Poa atropurpurea
Encyclopedia
Poa atropurpurea is a rare species of grass
known by the common name San Bernardino bluegrass. It is endemic to southern California
, where it is known from two regions, the San Bernardino Mountains
near Big Bear
and the Laguna Mountains
of San Diego County
.
perennial grass growing in small, loose tufts up to about half a meter tall. The firm, narrow leaves often have rolled or folded edges. It is a dioecious
plant, with male and female individuals bearing different flower types. The inflorescence
is somewhat lance-shaped, with branches appressed, spreading upwards along the stem axis. Male and female inflorescences look similar. They may hold up to 70 spikelets each, which are purplish in color.
and in the meadows of Mount Laguna
. There are fewer than twenty populations of this grass in existence and it is a federally listed endangered species
of the United States.
This species faces a number of threats, including the degradation of its meadow habitat by off-road vehicle
s and construction at the Big Bear airport
and ski areas
. Certain populations have been observed to contain only female individuals. Other threats include grazing
of cattle and trampling.
Poaceae
The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...
known by the common name San Bernardino bluegrass. It is endemic to southern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, where it is known from two regions, the San Bernardino Mountains
San Bernardino Mountains
The San Bernardino Mountains are a short transverse mountain range north and east of San Bernardino in Southern California in the United States. The mountains run for approximately 60 miles east-west on the southern edge of the Mojave Desert in southwestern San Bernardino County, north of the...
near Big Bear
Big Bear Lake
Big Bear Lake is a reservoir in the San Bernardino Mountains, in San Bernardino County, California, United States. At a surface elevation of , it has an east-west length of approximately 7 miles and is approximately 2.5 miles at its widest measurement, though the lake's width mostly averages a...
and the Laguna Mountains
Laguna Mountains
The Laguna Mountains are a section of the Peninsular Ranges in eastern San Diego County, California. The mountains run in a northwest/southeast alignment for approximately ....
of San Diego County
San Diego County, California
San Diego County is a large county located in the southwestern corner of the US state of California. Hence, San Diego County is also located in the southwestern corner of the 48 contiguous United States. Its county seat and largest city is San Diego. Its population was about 2,813,835 in the 2000...
.
Description
It grows in wet mountain meadows. It is a rhizomatousRhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
perennial grass growing in small, loose tufts up to about half a meter tall. The firm, narrow leaves often have rolled or folded edges. It is a dioecious
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
plant, with male and female individuals bearing different flower types. 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 somewhat lance-shaped, with branches appressed, spreading upwards along the stem axis. Male and female inflorescences look similar. They may hold up to 70 spikelets each, which are purplish in color.
Habitat
In the San Bernardino Mountains the grass occurs in the pebble plain habitat near Big Bear with other rare plant species. In San Diego County the grass has been observed on Palomar MountainPalomar Mountain
Palomar Mountain is a mountain in the Peninsular Ranges in northern San Diego County. It is famous as the location of the Palomar Observatory and Hale Telescope, and known for the Palomar Mountain State Park.-History:...
and in the meadows of Mount Laguna
Laguna Mountains
The Laguna Mountains are a section of the Peninsular Ranges in eastern San Diego County, California. The mountains run in a northwest/southeast alignment for approximately ....
. There are fewer than twenty populations of this grass in existence and it is a federally listed endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
of the United States.
This species faces a number of threats, including the degradation of its meadow habitat by 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...
s and construction at the Big Bear airport
Big Bear City Airport
Big Bear City Airport is a public airport located in Big Bear City, San Bernardino County, California, United States.- Arrival and Departure :...
and ski areas
Bear Mountain (Ski Area)
Bear Mountain , formerly Goldmine Mountain, is a ski area in Southern California. It is the sister resort of Snow Summit, together known as Big Bear Mountain Resorts. In 2002 Bear Mountain was purchased by Snow Summit, and the two resorts are now accessible with a single lift ticket...
. Certain populations have been observed to contain only female individuals. Other threats include grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
of cattle and trampling.