''Scalesia'' is a genus in the family

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the Galapagos Islands. It contains fifteen species that grow as shrubs or trees. This is unusual, because tree species are uncommon in Asteraceae. The genus ''Scalesia'' resulted from a blunder by Arnott who named it in honour of "W. Scales Esq., Cawdor Castle, Elginshire" but discovered after publication that the name should have read 'Stables', after Scottish botanist, William Alexander Stables (1810–1890). All of the species have soft,

pith Pith, or medulla, is a tissue in the stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other ...

y wood. ''Scalesia'' species have been called "the

Darwin's finches Darwin's finches (also known as the Galápagos finches) are a group of about 18 species of passerine birds. They are well known for their remarkable diversity in beak form and function. They are often classified as the subfamily Geospizinae or t ...

of the plant world" because they show a similarly dramatic pattern of

adaptive radiation In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic int ...

. One of the largest and most widespread species is ''

Scalesia pedunculata ''Scalesia pedunculata'' is a flowering plant species in the family Asteraceae, growing to a slender tree (20m tall, DBH 20 cm), and found in dense stands on the humid windward coasts of the islands of Santa Cruz, San Cristobal, Santiago ...

'' – a large tree which grows up to 15 to 20 metres tall, reaching maturity in a few years time. These trees typically grow in dense stands of the same species and age. They die around the same time, and then a new generation of seedlings grows up in the same place. The largest stands of ''Scalesia pedunculata'' are found on the humid windward sides of Santa Cruz, San Cristóbal,

Santiago Santiago (, ; ), also known as Santiago de Chile, is the capital and largest city of Chile as well as one of the largest cities in the Americas. It is the center of Chile's most densely populated region, the Santiago Metropolitan Region, whose ...

and

Floreana Floreana Island (Spanish: ''Isla Floreana'') is an island of the Galápagos Islands. It was named after Juan José Flores, the first president of Ecuador, during whose administration the government of Ecuador took possession of the archipelago. ...

islands, at an altitude of 400–700 m. The best known and most visited stand is on Santa Cruz Island, and is crossed by a road. '' Scalesia atractyloides'' and '' S. stewartii'' are two small tree species, very similar to each other.

References

* Eliasson, U.H. 1974. Studies in Galapagos Plants XIV. The Genus Scalesia Arn. Opera Botanica, 36: 1–117 Asteraceae genera Flora of the Galápagos Islands {{Heliantheae-stub