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Discocactus  
 Preface  Cultivation

 Fieldnumbers

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General
Sow
Where to sow
Grafting
Seed harvesting
Storing seed
Labeling
Watering
Cultivation climate
Growth season
Diseases
Importing

If we finally have obtained a collection of blooming  Discocacti  and do we possess several specimen from various species, then another aspect of our hobby comes forward, namely to harvest seeds.

Besides the pleasure we take in harvesting seeds, there is also a   necessity to do so . By the opening up and burning of large area's many finding places are threatened with destruction, while other species are most likely already exterminated. In order to preserve the species we need seed extraction from the Discocacti in our cultures, more so as by the SITES-law export of plants from this genus are strictly forbidden we think with reason. All species are on the CITES I  list.

As all sorts of this genus are cross-pollinators, we have to help active with the pollination. In nature the pollination of Discocacti is done by moth's of the Sphingides family de so called hawk-moth, so named after the protrusion that the caterpillar has on its backside. They are also called twilight butterflies, because they are active at the start of the twilight. Almost all Sphingides possess a long coiled up tongue. Normally its curled up under its head, but stretched out it exceeds the body length. When collecting the nectar they hover like hummimg-birds before or above the flower. This way they can easily reach the nectar glands placed at the bottom of the long tube shaped  flowers. When entering the chalice with their tongue it passes the stamen and pistil and because their tongue is not smooth and hairy therefore pollen will stick on it and are transported this way to the next flower.

In our garden we can observe this also, for example with the tube shaped flowers of the honey suckle (genus Lonicera). When the berries appear one can be sure the hawk-moth has done its work.

To pollinate the flowers of the Discocacti we can utilize a very fine paint brush, by entering it carefully into the floral tube a couple of times. We should take into account that in a few cases the pistil is situated very deep As long as we are pollinating one species the same paint brush may be used, however when we start with another species the brush have to be absolutely free of pollen from the preceding species. It is not possible to remove the pollen by just wiping it off. The only way to do it is to emerge the brush for a short period of time in alcohol of 70%.

Whenever we want to pollinate various species shortly after one another the afore mentioned method becomes difficult in practice. To avoid this we have found another utensil with more advantages. We use the same instrument that more or less resemblance the stretched out tongue of the hawk-moth. This could be for example the nerve-needle the dentist uses when he treats the root of your molar. This tool is a fairly long 3 to 4 cm has a good grip and the last cm is barbed. By fixing a bit of fluff from cotton wool at the end we've manufactured the perfect tool upon which lots of pollen will gather and can be easily transferred to the stamen of the next flower. We use a needle for each Discocactus.

When pollination is finished we store the needle airtight in a small bottle in which we have added a few pellets of silica gel (drugstore). These cobalt blue pellets are very hygroscopic (water absorbing) causing the pollen to remain dry. This is an absolute necessity otherwise it starts to grow mouldy. When storing these bottles or for example the plastic containers of pellicles in the fridge the pollen can be used for some months . The proof that this method produces excellent results will be seen when the cephalium shows the rich fruits after a few months. By this method of pollination we prevent the cross pollination with other species.

It could be interesting to see what will come out hybridization. But in principle we do our utmost to keep the known and described species as genuine as possible  With the harvesting of the seed from the genuine species Discocacti the first part of cultivation is finished.

Copyright 2003

email: Piet van der Laken