''Arabis aculeolata'' is a species of flowering plant in the
mustard family
Brassicaceae () or (the older) Cruciferae () is a medium-sized and economically important family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous plants, while some are shrubs. The le ...
known by the common name Waldo rockcress. It is native to a small range in the mountains of southern
Oregon, where it is an uncommon member of the
serpentine soil
Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially anti ...
s flora. Reports of its occurrence in Del Norte County,
California are unconfirmed.
Description
This is a perennial herb growing from a tough
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 ...
covered in large hairs and the bases of leaves shed in previous seasons. It produces one or more erect stems to heights between 20 and 35 centimeters. The stems are dark in color, often reddish or purplish, and are coated in stiff white hairs. The leaves form a basal rosette about the caudex. They are oval-shaped, green in color and sparsely covered in coarse white hairs, up to 4 centimeters long, and with smooth or wavy edges. Leaves located farther up the stem are smaller. The flowers have dark purple
sepals and lighter purple petals. The fruit is a long, thin, erect
silique up to 6.5 centimeters long.
See also
*
List of ''Arabis'' species
External links
*
Jepson Manual TreatmentUSDA Plants ProfilePhoto gallery
aculeolata
Flora of California
Flora of Oregon
Plants described in 1910
Flora without expected TNC conservation status
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