Floreana is one of the best opportunities visitors have to enjoy the captivating flora of the Galapagos Islands. Seven angiosperm genera are endemic to the Galapagos Archipelago. These plant groups have been isolated long enough to be completely different from those found in the rest of the world! Angiosperm means "vessel seeds", referring to the fact that the seeds in these types of plants are borne inside a fruit. Some 750 members of the Galapagos flora fit this description.
In today's picture we can appreciate an example of one of the most famous plant groups of the archipelago, the genus Scalesia. This widespread genus of plants is composed of shrubs and trees that have soft wood and gummy sap. This genus is particularly interesting for botanists, being one of the few members of the family Asteraceae (star-shaped flowers) that includes trees. Most of the Asteraceae are either shrubs or herbs, common examples are dandelions, sunflowers and daisies.
A very interesting concept in Biology, perfectly exemplified by the genus Scalesia, is that of "adaptive radiation". Following this concept, a particular animal or plant group adapts to a variety of habitats and, in a continuous process of changing, evolves into new entities. Darwin finches are the classical example of this phenomenon in Galapagos. From a common ancestor, 13 species evolved by adapting to the food resources available in several unfilled ecological niches. The morphological evidence of these adaptations is illustrated by their different beaks. The genus Scalesia represents the plant kingdom's best example of adaptive radiation in the Galapagos. The genus consists of 15 species, and a total of 19 members when subspecies and varieties are included. It has been suggested that the original ancestor arrived to Galapagos and started by colonizing the arid lowlands of an island. This was followed by adaptation to increasingly moist places and to other islands. In doing so, the leaves of these plants became markedly different from each other, both in shape and size. The "long haired scalesia" (Scalesia villosa), considered very rare, is easily identified by its extreme hairiness along the walk at Punta Cormorant in Floreana. This plant can be observed in today's picture. I have always admired these plants, even though I am a biologist with strong background in Zoology. To illustrate my admiration I always use the following phrase to emphasize the importance of these plants for Biology, "Scalesias are for the botanists what finches are for the ornithologists."
