Learn Science in your Garden

Learn Science in your Garden

Dr Abe V Rotor 

Living with Nature School on Blog 

Plants lose water by transpiration (through stomates) and gutation through special "valves." Here gutation is shown in Rhoeo discolor.  Droplets line the leaf edges mistaken as dewdrops in early morning. Excess water in the plant is released through special valves to protect the cells from plasmoptysis or excess pressure, the opposite of plasmolysis (shrinking of cells for lack of water). This is a physiological phenomenon existing in the plant world.  

Bagworm (Cryptothelea fuscescens) is the turtle in the insect world with the larva enclosed by a silk bag it builds which grows with the larva itself in four or five moltings becoming bigger in each instar (larval stage).  It spends its pupal phase outside, hanging at the posterior end, then emerges into a moth.  But in the case of the female, it spends its pupal and adult stages inside the bag. Because it is wingless mating is done through the posterior opening of the bag with the male attracted by pheromone (chemical scent).  After fertilization, it lays her eggs inside, squeezes out and dies on the ground.  

Lantana camara, a sturdy shrub exudes obnoxious odor from its flower and body, specially when disturbed.  Its leaves and young stems are covered with tough hairs that easily break when touched, thus emitting the characteristic odor that earned his name bang-bangsit, which means odorous in Ilocano.  This odor however makes the plant a repellant against a host of destructive insects, except for certain butterflies and other insects that pollinate the flowers.  With natural farming gaining popularity, Lantana is welcomed in garden as biological agent against pests. 

Lichens are indicators of good environment. They are plentiful when the environment is pristine, and the air is not polluted.  The three kinds of lichens indicate the degree of pollution. Fruticose (above, right) indicate very clean environment, foliose (leaf-like) indicates declining condition, and crustose (crust-like, left) tolerable level.  The less the lichens are found, the more the environment is deteriorating.  Thus the lichens are practical biological indicators. 

Preying mantis (Mantis religiosa), the executioner in the insect world, spares no insect - not even its own kind.  The female mantis kills her mate while in the act, devour it after for nutrition. But farmers and gardener like them for protecting their plants, and while they are villains in their world, they are harmless to humans.  Sometimes they are regarded as pets.  

Colony of aphids (Aphis sp) at the leaf axils of variegated fortune plant.  Black mass of fungus  grows on the sugary exudate of the aphids. It is this natural sugar made from the plant sap the insect sips that attract red ants.  these ants protect the aphids from predators like ladybugs. Note self regenerating capacity of the plant (right) that shows the plant's ability to survive the pest. 

Bumble bees have become rare in gardens, so with butterflies and honeybees. This is because the air is becoming more polluted, and there are less and less free spaces to build gardens specially in cities. Radiation emanating from transmission towers creates disorientation of pollinators, particularly honeybees as they search for nectar and pollen over long distances and returning to their hive. No wonder the cost of honey has gone up,  so with insect pollination-dependent fruits,vegetables and seeds - these apparently is a  result of our deteriorating environment.

Plant physiology. Apparently there are no common characteristics between bamboo and cactus in this photo. In the first place the bamboo can support itself, while the cactus has to depend on a support - a wall to cling on. Photosynthesis takes place in the green stem of the cactus which is not possible in the bamboo and its kind. The one thing they share, other than water and basic nutrients, is phototropism - both rise to reach for sunlight, and for space. But nature provided each one certain adaptive mechanisms to compete as well as to live under one niche. It is this principle that enables plants to live together naturally like in a forest.  

Poke marks caused by insects create a subject for abstract art.  Viewed against the bright sky the leaf shows netted venation, like veins and capillaries, which supply water and materials for photosynthesis, and it products mainly sugar, to other parts of the plant. Deep green coloration shows richness in chlorophyll.  The leaf structure is an engineering marvel that continues to inspire architecture and engineering.  In the field of medicine, the network of vascular and leaf tissues may provide the key to understanding tissue transplant and stem cell culture.  

 Makahiya (Mimosa pudica) makes a plaything for children and adults trying to steal a leaf without drooping, wishing almost anything in the world from love to fortune - if  they succeed. And no one will ever succeed in altering nature's gift to this shy plant. Special cells called pulvini control the drooping of the leaflets and the whole compound leaf, and restoring them fresh and erect once these cells are filled again with water.  The powder puff flowers attract bees and other pollinators without alarming the plant, thus insuring fertilization and production of seeds.