CTENANTHE

Ctenanthe is native to Brazil. Similar to the Calathea, Ctenanthe is mainly grown for its beautiful foliage. These plants are sometimes known by the name 'Phrynium'. Below is a list of species that are grown here.

Ctenanthe burle-marxii

Ctenanthe burle-marxii is a small, compact plant that grows to a height of about 30 cm. The elliptical leaves are largely silver-grey and green stripes radiate from the mid rib all the way to the edge. \

(Picture - WW)

Ctenanthe kummeriana

Ctenanthe kummeriana grows as a clump up to about 60 cm. On the upper side, lancoate green leaves have a distinctive white mid rib with rather feint white stripes that radiate from it and the undersides are purple.

Ctenanthe lubbersiana

Ctenanthe lubbersiana grows up to about 45 cm and its elliptical leaves have random zones of green and yellow. On the underside, the leaves are pale green.

(Picture - NParks)


Ctenanthe oppenheimiana

Ctenanthe oppenheimiana, also called the 'Never Never Plant', adopts a branching habit and grows up to 2 m. Leaves are lance-shaped and on the upper side, they are dark green and banded with silver, while the underside is maroon. The cultivar 'Tricolor' has leaves that are variegated with white, green and silver.

(Picture - NParks)

Ctenanthe setosa

Ctenanthe setosa will grow up to 90 cm high and has narrow, lanceoate green leaves, which are patterned with silver bands that radiate from the mid rib. The leaves are maroon on the reverse.


MARANTA

Maranta can be regarded as the "true" prayer plant as it exhibits the most conspicuous habit of folding up its leaves in response to low light intensity, compared to all other prayer plants described in this article. If you refer to any houseplant book for the prayer plant, you get Maranta. "Maranta" is derived from the name of the Venetian physician and botanist, Bartolomea Maranti.

Maranta leuconeura cultivars are the ones commonly grown as houseplants. They are low-growing plants that adopt a prostrating habit and are indigenous to Brazil. The stems of Maranta leuconeura are not swollen at the nodes and the roots are not tuberous, unlike those of Maranta arundinacea.

Maranta arundinacea

The cultivar 'Variegata' is more commonly grown and is characterized by its white and green variegated leaves. Maranta arundinacea adopt an upright growing habit and can reach a height of about 1 m. The non-variegated version of Maranta arundinacea, otherwise commonly known as 'Arrowroot', has starch-storing rhizomes and is native to the West Indies.

(Picture - WW)

Maranta leuconeura

Maranta leuconeura `Erythroneura'

Maranta leuconeura `Erythroneura', commonly referred as the red-vein maranta, or red nerve plant, has a bright red midrib and lateral veins, a feathered, light green-yellow central zone and a green-black outer background. The flowers are violet.

(Picture - WW)

Maranta leuconeura `Kerchoviana'

Maranta leuconeura `Kerchoviana' (also known as `Massangeana') is known by several common names like 'Rabbit's Foot' and "Rabbit's Track', because the elliptical, velveteen gray-green leaves have two rows of red-brown patches, which darken with age, that are parallel to the mid rib. White flowers may be produced occasionally.

(Picture - WW)

Maranta leuconeura `Leuconeura'

Known as the 'Silver Feather Maranta' or 'Black Maranta', Maranta leuconeura `Leuconeura' has a distinctive fishbone pattern on the top side of its leaves, which extends from the mid rib and outwards from a green central zone to an almost black outer background.


STROMANTHE

Stromanthe sanguinea and its cultivars

Stromanthe sanguinea, originating from tropical South America, is the common Stromanthe species grown as a houseplant here. It has large, lanceoate leaves, which are dark green and glossy. Leaves have a whitish mid rib on the upper surface and are maroon on the underside. Plants can grow up to a height of 1.5 m.

Four very attractive cultivars of Stromanthe sanguinea - 'Multicolour', 'Horticolor', 'Triostar' and 'Stripestar' - are popular houseplants. 'Horticolor' and 'Multicolour' have random splashes of red, green and white on its leaves. These two cultivars have more white and green leaf areas as compared to 'Triostar', which has more red areas. 'Stripestar' on the other hand, has green leaves with a white mid rib.

(Pictures - WW)



THAUMATOCOCCUS

Thaumatococcus daniellii

Thaumatococcus daniellii, native to the tropical rainforests of West Africa, is the only species in this genus. Similar to some large-leafed Calatheas, the leaves of this plant have traditionally been used to wrap food. The plant can grow up to 2.5 m tall and closely resembles Calathea, of which the uninitiated can be easily confused.

(Picture - WW)

In Singapore, Thaumatococcus daniellii can be found planted en masse in gardens, inside a large planter box or in a row to serve as a garden hedge or to conceal a boring wall. Interestingly, Thaumatococcus daniellii is better known for its use as a sweetener in its native country and hence its local name of 'Miracle Fruit'.

The plant bears attractive purplish pink flowers that are held on simple or forked spikes found close to the ground. The pyramid-shaped fruits are bright-red when ripe and within each fruit are seeds that are covered by a thin layer of translucent, sweet-tasting aril. The black hard seeds look like stones when dried.

(Picture - WW)

The translucent flesh of the fruit contains the protein, thaumatin, which is purportedly said to be several hundred times sweeter than table sugar! Thaumatin has already been approved as a food additive and alternative sweetener in the European Union as well as in many other countries.


CULTURE OF PRAYER PLANTS

Prayer plants are easy to grow as outdoor plants as long as they are grown in a cool and shady corner in the garden. The plants need to be given ample water just enough to keep their feet moist but not soggy. Hence, drainage is important.

