''Alternanthera echinocephala'', known as spiny-headed chaff flower, is a

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

by plant in the family Amaranthaceae native to the Galápagos Islands, mainland Ecuador, and Peru. Its relatively large spiny "heads" of flowers distinguish it from other species of '' Alternanthera'' found in the Galápagos.

Description

''Alternanthera echinocephala'' is a much-branched

up to tall. Its leaves are arranged oppositely and are narrow and pointed (lanceolate) with untoothed margins, long. The flowers are grouped into somewhat rounded spikes ("heads") about across. Each flower has one large and two small bracts below it, which form the most conspicuous part of the flower head. The bracts are greenish-white, sometimes with pinkish tones. The small sepals are similar in colour, only long. The flowers have no

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s and five

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s. Thirteen species of '' Alternanthera'' are found in the Galápagos Islands, of which six are

endemics 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 else ...

; ''A. echinocephala'' is said to be easy to distinguish based on its relatively large flower heads with their spiny appearance.

Taxonomy

The species was first described in 1847, from the Galápagos Islands, by Joseph Dalton Hooker as ''Brandesia echinocephala''.

Paul Carpenter Standley Paul Carpenter Standley (March 21, 1884 – June 2, 1963) was an American botanist known for his work on neotropical plants. __TOC__ Standley was born on March 21, 1884 in Avalon, Missouri. He attended Drury College in Springfield, Missouri an ...

transferred it to the genus ''Alternanthera'' in 1932. The specific epithet ''echinocephala'' is derived from the Greek words ''echinos'', hedgehog or sea urchin, hence meaning "spiny", and ''cephalos'', here meaning "headed"., pp. 266, 384

Distribution and habitat

, Tropicos shows the species to be distributed in the Galápagos Islands and the coast of mainland Ecuador. McMullen (1999) says that it is also known from Peru. Within the Galápagos, it is known from the islands of Española,

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. ...

, Isabela, Pinta, Pinzón, San Cristóbal, Santa Fe and Santiago, as well as from some of their neighbouring islets. It is a plant of the arid lowland regions of the Galápagos.

References

{{Taxonbar, from=Q2840382 Plants described in 1847 echinocephala Flora of the Galápagos Islands Flora of Ecuador Flora of Peru