Friday, February 22, 2013

Bird of Paradise or Crane Flower? Strelitzia

A common name of the genus Strelitzia is bird of paradise flower, because of a supposed resemblance of its flowers to the bird of paradise but we must admit this one's a stretch so we'll go with what in South Africa is commonly known as a crane flower! What do you think? Crane? Or Bird of Paradise?  A third option could be that 'paradise' is fictional so that it is a 'bird' of a fictional place.
      Strelitzia is a genus of five species of perennial plants, native to South Africa. It belongs to the plant family Strelitziaceae. The genus is named after the duchy of Mecklenburg-Strelitz, birthplace of Queen Charlotte of the United Kingdom.
      The species S. nicolai is the largest in the genus, reaching 10 m tall, with stately white and blue flowers; the other species typically reach 2 to 3.5 m tall, except S. caudata which is a tree of a typically smaller size than S. nicolai. The leaves are large, 30–200 cm long and 10–80 cm broad, similar to a banana leaf in appearance but with a longer petiole, and arranged strictly in two ranks to form a fan-like crown of evergreen foliage. The flowers are produced in a horizontal inflorescence emerging from a stout spathe. They are pollinated by sunbirds, which use the spathe as a perch when visiting the flowers; the weight of the bird on the spathe opens it to release the pollen onto the bird's feet, which is then deposited on the next flower it visits. Src : Wikipedia
Strelitzia

Crane
Bird of Paradise

Thursday, February 21, 2013

Soda Straws in a Cave?

Texas has great caves to explore. One feature that amazes are soda straws - complete with liquid! A soda straw (or simply straw) is a speleothem in the form of a hollow mineral tube. They grow in places where water leaches slowly through cracks in rock, such as on the roofs of caves. A soda straw can turn into a stalactite if the hole at the bottom is blocked, or if the water begins flowing on the outside surface of the tube.
These tubes form when calcium carbonate or calcium sulfate dissolved in the water comes out of solution and is deposited. In soda straws, as each drop hovers at the tip, it deposits a ring of mineral at its edge. It then falls and a new drop takes its place. Each successive drop of water deposits a little more mineral before falling, and eventually a tube is built up. Stalagmites or flowstone may form where the water drops hit the cave floor.
Soda straws are some of the most fragile of speleothems. Like helictites, they can be easily crushed or broken by the slightest touch. Because of this, soda straws are rarely seen within arms' reach in tourist caves. When left alone, soda straws have been known to grow up to 30 feet long.
Soda straws are also known as tubular stalactites.
Src : Wikipedia