant? For those of us who have seen it bloom, you will know what I mean. Water hyacinths are members of the Pontederiaceae family which produce spikes of pretty lavender flowers (like the bulbous hyacinths) on top of lush, shiny leaves. There are two species of water hyacinths that one can can choose from.

The first and most common species is Eichhornia crassipes. The leaves of this plant grow from a rosette and the rounded base of each leaf is inflated and spongy which helps to keep the plant afloat on the water surface. For those of us who have picked up one plant a pond, one will observe that the water hyacinth has feathery, freely hanging roots are almost black in colour. These roots do not anchor the plant to any base and hence a water hyacinth is free to float around. Under optimal growing conditions, water hyacinths are prolific bloomers but each flower is rather short-lived, lasting for at most a day or two.

Plants also propagate rather freely by sending out new plants via stolons like a strawberry plant. Although its growth rate can be a nightmare, people have put the water hyacinth to good use after finding out it has phytoremediation properties as it can soak up soluble heavy metal ions and cyanide in polluted waters. The water hyacinth plant also has abundant nitrogen content and it has been harvested and used a substrate for biogas production.

People have also harvested water hyacinths from overgrown colonies for making green manure, compost and mulch for soil improvement. It is sometimes used as a fodder for animals for buffalos and pigs (this is why in Singapore, the older generation calls this plant as the ‘pig plant’ (猪草)). The water hyacinth is also eaten has a leafy vegetable in Taiwan and Java but do exercise caution before consumption as this plant can be contaminated with toxins if it is harvested from polluted waters.

There is another species of water hyacinth known as Eichhornia azurea and its common name include the creeping water hyacinth, peacock water hyacinth. It is less common in Singapore and its flowers are more lavender in colour and smaller compared to Eichhornia crassipes. One will also notice that the yellow spot in the dorsal petal of this species to be more prominent which is not surrounded by a darker patch of purple seen in Eichhornia crassipes. The plant also adopts a slight different growth habit as it grows along a long stem unlike Eichhornia crassipes which adopts a rosette growth habit. Its roots are also less feathered. Eichhornia azurea is propagated via stem-cuttings instead of separation of its stolons (for Eichhornia crassipes). The stems of this species are used to make furniture and baskets.

Both water hyacinth species are sun-lovers and demand a location with more than 6 hours of direct sunshine to grow well. If they are grown in a shady area, one will notice they will simply disintegrate in a matter of a few days.

Water hyacinths are good for ponds which suffer frequently from algae blooms as they help to soak up excess nutrients! Always keep a look out for the growth of your water hyacinth plants in such a situation – promptly remove excess plants before they invade your pond.

If you are afraid they will take over your pond, grow them in a container of water that has some fertiliser added to it. Note the type of fertiliser added as some are harmful to fish if you intend to have fish in the containerised water garden. Fish is recommended as they help to eat up mosquito larvae.

Interestingly, water hyacinths can also be grown in soil. They do well in soggy soils as long as there is water over their crowns!

Sometimes found growing as a weed in wastelands, Crotalaria retusa grows as an annual herbaceous shrub that can attain a height of about 1 m. This plant can only be from seeds and the process is an easy one but trying to get some seeds can prove to be difficult. It loves a sunny spot that is also well draining. Being a legume, Crotalaria retusa can fix its own nitrogen from the atmosphere and hence can be grown in nitrogen-poor soils.

Besides being useful as an ornamental plant, Crotalaria retusa has an interesting characteristic that will probably interest kids. The pod-like fruit this plant produces, when mature and dry, becomes a rattlebox that can be shaken and heard. The common name of this plant ‘rattlebox’ is derived from this interesting feature.  The genus name Crotalaria is derived from the Greek word, κροταλον, which refers to the musical percussion instrument castanet. If you are looking for a candidate to grow in your sensory garden, plant Crotalaria retusa in it to confer the sound/audible component.

Like other legumes, Crotalaria retusa can be grown as a green manure, where mature plants can be worked back into the soil to add nitrogen. It is also grown as a source of plant-derived fibre and dye.  Crotalaria retusa is also grown as a medicinal plant. According to Plant Resources of South East Asia (PROSEA), its roots are used against coughing up blood while its leaves are mixed with those of another relative, Crotalaria quinquefolia, and consumed or applied externally against fever, scabies, lung diseases and impetigo. Flowers and leaves are both edible as vegetables due to their low alkaloid content and are purportedly sweet. Seeds are roasted and eaten in Vietnam. Note that this plant is also nematode-resistant and studies have found dried plant parts can be worked into the soil as a soil amendments to deter and reduce root galling by the root-knot nematode, Meloidogyne incognita.

Lastly, note that Crotalaria retusa is a butterfly host plant. According to the Butterfly Circle website, Crotalaria retusa is the food plant for the pea blue butterfly (Lampides boeticus). Unlike other butterfly caterpillars that chew up leaves, the first two instars of the pea blue bore into flower buds of this plant and consume the flower parts contained within. The larger 3rd and final instar caterpillars will move on to eat the developing seeds within seed pods. For more information on the pea blue butterfly, please refer to the webpage below:

http://butterflycircle.blogspot.com/2009_09_12_archive.html

Do your part for the wildlife and environment around us, try to grow this plant without the use of pesticides. In rapidly urbanising Singapore, we are losing loads of our native species of flora and fauna without many of us knowing. Butterflies have an important role in our environment and one of the most obvious role they play is that of a pollinator where they help to transfer pollen that help plants to set seed and ensure the survival of subsequent generations.