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Professional flower tours provide an opportunity for the amateur botanist to expand their knowledge with the help of qualified and passionate naturalists. Those who join flower tours to different parts of the world are able to explore unusual habitats and encounter endemic and exotic species they may never otherwise get to see. The Big, Beautiful Orchiaceae Family One of the more sought-after botanical sightings is of members of Orchidaceae; as one of the largest flowering plant families in the world, it has more than 25,000 recognised species across 880 genera. Renowned for their delicate beauty and scent, orchids come in a plethora of shapes, sizes, colours and aromas, all designed to attract the birds, bats, bees, butterflies and insects required to pollinate them. Despite extreme diversity amongst the species, these lovely flowers do all share the same basic characteristics. The Structure and Shape The orchid's construction comprises two ordinary petals, a third petal, which is the lip or labellum, and three sepals, which form the outside of the bud. They have a central column, called the gynostemium, which includes both the male stamens (anther) and a female pistil (stigma). The latter is their primary identifying feature as it is unique to the Orchidaceaes. Because the anther and stigma are housed in the same column, it also contains a barrier to prevent self-pollination, which is called the rostellum. Depending on the species, the bud may twist around so the labellum points downwards as it opens. Some remain in this position, while others continue to rotate and the flower is once again right way up when it is fully opened. The process is called resupination. Once open, each half of the flower is a perfect mirror image of the other. Some scientists and psychologists believe that this "bilateral symmetry" (like a human face) is why we find orchids so appealing. Pollination and Reproduction One fascinating and ingenious aspect of the Orchidaceaes is that many species' sexual organs are designed to look like the insects they need to attract to carry out pollination. An insect (for example a bee) lands on what it thinks is a mate and the sticky pollen attaches to its feet and wings. It then flies off, the process is repeated on another lookalike and pollination occurs. One species, Holcoglossum amesianum, is able to pollinate itself in an intricate manoeuver where it pops the top off the anther (which holds pollen) and, by use of a pliable rod called the stipe, is able to circumnavigate the rostellum and transport the pollen to the stigma. Some species also temporarily trap insects in order to get them to come in contact with pollen, and some emit certain odours that mimic urine, sap, dung and carrion to attract them. Preferred Habitat Orchids are highly prized and have been grown successfully in specially-controlled hothouses all over the world since the nineteenth century, including the cultivation of more than 100,000 hybrid species. In order to see them growing naturally, the greatest concentration is found in tropical and sub-tropical climates in South and Central America, Asia and Australasia – all destinations covered by professional flower tours. However, they're not just confined to the tropics and some species have been found in latitudes above the Arctic Circle. This exquisite flower has inspired us for centuries with its serene beauty and intriguing science, even leading to the claim: "When a man falls in love with orchids, he'll do anything to possess the one he wants." (Susan Orlean) Marissa Ellis-Snow is a freelance nature writer with a special interest in wildflowers. As a passionate lover of botany, Marissa chooses the expert-led flower tours organised by Naturetrek, which have brought her unforgettable encounter with a wide range of plant species in some of the most spectacular regions on Earth.
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