Monday, January 9, 2017

Landscape : Curbing the Curbs 3

If the main role of road curbs are to keep vehicles on the road, and preventing them off the green area and especially walkway, then it can be easily replaced with guardrails. 

In Malaysian environment, weather is a nuisance. There are times when it rains so heavily, causing flash floods ; and there are also times when there is not a single drop of rain for weeks. 

Cambered asphaltic concrete road (A) allows fast flow of water off the road surface.  If the surface water are directed straight to the drain (C), there will be minimal water seepage through the green area.

However, if the green areas are designed to trap water (B), not too much of course, just enough for some water to seep into the ground and thus more water available for trees and shrubs. 

The water from watering tank during dry spell too will be more effectively seep into the soil. In addition, it also trap the fertilizer from being easily washed away.

Sunday, July 31, 2016

Darwin : Phototropism

Darwin was fascinated by the effects of light on plant growth, as was his son Francis. In his final book, The Power of Movement in Plants, Darwin wrote: ‘There are extremely few [plants], of which some part … does not bend towards lateral light.’ Or in less verbose modern English: almost all plants bend towards the light.

In a very simple experiment, published in 1880, Darwin and his son showed that this bending was due to some inherent sensitivity to move towards the light.

For their experiment, Darwin and his son, Francis, grew a pot of canary grass (Phalaris canariensis) in a totally dark room for several days. Then they lit a very small gas lamp twelve feet (3.5 metres) from the pot and kept it so dim that they ‘could not see the seedlings themselves, nor see a pencil line on paper.’ But after only three hours, the plants had obviously curved towards the dim light. The curving always occurred at the same part of the young plant, an inch or so below the tip.

This led them to question which part of the plant saw the light. The Darwins carried out what has become a classic experiment in botany.  They hypothesized that the ‘eyes’ of the plant were found at the seedling tip and not at the part of the seedling that bends.

They checked phototropism in five different seedlings, illustrated by the following diagram:

a. The first seedling was untreated and shows that the conditions of the experiment are conducive to phototropism.
b. The second had its tip pruned off.
c. The third had its tip covered with a lightproof cap.
d. The fourth had its tip covered with a clear glass cap.
e. The fifth had its middle section covered by a lightproof tube.

They carried out the experiment on these seedlings in the same conditions as their initial experiment, and of course the untreated seedling bent towards the light.  Similarly, the seedling with the lightproof tube around its middle bent towards the light. If they removed the tip of a seedling, however, or covered it with a lightproof cap, it went blind and couldn’t bend towards the light. Then they witnessed the behaviour of the plant in scenario four (d): this seedling continued to bend towards the light even though it had a cap on its tip.  The difference here was that the cap was clear. The Darwins realized that the glass still allowed the light to shine onto the tip of the plant.

In this experiment, the Darwins proved that phototropism is the result of light hitting the tip of a plant’s shoot, which sees the light and transfers this information to the plant’s midsection to tell it to bend in that direction.

Extracted from What a Plant Knows – A Field Guide To The Senses Of Your Garden And Beyond, 2012, Daniel Chamovitz

Sunday, July 17, 2016

Buluh Lemang - Schizotachyum brachycladum

Lemang is a traditional Malay food made of glutinous rice, coconut milk and salt, cooked in a hollowed lemang bamboo, lined with banana leaves.

The lemang bamboo ( buluh lemang ) ( Schizotachyum brachycladum ) is used for cooking lemang because of its unique properties :

1. Availabililty – Not Too Difficult To Find
The bamboo is evergreen plant native to tropical Asia, abundance all over lowland secondary forest.  It produces several new stems annually, each stems grow to their maximum heights in their first year of growth.  Propagation is common, usually by rhizome and clum cuttings.

It has been used in Borneo, Java, Bali, Malesia, Cochinchina, etc for construction, handicraft, container for water and cooking, etc.

2. Length – Not Too Long, Not Too Short
Buluh lemang’s clum are erect and straight, about 10-15m in length, 6-8cm in diameter. With approximately 7-10 hollow internodes, each 20-50cm in length, buluh lemang is suitable as a vessel for cooking.

3. Thickness – Not Too Thick
The bamboo’s internode wall is thin, about 3-5mm think, comparable to other species of bamboo.  The thin wall is easy to cut through, shortened the cooking time and uses less firewood.  

Wednesday, June 1, 2016

Eucalyptus camaldulensis - River Red Gum

Eucalyptus camaldulensis is the river red gum, a tree of the Myrtaceae family.  It is native to Australia, where it naturally distributed along many inland water courses as well as floodplains.  Due to the proximity to watercourse, river red gum is subject to regulate flooding in its natural habitat.

The generic name ‘Eucalyptus’ is from the Greek words ‘eu’ good or well, and ‘kalyptos’ covered, referring to the calyx which forms a lid over the flowers when in bud.  Specific name “camaldulensis” referring to L’Hortus Camaldulensis di Napoli, from where the first specimen was first described by Frederick dehnhardt, in 1832.  The Camaldoli garden, which was established in 1816 by Francesco Ricciardi, Count Camaldoli, features collections of Acacia, Agavaceae, Melaleuca, Eucalyptus camaldulensis, and Quercus ilex.

