|Streptocarpus and nature
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|Author:||administrator [ Sun Feb 26, 2017 2:38 pm ]|
|Post subject:||Streptocarpus and nature|
As many people already know the word Streptocarpus did not come from English, but originated from the two Greek words that mean ‘twisted fruit’. Also, not the most romantic of terms, ‘twisted fruit’ refers to the twisting seed pod seen in mature plants. The very first wild Streptocarpus was ‘discovered’ in 1818 by James Bowie. By now approximately 150 species have been discovered. Streptocarpus species were found mostly in southern Africa and Madagascar.
Now Streptocarpus is recognized as a genus in the mostly tropical family of Gesneriads. Genus Streptocarpus has two subgenera: Streptocarpella and Streptocarpus. Species that belong to the first subgenera, ‘Streptocarpella’, have a stem. A recent nuclear DNA molecular comparison study shows that our famous plant genus Saintpaulias (African Violets) are originated from the subgenera Streptocarpella. More studies needs to be done to precisely place these two groups relative to each other. We will leave that to taxonomists.
In this publication we are only going to talk about the second subgenera of Streptocarpus that has the same name – Streptocarpus.
There are a few morphologically different groups of native Streptocarpus. One group comprises Streptocarpus species that grow only one large leaf. These species are called unifoliates. They produce a few flower stalks that bear seed pods and after that the whole plant is destined to die. Most of unifoliates are annuals.
The other group of species has a rosette form. These are perennials. All of the modern hybrids belong to this group. Having said that, it’s also true that hybridizers have used species from other groups in developing their hybrids.
Other groups of Streptocarpus species are also perennials, have more than one leaf and are morphologically situated somewhere in between the first two groups.
to be continued
|Author:||Francheska [ Sun Feb 26, 2017 9:40 pm ]|
|Post subject:||Re: Streptocarpus and nature|
Most of the Streptocarpus species bloom in summer, when the duration of light is longer. There are few species of streps that flower in winter.
There are species that bloom abundantly but for short period of time. Other species bloom less abundantly but for longer period of time. The same is with the hybrids. Some hybrids flower abundantly and some slowly over long period of time.
Hybridizers cross Streptocarpus species that naturally would never be able to. If the hybrid has genes from unifoliate and rosette forms, first leaf can be very large due to the ‘expression’ of the unifoliate genes. However, during growth, the rosette gene expression can switch on resulting in the next leaves growing smaller and creating a nice rosette. Even more interesting these switches can work in one environmental condition but not another. For example, differences in light or moisture may affect both if and how the genes express themselves.
Like any other plant, Streptocarpus is a complex living organism. In order to live it needs light, water, mineral nutrients in the form of different salts, and appropriate temperature.
Light is the energy. Without light plants, can’t exist. Let’s see what kinds of light Streptocarpus species acclimate to. Streptocarpus cannot be found among trees and bushes in jungles where African Violets ancestors feel very comfortable. Streptocarpus need to grow in more open spaces, where they get more filtered light, but are still protected from direct sun rays. In order to get full flowering potential Streptocarpus needs more of this filtered light than African Violets.
Many Streptocarpus species are ‘lithophytes’, plants which grow on the surface of rocks. Others are ‘epiphytes,’ plants (some orchids, for example) which do not have contact with ground and grow on other plants (such as tree trunks and branches) without been parasitic. They get (like most of the orchids) their moisture and nutrients from rain, air and debris that can be found on the plants that support them.
The Streptocarpus root system is well developed. It has long root hairs (much more than African violets) that, due to the huge absorption surface, are able to get minute amounts of moisture and nutrients from the very poor environment of barely decomposed organic materials. Streptocarpus roots display strong hydrotropism (ability to grow toward water), which enables them to find water from a distance. You can easily observe it when Streptocarpus grown in 100% humidity can send a root up in the air. Streptocarpus root systems can also adapt to airy environment and can withstand drying. Streptocarpus does not grow in well-composted soil that has a lot of readily available nutrients that can be found in the bottoms of ravines rich in organic and salts washed there by rain.
to be continued
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