''Boechera hoffmannii'' (formerly ''Arabis hoffmannii'') is a rare species of flowering plant in the family
Brassicaceae known by the common name Hoffmann's rockcress. It is
endemic to the
Channel Islands of California, where it is known from only three or four populations on two of the eight islands.
A 2005 report estimated a remaining global population of 244 individual plants.
[The Nature Conservancy]
/ref> It is a federally listed endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...
.
This is a perennial herb
In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...
producing one or more erect stems from a scaly, hairy caudex
A caudex (plural: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695
In the strict sense of the term, meaning a stem, "caudex" is m ...
. The stems reach a maximum height between 50 and 70 centimeters and branch near the top. Leaves are densely clustered around the caudex in a basal rosette. They are lance-shaped, leathery with hairy undersides, and up to 10 centimeters long. There are more widely spaced leaves along the stem which are 3 to 6 centimeters long. The inflorescence bears many white or purple flowers with thick, dark sepals. The fruit is a tough, hairless silique up to 10 centimeters long containing 2 rows of seeds.
The main threats to the existence of this rare plant are grazing and erosion caused by feral pigs and competition by invasive grasses.[ The populations of this plant are also slow to reproduce. They are monocarpic, with each individual living for a few years, fruiting once, and then dying, and each population has relatively few actively reproducing individuals in any given year.][
]
References
External links
Jepson Manual TreatmentUSDA Plants ProfilePhoto gallery
hoffmannii
Flora of California
NatureServe critically imperiled species
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