River red gum is tolerant to waterlogging, as well as drought, salinity, fire and frost.  Globally, E. camaldulensis is widely planted in arid and semi-arid lands.

E. camaldulensis can grow up to 45 meters tall.  The tree has a large, dense crown.  The base of the bole can be covered with rough, reddish-brown bark.   The dull blue-green coloured leaves contain oil-producing glands in the un-veined areas. 


Due to its fast-growing nature, it is cultivated for the wood.  Eucalyptus plantations are popular with honey producers, as they are safe and sheltered, and very few agro-chemicals are used.

River red gum wood is hard and dense (≈900kg/m3), but brittle, thus making hand working difficult.  It is used in rot resistant applications such as fence posts, sleepers, decks and wooden floors.  It is also popular firewood, the wood makes fine charcoal. 

E. camaldulensis is a natural biological drainage (biodrainage), often used to reclaim swampy sites.  The tree’s root can penetrate deep into the soil, capable to draw a tremendous amount of water from the ground, thus removing the water from the swamp.


River red gum and many other Eucalypts was nicknamed, “widow maker”, as they tends to drop large branch without warning.  This form of self-pruning may be a means of saving water or simply a result of its brittle wood.

E. camaldulensis is known to exhibit allelopathic characteristic.  Several volatile and water-soluble toxins found in Eucalyptus tissues inhibit other plant species from growing nearby.  Accumulated Eucalyptus litters inhibit seeds germination, and stunted seedling growth.

Eucalypts draw a tremendous amount of water from the soil through the process of transpiration.  This may contribute to depletion of ground water and soil moisture.

Large amount of Eucalpytus litters, combine with the volatile oil produced by the leaves, lead to fire hazard in Eucalpytus plantation.  

Thursday, May 12, 2016

Dicranopteris linearis - Resam

Dicranopteris linearis is a species of fern known as Resam ( in Malay ) or Old World forked fern, besides many other common names.  It is one of the most widely distributed ferns of the Old World tropics.

It grows easily on poorly drained, nutrient-poor soils and in disturbed habitat and steep slopes with open-canopy.  Thus making it a pioneer species on primary successional sites such as landslides, road-cuts, abandoned logging decks, post-agricultural sites, degraded forest lands etc.   Once established, D. linearis persist for a long time but is eventually shaded out by overtopping trees.

This fern spread via rhizome, capable to form thickets 3 meters thick or more.  The stems are very slow to decompose, thus may poses fire hazard during dry season.


Russell, A. E., et al. (1998). The ecology of the climbing fern Dicranopteris linearis on windward Mauna Loa, Hawaii. Journal of Ecology 86 765.

Thursday, April 21, 2016

Axonopus compressus : American Carpet Grass

Axonopus compressus (Sw.) P.Beauv.
Family : Poaceae
Subfamily : Panicoideae
Tribe : Paniceae

Axonopus compressus var. australis,
Milium compressum,
Paspalum compressum, P. platycaule, P. platycaulon.

Common Names
Cowgrass, broadleaf carpetgrass, American carpet grass, tropical carpet grass, blanket grass, lawn grass, Louisiana grass, savanna grass, Kearsney grass

Tropical America.

Tropical and subtropical regions

Shallow-rooted stoloniferous and shortly rhizomatous perennial, with glabrous, oval-section (± 3.5 x 2.5 mm) stolon internodes and bearded nodes;  forms a dense mat with foliage 15-20 cm tall, and flowering culms mostly 30-45 (-60) cm;  can be mowed to a turf. 
Leaf sheath compressed, keeled, glabrous or ±hirsute;  ligule a fringed membrane 0.5 mm long;  blades shiny, flat or folded, 4-18 mm wide, and 2-16 cm long, glabrous or hairy on the upper surface, margins ciliate, apex broadly acute or obtuse. 
Inflorescence a panicle comprising 2 or 3 (rarely 5) slender, spikelike racemes, paired or sub-digitately arranged on a long slender peduncle ;  racemes (2-) 3-7 (-10) cm long;  spikelets, 2.0-3.5 mm long, 1-1.25 mm broad, inserted alternately either side of a flattened rachis.  2.6-3.0 million seeds per kg.

Drought tolerance
Poor drought tolerance.
Tolerance to shade and heavy grazing.

Soil requirements
Adapted to well to moderately drained sandy or sandy-loam soils, but also to light clays and peats. 
Best in acid soils with pH (5.0-) 5.5-6 (-7), iron chlorosis above pH 7. 
Low tolerance of salinity (<4 dS/m).

Used as a permanent pasture, ground cover and turf in moist, low fertility soils, particularly in shaded situations.  It is generally too low growing to be useful in cut-and-carry systems or for fodder conservation .