Orchid Propogation

In rhizomatous forms the growing point in front spreads over newer and newer areas while the older portions die away from behind . Any branching which may occur on the rhizome and subsequent death of the portion where branching has occurred , results in the production of two individuals in the establishing two different colonies . This happens in epiphytic as well as terrestrial forms. The old pseudobulbs when they get detached from the rhizome are capable of developing new shoots from dormant buds.

In genera like Goodyera the rhizome gives off special lateral branches which turn up and produce aerial shoots . When they are properly rooted , they get detached from the mother plant and lead a separate existence .

In the tuberous terrestrial forms there are several methods of vegetative reproduction. Under ordinary conditions the mother tuber produces a single plant laterally which , as it grows , accumulates food in its own tuber , while the old tuber shrinks and dies . But when food supply is abundant and conditions favourable , more than one daughter plant is produced . With the death of the mother tuber , each of the daughter plants becomes a separate entity . This method of reproduction produces clusters of orchids which are commonly met with in meadows and swamps , eg. Habenaria barnesii , Disperis neilgherrense etc.

In a few tubers forms roots are produced from above the tubers ,each of which ends in a tubercle . These small tubers produce new plants the year after ,eg. Peristylus stenostachyus , Nervilia etc.

Summerhayes (1951) reports that in Listera ovata and the red helleborine , roots, as they grow , produce knob-like thickenings all along. Food materials are stored in these knobs which are later used up in the production of new plants .

The British orchid Hammarbya paludosa is unique among orchids in the production of offsprings. Here new plants are produced from nodules appearing on the edge of leaves under moist conditions (Summerhayes 1951).

Plants produced vegetatively usually reach flowering stage much earlier than those sprung from seeds.