''Poa atropurpurea'' is a rare species of

grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and spe ...

known by the common name San Bernardino bluegrass. It is

endemic Endemism is the state of a species being found only 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 foun ...

to southern

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, where it is known from two regions, the

San Bernardino Mountains The San Bernardino Mountains are a high and rugged mountain range in Southern California in the United States. Situated north and northeast of San Bernardino and spanning two California counties, the range tops out at at San Gorgonio Mountain ...

near

Big Bear Big Bear, also known as (; – 17 January 1888), was a powerful and popular Cree chief who played many pivotal roles in Canadian history. He was appointed to chief of his band at the age of 40 upon the death of his father, Black Powder, u ...

and the

Laguna Mountains The Laguna Mountains are a mountain range of the Peninsular Ranges in eastern San Diego County, California. The mountains run in a northwest/southeast alignment for approximately . The mountains have long been inhabited by the indigenous Kumey ...

San Diego County San Diego County (), officially the County of San Diego, is a county in the southwest corner of the U.S. state of California, north to its border with Mexico. As of the 2020 census, the population was 3,298,634; it is the second-most populous ...

Description

It grows in wet mountain meadows. It is a

rhizomatous In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

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 Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

plant, with male and female individuals bearing different flower types. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

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 A pebble is a clast of rock with a particle size of based on the Udden-Wentworth scale of sedimentology. Pebbles are generally considered larger than granules ( in diameter) and smaller than cobbles ( in diameter). A rock made predominan ...

habitat near Big Bear with other rare plant species.USFWS
Final rule to determine endangered or threatened status for six plants from the mountains of Southern California.
''Federal Register'' September 14, 1998. In San Diego County the grass has been observed on

Palomar Mountain Palomar Mountain ( ; ) is a mountain ridge in the Peninsular Ranges in northern San Diego County, California. It is known as the location of Palomar Observatory and Hale Telescope, and known for Palomar Mountain State Park. History The Luise� ...

and in the meadows of

Mount Laguna Mount Laguna is a small census-designated place (CDP) in San Diego County, California. It is approximately above sea level in a forest of Jeffrey pine, east of San Diego in the Laguna Mountains on the eastern edge of the Cleveland National Fores ...

. There are fewer than twenty populations of this grass in existence and 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, inv ...

of the United States. This species faces a number of threats, including the degradation of its meadow habitat by

off-road vehicle An off-road vehicle (ORV), also known as an off-highway vehicle (OHV), overland vehicle or adventure vehicle, is a type of transportation specifically engineered to navigate unpaved roads and surfaces. These include trails, forest roads, and ...

s and construction at the Big Bear airport and

ski areas A ski resort is a resort developed for skiing, snowboarding, and other winter sports. In Europe, most ski resorts are towns or villages in or adjacent to a ski area–a mountainous area with pistes (ski trails) and a ski lift system. In North ...

. Certain populations have been observed to contain only female individuals. Other threats include

grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to free range (roam around) and consume wild vegetations in order to feed conversion ratio, convert the otherwise indigestible (by human diges ...

of cattle and trampling.

References

External links

Jepson Manual Treatment — ''Poa atropurpurea''Grass Manual Treatment''Poa atropurpurea'' — U.C. Photo gallery
atropurpurea Endemic flora of California Native grasses of California Natural history of the Peninsular Ranges Natural history of the Transverse Ranges ~ Dioecious plants {{Pooideae-stub