''Crocanthemum greenei'' is a rare species of flowering plant in the
rock-rose family known by the common name island rush-rose. It is
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
Channel Islands of California
The Channel Islands () are an eight-island archipelago located within the Southern California Bight in the Pacific Ocean, off the coast of California. The four Northern Channel Islands are part of the Transverse Ranges geologic province, and ...
, where it grows in the
chaparral
Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...
of the rocky seaside slopes. It is present on three of the eight islands, where it has historically been threatened by feral herbivores such as the
Santa Cruz sheep and is making a gradual recovery. It is a federally listed threatened species.
This wildflower is an erect perennial herb reaching a maximum height near 30 centimeters. Its leafy stem is mostly green, with new growth and
inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
s at the top often appearing purple in color. The leaves are narrow, linear, and pointed, up to three centimeters long. The inflorescence is generally a panicle, producing many buds which open into golden yellow flowers one to two centimeters wide. Each rock-rose flower has five rounded petals over five smaller, fuzzy-haired
sepal
A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...
s. The fruit is an oval-shaped capsule half a centimeter wide.
Today this plant is found on
Santa Cruz,
Santa Catalina, and
Santa Rosa Islands; it has not been recorded on
San Miguel Island
San Miguel Island (Chumash: ''Tuqan'') is the westernmost of California's Channel Islands, located across the Santa Barbara Channel in the Pacific Ocean, within Santa Barbara County, California. San Miguel is the sixth-largest of the eight Cha ...
in several decades.
[USFWS]
Island Rush-rose Five-year Review.
June 2010.
References
External links
Jepson Manual TreatmentCenter for Plant ConservationThe Nature Conservancy
Photo gallery
Cistaceae
Flora of California
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