Apartment gardeners will find them difficult to please. Most of the problems encountered by apartment gardeners can be attributed to those arising from less than ideal growing conditions such as the lack of humidity and excessive wind, often encountered in the high-rise growing environment.

LIGHT

Prayer plants should be grown in spot that is away from direct sunlight, otherwise, the plants may suffer from sun scorch/burn. Sunburnt plants will show symptoms of irregularly bleached areas on the affected leaves. Overly hot conditions can also cause the leaves to roll up.

Although regarded as shade plants, prayer plants should not be grown in deep shade. They do better in positions where they can get a little filtered sunlight and this is especially crucial for the cultivation of outdoor flowering Calathea species as this aids flower production.

The same guideline applies to prayer plants grown as houseplants. Sufficient light in the form of filtered sunlight is required for prayer plants to keep their vibrant coloration.

HUMIDITY

Outdoor gardeners usually do not face the problem of insufficient humidity. Apartment gardeners should attempt to keep the relative humidity on the high side of around 70% if they are to grow these demanding plants successfully at home.

Try to grow the plant in a position that is exposed to the open environment to take advantage of the exteriors' humidity. Remember that increased air temperature in an enclosed room will lower the environment's humidity. When grown in an environment of low humidity for prolonged periods, the leaves may roll up and become prime spots for spider mites.

AIR CIRCULATION

Prayer plants should not be exposed to excessive wind as it will cause 'wind burn' where desiccation of the plant takes place. Plants respond by rolling up their leaves to indicate their displeasure and to reduce further moisture loss.

POTTING MEDIUM

In general, prayer plants like to be grown in a free-draining mix. Prayer plants also prefer a moisture retentive mix that is high in organic matter. Prayer plants in the garden appreciate the addition of organic compost to the soil. This helps to keep their roots cool in our hot climate.

Container gardeners must take note that they like to be pot-bound and hence try not to over-pot in too big a container. But do watch out for the symptoms of lack of water in pot-bound plants as less potting media translates into less moisture being retained.

WATER

Water regularly to ensure the soil remains moist but not soggy. The plants may benefit from slight drying out before the next watering. However, it is important to not to allow the soil to become overly dry for prolonged periods. Like in the case of excessive dessication, thirsty plants will roll up their leaves. Do not allow water to remain for prolonged periods on the leaves so as to minimize the incidence of fungal spots.

FEEDING

On a regular basis, feed plants with a slow release balanced fertiliser or one that promotes leaf growth (higher nitrogen (N) ratio) at a rate and amount recommended by the manufacturer. Water-soluble fertiliser may also be used monthly but must be more diluted.

Prayer plants are sensitive to salt accumulation at the root zone. Flush the root zone with water regularly to reduce accumulation of unabsorbed fertiliser salts. Excessive salt accumulation will result in the burning of leaf margins.

PRUNING

After flowers fade, some growers cut the entire shoot down to ground level, a method that is commonly practised in Heliconia. When left untouched, the shoot will slowly die away.

PROPAGATION

Prayer plants are most easily propagated via division of big clumps. Each division preferably should have several plants to ensure stronger growth. Propagation using a single rhizome will have a low success rate as it may be too weak to support robust, new growth. Mist the division often and it keep out of direct sunlight to minimise water loss.

PESTS & DISEASES

Pests that affect prayer plants grown outdoors include grasshoppers and caterpillars which ravage their leaves and make them unsightly. These have to manually caught and killed.

Mealybugs can also infest the leaf axils, the undersides of leaves and the roots, for both indoor and outdoor situations. Spider mites will appear on the undersides of leaves when the air is too dry, as a peppery veneer scattered with minute webbing. Small scale insects which appear as golden brown grains on the leaves may also attack weaker plants. These sucking pests produce secretions which not only attract ants, but promote the growth of unsightly sooty mould. The mould can be wiped off with a damp cloth or treated with fungicide.

Use insecticides as directed by the manufacturer. Root mealybugs can be eradicated by drenching the potting mix with insecticides like Malathion.


REFERENCES

Books:

Virginie F. & George A. Elbert. 1989. Foliage plants for decorating indoors: plants, design, maintenance for homes, offices, and interior gardens. Timber Press, Portland, Oregon.

Useful Web-based Resources (assessed on 10 June 2006):

Cultural Information

Poole R.T., Chase A.R. & Osborne L.S. Calathea Production Guide. CFREC-A Foliage Plant Research Note RH-91-9. http://mrec.ifas.ufl.edu/foliage/folnotes/calathea.htm

Poole R.T., Chase A.R. & Osborne L.S. Maranta Production Guide. CFREC-A Foliage Plant Research Note RH-91-22. http://mrec.ifas.ufl.edu/foliage/folnotes/maranta.htm

Commercial Websites

Aloha Tropicals. http://www.alohatropicals.com

Flowercouncil - Flower and Plant Bank. http://www.flowercouncil.org/int/plantscope/default.asp

Plant Group Co., Ltd. http://www.plant-group.com

Twyford International. http://www.twyford.com


ACKNOWLEDGEMENTS

Green Culture Singapore would like to express our gratitude to National Parks Board (NParks) and Ryan Su for allowing us to use the pictures of Ctenanthe and flowering Calathea, respectively, in this feature article.



COPYRIGHT 2004 - 2006 Green Culture Singapore All rights reserved
Best viewed with a resolution of 1024 x 768