Horkelia hendersonii
Encyclopedia
Horkelia hendersonii is a rare species of flowering plant in the rose family
known by the common name Henderson's horkelia. It is known from four populations in southern Oregon
, including Mount Ashland
, and one population south of the border in Siskiyou County, California
. It is a resident of dry forest habitat in the granite
soils of the Klamath Mountains
. This is a perennial herb producing a low mat of hairy, glandular gray-green foliage about a woody base. The leaves are cylindrical and sometimes tapering to a point, growing erect in a patch around the caudex
. Each leaf is 3 to 8 centimeters long and is made up of densely spaced pairs of minutely toothed leaflets. The leaflets are coated in silky hairs. The inflorescence
is a dense array flowers atop an erect stalk, each flower made up of five hairy, pointed sepal
s and five smaller, more delicate white petals.
Although few populations of the plant are known to exist, they are not in imminent danger of destruction and a federal listing as an endangered or threatened species was declined in 2003. The Mount Ashland populations of this plant are sometimes threatened by recreational activities at that site, including skiing
and maintenance of ski facilities, and off-road vehicle
use.
Rosaceae
Rosaceae are a medium-sized family of flowering plants, including about 2830 species in 95 genera. The name is derived from the type genus Rosa. Among the largest genera are Alchemilla , Sorbus , Crataegus , Cotoneaster , and Rubus...
known by the common name Henderson's horkelia. It is known from four populations in southern Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, including Mount Ashland
Mount Ashland
Mount Ashland ski area is located on Mount Ashland and features 23 trails on served by four lifts, in addition to chute skiing in a glacial cirque called The Bowl. The mountain receives over of snow annually with a season from early December until mid-April...
, and one population south of the border in Siskiyou County, California
Siskiyou County, California
Siskiyou County is a county located in the far northernmost part of the U.S. state of California, in the Shasta Cascade region on the Oregon border. Yreka is the county seat. Because of its substantial natural beauty, outdoor recreation opportunities, and Gold Rush era history, it is an important...
. It is a resident of dry forest habitat in the granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
soils of the Klamath Mountains
Klamath Mountains
The Klamath Mountains, which include the Siskiyou, Marble, Scott, Trinity, Trinity Alps, Salmon, and northern Yolla-Bolly Mountains, are a rugged lightly populated mountain range in northwest California and southwest Oregon in the United States...
. This is a perennial herb producing a low mat of hairy, glandular gray-green foliage about a woody base. The leaves are cylindrical and sometimes tapering to a point, growing erect in a patch around the caudex
Caudex
A caudex is a form of stem morphology appearing as a thickened, short, perennial stem that is either underground or near ground level . It may be swollen for the purpose of water storage, especially in xerophytes...
. Each leaf is 3 to 8 centimeters long and is made up of densely spaced pairs of minutely toothed leaflets. The leaflets are coated in silky hairs. The inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a dense array flowers atop an erect stalk, each flower made up of five hairy, pointed sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s and five smaller, more delicate white petals.
Although few populations of the plant are known to exist, they are not in imminent danger of destruction and a federal listing as an endangered or threatened species was declined in 2003. The Mount Ashland populations of this plant are sometimes threatened by recreational activities at that site, including skiing
Skiing
Skiing is a recreational activity using skis as equipment for traveling over snow. Skis are used in conjunction with boots that connect to the ski with use of a binding....
and maintenance of ski facilities, and off-road vehicle
Off-road vehicle
An off-road vehicle is considered to be any type of vehicle which is capable of driving on and off paved or gravel surface. It is generally characterized by having large tires with deep, open treads, a flexible suspension, or even caterpillar tracks...
use.